[Auto PR] Update translations (#7852)

* Specifically for "Maximum call stack size exceeded" errors.

.circleci/config.yml

@@ -13,17 +13,18 @@ orbs:
   aws-cli: circleci/aws-cli@2.0.6
   macos: circleci/macos@2.5.1 # For Rosetta (see below)
   node: circleci/node@5.2.0 # For a recent npm version (see below)
+  win: circleci/windows@5.1.0
 jobs:
-  # Build the **entire** app for macOS.
+  # Build the **entire** app for macOS (including the GDevelop.js library).
   build-macos:
     macos:
-      xcode: 14.2.0
-    resource_class: macos.m1.large.gen1
+      xcode: 16.4.0
+    resource_class: m4pro.medium
     steps:
       - checkout
       # Install Rosetta for AWS CLI and disable TSO to speed up S3 uploads (https://support.circleci.com/hc/en-us/articles/19334402064027-Troubleshooting-slow-uploads-to-S3-for-jobs-using-an-m1-macOS-resource-class)
       - macos/install-rosetta
-      - run: sudo sysctl net.inet.tcp.tso=0
+      # - run: sudo sysctl net.inet.tcp.tso=0
 
       # Install a recent version of npm to workaround a notarization issue because of a symlink made by npm: https://github.com/electron-userland/electron-builder/issues/7755
       # Node.js v20.14.0 comes with npm v10.7.0.
@@ -46,9 +47,9 @@ jobs:
       # GDevelop.js dependencies
       - restore_cache:
           keys:
-            - gd-macos-nodejs-dependencies-{{ checksum "newIDE/app/package.json" }}-{{ checksum "newIDE/electron-app/package.json" }}-{{ checksum "GDevelop.js/package.json" }}
+            - gd-macos-nodejs-dependencies-{{ checksum "newIDE/app/package.json" }}-{{ checksum "newIDE/electron-app/package.json" }}-{{ checksum "GDevelop.js/package.json" }}-{{ checksum "GDJS/package-lock.json" }}
             # fallback to using the latest cache if no exact match is found
-            - gd-macos-nodejs-dependencies---
+            - gd-macos-nodejs-dependencies-
 
       - run:
           name: Install GDevelop.js dependencies
@@ -69,7 +70,8 @@ jobs:
             - newIDE/electron-app/node_modules
             - newIDE/app/node_modules
             - GDevelop.js/node_modules
-          key: gd-macos-nodejs-dependencies-{{ checksum "newIDE/app/package.json" }}-{{ checksum "newIDE/electron-app/package.json" }}-{{ checksum "GDevelop.js/package.json" }}
+            - GDJS/node_modules
+          key: gd-macos-nodejs-dependencies-{{ checksum "newIDE/app/package.json" }}-{{ checksum "newIDE/electron-app/package.json" }}-{{ checksum "GDevelop.js/package.json" }}-{{ checksum "GDJS/package-lock.json" }}
 
       # Build GDevelop IDE (seems like we need to allow Node.js to use more space than usual)
       # Note: Code signing is done using CSC_LINK (see https://www.electron.build/code-signing).
@@ -86,15 +88,37 @@ jobs:
       - store_artifacts:
           path: newIDE/electron-app/dist
 
+
       # Upload artifacts (AWS)
       - run:
           name: Deploy to S3 (specific commit)
-          command: export PATH=~/.local/bin:$PATH && aws s3 sync newIDE/electron-app/dist s3://gdevelop-releases/$(git rev-parse --abbrev-ref HEAD)/commit/$(git rev-parse HEAD)/
+          command: |
+            export PATH=~/.local/bin:$PATH
+            for i in 1 2 3 4 5 6 7; do
+              aws s3 sync newIDE/electron-app/dist s3://gdevelop-releases/$(git rev-parse --abbrev-ref HEAD)/commit/$(git rev-parse HEAD)/ && break
+              echo "Retry $i failed... retrying in 10 seconds"
+              sleep 10
+            done
+            if [ $i -eq 7 ]; then
+              echo "All retries for deployment failed!" >&2
+              exit 1
+            fi
+
       - run:
           name: Deploy to S3 (latest)
-          command: export PATH=~/.local/bin:$PATH && aws s3 sync newIDE/electron-app/dist s3://gdevelop-releases/$(git rev-parse --abbrev-ref HEAD)/latest/
+          command: |
+            export PATH=~/.local/bin:$PATH
+            for i in 1 2 3 4 5 6 7; do
+              aws s3 sync newIDE/electron-app/dist s3://gdevelop-releases/$(git rev-parse --abbrev-ref HEAD)/latest/ && break
+              echo "Retry $i failed... retrying in 10 seconds"
+              sleep 10
+            done
+            if [ $i -eq 7 ]; then
+              echo "All retries for deployment failed!" >&2
+              exit 1
+            fi
 
-  # Build the **entire** app for Linux.
+  # Build the app for Linux (using a pre-built GDevelop.js library).
   build-linux:
     # CircleCI docker workers are failing if they don't have enough memory (no swap)
     resource_class: xlarge
@@ -107,51 +131,33 @@ jobs:
       - checkout
       - aws-cli/setup
 
-      # System dependencies (for Electron Builder and Emscripten)
+      # System dependencies (for Electron Builder)
       - run:
-          name: Install dependencies for Emscripten
-          command: sudo apt-get update && sudo apt install cmake
-
-      - run:
-          name: Install Python3 dependencies for Emscripten
-          command: sudo apt install python-is-python3 python3-distutils -y
-
-      - run:
-          name: Install Emscripten (for GDevelop.js)
-          command: git clone https://github.com/juj/emsdk.git && cd emsdk && ./emsdk install 3.1.21 && ./emsdk activate 3.1.21 && cd ..
+          name: Update system dependencies
+          command: sudo apt-get update
 
       - run:
           name: Install system dependencies for Electron builder
           command: sudo apt install icnsutils && sudo apt install graphicsmagick && sudo apt install rsync
 
-      # GDevelop.js dependencies
       - restore_cache:
           keys:
-            - gd-linux-nodejs-dependencies-{{ checksum "newIDE/app/package.json" }}-{{ checksum "newIDE/electron-app/package.json" }}-{{ checksum "GDevelop.js/package.json" }}
+            - gd-linux-nodejs-dependencies-{{ checksum "newIDE/app/package.json" }}-{{ checksum "newIDE/electron-app/package.json" }}-{{ checksum "GDevelop.js/package.json" }}-{{ checksum "GDJS/package-lock.json" }}
             # fallback to using the latest cache if no exact match is found
-            - gd-linux-nodejs-dependencies---
+            - gd-linux-nodejs-dependencies-
 
-      - run:
-          name: Install GDevelop.js dependencies and build it
-          command: cd GDevelop.js && npm install && cd ..
-
-      # Build GDevelop.js (and run tests to ensure it works)
-      - run:
-          name: Build GDevelop.js
-          # Use "--runInBand" as it's faster and avoid deadlocks on CircleCI Linux machines (probably because limited in processes number).
-          command: cd GDevelop.js && source ../emsdk/emsdk_env.sh && npm run build && npm test -- --runInBand && cd ..
-
-      # GDevelop IDE dependencies (after building GDevelop.js to avoid downloading a pre-built version)
+      # GDevelop IDE dependencies (using an exact version of GDevelop.js, built previously)
       - run:
           name: Install GDevelop IDE dependencies
-          command: cd newIDE/app && npm install && cd ../electron-app && npm install
+          command: export REQUIRES_EXACT_LIBGD_JS_VERSION=true && cd newIDE/app && npm install && cd ../electron-app && npm install
 
       - save_cache:
           paths:
             - newIDE/electron-app/node_modules
             - newIDE/app/node_modules
             - GDevelop.js/node_modules
-          key: gd-linux-nodejs-dependencies-{{ checksum "newIDE/app/package.json" }}-{{ checksum "newIDE/electron-app/package.json" }}-{{ checksum "GDevelop.js/package.json" }}
+            - GDJS/node_modules
+          key: gd-linux-nodejs-dependencies-{{ checksum "newIDE/app/package.json" }}-{{ checksum "newIDE/electron-app/package.json" }}-{{ checksum "GDevelop.js/package.json" }}-{{ checksum "GDJS/package-lock.json" }}
 
       # Build GDevelop IDE (seems like we need to allow Node.js to use more space than usual)
       - run:
@@ -295,14 +301,203 @@ jobs:
           name: Deploy to S3 (specific commit)
           command: aws s3 sync Binaries/embuild/GDevelop.js s3://gdevelop-gdevelop.js/$(git rev-parse --abbrev-ref HEAD)/variant/debug-sanitizers/commit/$(git rev-parse HEAD)/
 
+  # Trigger AppVeyor build, which also does a Windows build (keep it for redundancy).
+  trigger-appveyor-windows-build:
+    docker:
+      - image: cimg/node:16.13
+    steps:
+      - run:
+          name: Trigger AppVeyor Windows build
+          command: |
+            curl -H "Content-Type: application/json" \
+                 -H "Authorization: Bearer ${APPVEYOR_API_KEY}" \
+                 --data "{
+                   \"accountName\": \"4ian\",
+                   \"projectSlug\": \"gdevelop\",
+                   \"branch\": \"${CIRCLE_BRANCH}\"
+                 }" \
+                 -X POST https://ci.appveyor.com/api/builds
+
+  build-windows:
+    executor:
+      name: win/default
+      size: medium
+    working_directory: /home/circleci/project
+    steps:
+      - checkout
+      - run:
+          # See https://www.ssl.com/how-to/how-to-integrate-esigner-cka-with-ci-cd-tools-for-automated-code-signing/
+          #
+          # This is necessary because of "signing to be FIPS-140 compliant". See
+          # https://github.com/electron-userland/electron-builder/issues/6158
+          #
+          # Make sure to DISABLE "malware blocker" in SSL.com to avoid errors like:
+          # Error information: "Error: SignerSign() failed." (-2146893821/0x80090003)
+          name: Download and Unzip eSignerCKA Setup
+          command: |
+
+            Invoke-WebRequest -OutFile eSigner_CKA_1.0.3.zip "https://www.ssl.com/download/ssl-com-esigner-cka-1-0-3"
+
+            Expand-Archive -Force eSigner_CKA_1.0.3.zip
+
+            Remove-Item eSigner_CKA_1.0.3.zip
+
+            Move-Item -Destination "eSigner_CKA_1.0.3.exe" -Path "eSigner_CKA_*\*.exe"
+      - run:
+          name: Setup eSignerCKA in Silent Mode
+          command: |
+
+            mkdir -p "/home/circleci/project/eSignerCKA"
+
+            ./eSigner_CKA_1.0.3.exe /CURRENTUSER /VERYSILENT /SUPPRESSMSGBOXES /DIR="/home/circleci/project/eSignerCKA" | Out-Null
+      - run:
+          name: Config Account Information on eSignerCKA
+          command: |
+
+            /home/circleci/project/eSignerCKA/eSignerCKATool.exe config -mode product -user "$env:ESIGNER_USER_NAME" -pass "$env:ESIGNER_USER_PASSWORD" -totp "$env:ESIGNER_USER_TOTP" -key "/home/circleci/project/eSignerCKA/master.key" -r
+      - run:
+          name: Load Certificate into Windows Store
+          command: |
+
+            /home/circleci/project/eSignerCKA/eSignerCKATool.exe unload
+
+            /home/circleci/project/eSignerCKA/eSignerCKATool.exe load
+      - run:
+          name: Select Certificate From Windows Store and Sign Sample File with SignTool
+          command: |
+
+            $CodeSigningCert = Get-ChildItem Cert:\CurrentUser\My -CodeSigningCert | Select-Object -First 1
+
+            echo Certificate: $CodeSigningCert
+
+      - restore_cache:
+          name: Restore node_modules cache
+          keys:
+            - v1-win-node-{{ checksum "newIDE/app/package-lock.json" }}-{{ checksum "newIDE/electron-app/package-lock.json" }}-{{ checksum "GDJS/package-lock.json" }}
+            - v1-win-node-
+
+      - run:
+          name: Install dependencies
+          no_output_timeout: 25m
+          # Remove package-lock.json because they seems to cause the npm install to be stuck. We should try again after re-generating them.
+          # Also install setuptools as something requires distutils in electron-app, and it was removed in Python 3.12.
+          # setuptools will make distutils available again (but we should migrate our packages probably).
+          command: |
+            pip install setuptools
+
+            cd newIDE\app
+
+            npm -v
+
+            Remove-Item package-lock.json
+
+            $Env:REQUIRES_EXACT_LIBGD_JS_VERSION = "true"
+
+            npm install
+
+            cd ..\electron-app
+
+            Remove-Item package-lock.json
+
+            npm install
+
+            cd ..\..
+
+      - save_cache:
+          name: Save node_modules cache
+          key: v1-win-node-{{ checksum "newIDE/app/package-lock.json" }}-{{ checksum "newIDE/electron-app/package-lock.json" }}-{{ checksum "GDJS/package-lock.json" }}
+          paths:
+            - newIDE/app/node_modules
+            - newIDE/electron-app/node_modules
+            - GDJS/node_modules
+
+      - run:
+          name: Build NSIS executable (with code signing)
+          command: |
+            cd newIDE\electron-app
+
+            $CodeSigningCert = Get-ChildItem Cert:\CurrentUser\My -CodeSigningCert | Select-Object -First 1
+
+            echo Certificate: $CodeSigningCert
+
+            # Use a custom signtool path because of the signtool.exe bundled withy electron-builder not working for some reason.
+            # Can also be found in versioned folders like "C:/Program Files (x86)/Windows Kits/10/bin/10.0.22000.0/x86/signtool.exe".
+            # or "C:\Program Files (x86)\Windows Kits\10\bin\10.0.22621.0\x86\signtool.exe".
+
+            $Env:SIGNTOOL_PATH = "C:\Program Files (x86)\Windows Kits\10\App Certification Kit\signtool.exe"
+
+            # Extract thumbprint and subject name of the certificate (will be passed to electron-builder).
+
+            $Env:GD_SIGNTOOL_THUMBPRINT = $CodeSigningCert.Thumbprint
+
+            $Env:GD_SIGNTOOL_SUBJECT_NAME = ($CodeSigningCert.Subject -replace ", ?", "`n" | ConvertFrom-StringData).CN
+
+            # Build the nsis installer (signed: electron-builder will use SignTool.exe with the certificate)
+
+            node scripts/build.js --win nsis --publish=never
+
+            cd ..\..
+      - run:
+          name: Build AppX (without code signing)
+          # Don't sign the appx (it will be signed by the Microsoft Store).
+          command: |
+            cd newIDE\electron-app
+
+            # Build the appx (not signed). Ensure all variables used for code signing are empty.
+
+            $Env:GD_SIGNTOOL_THUMBPRINT = ''
+
+            $Env:GD_SIGNTOOL_SUBJECT_NAME = ''
+
+            $Env:CSC_LINK = ''
+
+            $Env:CSC_KEY_PASSWORD = ''
+
+            node scripts/build.js --skip-app-build --win appx --publish=never
+
+            cd ..\..
+
+      - run:
+          name: Clean binaries
+          shell: cmd.exe
+          command: |
+            rmdir /s /q newIDE\electron-app\dist\win-unpacked
+
+      - run:
+          name: Install AWS CLI
+          command: |
+            # Install the CLI for the current user
+
+            pip install --quiet --upgrade --user awscli
+
+            # Add the user-Scripts dir to PATH for this step and the next.
+
+            $binDir = (python -m site --user-base) + "\Scripts"
+            $Env:Path += ";$binDir"
+
+            # Sanity check:
+            aws --version
+
+      # Upload artifacts (S3)
+      - run:
+          name: Deploy to S3 (specific commit)
+          command: |
+            aws s3 sync newIDE\electron-app\dist "s3://gdevelop-releases/$Env:CIRCLE_BRANCH/commit/$Env:CIRCLE_SHA1/"
+
+      - run:
+          name: Deploy to S3 (latest)
+          command: |
+            aws s3 sync newIDE\electron-app\dist "s3://gdevelop-releases/$Env:CIRCLE_BRANCH/latest/"
+
+      # Upload artifacts (CircleCI)
+      - store_artifacts:
+          path: newIDE/electron-app/dist
+
 workflows:
-  gdevelop_js-wasm:
-    jobs:
-      - build-gdevelop_js-wasm-only
   gdevelop_js-wasm-extra-checks:
     jobs:
       - build-gdevelop_js-debug-sanitizers-and-extra-checks:
-          # Extra checks are resource intensive so don't all run them.
+          # Extra checks are resource intensive so don't always run them.
           filters:
             branches:
               only:
@@ -310,13 +505,36 @@ workflows:
                 - /experimental-build.*/
   builds:
     jobs:
+      - build-gdevelop_js-wasm-only
       - build-macos:
+          # The macOS version builds by itself GDevelop.js
+          # (so we verify we can build it on macOS).
+          # requires:
+          #   - build-gdevelop_js-wasm-only
           filters:
             branches:
               only:
                 - master
                 - /experimental-build.*/
       - build-linux:
+          requires:
+            - build-gdevelop_js-wasm-only
+          filters:
+            branches:
+              only:
+                - master
+                - /experimental-build.*/
+      - build-windows:
+          requires:
+            - build-gdevelop_js-wasm-only
+          filters:
+            branches:
+              only:
+                - master
+                - /experimental-build.*/
+      - trigger-appveyor-windows-build:
+          requires:
+            - build-gdevelop_js-wasm-only
           filters:
             branches:
               only:

.gitignore

@@ -33,3 +33,4 @@
 .Spotlight-V100
 .Trashes
 Thumbs.db
+.claude

.vscode/tasks.json

@@ -38,8 +38,7 @@
       "presentation": {
         "reveal": "silent"
       },
-      "isBackground": true,
-      "runOptions": { "instanceLimit": 1, "runOn": "folderOpen" }
+      "isBackground": true
     },
     {
       "type": "npm",

Core/GDCore/Events/Builtin/GroupEvent.cpp

@@ -61,10 +61,12 @@ void GroupEvent::UnserializeFrom(gd::Project& project,
       project, events, element.GetChild("events"));
 
   parameters.clear();
-  gd::SerializerElement& parametersElement = element.GetChild("parameters");
-  parametersElement.ConsiderAsArrayOf("parameters");
-  for (std::size_t i = 0; i < parametersElement.GetChildrenCount(); ++i)
-    parameters.push_back(parametersElement.GetChild(i).GetValue().GetString());
+  if (element.HasChild("parameters")) {
+    gd::SerializerElement& parametersElement = element.GetChild("parameters");
+    parametersElement.ConsiderAsArrayOf("parameters");
+    for (std::size_t i = 0; i < parametersElement.GetChildrenCount(); ++i)
+      parameters.push_back(parametersElement.GetChild(i).GetValue().GetString());
+  }
 }
 
 void GroupEvent::SetBackgroundColor(unsigned int colorR_,

Core/GDCore/Events/Builtin/LinkEvent.cpp

@@ -163,6 +163,21 @@ void LinkEvent::UnserializeFrom(gd::Project& project,
   // end of compatibility code
 }
 
+vector<gd::String> LinkEvent::GetAllSearchableStrings() const {
+  vector<gd::String> allSearchableStrings;
+
+  allSearchableStrings.push_back(target);
+
+  return allSearchableStrings;
+}
+
+bool LinkEvent::ReplaceAllSearchableStrings(
+    std::vector<gd::String> newSearchableString) {
+  if (newSearchableString[0] == target) return false;
+  SetTarget(newSearchableString[0]);
+  return true;
+}
+
 bool LinkEvent::AcceptVisitor(gd::EventVisitor &eventVisitor) {
   return BaseEvent::AcceptVisitor(eventVisitor) ||
          eventVisitor.VisitLinkEvent(*this);

Core/GDCore/Events/Builtin/LinkEvent.h

@@ -109,6 +109,10 @@ class GD_CORE_API LinkEvent : public gd::BaseEvent {
 
   virtual bool IsExecutable() const override { return true; };
 
+  virtual std::vector<gd::String> GetAllSearchableStrings() const override;
+  virtual bool ReplaceAllSearchableStrings(
+      std::vector<gd::String> newSearchableString) override;
+
   virtual void SerializeTo(SerializerElement& element) const override;
   virtual void UnserializeFrom(gd::Project& project,
                                const SerializerElement& element) override;

Core/GDCore/Events/CodeGeneration/EventsCodeGenerator.cpp

@@ -329,7 +329,6 @@ gd::String EventsCodeGenerator::GenerateConditionCode(
     condition.SetParameters(parameters);
   }
 
-  gd::EventsCodeGenerator::CheckBehaviorParameters(condition, instrInfos);
   // Verify that there are no mismatches between object type in parameters.
   for (std::size_t pNb = 0; pNb < instrInfos.parameters.GetParametersCount(); ++pNb) {
     if (ParameterMetadata::IsObject(instrInfos.parameters.GetParameter(pNb).GetType())) {
@@ -357,6 +356,11 @@ gd::String EventsCodeGenerator::GenerateConditionCode(
       }
     }
   }
+  bool isAnyBehaviorMissing =
+      gd::EventsCodeGenerator::CheckBehaviorParameters(condition, instrInfos);
+  if (isAnyBehaviorMissing) {
+    return "/* Missing behavior - skipped. */";
+  }
 
   if (instrInfos.IsObjectInstruction()) {
     gd::String objectName = condition.GetParameter(0).GetPlainString();
@@ -488,14 +492,16 @@ gd::String EventsCodeGenerator::GenerateConditionsListCode(
   return outputCode;
 }
 
-void EventsCodeGenerator::CheckBehaviorParameters(
+bool EventsCodeGenerator::CheckBehaviorParameters(
     const gd::Instruction &instruction,
     const gd::InstructionMetadata &instrInfos) {
-  gd::ParameterMetadataTools::IterateOverParameters(
+  bool isAnyBehaviorMissing = false;
+  gd::ParameterMetadataTools::IterateOverParametersWithIndex(
       instruction.GetParameters(), instrInfos.parameters,
-      [this](const gd::ParameterMetadata &parameterMetadata,
-             const gd::Expression &parameterValue,
-             const gd::String &lastObjectName) {
+      [this, &isAnyBehaviorMissing,
+       &instrInfos](const gd::ParameterMetadata &parameterMetadata,
+                    const gd::Expression &parameterValue, size_t parameterIndex,
+                    const gd::String &lastObjectName, size_t lastObjectIndex) {
         if (ParameterMetadata::IsBehavior(parameterMetadata.GetType())) {
           const gd::String &behaviorName = parameterValue.GetPlainString();
           const gd::String &actualBehaviorType =
@@ -506,13 +512,25 @@ void EventsCodeGenerator::CheckBehaviorParameters(
 
           if (!expectedBehaviorType.empty() &&
               actualBehaviorType != expectedBehaviorType) {
+            const auto &objectParameterMetadata =
+                instrInfos.GetParameter(lastObjectIndex);
+            // Event functions crash if some objects in a group are missing
+            // the required behaviors, since they lose reference to the original
+            // objects. Missing behaviors are considered "fatal" only for
+            // ObjectList parameters, in order to minimize side effects on
+            // built-in functions.
+            if (objectParameterMetadata.GetType() == "objectList") {
+              isAnyBehaviorMissing = true;
+            }
             gd::ProjectDiagnostic projectDiagnostic(
                 gd::ProjectDiagnostic::ErrorType::MissingBehavior, "",
                 actualBehaviorType, expectedBehaviorType, lastObjectName);
-            if (diagnosticReport) diagnosticReport->Add(projectDiagnostic);
+            if (diagnosticReport)
+              diagnosticReport->Add(projectDiagnostic);
           }
         }
       });
+  return isAnyBehaviorMissing;
 }
 
 /**
@@ -552,7 +570,6 @@ gd::String EventsCodeGenerator::GenerateActionCode(
     action.SetParameters(parameters);
   }
 
-  gd::EventsCodeGenerator::CheckBehaviorParameters(action, instrInfos);
   // Verify that there are no mismatches between object type in parameters.
   for (std::size_t pNb = 0; pNb < instrInfos.parameters.GetParametersCount(); ++pNb) {
     if (ParameterMetadata::IsObject(instrInfos.parameters.GetParameter(pNb).GetType())) {
@@ -579,6 +596,11 @@ gd::String EventsCodeGenerator::GenerateActionCode(
       }
     }
   }
+  bool isAnyBehaviorMissing =
+      gd::EventsCodeGenerator::CheckBehaviorParameters(action, instrInfos);
+  if (isAnyBehaviorMissing) {
+    return "/* Missing behavior - skipped. */";
+  }
 
   // Call free function first if available
   if (instrInfos.IsObjectInstruction()) {
@@ -769,7 +791,7 @@ gd::String EventsCodeGenerator::GenerateActionsListCode(
     } else {
       outputCode += actionCode;
     }
-    outputCode += "}";
+    outputCode += "}\n";
   }
 
   return outputCode;

Core/GDCore/Events/CodeGeneration/EventsCodeGenerator.h

@@ -837,7 +837,7 @@ protected:
   virtual gd::String GenerateGetBehaviorNameCode(
       const gd::String& behaviorName);
 
-  void CheckBehaviorParameters(
+  bool CheckBehaviorParameters(
       const gd::Instruction &instruction,
       const gd::InstructionMetadata &instrInfos);
 

Core/GDCore/Events/Event.h

@@ -286,6 +286,20 @@ class GD_CORE_API BaseEvent {
    * \brief True if the event should be folded in the events editor.
    */
   bool IsFolded() const { return folded; }
+
+  /**
+   * \brief Set the AI generated event ID.
+   */
+  void SetAiGeneratedEventId(const gd::String& aiGeneratedEventId_) {
+    aiGeneratedEventId = aiGeneratedEventId_;
+  }
+
+  /**
+   * \brief Get the AI generated event ID.
+   */
+  const gd::String& GetAiGeneratedEventId() const {
+    return aiGeneratedEventId;
+  }
   ///@}
 
   std::weak_ptr<gd::BaseEvent>
@@ -304,6 +318,7 @@ class GD_CORE_API BaseEvent {
   bool disabled;    ///< True if the event is disabled and must not be executed
   gd::String type;  ///< Type of the event. Must be assigned at the creation.
                     ///< Used for saving the event for instance.
+  gd::String aiGeneratedEventId;  ///< When generated by an AI/external tool.
 
   static gd::EventsList badSubEvents;
   static gd::VariablesContainer badLocalVariables;

Core/GDCore/Events/Serialization.cpp

@@ -221,6 +221,8 @@ void EventsListSerialization::UnserializeEventsFrom(
 
     event->SetDisabled(eventElem.GetBoolAttribute("disabled", false));
     event->SetFolded(eventElem.GetBoolAttribute("folded", false));
+    event->SetAiGeneratedEventId(
+        eventElem.GetStringAttribute("aiGeneratedEventId", ""));
 
     list.InsertEvent(event, list.GetEventsCount());
   }
@@ -236,6 +238,8 @@ void EventsListSerialization::SerializeEventsTo(const EventsList& list,
     if (event.IsDisabled())
       eventElem.SetAttribute("disabled", event.IsDisabled());
     if (event.IsFolded()) eventElem.SetAttribute("folded", event.IsFolded());
+    if (!event.GetAiGeneratedEventId().empty())
+      eventElem.SetAttribute("aiGeneratedEventId", event.GetAiGeneratedEventId());
     eventElem.AddChild("type").SetValue(event.GetType());
 
     event.SerializeTo(eventElem);

Core/GDCore/Extensions/Builtin/BaseObjectExtension.cpp

@@ -37,8 +37,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
       .SetIcon("res/actions/position24_black.png");
   extension.AddInstructionOrExpressionGroupMetadata(_("Angle"))
       .SetIcon("res/actions/direction24_black.png");
-  extension.AddInstructionOrExpressionGroupMetadata(_("Size"))
-      .SetIcon("res/actions/scale24_black.png");
+  extension.AddInstructionOrExpressionGroupMetadata(_("Size")).SetIcon(
+      "res/actions/scale24_black.png");
 
   gd::ObjectMetadata& obj = extension.AddObject<gd::ObjectConfiguration>(
       "", _("Base object"), _("Base object"), "res/objeticon24.png");
@@ -235,7 +235,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
 
   obj.AddAction("SetAngle",
                 _("Angle"),
-                _("Change the angle of rotation of an object (in degrees)."),
+                _("Change the angle of rotation of an object (in degrees). For "
+                  "3D objects, this is the rotation around the Z axis."),
                 _("the angle"),
                 _("Angle"),
                 "res/actions/direction24_black.png",
@@ -250,7 +251,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
   obj.AddAction("Rotate",
                 _("Rotate"),
                 _("Rotate an object, clockwise if the speed is positive, "
-                  "counterclockwise otherwise."),
+                  "counterclockwise otherwise. For 3D objects, this is the "
+                  "rotation around the Z axis."),
                 _("Rotate _PARAM0_ at speed _PARAM1_ deg/second"),
                 _("Angle"),
                 "res/actions/rotate24_black.png",
@@ -634,7 +636,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
 
   obj.AddCondition("Angle",
                    _("Angle"),
-                   _("Compare the angle of the specified object."),
+                   _("Compare the angle, in degrees, of the specified object. "
+                     "For 3D objects, this is the angle around the Z axis."),
                    _("the angle (in degrees)"),
                    _("Angle"),
                    "res/conditions/direction24_black.png",
@@ -835,14 +838,13 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
       .MarkAsAdvanced()
       .SetRelevantForLayoutEventsOnly();
 
-  obj.AddAction(
-         "PushBooleanToObjectVariable",
-         _("Add value to object array variable"),
-         _("Adds a boolean to the end of an object array variable."),
-         _("Add value _PARAM2_ to array variable _PARAM1_ of _PARAM0_"),
-         _("Variables ❯ Arrays and structures"),
-         "res/actions/var24.png",
-         "res/actions/var.png")
+  obj.AddAction("PushBooleanToObjectVariable",
+                _("Add value to object array variable"),
+                _("Adds a boolean to the end of an object array variable."),
+                _("Add value _PARAM2_ to array variable _PARAM1_ of _PARAM0_"),
+                _("Variables ❯ Arrays and structures"),
+                "res/actions/var24.png",
+                "res/actions/var.png")
       .AddParameter("object", _("Object"))
       .AddParameter("objectvar", _("Array variable"))
       .AddParameter("trueorfalse", _("Boolean to add"))
@@ -1268,7 +1270,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
 
   obj.AddExpression("Angle",
                     _("Angle"),
-                    _("Current angle, in degrees, of the object"),
+                    _("Current angle, in degrees, of the object. For 3D "
+                      "objects, this is the angle around the Z axis."),
                     _("Angle"),
                     "res/actions/direction_black.png")
       .AddParameter("object", _("Object"));
@@ -1571,7 +1574,9 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsBaseObjectExtension(
   extension
       .AddAction("Create",
                  _("Create an object"),
-                 _("Create an object at specified position"),
+                 _("Create an instance of the object at the specified position."
+                   "The created object instance will be available for the next "
+                   "actions and sub-events."),
                  _("Create object _PARAM1_ at position _PARAM2_;_PARAM3_ "
                    "(layer: _PARAM4_)"),
                  "",

Core/GDCore/Extensions/Builtin/Capabilities/AnimatableExtension.cpp

@@ -18,21 +18,21 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsAnimatableExtension(
     gd::PlatformExtension& extension) {
   extension
       .SetExtensionInformation("AnimatableCapability",
-                               _("Animatable capability"),
-                               _("Animate objects."),
+                               _("Objects with animations"),
+                               _("Actions and conditions for objects having animations (sprite, 3D models...)."),
                                "Florian Rival",
                                "Open source (MIT License)")
       .SetExtensionHelpPath("/objects");
-  extension.AddInstructionOrExpressionGroupMetadata(_("Animatable capability"))
+  extension.AddInstructionOrExpressionGroupMetadata(_("Objects with animations"))
       .SetIcon("res/actions/animation24.png");
   extension.AddInstructionOrExpressionGroupMetadata(_("Animations and images"))
       .SetIcon("res/actions/animation24.png");
 
   gd::BehaviorMetadata& aut = extension.AddBehavior(
       "AnimatableBehavior",
-      _("Animatable capability"),
+      _("Objects with animations"),
       "Animation",
-      _("Animate objects."),
+      _("Actions and conditions for objects having animations (sprite, 3D models...).."),
       "",
       "res/actions/animation24.png",
       "AnimatableBehavior",

Core/GDCore/Extensions/Builtin/Capabilities/EffectExtension.cpp

@@ -18,8 +18,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsEffectExtension(
     gd::PlatformExtension& extension) {
   extension
       .SetExtensionInformation("EffectCapability",
-                               _("Effect capability"),
-                               _("Apply visual effects to objects."),
+                               _("Objects with effects"),
+                               _("Actions/conditions to enable/disable and change parameters of visual effects applied on objects."),
                                "Florian Rival",
                                "Open source (MIT License)")
       .SetExtensionHelpPath("/objects");
@@ -28,9 +28,9 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsEffectExtension(
 
   gd::BehaviorMetadata& aut = extension.AddBehavior(
       "EffectBehavior",
-      _("Effect capability"),
+      _("Objects with effects"),
       "Effect",
-      _("Apply visual effects to objects."),
+      _("Actions/conditions to enable/disable and change parameters of visual effects applied on objects."),
       "",
       "res/actions/effect_black.svg",
       "EffectBehavior",

Core/GDCore/Extensions/Builtin/Capabilities/FlippableExtension.cpp

@@ -18,8 +18,8 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsFlippableExtension(
     gd::PlatformExtension& extension) {
   extension
       .SetExtensionInformation("FlippableCapability",
-                               _("Flippable capability"),
-                               _("Flip objects."),
+                               _("Flippable objects"),
+                               _("Actions/conditions for objects which can be flipped horizontally or vertically."),
                                "Florian Rival",
                                "Open source (MIT License)")
       .SetExtensionHelpPath("/objects");
@@ -28,9 +28,9 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsFlippableExtension(
 
   gd::BehaviorMetadata& aut = extension.AddBehavior(
       "FlippableBehavior",
-      _("Flippable capability"),
+      _("Flippable objects"),
       "Flippable",
-      _("Flip objects."),
+      _("Actions/conditions for objects which can be flipped horizontally or vertically."),
       "",
       "res/actions/flipX24.png",
       "FlippableBehavior",

Core/GDCore/Extensions/Builtin/Capabilities/OpacityExtension.cpp

@@ -18,27 +18,30 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsOpacityExtension(
     gd::PlatformExtension& extension) {
   extension
       .SetExtensionInformation("OpacityCapability",
-                               _("Opacity capability"),
-                               _("Change the object opacity."),
+                               _("Objects with opacity"),
+                               _("Action/condition/expression to change or "
+                                 "check the opacity of an object (0-255)."),
                                "Florian Rival",
                                "Open source (MIT License)")
       .SetExtensionHelpPath("/objects");
-  extension.AddInstructionOrExpressionGroupMetadata(_("Opacity capability"))
+  extension.AddInstructionOrExpressionGroupMetadata(_("Objects with opacity"))
       .SetIcon("res/actions/opacity24.png");
   extension.AddInstructionOrExpressionGroupMetadata(_("Visibility"))
       .SetIcon("res/actions/opacity24.png");
 
-  gd::BehaviorMetadata& aut = extension.AddBehavior(
-      "OpacityBehavior",
-      _("Opacity capability"),
-      "Opacity",
-      _("Change the object opacity."),
-      "",
-      "res/actions/opacity24.png",
-      "OpacityBehavior",
-      std::make_shared<gd::Behavior>(),
-      std::make_shared<gd::BehaviorsSharedData>())
-    .SetHidden();
+  gd::BehaviorMetadata& aut =
+      extension
+          .AddBehavior("OpacityBehavior",
+                       _("Objects with opacity"),
+                       "Opacity",
+                       _("Action/condition/expression to change or check the "
+                         "opacity of an object (0-255)."),
+                       "",
+                       "res/actions/opacity24.png",
+                       "OpacityBehavior",
+                       std::make_shared<gd::Behavior>(),
+                       std::make_shared<gd::BehaviorsSharedData>())
+          .SetHidden();
 
   aut.AddExpressionAndConditionAndAction(
          "number",
@@ -52,8 +55,9 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsOpacityExtension(
       .AddParameter("object", _("Object"))
       .AddParameter("behavior", _("Behavior"), "OpacityBehavior")
       .UseStandardParameters(
-          "number", gd::ParameterOptions::MakeNewOptions().SetDescription(
-                        _("Opacity (0-255)")))
+          "number",
+          gd::ParameterOptions::MakeNewOptions().SetDescription(
+              _("Opacity (0-255)")))
       .SetFunctionName("setOpacity")
       .SetGetter("getOpacity");
   aut.GetAllExpressions()["Value"].SetGroup("");

Core/GDCore/Extensions/Builtin/Capabilities/ResizableExtension.cpp

@@ -16,11 +16,13 @@ namespace gd {
 void GD_CORE_API BuiltinExtensionsImplementer::ImplementsResizableExtension(
     gd::PlatformExtension &extension) {
   extension
-      .SetExtensionInformation("ResizableCapability",
-                               _("Resizable capability"),
-                               _("Change the object dimensions."),
-                               "Florian Rival",
-                               "Open source (MIT License)")
+      .SetExtensionInformation(
+          "ResizableCapability",
+          _("Resizable objects"),
+          _("Change or compare the size (width/height) of an object which can "
+            "be resized (i.e: most objects)."),
+          "Florian Rival",
+          "Open source (MIT License)")
       .SetExtensionHelpPath("/objects");
   extension.AddInstructionOrExpressionGroupMetadata(_("Size")).SetIcon(
       "res/actions/scale24_black.png");
@@ -28,9 +30,10 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsResizableExtension(
   gd::BehaviorMetadata &aut =
       extension
           .AddBehavior("ResizableBehavior",
-                       _("Resizable capability"),
+                       _("Resizable objects"),
                        "Resizable",
-                       _("Change the object dimensions."),
+                       _("Change or compare the size (width/height) of an "
+                         "object which can be resized (i.e: most objects)."),
                        "",
                        "res/actions/scale24_black.png",
                        "ResizableBehavior",

Core/GDCore/Extensions/Builtin/Capabilities/ScalableExtension.cpp

@@ -18,27 +18,30 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsScalableExtension(
     gd::PlatformExtension& extension) {
   extension
       .SetExtensionInformation("ScalableCapability",
-                               _("Scalable capability"),
-                               _("Change the object scale."),
+                               _("Scalable objects"),
+                               _("Actions/conditions/expression to change or "
+                                 "check the scale of an object (default: 1)."),
                                "Florian Rival",
                                "Open source (MIT License)")
       .SetExtensionHelpPath("/objects");
-  extension.AddInstructionOrExpressionGroupMetadata(_("Scalable capability"))
-      .SetIcon("res/actions/scale24_black.png");
-  extension.AddInstructionOrExpressionGroupMetadata(_("Size"))
+  extension.AddInstructionOrExpressionGroupMetadata(_("Scalable objects"))
       .SetIcon("res/actions/scale24_black.png");
+  extension.AddInstructionOrExpressionGroupMetadata(_("Size")).SetIcon(
+      "res/actions/scale24_black.png");
 
-  gd::BehaviorMetadata& aut = extension.AddBehavior(
-      "ScalableBehavior",
-      _("Scalable capability"),
-      "Scale",
-      _("Change the object scale."),
-      "",
-      "res/actions/scale24_black.png",
-      "ResizableBehavior",
-      std::make_shared<gd::Behavior>(),
-      std::make_shared<gd::BehaviorsSharedData>())
-    .SetHidden();
+  gd::BehaviorMetadata& aut =
+      extension
+          .AddBehavior("ScalableBehavior",
+                       _("Scalable objects"),
+                       "Scale",
+                       _("Actions/conditions/expression to change or check the "
+                         "scale of an object (default: 1)."),
+                       "",
+                       "res/actions/scale24_black.png",
+                       "ResizableBehavior",
+                       std::make_shared<gd::Behavior>(),
+                       std::make_shared<gd::BehaviorsSharedData>())
+          .SetHidden();
 
   aut.AddExpressionAndConditionAndAction(
          "number",

Core/GDCore/Extensions/Builtin/Capabilities/TextContainerExtension.cpp

@@ -18,19 +18,19 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsTextContainerExtension(
     gd::PlatformExtension& extension) {
   extension
       .SetExtensionInformation("TextContainerCapability",
-                               _("Text capability"),
-                               _("Animate objects."),
+                               _("Objects containing a text"),
+                               _("Allows an object to contain a text, usually shown on screen, that can be modified."),
                                "Florian Rival",
                                "Open source (MIT License)")
       .SetExtensionHelpPath("/objects");
-  extension.AddInstructionOrExpressionGroupMetadata(_("Text capability"))
+  extension.AddInstructionOrExpressionGroupMetadata(_("Objects containing a text"))
       .SetIcon("res/conditions/text24_black.png");
 
   gd::BehaviorMetadata& aut = extension.AddBehavior(
       "TextContainerBehavior",
-      _("Text capability"),
+      _("Objects containing a text"),
       "Text",
-      _("Access objects text."),
+      _("Allows an object to contain a text, usually shown on screen, that can be modified."),
       "",
       "res/conditions/text24_black.png",
       "TextContainerBehavior",

Core/GDCore/Extensions/Builtin/CommonConversionsExtension.cpp

@@ -16,7 +16,9 @@ BuiltinExtensionsImplementer::ImplementsCommonConversionsExtension(
       .SetExtensionInformation(
           "BuiltinCommonConversions",
           _("Conversion"),
-          "Expressions to convert number, texts and quantities.",
+          "Expressions to convert numbers to string, strings to numbers, "
+          "angles (degrees from/to radians) and a GDevelop variable to/from a "
+          "JSON string.",
           "Florian Rival",
           "Open source (MIT License)")
       .SetExtensionHelpPath("/all-features/common-conversions");
@@ -41,7 +43,7 @@ BuiltinExtensionsImplementer::ImplementsCommonConversionsExtension(
 
   extension
       .AddStrExpression("LargeNumberToString",
-                        _("Number > Text ( without scientific notation )"),
+                        _("Number > Text (without scientific notation)"),
                         _("Convert the result of the expression to text, "
                           "without using the scientific notation"),
                         "",
@@ -72,7 +74,8 @@ BuiltinExtensionsImplementer::ImplementsCommonConversionsExtension(
                         _("Convert a variable to JSON"),
                         _("JSON"),
                         "res/conditions/toujours24_black.png")
-      .AddParameter("variable", _("The variable to be stringified"),
+      .AddParameter("variable",
+                    _("The variable to be stringified"),
                     "AllowUndeclaredVariable");
 
   // Deprecated

Core/GDCore/Extensions/Builtin/CommonInstructionsExtension.cpp

@@ -59,36 +59,44 @@ BuiltinExtensionsImplementer::ImplementsCommonInstructionsExtension(
   // end of compatibility code
 
   extension
-      .AddCondition("Or",
-                    _("Or"),
-                    _("Check if one of the sub conditions is true"),
-                    _("If one of these conditions is true:"),
-                    "",
-                    "res/conditions/or24_black.png",
-                    "res/conditions/or_black.png")
-      .SetCanHaveSubInstructions()
-      .MarkAsAdvanced();
-
-  extension
-      .AddCondition("And",
-                    _("And"),
-                    _("Check if all sub conditions are true"),
-                    _("If all of these conditions are true:"),
-                    "",
-                    "res/conditions/and24_black.png",
-                    "res/conditions/and_black.png")
+      .AddCondition(
+          "Or",
+          _("Or"),
+          _("Checks if at least one sub-condition is true. If no "
+            "sub-condition is specified, it will always be false. "
+            "This is rarely used — multiple events and sub-events are "
+            "usually a better approach."),
+          _("If one of these conditions is true:"),
+          "",
+          "res/conditions/or24_black.png",
+          "res/conditions/or_black.png")
       .SetCanHaveSubInstructions()
       .MarkAsAdvanced();
 
   extension
       .AddCondition(
-          "Not",
-          _("Not"),
-          _("Return the contrary of the result of the sub conditions"),
-          _("Invert the logical result of these conditions:"),
+          "And",
+          _("And"),
+          _("Checks if all sub-conditions are true. If no sub-condition is "
+            "specified, it will always be false. This is rarely needed, as "
+            "events already check all conditions before running actions."),
+          _("If all of these conditions are true:"),
           "",
-          "res/conditions/not24_black.png",
-          "res/conditions/not_black.png")
+          "res/conditions/and24_black.png",
+          "res/conditions/and_black.png")
+      .SetCanHaveSubInstructions()
+      .MarkAsAdvanced();
+
+  extension
+      .AddCondition("Not",
+                    _("Not"),
+                    _("Returns the opposite of the sub-condition(s) result. "
+                      "This is rarely needed, as most conditions can be "
+                      "inverted or expressed more simply."),
+                    _("Invert the logical result of these conditions:"),
+                    "",
+                    "res/conditions/not24_black.png",
+                    "res/conditions/not_black.png")
       .SetCanHaveSubInstructions()
       .MarkAsAdvanced();
 

Core/GDCore/Extensions/Builtin/FileExtension.cpp

@@ -42,13 +42,17 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsFileExtension(
   extension
       .AddAction(
           "LoadFile",
-          _("Load a storage in memory"),
-          _("This action loads the specified storage in memory, so you can "
-            "write and read it.\nYou can open and write without using this "
-            "action, but it will be slower.\nIf you use this action, do not "
-            "forget to unload the storage from memory."),
-          _("Load storage _PARAM0_ in memory"),
-          "",
+          _("Manually preload a storage in memory"),
+          _("Forces the specified storage to be loaded and kept in "
+            "memory, allowing faster reads/writes. "
+            "However, it requires manual management: if you use this "
+            "action, you *must* also unload the storage manually when "
+            "it's no longer needed to ensure data is persisted.\n\n"
+            "Unless you have a specific performance need, avoid using this "
+            "action. The system already handles loading/unloading "
+            "automatically."),
+          _("Load data storage _PARAM0_ in memory"),
+          _("Advanced"),
           "res/actions/fichier24.png",
           "res/actions/fichier.png")
       .AddParameter("string", _("Storage name"))
@@ -56,11 +60,11 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsFileExtension(
 
   extension
       .AddAction("UnloadFile",
-                 _("Close a storage"),
-                 _("This action closes the structured data previously loaded "
+                 _("Manually unload and persist a storage"),
+                 _("Close the specified storage previously loaded "
                    "in memory, saving all changes made."),
-                 _("Close structured data _PARAM0_"),
-                 "",
+                 _("Unload and persist data storage _PARAM0_"),
+                 _("Advanced"),
                  "res/actions/fichier24.png",
                  "res/actions/fichier.png")
       .AddParameter("string", _("Storage name"))

Core/GDCore/Extensions/Builtin/KeyboardExtension.cpp

@@ -15,10 +15,11 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsKeyboardExtension(
       .SetExtensionInformation(
           "BuiltinKeyboard",
           _("Keyboard"),
-          _("Allows your game to respond to keyboard input. Note that this "
+          _("Conditions to check keys pressed on a keyboard. Note that this "
             "does not work with on-screen keyboard on touch devices: use "
-            "instead conditions related to touch when making a game for "
-            "mobile/touchscreen devices."),
+            "instead mouse/touch conditions when making a game for "
+            "mobile/touchscreen devices or when making a new game from "
+            "scratch."),
           "Florian Rival",
           "Open source (MIT License)")
       .SetExtensionHelpPath("/all-features/keyboard")
@@ -51,10 +52,25 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsKeyboardExtension(
       .SetHidden();
 
   extension
-      .AddCondition("KeyFromTextPressed",
-                    _("Key pressed"),
-                    _("Check if a key is pressed"),
-                    _("_PARAM1_ key is pressed"),
+      .AddCondition(
+          "KeyFromTextPressed",
+          _("Key pressed"),
+          _("Check if a key is pressed. This stays true as long as "
+            "the key is held down. To check if a key was pressed during "
+            "the frame, use \"Key just pressed\" instead."),
+          _("_PARAM1_ key is pressed"),
+          "",
+          "res/conditions/keyboard24.png",
+          "res/conditions/keyboard.png")
+      .AddCodeOnlyParameter("currentScene", "")
+      .AddParameter("keyboardKey", _("Key to check"))
+      .MarkAsSimple();
+
+  extension
+      .AddCondition("KeyFromTextJustPressed",
+                    _("Key just pressed"),
+                    _("Check if a key was just pressed."),
+                    _("_PARAM1_ key was just pressed"),
                     "",
                     "res/conditions/keyboard24.png",
                     "res/conditions/keyboard.png")
@@ -65,7 +81,7 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsKeyboardExtension(
   extension
       .AddCondition("KeyFromTextReleased",
                     _("Key released"),
-                    _("Check if a key was just released"),
+                    _("Check if a key was just released."),
                     _("_PARAM1_ key is released"),
                     "",
                     "res/conditions/keyboard24.png",
@@ -84,7 +100,7 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsKeyboardExtension(
                     "res/conditions/keyboard.png")
       .AddCodeOnlyParameter("currentScene", "");
 
- extension
+  extension
       .AddCondition("AnyKeyReleased",
                     _("Any key released"),
                     _("Check if any key is released"),

Core/GDCore/Extensions/Builtin/MathematicalToolsExtension.cpp

@@ -72,7 +72,8 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
 
   extension
       .AddExpression("normalize",
-                     _("Normalize a value between `min` and `max` to a value between 0 and 1."),
+                     _("Normalize a value between `min` and `max` to a value "
+                       "between 0 and 1."),
                      _("Remap a value between 0 and 1."),
                      "",
                      "res/mathfunction.png")
@@ -124,7 +125,8 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
   extension
       .AddExpression("mod",
                      _("Modulo"),
-                     _("x mod y"),
+                     _("Compute \"x mod y\". GDevelop does NOT support the \% "
+                       "operator. Use this mod(x, y) function instead."),
                      "",
                      "res/mathfunction.png")
       .AddParameter("expression", _("x (as in x mod y)"))
@@ -184,11 +186,8 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
       .AddParameter("expression", _("Expression"));
 
   extension
-      .AddExpression("asinh",
-                     _("Arcsine"),
-                     _("Arcsine"),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "asinh", _("Arcsine"), _("Arcsine"), "", "res/mathfunction.png")
       .AddParameter("expression", _("Expression"));
 
   extension
@@ -218,11 +217,8 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
       .AddParameter("expression", _("Expression"));
 
   extension
-      .AddExpression("cbrt",
-                     _("Cube root"),
-                     _("Cube root"),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "cbrt", _("Cube root"), _("Cube root"), "", "res/mathfunction.png")
       .AddParameter("expression", _("Expression"));
 
   extension
@@ -260,12 +256,13 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
       .AddParameter("expression", _("Expression"), "", true);
 
   extension
-      .AddExpression("cos",
-                     _("Cosine"),
-                     _("Cosine of an angle (in radian). "
-                       "If you want to use degrees, use`ToRad`: `sin(ToRad(45))`."),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "cos",
+          _("Cosine"),
+          _("Cosine of an angle (in radian). "
+            "If you want to use degrees, use`ToRad`: `sin(ToRad(45))`."),
+          "",
+          "res/mathfunction.png")
       .AddParameter("expression", _("Expression"));
 
   extension
@@ -293,29 +290,20 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
       .AddParameter("expression", _("Expression"));
 
   extension
-      .AddExpression("int",
-                     _("Round"),
-                     _("Round a number"),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "int", _("Round"), _("Round a number"), "", "res/mathfunction.png")
       .SetHidden()
       .AddParameter("expression", _("Expression"));
 
   extension
-      .AddExpression("rint",
-                     _("Round"),
-                     _("Round a number"),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "rint", _("Round"), _("Round a number"), "", "res/mathfunction.png")
       .SetHidden()
       .AddParameter("expression", _("Expression"));
 
   extension
-      .AddExpression("round",
-                     _("Round"),
-                     _("Round a number"),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "round", _("Round"), _("Round a number"), "", "res/mathfunction.png")
       .AddParameter("expression", _("Expression"));
 
   extension
@@ -324,8 +312,8 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
                      _("Round a number to the Nth decimal place"),
                      "",
                      "res/mathfunction.png")
-      .AddParameter("expression", _("Expression"))
-      .AddParameter("expression", _("Expression"), "", true);
+      .AddParameter("expression", _("Number to Round"))
+      .AddParameter("expression", _("Decimal Places"), "", true);
 
   extension
       .AddExpression("exp",
@@ -336,19 +324,13 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
       .AddParameter("expression", _("Expression"));
 
   extension
-      .AddExpression("log",
-                     _("Logarithm"),
-                     _("Logarithm"),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "log", _("Logarithm"), _("Logarithm"), "", "res/mathfunction.png")
       .AddParameter("expression", _("Expression"));
 
   extension
-      .AddExpression("ln",
-                     _("Logarithm"),
-                     _("Logarithm"),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "ln", _("Logarithm"), _("Logarithm"), "", "res/mathfunction.png")
       .SetHidden()
       .AddParameter("expression", _("Expression"));
 
@@ -387,11 +369,8 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
       .AddParameter("expression", _("The exponent (n in x^n)"));
 
   extension
-      .AddExpression("sec",
-                     _("Secant"),
-                     _("Secant"),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "sec", _("Secant"), _("Secant"), "", "res/mathfunction.png")
       .AddParameter("expression", _("Expression"));
 
   extension
@@ -403,12 +382,13 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
       .AddParameter("expression", _("Expression"));
 
   extension
-      .AddExpression("sin",
-                     _("Sine"),
-                     _("Sine of an angle (in radian). "
-                       "If you want to use degrees, use`ToRad`: `sin(ToRad(45))`."),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "sin",
+          _("Sine"),
+          _("Sine of an angle (in radian). "
+            "If you want to use degrees, use`ToRad`: `sin(ToRad(45))`."),
+          "",
+          "res/mathfunction.png")
       .AddParameter("expression", _("Expression"));
 
   extension
@@ -428,12 +408,13 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
       .AddParameter("expression", _("Expression"));
 
   extension
-      .AddExpression("tan",
-                     _("Tangent"),
-                     _("Tangent of an angle (in radian). "
-                       "If you want to use degrees, use`ToRad`: `tan(ToRad(45))`."),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "tan",
+          _("Tangent"),
+          _("Tangent of an angle (in radian). "
+            "If you want to use degrees, use`ToRad`: `tan(ToRad(45))`."),
+          "",
+          "res/mathfunction.png")
       .AddParameter("expression", _("Expression"));
 
   extension
@@ -463,26 +444,28 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
       .AddParameter("expression", _("x (in a+(b-a)*x)"));
 
   extension
-      .AddExpression("XFromAngleAndDistance",
-                     _("X position from angle and distance"),
-                     _("Compute the X position when given an angle and distance "
-                      "relative to the origin (0;0). This is also known as "
-                      "getting the cartesian coordinates of a 2D vector, using "
-                      "its polar coordinates."),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "XFromAngleAndDistance",
+          _("X position from angle and distance"),
+          _("Compute the X position when given an angle and distance "
+            "relative to the origin (0;0). This is also known as "
+            "getting the cartesian coordinates of a 2D vector, using "
+            "its polar coordinates."),
+          "",
+          "res/mathfunction.png")
       .AddParameter("expression", _("Angle, in degrees"))
       .AddParameter("expression", _("Distance"));
 
   extension
-      .AddExpression("YFromAngleAndDistance",
-                     _("Y position from angle and distance"),
-                     _("Compute the Y position when given an angle and distance "
-                      "relative to the origin (0;0). This is also known as "
-                      "getting the cartesian coordinates of a 2D vector, using "
-                      "its polar coordinates."),
-                     "",
-                     "res/mathfunction.png")
+      .AddExpression(
+          "YFromAngleAndDistance",
+          _("Y position from angle and distance"),
+          _("Compute the Y position when given an angle and distance "
+            "relative to the origin (0;0). This is also known as "
+            "getting the cartesian coordinates of a 2D vector, using "
+            "its polar coordinates."),
+          "",
+          "res/mathfunction.png")
       .AddParameter("expression", _("Angle, in degrees"))
       .AddParameter("expression", _("Distance"));
 
@@ -497,7 +480,8 @@ BuiltinExtensionsImplementer::ImplementsMathematicalToolsExtension(
   extension
       .AddExpression("lerpAngle",
                      _("Lerp (Linear interpolation) between two angles"),
-                     _("Linearly interpolates between two angles (in degrees) by taking the shortest direction around the circle."),
+                     _("Linearly interpolates between two angles (in degrees) "
+                       "by taking the shortest direction around the circle."),
                      "",
                      "res/mathfunction.png")
       .AddParameter("expression", _("Starting angle, in degrees"))

Core/GDCore/Extensions/Builtin/MouseExtension.cpp

@@ -16,8 +16,11 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsMouseExtension(
       .SetExtensionInformation(
           "BuiltinMouse",
           _("Mouse and touch"),
-          "Conditions and actions to handle either the mouse or touches on "
-          "touchscreen. By default, conditions related to the mouse will also "
+          "Conditions, actions and expressions to handle either the mouse or "
+          "touches on a touchscreen. Notably: cursor position, mouse wheel, "
+          "mouse buttons, touch positions, started/end touches, etc...\n"
+          "\n"
+          "By default, conditions related to the mouse will also "
           "handle the touches - so that it's easier to handle both in your "
           "game. You can disable this behavior if you want to handle them "
           "separately in different events.",
@@ -273,28 +276,26 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsMouseExtension(
       .SetHidden();
 
   extension
-      .AddCondition(
-          "MouseButtonFromTextPressed",
-          _("Mouse button pressed or touch held"),
-          _("Check if the specified mouse button is pressed or "
-              "if a touch is in contact with the screen."),
-          _("Touch or _PARAM1_ mouse button is down"),
-          "",
-          "res/conditions/mouse24.png",
-          "res/conditions/mouse.png")
+      .AddCondition("MouseButtonFromTextPressed",
+                    _("Mouse button pressed or touch held"),
+                    _("Check if the specified mouse button is pressed or "
+                      "if a touch is in contact with the screen."),
+                    _("Touch or _PARAM1_ mouse button is down"),
+                    "",
+                    "res/conditions/mouse24.png",
+                    "res/conditions/mouse.png")
       .AddCodeOnlyParameter("currentScene", "")
       .AddParameter("mouseButton", _("Button to check"))
       .MarkAsSimple();
 
   extension
-      .AddCondition(
-          "MouseButtonFromTextReleased",
-          _("Mouse button released"),
-          _("Check if the specified mouse button was released."),
-          _("Touch or _PARAM1_ mouse button is released"),
-          "",
-          "res/conditions/mouse24.png",
-          "res/conditions/mouse.png")
+      .AddCondition("MouseButtonFromTextReleased",
+                    _("Mouse button released"),
+                    _("Check if the specified mouse button was released."),
+                    _("Touch or _PARAM1_ mouse button is released"),
+                    "",
+                    "res/conditions/mouse24.png",
+                    "res/conditions/mouse.png")
       .AddCodeOnlyParameter("currentScene", "")
       .AddParameter("mouseButton", _("Button to check"))
       .MarkAsSimple();

Core/GDCore/Extensions/Builtin/NetworkExtension.cpp

@@ -15,8 +15,9 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsNetworkExtension(
       .SetExtensionInformation(
           "BuiltinNetwork",
           _("Network"),
-          _("Features to send web requests, communicate with external \"APIs\" "
-            "and other network related tasks."),
+          _("Actions to send web requests, communicate with external \"APIs\" "
+            "and other network related tasks. Also contains an action to open "
+            "a URL on the device browser."),
           "Florian Rival",
           "Open source (MIT License)")
       .SetExtensionHelpPath("/all-features/network")

Core/GDCore/Extensions/Builtin/SceneExtension.cpp

@@ -4,8 +4,8 @@
  * reserved. This project is released under the MIT License.
  */
 #include "AllBuiltinExtensions.h"
-#include "GDCore/Tools/Localization.h"
 #include "GDCore/Extensions/Metadata/MultipleInstructionMetadata.h"
+#include "GDCore/Tools/Localization.h"
 
 using namespace std;
 namespace gd {
@@ -16,7 +16,11 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsSceneExtension(
       .SetExtensionInformation(
           "BuiltinScene",
           _("Scene"),
-          _("Actions and conditions to manipulate the scenes during the game."),
+          _("Actions/conditions to change the current scene (or pause it and "
+            "launch another one, or go back to the previous one), check if a "
+            "scene or the game has just started/resumed, preload assets of a "
+            "scene, get the current scene name or loading progress, quit the "
+            "game, set background color, or disable input when focus is lost."),
           "Florian Rival",
           "Open source (MIT License)")
       .SetExtensionHelpPath("" /*TODO: Add a documentation page for this */);
@@ -166,25 +170,28 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsSceneExtension(
       .AddCodeOnlyParameter("currentScene", "");
 
   extension
-      .AddAction("PrioritizeLoadingOfScene",
-                 _("Preload scene"),
-                 _("Preload a scene resources as soon as possible in background."),
-                 _("Preload scene _PARAM1_ in background"),
-                 "",
-                 "res/actions/hourglass_black.svg",
-                 "res/actions/hourglass_black.svg")
+      .AddAction(
+          "PrioritizeLoadingOfScene",
+          _("Preload scene"),
+          _("Preload a scene resources as soon as possible in background."),
+          _("Preload scene _PARAM1_ in background"),
+          "",
+          "res/actions/hourglass_black.svg",
+          "res/actions/hourglass_black.svg")
       .SetHelpPath("/all-features/resources-loading")
       .AddCodeOnlyParameter("currentScene", "")
       .AddParameter("sceneName", _("Name of the new scene"))
       .MarkAsAdvanced();
 
-  extension.AddExpressionAndCondition("number",
-                                "SceneLoadingProgress",
-                                _("Scene loading progress"),
-                                _("The progress of resources loading in background for a scene (between 0 and 1)."),
-                                _("_PARAM0_ loading progress"),
-                                _(""),
-                                "res/actions/hourglass_black.svg")
+  extension
+      .AddExpressionAndCondition("number",
+                                 "SceneLoadingProgress",
+                                 _("Scene loading progress"),
+                                 _("The progress of resources loading in "
+                                   "background for a scene (between 0 and 1)."),
+                                 _("_PARAM1_ loading progress"),
+                                 _(""),
+                                 "res/actions/hourglass_black.svg")
       .SetHelpPath("/all-features/resources-loading")
       .AddCodeOnlyParameter("currentScene", "")
       .AddParameter("sceneName", _("Scene name"))
@@ -192,13 +199,14 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsSceneExtension(
       .MarkAsAdvanced();
 
   extension
-      .AddCondition("AreSceneAssetsLoaded",
-                    _("Scene preloaded"),
-                    _("Check if scene resources have finished to load in background."),
-                    _("Scene _PARAM1_ was preloaded in background"),
-                    "",
-                    "res/actions/hourglass_black.svg",
-                    "res/actions/hourglass_black.svg")
+      .AddCondition(
+          "AreSceneAssetsLoaded",
+          _("Scene preloaded"),
+          _("Check if scene resources have finished to load in background."),
+          _("Scene _PARAM1_ was preloaded in background"),
+          "",
+          "res/actions/hourglass_black.svg",
+          "res/actions/hourglass_black.svg")
       .SetHelpPath("/all-features/resources-loading")
       .AddCodeOnlyParameter("currentScene", "")
       .AddParameter("sceneName", _("Scene name"))

Core/GDCore/Extensions/Builtin/SpriteExtension/SpriteExtension.cpp

@@ -15,12 +15,13 @@ namespace gd {
 void GD_CORE_API BuiltinExtensionsImplementer::ImplementsSpriteExtension(
     gd::PlatformExtension& extension) {
   extension
-      .SetExtensionInformation("Sprite",
-                               _("Sprite"),
-                               _("Sprite are animated object which can be used "
-                                 "for most elements of a game."),
-                               "Florian Rival",
-                               "Open source (MIT License)")
+      .SetExtensionInformation(
+          "Sprite",
+          _("Sprite"),
+          _("Sprite are animated objects which can be used "
+            "for most elements of a 2D game."),
+          "Florian Rival",
+          "Open source (MIT License)")
       .SetExtensionHelpPath("/objects/sprite");
   extension.AddInstructionOrExpressionGroupMetadata(_("Sprite"))
       .SetIcon("CppPlatform/Extensions/spriteicon.png");
@@ -30,7 +31,7 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsSpriteExtension(
           .AddObject<SpriteObject>("Sprite",
                                    _("Sprite"),
                                    _("Animated object which can be used for "
-                                     "most elements of a game."),
+                                     "most elements of a 2D game."),
                                    "CppPlatform/Extensions/spriteicon.png")
           .SetCategoryFullName(_("General"))
           .SetOpenFullEditorLabel(_("Edit animations"))
@@ -645,11 +646,12 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsSpriteExtension(
                     "res/actions/sprite.png")
       .AddParameter("object", _("Object"), "Sprite");
 
-  obj.AddExpression("AnimationFrameCount",
-                    _("Number of frames"),
-                    _("Number of frames in the current animation of the object"),
-                    _("Animations and images"),
-                    "res/actions/sprite.png")
+  obj.AddExpression(
+         "AnimationFrameCount",
+         _("Number of frames"),
+         _("Number of frames in the current animation of the object"),
+         _("Animations and images"),
+         "res/actions/sprite.png")
       .AddParameter("object", _("Object"), "Sprite");
 
   // Deprecated

Core/GDCore/Extensions/Builtin/StringInstructionsExtension.cpp

@@ -16,7 +16,8 @@ BuiltinExtensionsImplementer::ImplementsStringInstructionsExtension(
       .SetExtensionInformation(
           "BuiltinStringInstructions",
           _("Text manipulation"),
-          "Provides expressions to manipulate strings (also called texts).",
+          "Provides expressions to manipulate strings (also called texts): new "
+          "line, upper/lowercase, substring, find, replace, etc...",
           "Florian Rival",
           "Open source (MIT License)")
       .SetExtensionHelpPath("" /*TODO: Add a documentation page for this */);
@@ -191,7 +192,8 @@ BuiltinExtensionsImplementer::ImplementsStringInstructionsExtension(
                         "res/conditions/toujours24_black.png")
       .AddParameter("string", _("Text in which the replacement must be done"))
       .AddParameter("string", _("Text to find inside the first text"))
-      .AddParameter("string", _("Replacement to put instead of the text to find"));
+      .AddParameter("string",
+                    _("Replacement to put instead of the text to find"));
 
   extension
       .AddStrExpression("StrReplaceAll",
@@ -199,10 +201,11 @@ BuiltinExtensionsImplementer::ImplementsStringInstructionsExtension(
                         _("Replace all occurrences of a text by another."),
                         "",
                         "res/conditions/toujours24_black.png")
-      .AddParameter("string", _("Text in which the replacement(s) must be done"))
+      .AddParameter("string",
+                    _("Text in which the replacement(s) must be done"))
       .AddParameter("string", _("Text to find inside the first text"))
-      .AddParameter("string", _("Replacement to put instead of the text to find"));
-
+      .AddParameter("string",
+                    _("Replacement to put instead of the text to find"));
 }
 
 }  // namespace gd

Core/GDCore/Extensions/Builtin/TimeExtension.cpp

@@ -15,9 +15,12 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsTimeExtension(
       .SetExtensionInformation(
           "BuiltinTime",
           _("Timers and time"),
-          "Actions and conditions to run timers, get the current time or "
-          "modify the time scale (speed at which the game is running - useful "
-          "for slow motion effects).",
+          "Actions and conditions to start, pause or reset scene timers, "
+          "modify the time scale (speed at which the game "
+          "is running - useful for slow motion effects). Also contains an "
+          "action that wait for a delay before running the next actions and "
+          "sub-events and expressions to read the time scale, time delta of "
+          "the last frame or timer elapsed time.",
           "Florian Rival",
           "Open source (MIT License)")
       .SetExtensionHelpPath("/all-features/timers-and-time");
@@ -43,7 +46,9 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsTimeExtension(
       .AddCondition("CompareTimer",
                     _("Value of a scene timer"),
                     _("Compare the elapsed time of a scene timer. This "
-                      "condition doesn't start the timer."),
+                      "condition doesn't start the timer and will always be "
+                      "false if the timer was not started previously (whatever "
+                      "the comparison being made)."),
                     _("The timer _PARAM1_ _PARAM2_ _PARAM3_ seconds"),
 
                     "",
@@ -190,26 +195,28 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsTimeExtension(
   extension
       .AddExpression("TimerElapsedTime",
                      _("Scene timer value"),
-                     _("Value of a scene timer"),
+                     _("Value of a scene timer (in seconds)"),
                      "",
                      "res/actions/time.png")
       .AddCodeOnlyParameter("currentScene", "")
       .AddParameter("identifier", _("Timer's name"), "sceneTimer");
 
   extension
-      .AddExpression("TimeFromStart",
-                     _("Time elapsed since the beginning of the scene"),
-                     _("Time elapsed since the beginning of the scene"),
-                     "",
-                     "res/actions/time.png")
+      .AddExpression(
+          "TimeFromStart",
+          _("Time elapsed since the beginning of the scene (in seconds)."),
+          _("Time elapsed since the beginning of the scene (in seconds)."),
+          "",
+          "res/actions/time.png")
       .AddCodeOnlyParameter("currentScene", "");
 
   extension
-      .AddExpression("TempsDebut",
-                     _("Time elapsed since the beginning of the scene"),
-                     _("Time elapsed since the beginning of the scene"),
-                     "",
-                     "res/actions/time.png")
+      .AddExpression(
+          "TempsDebut",
+          _("Time elapsed since the beginning of the scene (in seconds)."),
+          _("Time elapsed since the beginning of the scene (in seconds)."),
+          "",
+          "res/actions/time.png")
       .SetHidden()
       .AddCodeOnlyParameter("currentScene", "");
 
@@ -224,16 +231,21 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsTimeExtension(
   extension
       .AddExpression("Time",
                      _("Current time"),
-                     _("Current time"),
+                     _("Gives the current time"),
                      "",
                      "res/actions/time.png")
       .AddCodeOnlyParameter("currentScene", "")
       .AddParameter(
           "stringWithSelector",
-          _("Hour: hour - Minutes: min - Seconds: sec - Day of month: "
-            "mday - Months since January: mon - Year since 1900: year - Days "
-            "since Sunday: wday - Days since Jan 1st: yday - Timestamp (ms): "
-            "timestamp\""),
+          _("- Hour of the day: \"hour\"\n"
+            "- Minutes: \"min\"\n"
+            "- Seconds: \"sec\"\n"
+            "- Day of month: \"mday\"\n"
+            "- Months since January: \"mon\"\n"
+            "- Year since 1900: \"year\"\n"
+            "- Days since Sunday: \"wday\"\n"
+            "- Days since Jan 1st: \"yday\"\n"
+            "- Timestamp (ms): \"timestamp\""),
           "[\"hour\", \"min\", \"sec\", \"mon\", \"year\", \"wday\", \"mday\", "
           "\"yday\", \"timestamp\"]");
 }

Core/GDCore/Extensions/Builtin/WindowExtension.cpp

@@ -15,16 +15,17 @@ void GD_CORE_API BuiltinExtensionsImplementer::ImplementsWindowExtension(
       .SetExtensionInformation(
           "BuiltinWindow",
           _("Game window and resolution"),
-          "Provides actions and conditions to manipulate the game window. "
+          "Actions and conditions to manipulate the game window or change how "
+          "the game is resized according to the screen size. "
           "Depending on the platform on which the game is running, not all of "
-          "these features can be applied.",
+          "these features can be applied.\n"
+          "Also contains expressions to read the screen size.",
           "Florian Rival",
           "Open source (MIT License)")
       .SetCategory("User interface")
       .SetExtensionHelpPath("/all-features/window");
   extension
-      .AddInstructionOrExpressionGroupMetadata(
-          _("Game window and resolution"))
+      .AddInstructionOrExpressionGroupMetadata(_("Game window and resolution"))
       .SetIcon("res/actions/window24.png");
 
   extension

Core/GDCore/Extensions/Metadata/BehaviorMetadata.h

@@ -298,6 +298,19 @@ class GD_CORE_API BehaviorMetadata : public InstructionOrExpressionContainerMeta
     return *this;
   }
 
+  /**
+   * Check if the behavior can be used on objects from event-based objects.
+   */
+  bool IsRelevantForChildObjects() const { return isRelevantForChildObjects; }
+
+  /**
+   * Set that behavior can't be used on objects from event-based objects.
+   */
+  BehaviorMetadata &MarkAsIrrelevantForChildObjects() {
+    isRelevantForChildObjects = false;
+    return *this;
+  }
+
   QuickCustomization::Visibility GetQuickCustomizationVisibility() const {
     return quickCustomizationVisibility;
   }
@@ -393,6 +406,7 @@ class GD_CORE_API BehaviorMetadata : public InstructionOrExpressionContainerMeta
   mutable std::vector<gd::String> requiredBehaviors;
   bool isPrivate = false;
   bool isHidden = false;
+  bool isRelevantForChildObjects = true;
   gd::String openFullEditorLabel;
   QuickCustomization::Visibility quickCustomizationVisibility = QuickCustomization::Visibility::Default;
 

Core/GDCore/Extensions/Metadata/MetadataProvider.h

@@ -277,6 +277,10 @@ class GD_CORE_API MetadataProvider {
     return &metadata == &badObjectInfo;
   }
 
+  static bool IsBadEffectMetadata(const gd::EffectMetadata& metadata) {
+    return &metadata == &badEffectMetadata;
+  }
+
   virtual ~MetadataProvider();
 
  private:

Core/GDCore/Extensions/Metadata/ParameterMetadataTools.cpp

@@ -194,7 +194,8 @@ void ParameterMetadataTools::IterateOverParameters(
       [&fn](const gd::ParameterMetadata& parameterMetadata,
             const gd::Expression& parameterValue,
             size_t parameterIndex,
-            const gd::String& lastObjectName) {
+            const gd::String& lastObjectName,
+            size_t lastObjectIndex) {
         fn(parameterMetadata, parameterValue, lastObjectName);
       });
 }
@@ -205,8 +206,10 @@ void ParameterMetadataTools::IterateOverParametersWithIndex(
     std::function<void(const gd::ParameterMetadata& parameterMetadata,
                        const gd::Expression& parameterValue,
                        size_t parameterIndex,
-                       const gd::String& lastObjectName)> fn) {
+                       const gd::String& lastObjectName,
+                       size_t lastObjectIndex)> fn) {
   gd::String lastObjectName = "";
+  size_t lastObjectIndex = 0;
   for (std::size_t pNb = 0; pNb < parametersMetadata.GetParametersCount();
        ++pNb) {
     const gd::ParameterMetadata &parameterMetadata =
@@ -218,15 +221,17 @@ void ParameterMetadataTools::IterateOverParametersWithIndex(
             ? Expression(parameterMetadata.GetDefaultValue())
             : parameterValue;
 
-    fn(parameterMetadata, parameterValueOrDefault, pNb, lastObjectName);
+    fn(parameterMetadata, parameterValueOrDefault, pNb, lastObjectName, lastObjectIndex);
 
     // Memorize the last object name. By convention, parameters that require
     // an object (mainly, "objectvar" and "behavior") should be placed after
     // the object in the list of parameters (if possible, just after).
     // Search "lastObjectName" in the codebase for other place where this
     // convention is enforced.
-    if (gd::ParameterMetadata::IsObject(parameterMetadata.GetType()))
+    if (gd::ParameterMetadata::IsObject(parameterMetadata.GetType())) {
       lastObjectName = parameterValueOrDefault.GetPlainString();
+      lastObjectIndex = pNb;
+    }
   }
 }
 

Core/GDCore/Extensions/Metadata/ParameterMetadataTools.h

@@ -64,7 +64,8 @@ class GD_CORE_API ParameterMetadataTools {
       std::function<void(const gd::ParameterMetadata& parameterMetadata,
                          const gd::Expression& parameterValue,
                          size_t parameterIndex,
-                         const gd::String& lastObjectName)> fn);
+                         const gd::String& lastObjectName,
+                         size_t lastObjectIndex)> fn);
 
   /**
    * Iterate over the parameters of a FunctionCallNode.

Core/GDCore/Extensions/PlatformExtension.cpp

@@ -779,6 +779,26 @@ gd::String PlatformExtension::GetBehaviorFullType(
   return extensionName + separator + behaviorName;
 }
 
+gd::String PlatformExtension::GetExtensionFromFullBehaviorType(
+    const gd::String& type) {
+  const auto separatorIndex =
+      type.find(PlatformExtension::GetNamespaceSeparator());
+  if (separatorIndex == std::string::npos) {
+    return "";
+  }
+  return type.substr(0, separatorIndex);
+}
+
+gd::String PlatformExtension::GetBehaviorNameFromFullBehaviorType(
+    const gd::String& type) {
+  const auto separatorIndex =
+      type.find(PlatformExtension::GetNamespaceSeparator());
+  if (separatorIndex == std::string::npos) {
+    return "";
+  }
+  return type.substr(separatorIndex + 2);
+}
+
 gd::String PlatformExtension::GetObjectEventsFunctionFullType(
     const gd::String& extensionName,
     const gd::String& objectName,

Core/GDCore/Extensions/PlatformExtension.h

@@ -651,6 +651,10 @@ class GD_CORE_API PlatformExtension {
   static gd::String GetBehaviorFullType(const gd::String& extensionName,
                                         const gd::String& behaviorName);
 
+  static gd::String GetExtensionFromFullBehaviorType(const gd::String& type);
+
+  static gd::String GetBehaviorNameFromFullBehaviorType(const gd::String& type);
+
   static gd::String GetObjectEventsFunctionFullType(
       const gd::String& extensionName,
       const gd::String& objectName,

Core/GDCore/IDE/Events/BehaviorParametersFiller.cpp

@@ -29,7 +29,7 @@ bool BehaviorParametersFiller::DoVisitInstruction(gd::Instruction &instruction,
       instruction.GetParameters(), metadata.GetParameters(),
       [&](const gd::ParameterMetadata &parameterMetadata,
           const gd::Expression &parameterValue, size_t parameterIndex,
-          const gd::String &lastObjectName) {
+          const gd::String &lastObjectName, size_t lastObjectIndex) {
         if (parameterMetadata.GetValueTypeMetadata().IsBehavior() &&
             parameterValue.GetPlainString().length() == 0) {
 

Core/GDCore/IDE/Events/EventsBehaviorRenamer.cpp

@@ -108,12 +108,10 @@ bool EventsBehaviorRenamer::DoVisitInstruction(gd::Instruction& instruction,
                                    platform, instruction.GetType());
 
   gd::ParameterMetadataTools::IterateOverParametersWithIndex(
-      instruction.GetParameters(),
-      metadata.GetParameters(),
-      [&](const gd::ParameterMetadata& parameterMetadata,
-          const gd::Expression& parameterValue,
-          size_t parameterIndex,
-          const gd::String& lastObjectName) {
+      instruction.GetParameters(), metadata.GetParameters(),
+      [&](const gd::ParameterMetadata &parameterMetadata,
+          const gd::Expression &parameterValue, size_t parameterIndex,
+          const gd::String &lastObjectName, size_t lastObjectIndex) {
         const gd::String& type = parameterMetadata.GetType();
 
         if (gd::ParameterMetadata::IsBehavior(type)) {

Core/GDCore/IDE/Events/EventsParameterReplacer.cpp

@@ -183,12 +183,10 @@ bool EventsParameterReplacer::DoVisitInstruction(gd::Instruction& instruction,
                                    platform, instruction.GetType());
 
   gd::ParameterMetadataTools::IterateOverParametersWithIndex(
-      instruction.GetParameters(),
-      metadata.GetParameters(),
-      [&](const gd::ParameterMetadata& parameterMetadata,
-          const gd::Expression& parameterValue,
-          size_t parameterIndex,
-          const gd::String& lastObjectName) {
+      instruction.GetParameters(), metadata.GetParameters(),
+      [&](const gd::ParameterMetadata &parameterMetadata,
+          const gd::Expression &parameterValue, size_t parameterIndex,
+          const gd::String &lastObjectName, size_t lastObjectIndex) {
         if (!gd::EventsParameterReplacer::CanContainParameter(
           parameterMetadata.GetValueTypeMetadata())) {
           return;

Core/GDCore/IDE/Events/EventsPropertyReplacer.cpp

@@ -217,12 +217,10 @@ bool EventsPropertyReplacer::DoVisitInstruction(gd::Instruction& instruction,
   bool shouldDeleteInstruction = false;
 
   gd::ParameterMetadataTools::IterateOverParametersWithIndex(
-      instruction.GetParameters(),
-      metadata.GetParameters(),
-      [&](const gd::ParameterMetadata& parameterMetadata,
-          const gd::Expression& parameterValue,
-          size_t parameterIndex,
-          const gd::String& lastObjectName) {
+      instruction.GetParameters(), metadata.GetParameters(),
+      [&](const gd::ParameterMetadata &parameterMetadata,
+          const gd::Expression &parameterValue, size_t parameterIndex,
+          const gd::String &lastObjectName, size_t lastObjectIndex) {
         if (!gd::EventsPropertyReplacer::CanContainProperty(
           parameterMetadata.GetValueTypeMetadata())) {
           return;

Core/GDCore/IDE/Events/EventsRefactorer.cpp

@@ -334,7 +334,7 @@ private:
         instruction.GetParameters(), metadata.GetParameters(),
         [&](const gd::ParameterMetadata &parameterMetadata,
             const gd::Expression &parameterValue, size_t parameterIndex,
-            const gd::String &lastObjectName) {
+            const gd::String &lastObjectName, size_t lastObjectIndex) {
           if (!gd::EventsObjectReplacer::CanContainObject(
                   parameterMetadata.GetValueTypeMetadata())) {
             return;

Core/GDCore/IDE/Events/EventsVariableInstructionTypeSwitcher.cpp

@@ -42,18 +42,16 @@ bool EventsVariableInstructionTypeSwitcher::DoVisitInstruction(gd::Instruction&
                                    platform, instruction.GetType());
 
   gd::ParameterMetadataTools::IterateOverParametersWithIndex(
-      instruction.GetParameters(),
-      metadata.GetParameters(),
-      [&](const gd::ParameterMetadata& parameterMetadata,
-          const gd::Expression& parameterValue,
-          size_t parameterIndex,
-          const gd::String& lastObjectName) {
+      instruction.GetParameters(), metadata.GetParameters(),
+      [&](const gd::ParameterMetadata &parameterMetadata,
+          const gd::Expression &parameterValue, size_t parameterIndex,
+          const gd::String &lastObjectName, size_t lastObjectIndex) {
         const gd::String& type = parameterMetadata.GetType();
 
         if (!gd::ParameterMetadata::IsExpression("variable", type) ||
             !gd::VariableInstructionSwitcher::IsSwitchableVariableInstruction(
                 instruction.GetType())) {
-                  return;
+          return;
         }
         const auto variableName =
             gd::ExpressionVariableNameFinder::GetVariableName(
@@ -72,10 +70,11 @@ bool EventsVariableInstructionTypeSwitcher::DoVisitInstruction(gd::Instruction&
                     .GetObjectOrGroupVariablesContainer(lastObjectName);
           }
         } else if (type == "variableOrProperty") {
-            variablesContainer =
-                &GetProjectScopedContainers()
-                      .GetVariablesContainersList()
-                      .GetVariablesContainerFromVariableOrPropertyName(variableName);
+          variablesContainer =
+              &GetProjectScopedContainers()
+                   .GetVariablesContainersList()
+                   .GetVariablesContainerFromVariableOrPropertyName(
+                       variableName);
         } else {
           if (GetProjectScopedContainers().GetVariablesContainersList().Has(
                   variableName)) {

Core/GDCore/IDE/Events/EventsVariableReplacer.cpp

@@ -448,12 +448,10 @@ bool EventsVariableReplacer::DoVisitInstruction(gd::Instruction& instruction,
   bool shouldDeleteInstruction = false;
 
   gd::ParameterMetadataTools::IterateOverParametersWithIndex(
-      instruction.GetParameters(),
-      metadata.GetParameters(),
-      [&](const gd::ParameterMetadata& parameterMetadata,
-          const gd::Expression& parameterValue,
-          size_t parameterIndex,
-          const gd::String& lastObjectName) {
+      instruction.GetParameters(), metadata.GetParameters(),
+      [&](const gd::ParameterMetadata &parameterMetadata,
+          const gd::Expression &parameterValue, size_t parameterIndex,
+          const gd::String &lastObjectName, size_t lastObjectIndex) {
         const gd::String& type = parameterMetadata.GetType();
 
         if (!gd::ParameterMetadata::IsExpression("variable", type) &&

Core/GDCore/IDE/Events/ProjectElementRenamer.cpp

@@ -150,7 +150,7 @@ bool ProjectElementRenamer::DoVisitInstruction(gd::Instruction &instruction,
       instruction.GetParameters(), metadata.GetParameters(),
       [&](const gd::ParameterMetadata &parameterMetadata,
           const gd::Expression &parameterValue, size_t parameterIndex,
-          const gd::String &lastObjectName) {
+          const gd::String &lastObjectName, size_t lastObjectIndex) {
         if (parameterMetadata.GetType() == "layer") {
           if (parameterValue.GetPlainString().length() < 2) {
             // This is either the base layer or an invalid layer name.

Core/GDCore/IDE/EventsBasedObjectVariantHelper.cpp

@@ -0,0 +1,154 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#include "EventsBasedObjectVariantHelper.h"
+
+#include "GDCore/Project/EventsBasedObject.h"
+#include "GDCore/Project/InitialInstancesContainer.h"
+#include "GDCore/Project/Object.h"
+#include "GDCore/Project/ObjectGroup.h"
+#include "GDCore/Project/ObjectsContainer.h"
+#include "GDCore/Project/ObjectsContainersList.h"
+#include "GDCore/Project/Project.h"
+#include "GDCore/Project/Variable.h"
+#include "GDCore/Project/VariablesContainer.h"
+#include "GDCore/String.h"
+
+namespace gd {
+
+void EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+    const gd::Project &project, gd::EventsBasedObject &eventsBasedObject) {
+  auto &defaultObjects = eventsBasedObject.GetDefaultVariant().GetObjects();
+
+  for (const auto &variant :
+       eventsBasedObject.GetVariants().GetInternalVector()) {
+    auto &objects = variant->GetObjects();
+
+    // Delete extra objects
+    for (auto it = objects.GetObjects().begin();
+         it != objects.GetObjects().end(); ++it) {
+      const auto &objectName = it->get()->GetName();
+      if (!defaultObjects.HasObjectNamed(objectName)) {
+        variant->GetInitialInstances().RemoveInitialInstancesOfObject(
+            objectName);
+        // Do it in last because it unalloc objectName.
+        objects.RemoveObject(objectName);
+        --it;
+      }
+    }
+    for (const auto &defaultObject : defaultObjects.GetObjects()) {
+      const auto &objectName = defaultObject->GetName();
+      const auto &defaultVariables = defaultObject->GetVariables();
+      const auto &defaultBehaviors = defaultObject->GetAllBehaviorContents();
+
+      // Copy missing objects
+      if (!objects.HasObjectNamed(objectName)) {
+        objects.InsertObject(*defaultObject,
+                             defaultObjects.GetObjectPosition(objectName));
+        objects.AddMissingObjectsInRootFolder();
+        continue;
+      }
+      // Change object types
+      auto &object = objects.GetObject(objectName);
+      if (object.GetType() != defaultObject->GetType()) {
+        // Keep a copy of the old object.
+        auto oldObject = objects.GetObject(objectName);
+        objects.RemoveObject(objectName);
+        objects.InsertObject(*defaultObject,
+                             defaultObjects.GetObjectPosition(objectName));
+        object.CopyWithoutConfiguration(oldObject);
+        objects.AddMissingObjectsInRootFolder();
+      }
+
+      // Copy missing behaviors
+      for (const auto &pair : defaultBehaviors) {
+        const auto &behaviorName = pair.first;
+        const auto &defaultBehavior = pair.second;
+
+        if (object.HasBehaviorNamed(behaviorName) &&
+            object.GetBehavior(behaviorName).GetTypeName() !=
+                defaultBehavior->GetTypeName()) {
+          object.RemoveBehavior(behaviorName);
+        }
+        if (!object.HasBehaviorNamed(behaviorName)) {
+          auto *behavior = object.AddNewBehavior(
+              project, defaultBehavior->GetTypeName(), behaviorName);
+          gd::SerializerElement element;
+          defaultBehavior->SerializeTo(element);
+          behavior->UnserializeFrom(element);
+        }
+      }
+      // Delete extra behaviors
+      for (auto &behaviorName : object.GetAllBehaviorNames()) {
+        if (!defaultObject->HasBehaviorNamed(behaviorName)) {
+          object.RemoveBehavior(behaviorName);
+        }
+      }
+
+      // Sort and copy missing variables
+      auto &variables = object.GetVariables();
+      for (size_t defaultVariableIndex = 0;
+           defaultVariableIndex < defaultVariables.Count();
+           defaultVariableIndex++) {
+        const auto &variableName =
+            defaultVariables.GetNameAt(defaultVariableIndex);
+        const auto &defaultVariable =
+            defaultVariables.Get(defaultVariableIndex);
+
+        auto variableIndex = variables.GetPosition(variableName);
+        if (variableIndex == gd::String::npos) {
+          variables.Insert(variableName, defaultVariable, defaultVariableIndex);
+        } else {
+          variables.Move(variableIndex, defaultVariableIndex);
+        }
+        if (variables.Get(variableName).GetType() != defaultVariable.GetType()) {
+          variables.Remove(variableName);
+          variables.Insert(variableName, defaultVariable, defaultVariableIndex);
+        }
+      }
+      // Remove extra variables
+      auto variableToRemoveCount = variables.Count() - defaultVariables.Count();
+      for (size_t iteration = 0; iteration < variableToRemoveCount;
+           iteration++) {
+        variables.Remove(variables.GetNameAt(variables.Count() - 1));
+      }
+
+      // Remove extra instance variables
+      variant->GetInitialInstances().IterateOverInstances(
+          [&objectName,
+           &defaultVariables](gd::InitialInstance &initialInstance) {
+            if (initialInstance.GetObjectName() != objectName) {
+              return false;
+            }
+            auto &instanceVariables = initialInstance.GetVariables();
+            for (size_t instanceVariableIndex = 0;
+                 instanceVariableIndex < instanceVariables.Count();
+                 instanceVariableIndex++) {
+              const auto &variableName =
+                  defaultVariables.GetNameAt(instanceVariableIndex);
+
+              if (!defaultVariables.Has(variableName)) {
+                instanceVariables.Remove(variableName);
+              }
+            }
+            return false;
+          });
+    }
+    auto &defaultObjectGroups =
+        eventsBasedObject.GetDefaultVariant().GetObjects().GetObjectGroups();
+    auto &objectGroups = variant->GetObjects().GetObjectGroups();
+    auto objectGroupsCount = objectGroups.Count();
+    // Clear groups
+    for (size_t index = 0; index < objectGroupsCount; index++) {
+      objectGroups.Remove(objectGroups.Get(0).GetName());
+    }
+    // Copy groups
+    for (size_t index = 0; index < defaultObjectGroups.Count(); index++) {
+      objectGroups.Insert(defaultObjectGroups.Get(index), index);
+    }
+  }
+}
+
+} // namespace gd

Core/GDCore/IDE/EventsBasedObjectVariantHelper.h

@@ -0,0 +1,26 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#pragma once
+
+namespace gd {
+class EventsBasedObject;
+class Project;
+} // namespace gd
+
+namespace gd {
+
+class GD_CORE_API EventsBasedObjectVariantHelper {
+public:
+  /**
+   * @brief Apply the changes done on events-based object children to all its
+   * variants.
+   */
+  static void
+  ComplyVariantsToEventsBasedObject(const gd::Project &project,
+                                    gd::EventsBasedObject &eventsBasedObject);
+};
+
+} // namespace gd

Core/GDCore/IDE/ObjectAssetSerializer.cpp

@@ -17,6 +17,8 @@
 #include "GDCore/IDE/Project/ResourcesRenamer.h"
 #include "GDCore/Project/Behavior.h"
 #include "GDCore/Project/CustomBehavior.h"
+#include "GDCore/Project/CustomObjectConfiguration.h"
+#include "GDCore/Project/EventsBasedObjectVariant.h"
 #include "GDCore/Project/EventsFunctionsExtension.h"
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/Object.h"
@@ -60,9 +62,6 @@ void ObjectAssetSerializer::SerializeTo(
   element.SetAttribute("version", "");
   element.SetIntAttribute("animationsCount", 1);
   element.SetIntAttribute("maxFramesCount", 1);
-  // TODO Find the right object dimensions.
-  element.SetIntAttribute("width", 0);
-  element.SetIntAttribute("height", 0);
   SerializerElement &authorsElement = element.AddChild("authors");
   authorsElement.ConsiderAsArrayOf("author");
   SerializerElement &tagsElement = element.AddChild("tags");
@@ -75,6 +74,28 @@ void ObjectAssetSerializer::SerializeTo(
 
   cleanObject->SerializeTo(objectAssetElement.AddChild("object"));
 
+  double width = 0;
+  double height = 0;
+  std::unordered_set<gd::String> alreadyUsedVariantIdentifiers;
+  if (project.HasEventsBasedObject(object.GetType())) {
+    SerializerElement &variantsElement =
+        objectAssetElement.AddChild("variants");
+    variantsElement.ConsiderAsArrayOf("variant");
+
+    const auto *variant = ObjectAssetSerializer::GetVariant(project, object);
+    if (variant) {
+      width = variant->GetAreaMaxX() - variant->GetAreaMinX();
+      height = variant->GetAreaMaxY() - variant->GetAreaMinY();
+    }
+
+    gd::ObjectAssetSerializer::SerializeUsedVariantsTo(
+        project, object, variantsElement, alreadyUsedVariantIdentifiers);
+  }
+
+  // TODO Find the right object dimensions when their is no variant.
+  element.SetIntAttribute("width", width);
+  element.SetIntAttribute("height", height);
+
   SerializerElement &resourcesElement =
       objectAssetElement.AddChild("resources");
   resourcesElement.ConsiderAsArrayOf("resource");
@@ -93,14 +114,24 @@ void ObjectAssetSerializer::SerializeTo(
     resourceElement.SetAttribute("name", resource.GetName());
   }
 
+  std::unordered_set<gd::String> usedExtensionNames;
+  usedExtensionNames.insert(extensionName);
+  for (auto &usedVariantIdentifier : alreadyUsedVariantIdentifiers) {
+    usedExtensionNames.insert(PlatformExtension::GetExtensionFromFullObjectType(
+        usedVariantIdentifier));
+  }
   SerializerElement &requiredExtensionsElement =
       objectAssetElement.AddChild("requiredExtensions");
   requiredExtensionsElement.ConsiderAsArrayOf("requiredExtension");
-  if (project.HasEventsFunctionsExtensionNamed(extensionName)) {
-    SerializerElement &requiredExtensionElement =
-        requiredExtensionsElement.AddChild("requiredExtension");
-    requiredExtensionElement.SetAttribute("extensionName", extensionName);
-    requiredExtensionElement.SetAttribute("extensionVersion", "1.0.0");
+  for (auto &usedExtensionName : usedExtensionNames) {
+    if (project.HasEventsFunctionsExtensionNamed(usedExtensionName)) {
+      auto &extension = project.GetEventsFunctionsExtension(usedExtensionName);
+      SerializerElement &requiredExtensionElement =
+          requiredExtensionsElement.AddChild("requiredExtension");
+      requiredExtensionElement.SetAttribute("extensionName", usedExtensionName);
+      requiredExtensionElement.SetAttribute("extensionVersion",
+                                            extension.GetVersion());
+    }
   }
 
   // TODO This can be removed when the asset script no longer require it.
@@ -108,4 +139,59 @@ void ObjectAssetSerializer::SerializeTo(
       objectAssetElement.AddChild("customization");
   customizationElement.ConsiderAsArrayOf("empty");
 }
+
+void ObjectAssetSerializer::SerializeUsedVariantsTo(
+    gd::Project &project, const gd::Object &object,
+    SerializerElement &variantsElement,
+    std::unordered_set<gd::String> &alreadyUsedVariantIdentifiers) {
+  const auto *variant = ObjectAssetSerializer::GetVariant(project, object);
+  if (!variant) {
+    return;
+  }
+  const auto &variantIdentifier =
+      object.GetType() + gd::PlatformExtension::GetNamespaceSeparator() +
+      variant->GetName();
+  auto insertResult = alreadyUsedVariantIdentifiers.insert(variantIdentifier);
+  if (!insertResult.second) {
+    return;
+  }
+  SerializerElement &pairElement = variantsElement.AddChild("variant");
+  pairElement.SetAttribute("objectType", object.GetType());
+  SerializerElement &variantElement = pairElement.AddChild("variant");
+  variant->SerializeTo(variantElement);
+
+  for (auto &object : variant->GetObjects().GetObjects()) {
+    gd::ObjectAssetSerializer::SerializeUsedVariantsTo(
+        project, *object, variantsElement, alreadyUsedVariantIdentifiers);
+  }
+}
+
+const gd::EventsBasedObjectVariant *
+ObjectAssetSerializer::GetVariant(gd::Project &project,
+                                  const gd::Object &object) {
+  if (!project.HasEventsBasedObject(object.GetType())) {
+    return nullptr;
+  }
+  const auto &eventsBasedObject =
+      project.GetEventsBasedObject(object.GetType());
+  const auto &variants = eventsBasedObject.GetVariants();
+  const auto *customObjectConfiguration =
+      dynamic_cast<const gd::CustomObjectConfiguration *>(
+          &object.GetConfiguration());
+  const auto &variantName = customObjectConfiguration->GetVariantName();
+  if (!variants.HasVariantNamed(variantName) &&
+      (customObjectConfiguration
+           ->IsMarkedAsOverridingEventsBasedObjectChildrenConfiguration() ||
+       customObjectConfiguration
+           ->IsForcedToOverrideEventsBasedObjectChildrenConfiguration())) {
+    return nullptr;
+  }
+  const auto &variantIdentifier =
+      object.GetType() + gd::PlatformExtension::GetNamespaceSeparator() +
+      variantName;
+  const auto &variant = variants.HasVariantNamed(variantName)
+                            ? variants.GetVariant(variantName)
+                            : eventsBasedObject.GetDefaultVariant();
+  return &variant;
+}
 } // namespace gd

Core/GDCore/IDE/ObjectAssetSerializer.h

@@ -6,6 +6,7 @@
 #pragma once
 #include <map>
 #include <vector>
+#include <unordered_set>
 
 #include "GDCore/String.h"
 
@@ -20,6 +21,7 @@ class InitialInstance;
 class SerializerElement;
 class EffectsContainer;
 class AbstractFileSystem;
+class EventsBasedObjectVariant;
 } // namespace gd
 
 namespace gd {
@@ -52,6 +54,13 @@ private:
   ObjectAssetSerializer(){};
 
   static gd::String GetObjectExtensionName(const gd::Object &object);
+
+  static void SerializeUsedVariantsTo(
+      gd::Project &project, const gd::Object &object,
+      SerializerElement &variantsElement,
+      std::unordered_set<gd::String> &alreadyUsedVariantIdentifiers);
+
+  static const gd::EventsBasedObjectVariant* GetVariant(gd::Project &project, const gd::Object &object);
 };
 
 } // namespace gd

Core/GDCore/IDE/ObjectVariableHelper.cpp

@@ -6,6 +6,7 @@
 #include "ObjectVariableHelper.h"
 
 #include "GDCore/IDE/WholeProjectRefactorer.h"
+#include "GDCore/Project/EventsBasedObject.h"
 #include "GDCore/Project/InitialInstancesContainer.h"
 #include "GDCore/Project/Object.h"
 #include "GDCore/Project/ObjectGroup.h"
@@ -173,6 +174,7 @@ void ObjectVariableHelper::ApplyChangesToObjects(
                                 groupVariablesContainer.Get(variableName),
                                 variablesContainer.Count());
     }
+    // TODO Check what happens if 2 variables exchange their names.
     for (const auto &pair : changeset.oldToNewVariableNames) {
       const gd::String &oldVariableName = pair.first;
       const gd::String &newVariableName = pair.second;
@@ -215,6 +217,7 @@ void ObjectVariableHelper::ApplyChangesToObjectInstances(
               destinationVariablesContainer.Remove(variableName);
             }
           }
+          // TODO Check what happens if 2 variables exchange their names.
           for (const auto &pair : changeset.oldToNewVariableNames) {
             const gd::String &oldVariableName = pair.first;
             const gd::String &newVariableName = pair.second;
@@ -236,6 +239,66 @@ void ObjectVariableHelper::ApplyChangesToObjectInstances(
             }
           }
         }
+        return false;
       });
 }
+
+void ObjectVariableHelper::ApplyChangesToVariants(
+    gd::EventsBasedObject &eventsBasedObject, const gd::String &objectName,
+    const gd::VariablesChangeset &changeset) {
+  auto &defaultVariablesContainer = eventsBasedObject.GetDefaultVariant()
+                                        .GetObjects()
+                                        .GetObject(objectName)
+                                        .GetVariables();
+  for (auto &variant : eventsBasedObject.GetVariants().GetInternalVector()) {
+    if (!variant->GetObjects().HasObjectNamed(objectName)) {
+      continue;
+    }
+    auto &object = variant->GetObjects().GetObject(objectName);
+    auto &variablesContainer = object.GetVariables();
+
+    for (const gd::String &variableName : changeset.removedVariableNames) {
+      variablesContainer.Remove(variableName);
+    }
+    for (const gd::String &variableName : changeset.addedVariableNames) {
+      if (variablesContainer.Has(variableName)) {
+        // It can happens if a child-object already had the variable but it was
+        // missing in other variant child-object.
+        continue;
+      }
+      variablesContainer.Insert(variableName,
+                                defaultVariablesContainer.Get(variableName),
+                                variablesContainer.Count());
+    }
+    // TODO Check what happens if 2 variables exchange their names.
+    for (const auto &pair : changeset.oldToNewVariableNames) {
+      const gd::String &oldVariableName = pair.first;
+      const gd::String &newVariableName = pair.second;
+      if (variablesContainer.Has(newVariableName)) {
+        // It can happens if a child-object already had the variable but it was
+        // missing in other variant child-object.
+        variablesContainer.Remove(oldVariableName);
+      } else {
+        variablesContainer.Rename(oldVariableName, newVariableName);
+      }
+    }
+    // Apply type changes
+    for (const gd::String &variableName : changeset.valueChangedVariableNames) {
+      size_t index = variablesContainer.GetPosition(variableName);
+
+      if (variablesContainer.Has(variableName) &&
+          variablesContainer.Get(variableName).GetType() !=
+              defaultVariablesContainer.Get(variableName).GetType()) {
+        variablesContainer.Remove(variableName);
+        variablesContainer.Insert(
+            variableName, defaultVariablesContainer.Get(variableName), index);
+      }
+    }
+
+    gd::ObjectVariableHelper::ApplyChangesToObjectInstances(
+        variablesContainer, variant->GetInitialInstances(), objectName,
+        changeset);
+  }
+}
+
 } // namespace gd

Core/GDCore/IDE/ObjectVariableHelper.h

@@ -8,6 +8,7 @@
 #include "GDCore/Project/VariablesContainer.h"
 
 namespace gd {
+class EventsBasedObject;
 class InitialInstancesContainer;
 class ObjectsContainersList;
 class ObjectsContainer;
@@ -53,7 +54,7 @@ public:
    * Objects can be added during the group edition and may not necessarily have
    * all the variables initially shared by the group.
    *
-   * \see gd::GroupVariableHelper::MergeVariableContainers
+   * \see gd::ObjectVariableHelper::MergeVariableContainers
    */
   static void FillMissingGroupVariablesToObjects(
       gd::ObjectsContainer &globalObjectsContainer,
@@ -72,16 +73,21 @@ public:
                         const gd::ObjectGroup &objectGroup,
                         const gd::VariablesChangeset &changeset);
 
+  /**
+   * @brief Apply the changes done on an object to all its instances.
+   */
   static void ApplyChangesToObjectInstances(
       gd::VariablesContainer &objectVariablesContainer,
       gd::InitialInstancesContainer &initialInstancesContainer,
       const gd::String &objectName, const gd::VariablesChangeset &changeset);
 
-private:
-  static void ApplyChangesToVariableContainer(
-      const gd::VariablesContainer &originalVariablesContainer,
-      gd::VariablesContainer &destinationVariablesContainer,
-      const gd::VariablesChangeset &changeset, bool shouldApplyValueChanges);
+  /**
+   * @brief Apply the changes done on events-based object child to all its
+   * variants.
+   */
+  static void ApplyChangesToVariants(gd::EventsBasedObject &eventsBasedObject,
+                                     const gd::String &objectName,
+                                     const gd::VariablesChangeset &changeset);
 };
 
 } // namespace gd

Core/GDCore/IDE/Project/ArbitraryResourceWorker.cpp

@@ -227,12 +227,11 @@ bool ResourceWorkerInEventsWorker::DoVisitInstruction(gd::Instruction& instructi
                                     platform, instruction.GetType());
 
   gd::ParameterMetadataTools::IterateOverParametersWithIndex(
-      instruction.GetParameters(),
-      metadata.GetParameters(),
-      [this, &instruction](const gd::ParameterMetadata& parameterMetadata,
-                            const gd::Expression& parameterExpression,
-                            size_t parameterIndex,
-                            const gd::String& lastObjectName) {
+      instruction.GetParameters(), metadata.GetParameters(),
+      [this, &instruction](
+          const gd::ParameterMetadata &parameterMetadata,
+          const gd::Expression &parameterExpression, size_t parameterIndex,
+          const gd::String &lastObjectName, size_t lastObjectIndex) {
         const String& parameterValue = parameterExpression.GetPlainString();
         if (parameterMetadata.GetType() == "fontResource") {
           gd::String updatedParameterValue = parameterValue;

Core/GDCore/IDE/ProjectBrowserHelper.cpp

@@ -314,6 +314,12 @@ void ProjectBrowserHelper::ExposeProjectObjects(
          eventsFunctionsExtension.GetEventsBasedObjects().GetInternalVector()) {
       auto eventsBasedObject = eventsBasedObjectUniquePtr.get();
       worker.Launch(eventsBasedObject->GetObjects());
+
+      for (auto &&variantUniquePtr :
+           eventsBasedObject->GetVariants().GetInternalVector()) {
+        auto variant = variantUniquePtr.get();
+        worker.Launch(variant->GetObjects());
+      }
     }
   }
 };

Core/GDCore/IDE/PropertyFunctionGenerator.cpp

@@ -248,12 +248,13 @@ gd::String PropertyFunctionGenerator::GetStringifiedExtraInfo(
     gd::String arrayString;
     arrayString += "[";
     bool isFirst = true;
-    for (const gd::String &choice : property.GetExtraInfo()) {
+    for (const auto &choice : property.GetChoices()) {
       if (!isFirst) {
         arrayString += ",";
       }
       isFirst = false;
-      arrayString += "\"" + choice + "\"";
+      // TODO Handle labels (and search "choice label")
+      arrayString += "\"" + choice.GetValue() + "\"";
     }
     arrayString += "]";
     return arrayString;

Core/GDCore/IDE/ResourceExposer.cpp

@@ -75,6 +75,17 @@ void ResourceExposer::ExposeProjectResources(
   // Expose global objects configuration resources
   auto objectWorker = gd::GetResourceWorkerOnObjects(project, worker);
   objectWorker.Launch(project.GetObjects());
+
+  // Exposed extension event resources
+  // Note that using resources in extensions is very unlikely and probably not
+  // worth the effort of something smart.
+  auto eventWorker = gd::GetResourceWorkerOnEvents(project, worker);
+  for (std::size_t e = 0; e < project.GetEventsFunctionsExtensionsCount();
+       e++) {
+    auto &eventsFunctionsExtension = project.GetEventsFunctionsExtension(e);
+    gd::ProjectBrowserHelper::ExposeEventsFunctionsExtensionEvents(
+        project, eventsFunctionsExtension, eventWorker);
+  }
 }
 
 void ResourceExposer::ExposeLayoutResources(
@@ -103,16 +114,6 @@ void ResourceExposer::ExposeLayoutResources(
   auto eventWorker = gd::GetResourceWorkerOnEvents(project, worker);
   gd::ProjectBrowserHelper::ExposeLayoutEventsAndDependencies(
       project, layout, eventWorker);
-
-  // Exposed extension event resources
-  // Note that using resources in extensions is very unlikely and probably not
-  // worth the effort of something smart.
-  for (std::size_t e = 0; e < project.GetEventsFunctionsExtensionsCount();
-       e++) {
-    auto &eventsFunctionsExtension = project.GetEventsFunctionsExtension(e);
-    gd::ProjectBrowserHelper::ExposeEventsFunctionsExtensionEvents(
-        project, eventsFunctionsExtension, eventWorker);
-  }
 }
 
 void ResourceExposer::ExposeEffectResources(

Core/GDCore/IDE/WholeProjectRefactorer.cpp

@@ -1781,6 +1781,14 @@ void WholeProjectRefactorer::DoRenameBehavior(
   projectBrowser.ExposeFunctions(project, behaviorParameterRenamer);
 }
 
+void WholeProjectRefactorer::UpdateBehaviorsSharedData(gd::Project &project) {
+  for (std::size_t i = 0; i < project.GetLayoutsCount(); ++i) {
+    gd::Layout &layout = project.GetLayout(i);
+
+    layout.UpdateBehaviorsSharedData(project);
+  }
+}
+
 void WholeProjectRefactorer::DoRenameObject(
     gd::Project &project, const gd::String &oldObjectType,
     const gd::String &newObjectType, const gd::ProjectBrowser &projectBrowser) {
@@ -2129,6 +2137,26 @@ void WholeProjectRefactorer::ObjectOrGroupRenamedInEventsBasedObject(
       groups[g].RenameObject(oldName, newName);
     }
   }
+
+  for (auto &variant : eventsBasedObject.GetVariants().GetInternalVector()) {
+    auto &variantObjects = variant->GetObjects();
+    auto &variantObjectGroups = variantObjects.GetObjectGroups();
+    if (isObjectGroup) {
+      if (variantObjectGroups.Has(oldName)) {
+        variantObjectGroups.Get(oldName).SetName(newName);
+      }
+      // Object groups can't have instances or be in other groups
+    }
+    else {
+      if (variantObjects.HasObjectNamed(oldName)) {
+        variantObjects.GetObject(oldName).SetName(newName);
+      }
+      variant->GetInitialInstances().RenameInstancesOfObject(oldName, newName);
+      for (std::size_t g = 0; g < variantObjectGroups.size(); ++g) {
+        variantObjectGroups[g].RenameObject(oldName, newName);
+      }
+    }
+  }
 }
 
 void WholeProjectRefactorer::ObjectOrGroupRenamedInEventsFunction(

Core/GDCore/IDE/WholeProjectRefactorer.h

@@ -704,6 +704,16 @@ class GD_CORE_API WholeProjectRefactorer {
   static size_t GetLayoutAndExternalLayoutLayerInstancesCount(
       gd::Project &project, gd::Layout &layout, const gd::String &layerName);
 
+  /**
+   * This ensures that the scenes had an instance of shared data for
+   * every behavior of every object that can be used on the scene
+   * (i.e. the objects of the scene and the global objects)
+   *
+   * Must be called when a behavior have been added/deleted
+   * from a global object or an object has been made global.
+   */
+  static void UpdateBehaviorsSharedData(gd::Project &project);
+
   virtual ~WholeProjectRefactorer(){};
 
  private:

Core/GDCore/Project/CustomObjectConfiguration.cpp

@@ -19,6 +19,7 @@ using namespace gd;
 
 void CustomObjectConfiguration::Init(const gd::CustomObjectConfiguration& objectConfiguration) {
   project = objectConfiguration.project;
+  variantName = objectConfiguration.variantName;
   objectContent = objectConfiguration.objectContent;
   animations = objectConfiguration.animations;
   isMarkedAsOverridingEventsBasedObjectChildrenConfiguration =
@@ -165,6 +166,7 @@ void CustomObjectConfiguration::DoSerializeTo(SerializerElement& element) const
     animations.SerializeTo(animatableElement);
   }
 
+  element.SetAttribute("variant", variantName);
   if (IsOverridingEventsBasedObjectChildrenConfiguration()) {
     auto &childrenContentElement = element.AddChild("childrenContent");
     for (auto &pair : childObjectConfigurations) {
@@ -184,6 +186,7 @@ void CustomObjectConfiguration::DoUnserializeFrom(Project& project,
     animations.UnserializeFrom(animatableElement);
   }
 
+  variantName = element.GetStringAttribute("variant");
   isMarkedAsOverridingEventsBasedObjectChildrenConfiguration =
       element.HasChild("childrenContent");
   if (isMarkedAsOverridingEventsBasedObjectChildrenConfiguration) {
@@ -247,9 +250,29 @@ void CustomObjectConfiguration::ExposeResources(gd::ArbitraryResourceWorker& wor
   }
   const auto &eventsBasedObject = project->GetEventsBasedObject(GetType());
 
-  for (auto& childObject : eventsBasedObject.GetObjects().GetObjects()) {
-    auto &configuration = GetChildObjectConfiguration(childObject->GetName());
-    configuration.ExposeResources(worker);
+  if (IsForcedToOverrideEventsBasedObjectChildrenConfiguration()) {
+    for (auto &childObject : eventsBasedObject.GetObjects().GetObjects()) {
+      auto &configuration = GetChildObjectConfiguration(childObject->GetName());
+      configuration.ExposeResources(worker);
+    }
+  }
+  else if (eventsBasedObject.GetVariants().HasVariantNamed(variantName)) {
+    for (auto &childObject : eventsBasedObject.GetVariants()
+                                 .GetVariant(variantName)
+                                 .GetObjects()
+                                 .GetObjects()) {
+      childObject->GetConfiguration().ExposeResources(worker);
+    }
+  } else if (isMarkedAsOverridingEventsBasedObjectChildrenConfiguration) {
+    for (auto &childObject : eventsBasedObject.GetObjects().GetObjects()) {
+      auto &configuration = GetChildObjectConfiguration(childObject->GetName());
+      configuration.ExposeResources(worker);
+    }
+  } else {
+    for (auto &childObject :
+         eventsBasedObject.GetDefaultVariant().GetObjects().GetObjects()) {
+      childObject->GetConfiguration().ExposeResources(worker);
+    }
   }
 }
 

Core/GDCore/Project/CustomObjectConfiguration.h

@@ -29,9 +29,9 @@ namespace gd {
  * "resource".
  */
 class CustomObjectConfiguration : public gd::ObjectConfiguration {
- public:
-  CustomObjectConfiguration(const Project& project_, const String& type_)
-      : project(&project_), isMarkedAsOverridingEventsBasedObjectChildrenConfiguration(false) {
+public:
+  CustomObjectConfiguration(const Project &project_, const String &type_)
+      : project(&project_) {
     SetType(type_);
   }
   std::unique_ptr<gd::ObjectConfiguration> Clone() const override;
@@ -66,6 +66,27 @@ class CustomObjectConfiguration : public gd::ObjectConfiguration {
 
   void ExposeResources(gd::ArbitraryResourceWorker& worker) override;
 
+  /**
+   * \brief Get the name of the events-based object variant used by this custom object.
+   */
+  const gd::String &GetVariantName() const { return variantName; };
+
+  /**
+   * \brief Set the name of the events-based object variant used by this custom object.
+   */
+  void SetVariantName(const gd::String &variantName_) {
+    variantName = variantName_;
+  }
+
+  /**
+   * Legacy events-based objects don't have any instance in their default
+   * variant since there wasn't a graphical editor at the time. In this case,
+   * the editor doesn't allow to choose a variant, but a variant may have stayed
+   * after a user rolled back the extension. This variant must be ignored.
+   *
+   * @return true when its events-based object doesn't have any initial
+   * instance.
+   */
   bool IsForcedToOverrideEventsBasedObjectChildrenConfiguration() const;
 
   bool IsMarkedAsOverridingEventsBasedObjectChildrenConfiguration() const {
@@ -145,6 +166,7 @@ protected:
   gd::SerializerElement objectContent;
   std::unordered_set<gd::String> unfoldedChildren;
 
+  gd::String variantName = "";
   bool isMarkedAsOverridingEventsBasedObjectChildrenConfiguration = false;
   mutable std::map<gd::String, std::unique_ptr<gd::ObjectConfiguration>> childObjectConfigurations;
 

Core/GDCore/Project/Effect.cpp

@@ -8,6 +8,8 @@
 #include "GDCore/Serialization/SerializerElement.h"
 
 namespace gd {
+  
+gd::String Effect::badStringParameterValue;
 
 void Effect::SerializeTo(SerializerElement& element) const {
   element.SetAttribute("name", GetName());

Core/GDCore/Project/Effect.h

@@ -3,8 +3,7 @@
  * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
  * reserved. This project is released under the MIT License.
  */
-#ifndef GDCORE_EFFECT_H
-#define GDCORE_EFFECT_H
+#pragma once
 #include <map>
 namespace gd {
 class SerializerElement;
@@ -35,28 +34,43 @@ class GD_CORE_API Effect {
   void SetFolded(bool fold = true) { folded = fold; }
   bool IsFolded() const { return folded; }
 
-  void SetDoubleParameter(const gd::String& name, double value) {
+  void SetDoubleParameter(const gd::String &name, double value) {
     doubleParameters[name] = value;
   }
 
-  double GetDoubleParameter(const gd::String& name) {
-    return doubleParameters[name];
+  double GetDoubleParameter(const gd::String &name) const {
+    auto itr = doubleParameters.find(name);
+    return itr == doubleParameters.end() ? 0 : itr->second;
   }
 
-  void SetStringParameter(const gd::String& name, const gd::String& value) {
+  bool HasDoubleParameter(const gd::String &name) const {
+    return doubleParameters.find(name) != doubleParameters.end();
+  }
+
+  void SetStringParameter(const gd::String &name, const gd::String &value) {
     stringParameters[name] = value;
   }
 
-  const gd::String& GetStringParameter(const gd::String& name) {
-    return stringParameters[name];
+  const gd::String &GetStringParameter(const gd::String &name) const {
+    auto itr = stringParameters.find(name);
+    return itr == stringParameters.end() ? badStringParameterValue : itr->second;
   }
 
-  void SetBooleanParameter(const gd::String& name, bool value) {
+  bool HasStringParameter(const gd::String &name) const {
+    return stringParameters.find(name) != stringParameters.end();
+  }
+
+  void SetBooleanParameter(const gd::String &name, bool value) {
     booleanParameters[name] = value;
   }
 
-  bool GetBooleanParameter(const gd::String& name) {
-    return booleanParameters[name];
+  bool GetBooleanParameter(const gd::String &name) const {
+    auto itr = booleanParameters.find(name);
+    return itr == booleanParameters.end() ? false : itr->second;
+  }
+
+  bool HasBooleanParameter(const gd::String &name) const {
+    return booleanParameters.find(name) != booleanParameters.end();
   }
 
   const std::map<gd::String, double>& GetAllDoubleParameters() const {
@@ -94,7 +108,9 @@ class GD_CORE_API Effect {
   std::map<gd::String, double> doubleParameters; ///< Values of parameters being doubles, keyed by names.
   std::map<gd::String, gd::String> stringParameters; ///< Values of parameters being strings, keyed by names.
   std::map<gd::String, bool> booleanParameters; ///< Values of parameters being booleans, keyed by names.
+
+  static gd::String badStringParameterValue;  ///< Empty string returned by
+                                              ///< GeStringParameter
 };
 
 }  // namespace gd
-#endif

Core/GDCore/Project/EventsBasedObject.cpp

@@ -17,19 +17,13 @@ EventsBasedObject::EventsBasedObject()
     isAnimatable(false),
     isTextContainer(false),
     isInnerAreaFollowingParentSize(false),
-    isUsingLegacyInstancesRenderer(false),
-    areaMinX(0),
-    areaMinY(0),
-    areaMinZ(0),
-    areaMaxX(64),
-    areaMaxY(64),
-    areaMaxZ(64),
-    objectsContainer(gd::ObjectsContainer::SourceType::Object) {
+    isUsingLegacyInstancesRenderer(false) {
 }
 
 EventsBasedObject::~EventsBasedObject() {}
 
-void EventsBasedObject::SerializeTo(SerializerElement& element) const {
+
+void EventsBasedObject::SerializeToExternal(SerializerElement& element) const {
   element.SetAttribute("defaultName", defaultName);
   if (isRenderedIn3D) {
     element.SetBoolAttribute("is3D", true);
@@ -44,20 +38,16 @@ void EventsBasedObject::SerializeTo(SerializerElement& element) const {
     element.SetBoolAttribute("isInnerAreaFollowingParentSize", true);
   }
   element.SetBoolAttribute("isUsingLegacyInstancesRenderer", isUsingLegacyInstancesRenderer);
-  element.SetIntAttribute("areaMinX", areaMinX);
-  element.SetIntAttribute("areaMinY", areaMinY);
-  element.SetIntAttribute("areaMinZ", areaMinZ);
-  element.SetIntAttribute("areaMaxX", areaMaxX);
-  element.SetIntAttribute("areaMaxY", areaMaxY);
-  element.SetIntAttribute("areaMaxZ", areaMaxZ);
 
+  // The EventsBasedObjectVariant SerializeTo method override the name.
+  // AbstractEventsBasedEntity::SerializeTo must be done after.
+  defaultVariant.SerializeTo(element);
   AbstractEventsBasedEntity::SerializeTo(element);
-  objectsContainer.SerializeObjectsTo(element.AddChild("objects"));
-  objectsContainer.SerializeFoldersTo(element.AddChild("objectsFolderStructure"));
-  objectsContainer.GetObjectGroups().SerializeTo(element.AddChild("objectsGroups"));
+}
 
-  layers.SerializeLayersTo(element.AddChild("layers"));
-  initialInstances.SerializeTo(element.AddChild("instances"));
+void EventsBasedObject::SerializeTo(SerializerElement& element) const {
+  SerializeToExternal(element);
+  variants.SerializeVariantsTo(element.AddChild("variants"));
 }
 
 void EventsBasedObject::UnserializeFrom(gd::Project& project,
@@ -68,36 +58,22 @@ void EventsBasedObject::UnserializeFrom(gd::Project& project,
   isTextContainer = element.GetBoolAttribute("isTextContainer", false);
   isInnerAreaFollowingParentSize =
       element.GetBoolAttribute("isInnerAreaFollowingParentSize", false);
-  areaMinX = element.GetIntAttribute("areaMinX", 0);
-  areaMinY = element.GetIntAttribute("areaMinY", 0);
-  areaMinZ = element.GetIntAttribute("areaMinZ", 0);
-  areaMaxX = element.GetIntAttribute("areaMaxX", 64);
-  areaMaxY = element.GetIntAttribute("areaMaxY", 64);
-  areaMaxZ = element.GetIntAttribute("areaMaxZ", 64);
 
+  defaultVariant.UnserializeFrom(project, element);
+  defaultVariant.SetName("");
   AbstractEventsBasedEntity::UnserializeFrom(project, element);
-  objectsContainer.UnserializeObjectsFrom(project, element.GetChild("objects"));
-  if (element.HasChild("objectsFolderStructure")) {
-    objectsContainer.UnserializeFoldersFrom(project, element.GetChild("objectsFolderStructure", 0));
-  }
-  objectsContainer.AddMissingObjectsInRootFolder();
-  objectsContainer.GetObjectGroups().UnserializeFrom(
-      element.GetChild("objectsGroups"));
 
-  if (element.HasChild("layers")) {
-    layers.UnserializeLayersFrom(element.GetChild("layers"));
-  } else {
-    layers.Reset();
+  if (element.HasChild("variants")) {
+    variants.UnserializeVariantsFrom(project, element.GetChild("variants"));
   }
 
-  initialInstances.UnserializeFrom(element.GetChild("instances"));
   if (element.HasChild("isUsingLegacyInstancesRenderer")) {
     isUsingLegacyInstancesRenderer =
         element.GetBoolAttribute("isUsingLegacyInstancesRenderer", false);
   }
   else {
     // Compatibility with GD <= 5.4.212
-    isUsingLegacyInstancesRenderer = initialInstances.GetInstancesCount() == 0;
+    isUsingLegacyInstancesRenderer = GetInitialInstances().GetInstancesCount() == 0;
     // end of compatibility code
   }
 }

Core/GDCore/Project/EventsBasedObject.h

@@ -7,6 +7,8 @@
 
 #include <vector>
 #include "GDCore/Project/AbstractEventsBasedEntity.h"
+#include "GDCore/Project/EventsBasedObjectVariant.h"
+#include "GDCore/Project/EventsBasedObjectVariantsContainer.h"
 #include "GDCore/Project/ObjectsContainer.h"
 #include "GDCore/Project/InitialInstancesContainer.h"
 #include "GDCore/Project/LayersContainer.h"
@@ -162,18 +164,38 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
    */
   bool IsTextContainer() const { return isTextContainer; }
 
+  /**
+   * \brief Get the default variant of the custom object.
+   */
+  const gd::EventsBasedObjectVariant& GetDefaultVariant() const { return defaultVariant; }
+
+  /**
+   * \brief Get the default variant of the custom object.
+   */
+  gd::EventsBasedObjectVariant& GetDefaultVariant() { return defaultVariant; }
+
+  /**
+   * \brief Get the variants of the custom object.
+   */
+  const gd::EventsBasedObjectVariantsContainer& GetVariants() const { return variants; }
+
+  /**
+   * \brief Get the variants of the custom object.
+   */
+  gd::EventsBasedObjectVariantsContainer& GetVariants() { return variants; }
+
   /** \name Layers
    */
   ///@{
   /**
    * \brief Get the layers of the custom object.
    */
-  const gd::LayersContainer& GetLayers() const { return layers; }
+  const gd::LayersContainer& GetLayers() const { return defaultVariant.GetLayers(); }
 
   /**
    * \brief Get the layers of the custom object.
    */
-  gd::LayersContainer& GetLayers() { return layers; }
+  gd::LayersContainer& GetLayers() { return defaultVariant.GetLayers(); }
   ///@}
 
   /** \name Child objects
@@ -183,14 +205,14 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
    * \brief Get the objects of the custom object.
    */
   gd::ObjectsContainer& GetObjects() {
-    return objectsContainer;
+    return defaultVariant.GetObjects();
   }
 
   /**
    * \brief Get the objects of the custom object.
    */
   const gd::ObjectsContainer& GetObjects() const {
-    return objectsContainer;
+    return defaultVariant.GetObjects();
   }
   ///@}
 
@@ -201,14 +223,14 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
    * \brief Get the instances of the custom object.
    */
   gd::InitialInstancesContainer& GetInitialInstances() {
-    return initialInstances;
+    return defaultVariant.GetInitialInstances();
   }
 
   /**
    * \brief Get the instances of the custom object.
    */
   const gd::InitialInstancesContainer& GetInitialInstances() const {
-    return initialInstances;
+    return defaultVariant.GetInitialInstances();
   }
 
   /**
@@ -219,14 +241,14 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
    * \see EventsBasedObject::GetInitialInstances
    */
   int GetAreaMinX() const {
-    return areaMinX;
+    return defaultVariant.GetAreaMinX();
   }
 
   /**
    * \brief Set the left bound of the custom object.
    */
-  void SetAreaMinX(int areaMinX_) {
-    areaMinX = areaMinX_;
+  void SetAreaMinX(int areaMinX) {
+    defaultVariant.SetAreaMinX(areaMinX);
   }
 
   /**
@@ -237,14 +259,14 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
    * \see EventsBasedObject::GetInitialInstances
    */
   int GetAreaMinY() const {
-    return areaMinY;
+    return defaultVariant.GetAreaMinY();
   }
 
   /**
    * \brief Set the top bound of the custom object.
    */
-  void SetAreaMinY(int areaMinY_) {
-    areaMinY = areaMinY_;
+  void SetAreaMinY(int areaMinY) {
+    defaultVariant.SetAreaMinY(areaMinY);
   }
 
   /**
@@ -255,14 +277,14 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
    * \see EventsBasedObject::GetInitialInstances
    */
   int GetAreaMinZ() const {
-    return areaMinZ;
+    return defaultVariant.GetAreaMinZ();
   }
 
   /**
    * \brief Set the min Z bound of the custom object.
    */
-  void SetAreaMinZ(int areaMinZ_) {
-    areaMinZ = areaMinZ_;
+  void SetAreaMinZ(int areaMinZ) {
+    defaultVariant.SetAreaMinZ(areaMinZ);
   }
 
   /**
@@ -273,14 +295,14 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
    * \see EventsBasedObject::GetInitialInstances
    */
   int GetAreaMaxX() const {
-    return areaMaxX;
+    return defaultVariant.GetAreaMaxX();
   }
 
   /**
    * \brief Set the right bound of the custom object.
    */
-  void SetAreaMaxX(int areaMaxX_) {
-    areaMaxX = areaMaxX_;
+  void SetAreaMaxX(int areaMaxX) {
+    defaultVariant.SetAreaMaxX(areaMaxX);
   }
 
   /**
@@ -291,14 +313,14 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
    * \see EventsBasedObject::GetInitialInstances
    */
   int GetAreaMaxY() const {
-    return areaMaxY;
+    return defaultVariant.GetAreaMaxY();
   }
 
   /**
    * \brief Set the bottom bound of the custom object.
    */
-  void SetAreaMaxY(int areaMaxY_) {
-    areaMaxY = areaMaxY_;
+  void SetAreaMaxY(int areaMaxY) {
+    defaultVariant.SetAreaMaxY(areaMaxY);
   }
 
   /**
@@ -309,16 +331,22 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
    * \see EventsBasedObject::GetInitialInstances
    */
   int GetAreaMaxZ() const {
-    return areaMaxZ;
+    return defaultVariant.GetAreaMaxZ();
   }
 
   /**
    * \brief Set the bottom bound of the custom object.
    */
-  void SetAreaMaxZ(int areaMaxZ_) {
-    areaMaxZ = areaMaxZ_;
+  void SetAreaMaxZ(int areaMaxZ) {
+    defaultVariant.SetAreaMaxZ(areaMaxZ);
   }
   ///@}
+  
+  /**
+   * @brief Serialize the events-based object for an extension in an external file.
+   * Variants are not serialized.
+   */
+  void SerializeToExternal(SerializerElement& element) const;
 
   void SerializeTo(SerializerElement& element) const override;
 
@@ -332,15 +360,8 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
   bool isTextContainer;
   bool isInnerAreaFollowingParentSize;
   bool isUsingLegacyInstancesRenderer;
-  gd::InitialInstancesContainer initialInstances;
-  gd::LayersContainer layers;
-  gd::ObjectsContainer objectsContainer;
-  double areaMinX;
-  double areaMinY;
-  double areaMinZ;
-  double areaMaxX;
-  double areaMaxY;
-  double areaMaxZ;
+  gd::EventsBasedObjectVariant defaultVariant;
+  gd::EventsBasedObjectVariantsContainer variants;
 };
 
 }  // namespace gd

Core/GDCore/Project/EventsBasedObjectVariant.cpp

@@ -0,0 +1,71 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#include "EventsBasedObjectVariant.h"
+#include "GDCore/Project/Object.h"
+#include "GDCore/Serialization/SerializerElement.h"
+
+namespace gd {
+
+EventsBasedObjectVariant::EventsBasedObjectVariant()
+    : areaMinX(0), areaMinY(0), areaMinZ(0), areaMaxX(64), areaMaxY(64),
+      areaMaxZ(64), objectsContainer(gd::ObjectsContainer::SourceType::Object) {
+}
+
+EventsBasedObjectVariant::~EventsBasedObjectVariant() {}
+
+void EventsBasedObjectVariant::SerializeTo(SerializerElement &element) const {
+  element.SetAttribute("name", name);
+  if (!GetAssetStoreAssetId().empty() && !GetAssetStoreOriginalName().empty()) {
+    element.SetAttribute("assetStoreAssetId", GetAssetStoreAssetId());
+    element.SetAttribute("assetStoreOriginalName", GetAssetStoreOriginalName());
+  }
+  element.SetIntAttribute("areaMinX", areaMinX);
+  element.SetIntAttribute("areaMinY", areaMinY);
+  element.SetIntAttribute("areaMinZ", areaMinZ);
+  element.SetIntAttribute("areaMaxX", areaMaxX);
+  element.SetIntAttribute("areaMaxY", areaMaxY);
+  element.SetIntAttribute("areaMaxZ", areaMaxZ);
+
+  objectsContainer.SerializeObjectsTo(element.AddChild("objects"));
+  objectsContainer.SerializeFoldersTo(
+      element.AddChild("objectsFolderStructure"));
+  objectsContainer.GetObjectGroups().SerializeTo(
+      element.AddChild("objectsGroups"));
+
+  layers.SerializeLayersTo(element.AddChild("layers"));
+  initialInstances.SerializeTo(element.AddChild("instances"));
+}
+
+void EventsBasedObjectVariant::UnserializeFrom(
+    gd::Project &project, const SerializerElement &element) {
+  name = element.GetStringAttribute("name");
+  assetStoreAssetId = element.GetStringAttribute("assetStoreAssetId");
+  assetStoreOriginalName = element.GetStringAttribute("assetStoreOriginalName");
+  areaMinX = element.GetIntAttribute("areaMinX", 0);
+  areaMinY = element.GetIntAttribute("areaMinY", 0);
+  areaMinZ = element.GetIntAttribute("areaMinZ", 0);
+  areaMaxX = element.GetIntAttribute("areaMaxX", 64);
+  areaMaxY = element.GetIntAttribute("areaMaxY", 64);
+  areaMaxZ = element.GetIntAttribute("areaMaxZ", 64);
+
+  objectsContainer.UnserializeObjectsFrom(project, element.GetChild("objects"));
+  if (element.HasChild("objectsFolderStructure")) {
+    objectsContainer.UnserializeFoldersFrom(
+        project, element.GetChild("objectsFolderStructure", 0));
+  }
+  objectsContainer.AddMissingObjectsInRootFolder();
+  objectsContainer.GetObjectGroups().UnserializeFrom(
+      element.GetChild("objectsGroups"));
+
+  if (element.HasChild("layers")) {
+    layers.UnserializeLayersFrom(element.GetChild("layers"));
+  } else {
+    layers.Reset();
+  }
+  initialInstances.UnserializeFrom(element.GetChild("instances"));
+}
+
+} // namespace gd

Core/GDCore/Project/EventsBasedObjectVariant.h

@@ -0,0 +1,229 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2025 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#pragma once
+
+#include "GDCore/Project/InitialInstancesContainer.h"
+#include "GDCore/Project/LayersContainer.h"
+#include "GDCore/Project/ObjectsContainer.h"
+#include "GDCore/String.h"
+#include <vector>
+
+namespace gd {
+class SerializerElement;
+class Project;
+} // namespace gd
+
+namespace gd {
+/**
+ * \brief Represents a variation of style of an events-based object.
+ *
+ * \ingroup PlatformDefinition
+ */
+class GD_CORE_API EventsBasedObjectVariant {
+public:
+  EventsBasedObjectVariant();
+  virtual ~EventsBasedObjectVariant();
+
+  /**
+   * \brief Return a pointer to a new EventsBasedObjectVariant constructed from
+   * this one.
+   */
+  EventsBasedObjectVariant *Clone() const {
+    return new EventsBasedObjectVariant(*this);
+  };
+
+  /**
+   * \brief Get the name of the variant.
+   */
+  const gd::String &GetName() const { return name; };
+
+  /**
+   * \brief Set the name of the variant.
+   */
+  EventsBasedObjectVariant &SetName(const gd::String &name_) {
+    name = name_;
+    return *this;
+  }
+
+  /** \name Layers
+   */
+  ///@{
+  /**
+   * \brief Get the layers of the variant.
+   */
+  const gd::LayersContainer &GetLayers() const { return layers; }
+
+  /**
+   * \brief Get the layers of the variant.
+   */
+  gd::LayersContainer &GetLayers() { return layers; }
+  ///@}
+
+  /** \name Child objects
+   */
+  ///@{
+  /**
+   * \brief Get the objects of the variant.
+   */
+  gd::ObjectsContainer &GetObjects() { return objectsContainer; }
+
+  /**
+   * \brief Get the objects of the variant.
+   */
+  const gd::ObjectsContainer &GetObjects() const { return objectsContainer; }
+  ///@}
+
+  /** \name Instances
+   */
+  ///@{
+  /**
+   * \brief Get the instances of the variant.
+   */
+  gd::InitialInstancesContainer &GetInitialInstances() {
+    return initialInstances;
+  }
+
+  /**
+   * \brief Get the instances of the variant.
+   */
+  const gd::InitialInstancesContainer &GetInitialInstances() const {
+    return initialInstances;
+  }
+
+  /**
+   * \brief Get the left bound of the variant.
+   *
+   * This is used only if there is any initial instances.
+   *
+   * \see EventsBasedObjectVariant::GetInitialInstances
+   */
+  int GetAreaMinX() const { return areaMinX; }
+
+  /**
+   * \brief Set the left bound of the variant.
+   */
+  void SetAreaMinX(int areaMinX_) { areaMinX = areaMinX_; }
+
+  /**
+   * \brief Get the top bound of the variant.
+   *
+   * This is used only if there is any initial instances.
+   *
+   * \see EventsBasedObjectVariant::GetInitialInstances
+   */
+  int GetAreaMinY() const { return areaMinY; }
+
+  /**
+   * \brief Set the top bound of the variant.
+   */
+  void SetAreaMinY(int areaMinY_) { areaMinY = areaMinY_; }
+
+  /**
+   * \brief Get the min Z bound of the variant.
+   *
+   * This is used only if there is any initial instances.
+   *
+   * \see EventsBasedObjectVariant::GetInitialInstances
+   */
+  int GetAreaMinZ() const { return areaMinZ; }
+
+  /**
+   * \brief Set the min Z bound of the variant.
+   */
+  void SetAreaMinZ(int areaMinZ_) { areaMinZ = areaMinZ_; }
+
+  /**
+   * \brief Get the right bound of the variant.
+   *
+   * This is used only if there is any initial instances.
+   *
+   * \see EventsBasedObjectVariant::GetInitialInstances
+   */
+  int GetAreaMaxX() const { return areaMaxX; }
+
+  /**
+   * \brief Set the right bound of the variant.
+   */
+  void SetAreaMaxX(int areaMaxX_) { areaMaxX = areaMaxX_; }
+
+  /**
+   * \brief Get the bottom bound of the variant.
+   *
+   * This is used only if there is any initial instances.
+   *
+   * \see EventsBasedObjectVariant::GetInitialInstances
+   */
+  int GetAreaMaxY() const { return areaMaxY; }
+
+  /**
+   * \brief Set the bottom bound of the variant.
+   */
+  void SetAreaMaxY(int areaMaxY_) { areaMaxY = areaMaxY_; }
+
+  /**
+   * \brief Get the max Z bound of the variant.
+   *
+   * This is used only if there is any initial instances.
+   *
+   * \see EventsBasedObjectVariant::GetInitialInstances
+   */
+  int GetAreaMaxZ() const { return areaMaxZ; }
+
+  /**
+   * \brief Set the bottom bound of the variant.
+   */
+  void SetAreaMaxZ(int areaMaxZ_) { areaMaxZ = areaMaxZ_; }
+  ///@}
+
+  /** \brief Change the object asset store id of this variant.
+   */
+  void SetAssetStoreAssetId(const gd::String &assetStoreId_) {
+    assetStoreAssetId = assetStoreId_;
+  };
+
+  /** \brief Return the object asset store id of this variant.
+   */
+  const gd::String &GetAssetStoreAssetId() const { return assetStoreAssetId; };
+
+  /** \brief Change the original name of the variant in the asset.
+   */
+  void SetAssetStoreOriginalName(const gd::String &assetStoreOriginalName_) {
+    assetStoreOriginalName = assetStoreOriginalName_;
+  };
+
+  /** \brief Return the original name of the variant in the asset.
+   */
+  const gd::String &GetAssetStoreOriginalName() const {
+    return assetStoreOriginalName;
+  };
+
+  void SerializeTo(SerializerElement &element) const;
+
+  void UnserializeFrom(gd::Project &project, const SerializerElement &element);
+
+private:
+  gd::String name;
+  gd::InitialInstancesContainer initialInstances;
+  gd::LayersContainer layers;
+  gd::ObjectsContainer objectsContainer;
+  double areaMinX;
+  double areaMinY;
+  double areaMinZ;
+  double areaMaxX;
+  double areaMaxY;
+  double areaMaxZ;
+  /**
+   * The ID of the asset if the object comes from the store.
+   */
+  gd::String assetStoreAssetId;
+  /**
+   * The original name of the variant in the asset if the object comes from the
+   * store.
+   */
+  gd::String assetStoreOriginalName;
+};
+
+} // namespace gd

Core/GDCore/Project/EventsBasedObjectVariantsContainer.h

@@ -0,0 +1,160 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-present Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#pragma once
+
+#include <vector>
+#include "GDCore/Project/EventsBasedObjectVariant.h"
+#include "GDCore/String.h"
+#include "GDCore/Tools/SerializableWithNameList.h"
+
+namespace gd {
+class SerializerElement;
+}
+
+namespace gd {
+
+/**
+ * \brief Used as a base class for classes that will own events-backed
+ * variants.
+ *
+ * \see gd::EventsBasedObjectVariantContainer
+ * \ingroup PlatformDefinition
+ */
+class GD_CORE_API EventsBasedObjectVariantsContainer
+    : private SerializableWithNameList<gd::EventsBasedObjectVariant> {
+public:
+  EventsBasedObjectVariantsContainer() {}
+
+  EventsBasedObjectVariantsContainer(const EventsBasedObjectVariantsContainer &other) {
+    Init(other);
+  }
+
+  EventsBasedObjectVariantsContainer &operator=(const EventsBasedObjectVariantsContainer &other) {
+    if (this != &other) {
+      Init(other);
+    }
+    return *this;
+  }
+
+  /** \name Events Functions management
+   */
+  ///@{
+  /**
+   * \brief Check if the variant with the specified name exists.
+   */
+  bool HasVariantNamed(const gd::String& name) const {
+    return Has(name);
+  }
+
+  /**
+   * \brief Get the variant with the specified name.
+   *
+   * \warning Trying to access to a not existing variant will result in
+   * undefined behavior.
+   */
+  gd::EventsBasedObjectVariant& GetVariant(const gd::String& name) {
+    return Get(name);
+  }
+
+  /**
+   * \brief Get the variant with the specified name.
+   *
+   * \warning Trying to access to a not existing variant will result in
+   * undefined behavior.
+   */
+  const gd::EventsBasedObjectVariant& GetVariant(const gd::String& name) const {
+    return Get(name);
+  }
+
+  /**
+   * \brief Get the variant at the specified index in the list.
+   *
+   * \warning Trying to access to a not existing variant will result in
+   * undefined behavior.
+   */
+  gd::EventsBasedObjectVariant& GetVariant(std::size_t index) {
+    return Get(index);
+  }
+
+  /**
+   * \brief Get the variant at the specified index in the list.
+   *
+   * \warning Trying to access to a not existing variant will result in
+   * undefined behavior.
+   */
+  const gd::EventsBasedObjectVariant& GetVariant(std::size_t index) const {
+    return Get(index);
+  }
+
+  /**
+   * \brief Return the number of variants.
+   */
+  std::size_t GetVariantsCount() const { return GetCount(); }
+
+  gd::EventsBasedObjectVariant& InsertNewVariant(const gd::String& name,
+                                              std::size_t position) {
+    return InsertNew(name, position);
+  }
+  gd::EventsBasedObjectVariant& InsertVariant(const gd::EventsBasedObjectVariant& object,
+                                           std::size_t position) {
+    return Insert(object, position);
+  }
+  void RemoveVariant(const gd::String& name) { return Remove(name); }
+  void ClearVariants() { return Clear(); }
+  void MoveVariant(std::size_t oldIndex, std::size_t newIndex) {
+    return Move(oldIndex, newIndex);
+  };
+  std::size_t GetVariantPosition(const gd::EventsBasedObjectVariant& eventsFunction) {
+    return GetPosition(eventsFunction);
+  };
+
+  /**
+   * \brief Provide a raw access to the vector containing the variants.
+   */
+  const std::vector<std::unique_ptr<gd::EventsBasedObjectVariant>>& GetInternalVector()
+      const {
+    return elements;
+  };
+
+  /**
+   * \brief Provide a raw access to the vector containing the variants.
+   */
+  std::vector<std::unique_ptr<gd::EventsBasedObjectVariant>>& GetInternalVector() {
+    return elements;
+  };
+  ///@}
+
+  /** \name Serialization
+   */
+  ///@{
+  /**
+   * \brief Serialize events variants.
+   */
+  void SerializeVariantsTo(SerializerElement& element) const {
+    return SerializeElementsTo("variant", element);
+  };
+
+  /**
+   * \brief Unserialize the events variants.
+   */
+  void UnserializeVariantsFrom(gd::Project& project,
+                                      const SerializerElement& element) {
+    return UnserializeElementsFrom("variant", project, element);
+  };
+  ///@}
+ protected:
+  /**
+   * Initialize object using another object. Used by copy-ctor and assign-op.
+   * Don't forget to update me if members were changed!
+   */
+  void Init(const gd::EventsBasedObjectVariantsContainer& other) {
+    return SerializableWithNameList<gd::EventsBasedObjectVariant>::Init(other);
+  };
+
+private:
+};
+
+}  // namespace gd

Core/GDCore/Project/EventsFunctionsExtension.cpp

@@ -55,7 +55,7 @@ void EventsFunctionsExtension::Init(const gd::EventsFunctionsExtension& other) {
   sceneVariables = other.GetSceneVariables();
 }
 
-void EventsFunctionsExtension::SerializeTo(SerializerElement& element) const {
+void EventsFunctionsExtension::SerializeTo(SerializerElement& element, bool isExternal) const {
   element.SetAttribute("version", version);
   element.SetAttribute("extensionNamespace", extensionNamespace);
   element.SetAttribute("shortDescription", shortDescription);
@@ -83,6 +83,9 @@ void EventsFunctionsExtension::SerializeTo(SerializerElement& element) const {
   element.SetAttribute("iconUrl", iconUrl);
   element.SetAttribute("helpPath", helpPath);
   element.SetAttribute("gdevelopVersion", gdevelopVersion);
+  if (changelog.GetChangesCount() > 0) {
+    changelog.SerializeTo(element.AddChild("changelog"));
+  }
   auto& dependenciesElement = element.AddChild("dependencies");
   dependenciesElement.ConsiderAsArray();
   for (auto& dependency : dependencies)
@@ -102,8 +105,18 @@ void EventsFunctionsExtension::SerializeTo(SerializerElement& element) const {
       element.AddChild("eventsFunctions"));
   eventsBasedBehaviors.SerializeElementsTo(
       "eventsBasedBehavior", element.AddChild("eventsBasedBehaviors"));
-  eventsBasedObjects.SerializeElementsTo(
-      "eventsBasedObject", element.AddChild("eventsBasedObjects"));
+  if (isExternal) {
+    auto &eventsBasedObjectElement = element.AddChild("eventsBasedObjects");
+    eventsBasedObjectElement.ConsiderAsArrayOf("eventsBasedObject");
+    for (const auto &eventsBasedObject :
+         eventsBasedObjects.GetInternalVector()) {
+      eventsBasedObject->SerializeToExternal(
+          eventsBasedObjectElement.AddChild("eventsBasedObject"));
+    }
+  } else {
+    eventsBasedObjects.SerializeElementsTo(
+        "eventsBasedObject", element.AddChild("eventsBasedObjects"));
+  }
 }
 
 void EventsFunctionsExtension::UnserializeFrom(
@@ -129,6 +142,9 @@ void EventsFunctionsExtension::UnserializeExtensionDeclarationFrom(
   iconUrl = element.GetStringAttribute("iconUrl");
   helpPath = element.GetStringAttribute("helpPath");
   gdevelopVersion = element.GetStringAttribute("gdevelopVersion");
+  if (element.HasChild("changelog")) {
+    changelog.UnserializeFrom(element.GetChild("changelog"));
+  }
 
   if (element.HasChild("origin")) {
     gd::String originName =

Core/GDCore/Project/EventsFunctionsExtension.h

@@ -12,9 +12,11 @@
 #include "GDCore/Project/EventsBasedBehavior.h"
 #include "GDCore/Project/EventsBasedObject.h"
 #include "GDCore/Project/EventsFunctionsContainer.h"
+#include "GDCore/Project/EventsFunctionsExtensionChangelog.h"
 #include "GDCore/Project/VariablesContainer.h"
 #include "GDCore/String.h"
 #include "GDCore/Tools/SerializableWithNameList.h"
+
 namespace gd {
 class SerializerElement;
 class Project;
@@ -286,7 +288,14 @@ class GD_CORE_API EventsFunctionsExtension {
   /**
    * \brief Serialize the EventsFunctionsExtension to the specified element
    */
-  void SerializeTo(gd::SerializerElement& element) const;
+  void SerializeTo(gd::SerializerElement& element, bool isExternal = false) const;
+
+  /**
+   * \brief Serialize the EventsFunctionsExtension to the specified element
+   */
+  void SerializeToExternal(gd::SerializerElement& element) const {
+    SerializeTo(element, true);
+  }
 
   /**
    * \brief Load the EventsFunctionsExtension from the specified element.
@@ -399,6 +408,7 @@ class GD_CORE_API EventsFunctionsExtension {
   gd::String helpPath;  ///< The relative path to the help for this extension in
                         ///< the documentation (or an absolute URL).
   gd::String gdevelopVersion;
+  gd::EventsFunctionsExtensionChangelog changelog;
   gd::SerializableWithNameList<EventsBasedBehavior> eventsBasedBehaviors;
   gd::SerializableWithNameList<EventsBasedObject> eventsBasedObjects;
   std::vector<gd::DependencyMetadata> dependencies;

Core/GDCore/Project/EventsFunctionsExtensionChangelog.h

@@ -0,0 +1,105 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#pragma once
+
+#include <vector>
+
+#include "GDCore/Serialization/SerializerElement.h"
+#include "GDCore/String.h"
+
+namespace gd {
+
+/**
+ * @brief The change of a specific extension version (only the breaking
+ * changes).
+ */
+class GD_CORE_API EventsFunctionsExtensionVersionChange {
+public:
+  EventsFunctionsExtensionVersionChange(){};
+  virtual ~EventsFunctionsExtensionVersionChange(){};
+
+  const gd::String &GetVersion() const { return version; };
+  gd::EventsFunctionsExtensionVersionChange &
+  SetVersion(const gd::String &version_) {
+    version = version_;
+    return *this;
+  }
+
+  const gd::String &GetBreakingChangesDescription() const { return version; };
+  gd::EventsFunctionsExtensionVersionChange &
+  GetBreakingChangesDescription(const gd::String &breakingChangesDescription_) {
+    breakingChangesDescription = breakingChangesDescription_;
+    return *this;
+  }
+
+  /**
+   * \brief Serialize the EventsFunctionsExtensionVersionChange to the specified
+   * element
+   */
+  void SerializeTo(gd::SerializerElement &element) const {
+    element.SetAttribute("version", version);
+    element.AddChild("breaking")
+        .SetMultilineStringValue(breakingChangesDescription);
+  }
+
+  /**
+   * \brief Load the EventsFunctionsExtensionVersionChange from the specified
+   * element.
+   */
+  void UnserializeFrom(const gd::SerializerElement &element) {
+    version = element.GetStringAttribute("version");
+    breakingChangesDescription =
+        element.GetChild("breaking").GetMultilineStringValue();
+  }
+
+private:
+  gd::String version;
+  gd::String breakingChangesDescription;
+};
+
+/**
+ * @brief The changelog of an extension (only the breaking changes).
+ */
+class GD_CORE_API EventsFunctionsExtensionChangelog {
+public:
+  EventsFunctionsExtensionChangelog(){};
+  virtual ~EventsFunctionsExtensionChangelog(){};
+
+  /**
+   * \brief Return the number of variants.
+   */
+  std::size_t GetChangesCount() const { return versionChanges.size(); }
+
+  /**
+   * \brief Serialize the EventsFunctionsExtensionChangelog to the specified
+   * element
+   */
+  void SerializeTo(gd::SerializerElement &element) const {
+    element.ConsiderAsArray();
+    for (const auto &versionChange : versionChanges) {
+      versionChange.SerializeTo(element.AddChild(""));
+    }
+  }
+
+  /**
+   * \brief Load the EventsFunctionsExtensionChangelog from the specified
+   * element.
+   */
+  void UnserializeFrom(const gd::SerializerElement &element) {
+    versionChanges.clear();
+    element.ConsiderAsArray();
+    for (std::size_t i = 0; i < element.GetChildrenCount(); ++i) {
+      gd::EventsFunctionsExtensionVersionChange versionChange;
+      versionChange.UnserializeFrom(element.GetChild(i));
+      versionChanges.push_back(versionChange);
+    }
+  }
+
+private:
+  std::vector<gd::EventsFunctionsExtensionVersionChange> versionChanges;
+};
+
+} // namespace gd

Core/GDCore/Project/InitialInstance.h

@@ -365,6 +365,8 @@ class GD_CORE_API InitialInstance {
    * the same initial instance between serialization.
    */
   InitialInstance& ResetPersistentUuid();
+
+  const gd::String& GetPersistentUuid() const { return persistentUuid; }
   ///@}
 
  private:

Core/GDCore/Project/InitialInstancesContainer.cpp

@@ -42,8 +42,13 @@ void InitialInstancesContainer::IterateOverInstances(
 }
 
 void InitialInstancesContainer::IterateOverInstances(
-  const std::function< void(gd::InitialInstance &) >& func) {
-  for (auto& instance : initialInstances) func(instance);
+  const std::function< bool(gd::InitialInstance &) >& func) {
+  for (auto& instance : initialInstances) {
+    bool shouldStop = func(instance);
+    if (shouldStop) {
+      return;
+    }
+  }
 }
 
 void InitialInstancesContainer::IterateOverInstancesWithZOrdering(

Core/GDCore/Project/InitialInstancesContainer.h

@@ -92,7 +92,7 @@ class GD_CORE_API InitialInstancesContainer {
    * \see InitialInstanceFunctor
    */
   void IterateOverInstances(
-    const std::function< void(gd::InitialInstance &) >& func);
+    const std::function< bool(gd::InitialInstance &) >& func);
 
   /**
    * Get the instances on the specified layer,

Core/GDCore/Project/Layout.cpp

@@ -36,7 +36,7 @@ namespace gd {
 
 gd::BehaviorsSharedData Layout::badBehaviorSharedData("", "");
 
-Layout::Layout(const Layout &other)
+Layout::Layout(const Layout& other)
     : objectsContainer(gd::ObjectsContainer::SourceType::Scene) {
   Init(other);
 }
@@ -54,6 +54,8 @@ Layout::Layout()
       backgroundColorG(209),
       backgroundColorB(209),
       stopSoundsOnStartup(true),
+      resourcesPreloading("inherit"),
+      resourcesUnloading("inherit"),
       standardSortMethod(true),
       disableInputWhenNotFocused(true),
       variables(gd::VariablesContainer::SourceType::Scene),
@@ -244,6 +246,10 @@ void Layout::SerializeTo(SerializerElement& element) const {
   element.SetAttribute("title", GetWindowDefaultTitle());
   element.SetAttribute("standardSortMethod", standardSortMethod);
   element.SetAttribute("stopSoundsOnStartup", stopSoundsOnStartup);
+  if (resourcesPreloading != "inherit")
+    element.SetAttribute("resourcesPreloading", resourcesPreloading);
+  if (resourcesUnloading != "inherit")
+    element.SetAttribute("resourcesUnloading", resourcesUnloading);
   element.SetAttribute("disableInputWhenNotFocused",
                        disableInputWhenNotFocused);
 
@@ -304,6 +310,10 @@ void Layout::UnserializeFrom(gd::Project& project,
       element.GetStringAttribute("title", "(No title)", "titre"));
   standardSortMethod = element.GetBoolAttribute("standardSortMethod");
   stopSoundsOnStartup = element.GetBoolAttribute("stopSoundsOnStartup");
+  resourcesPreloading =
+      element.GetStringAttribute("resourcesPreloading", "inherit");
+  resourcesUnloading =
+      element.GetStringAttribute("resourcesUnloading", "inherit");
   disableInputWhenNotFocused =
       element.GetBoolAttribute("disableInputWhenNotFocused");
 
@@ -391,6 +401,8 @@ void Layout::Init(const Layout& other) {
   standardSortMethod = other.standardSortMethod;
   title = other.title;
   stopSoundsOnStartup = other.stopSoundsOnStartup;
+  resourcesPreloading = other.resourcesPreloading;
+  resourcesUnloading = other.resourcesUnloading;
   disableInputWhenNotFocused = other.disableInputWhenNotFocused;
   initialInstances = other.initialInstances;
   layers = other.layers;

Core/GDCore/Project/Layout.h

@@ -349,6 +349,36 @@ class GD_CORE_API Layout {
    * launched
    */
   bool StopSoundsOnStartup() const { return stopSoundsOnStartup; }
+
+  /**
+   * Set when the scene must preload its resources: `at-startup`, `never` or
+   * `inherit` (default).
+   */
+  void SetResourcesPreloading(gd::String resourcesPreloading_) {
+    resourcesPreloading = resourcesPreloading_;
+  }
+
+  /**
+   * Get when the scene must preload its resources: `at-startup`, `never` or
+   * `inherit` (default).
+   */
+  const gd::String& GetResourcesPreloading() const {
+    return resourcesPreloading;
+  }
+
+  /**
+   * Set when the scene must unload its resources: `at-scene-exit`, `never` or
+   * `inherit` (default).
+   */
+  void SetResourcesUnloading(gd::String resourcesUnloading_) {
+    resourcesUnloading = resourcesUnloading_;
+  }
+
+  /**
+   * Get when the scene must unload its resources: `at-scene-exit`, `never` or
+   * `inherit` (default).
+   */
+  const gd::String& GetResourcesUnloading() const { return resourcesUnloading; }
   ///@}
 
   /** \name Saving and loading
@@ -381,6 +411,10 @@ class GD_CORE_API Layout {
       behaviorsSharedData;   ///< Initial shared datas of behaviors
   bool stopSoundsOnStartup = true;  ///< True to make the scene stop all sounds at
                                     ///< startup.
+  gd::String
+      resourcesPreloading;  ///< `at-startup`, `never` or `inherit` (default).
+  gd::String
+      resourcesUnloading;  ///< `at-scene-exit`, `never` or `inherit` (default).
   bool standardSortMethod = true;   ///< True to sort objects using standard sort.
   bool disableInputWhenNotFocused = true;  /// If set to true, the input must be
                                            /// disabled when the window do not have the

Core/GDCore/Project/Object.cpp

@@ -41,6 +41,11 @@ Object::Object(const gd::String& name_,
 }
 
 void Object::Init(const gd::Object& object) {
+  CopyWithoutConfiguration(object);
+  configuration = object.configuration->Clone();
+}
+
+void Object::CopyWithoutConfiguration(const gd::Object& object) {
   persistentUuid = object.persistentUuid;
   name = object.name;
   assetStoreId = object.assetStoreId;
@@ -51,8 +56,6 @@ void Object::Init(const gd::Object& object) {
   for (auto& it : object.behaviors) {
     behaviors[it.first] = gd::make_unique<gd::Behavior>(*it.second);
   }
-
-  configuration = object.configuration->Clone();
 }
 
 gd::ObjectConfiguration& Object::GetConfiguration() { return *configuration; }

Core/GDCore/Project/Object.h

@@ -82,6 +82,8 @@ class GD_CORE_API Object {
     return gd::make_unique<gd::Object>(*this);
   }
 
+  void CopyWithoutConfiguration(const gd::Object& object);
+
   /**
    * \brief Return the object configuration.
    */

Core/GDCore/Project/ObjectsContainersList.h

@@ -81,6 +81,11 @@ class GD_CORE_API ObjectsContainersList {
   /**
    * \brief Return the container of the variables for the specified object or
    * group of objects.
+   *
+   * \warning In most cases, prefer to use other methods to access variables or use
+   * ObjectVariableHelper::MergeVariableContainers if you know you're dealing with a group.
+   * This is because the variables container of an object group does not exist and the one from
+   * first object of the group will be returned.
    */
   const gd::VariablesContainer* GetObjectOrGroupVariablesContainer(
       const gd::String& objectOrGroupName) const;

Core/GDCore/Project/Project.cpp

@@ -74,7 +74,9 @@ Project::Project()
       gdMinorVersion(gd::VersionWrapper::Minor()),
       gdBuildVersion(gd::VersionWrapper::Build()),
       variables(gd::VariablesContainer::SourceType::Global),
-      objectsContainer(gd::ObjectsContainer::SourceType::Global) {}
+      objectsContainer(gd::ObjectsContainer::SourceType::Global),
+      sceneResourcesPreloading("at-startup"),
+      sceneResourcesUnloading("never") {}
 
 Project::~Project() {}
 
@@ -920,6 +922,7 @@ void Project::UnserializeAndInsertExtensionsFrom(
       "eventsFunctionsExtension");
 
   std::map<gd::String, size_t> extensionNameToElementIndex;
+  std::map<gd::String, gd::SerializerElement> objectTypeToVariantsElement;
 
   // First, only unserialize behaviors and objects names.
   // As event based objects can contains custom behaviors and custom objects,
@@ -938,6 +941,16 @@ void Project::UnserializeAndInsertExtensionsFrom(
             ? GetEventsFunctionsExtension(name)
             : InsertNewEventsFunctionsExtension(
                   name, GetEventsFunctionsExtensionsCount());
+
+    // Backup the events-based object variants
+    for (auto &eventsBasedObject :
+         eventsFunctionsExtension.GetEventsBasedObjects().GetInternalVector()) {
+      gd::SerializerElement variantsElement;
+      eventsBasedObject->GetVariants().SerializeVariantsTo(variantsElement);
+      objectTypeToVariantsElement[gd::PlatformExtension::GetObjectFullType(
+          name, eventsBasedObject->GetName())] = variantsElement;
+    }
+
     eventsFunctionsExtension.UnserializeExtensionDeclarationFrom(
         *this, eventsFunctionsExtensionElement);
   }
@@ -966,6 +979,15 @@ void Project::UnserializeAndInsertExtensionsFrom(
     partiallyLoadedExtension
         ->UnserializeExtensionImplementationFrom(
             *this, eventsFunctionsExtensionElement);
+
+    for (auto &pair : objectTypeToVariantsElement) {
+      auto &objectType = pair.first;
+      auto &variantsElement = pair.second;
+
+      auto &eventsBasedObject = GetEventsBasedObject(objectType);
+      eventsBasedObject.GetVariants().UnserializeVariantsFrom(*this,
+                                                              variantsElement);
+    }
   }
 }
 
@@ -1146,6 +1168,13 @@ void Project::SerializeTo(SerializerElement& element) const {
   else
     std::cout << "ERROR: The project current platform is NULL.";
 
+  if (sceneResourcesPreloading != "at-startup") {
+    propElement.SetAttribute("sceneResourcesPreloading", sceneResourcesPreloading);
+  }
+  if (sceneResourcesUnloading != "never") {
+    propElement.SetAttribute("sceneResourcesUnloading", sceneResourcesUnloading);
+  }
+
   resourcesManager.SerializeTo(element.AddChild("resources"));
   objectsContainer.SerializeObjectsTo(element.AddChild("objects"));
   objectsContainer.SerializeFoldersTo(element.AddChild("objectsFolderStructure"));
@@ -1287,6 +1316,9 @@ void Project::Init(const gd::Project& game) {
   variables = game.GetVariables();
 
   projectFile = game.GetProjectFile();
+
+  sceneResourcesPreloading = game.sceneResourcesPreloading;
+  sceneResourcesUnloading = game.sceneResourcesUnloading;
 }
 
 }  // namespace gd

Core/GDCore/Project/Project.h

@@ -964,6 +964,37 @@ class GD_CORE_API Project {
    */
   ResourcesManager& GetResourcesManager() { return resourcesManager; }
 
+  /**
+   * Set when the scenes must preload their resources: `at-startup`, `never`
+   * (default).
+   */
+  void SetSceneResourcesPreloading(gd::String sceneResourcesPreloading_) {
+    sceneResourcesPreloading = sceneResourcesPreloading_;
+  }
+
+  /**
+   * Get when the scenes must preload their resources: `at-startup`, `never`
+   * (default).
+   */
+  const gd::String& GetSceneResourcesPreloading() const {
+    return sceneResourcesPreloading;
+  }
+
+  /**
+   * Set when the scenes must unload their resources: `at-scene-exit`, `never`
+   * (default).
+   */
+  void SetSceneResourcesUnloading(gd::String sceneResourcesUnloading_) {
+    sceneResourcesUnloading = sceneResourcesUnloading_;
+  }
+
+  /**
+   * Get when the scenes must unload their resources: `at-scene-exit`, `never`
+   * (default).
+   */
+  const gd::String& GetSceneResourcesUnloading() const {
+    return sceneResourcesUnloading;
+  }
   ///@}
 
   /** \name Variable management
@@ -1121,6 +1152,10 @@ class GD_CORE_API Project {
   ExtensionProperties
       extensionProperties;  ///< The properties of the extensions.
   gd::WholeProjectDiagnosticReport wholeProjectDiagnosticReport;
+  gd::String sceneResourcesPreloading;  ///< `at-startup` or `never`
+                                        ///< (default: `at-startup`).
+  gd::String sceneResourcesUnloading;   ///< `at-scene-exit` or `never`
+                                        ///< (default: `never`).
   mutable unsigned int gdMajorVersion =
       0;  ///< The GD major version used the last
           ///< time the project was saved.

Core/GDCore/Project/PropertyDescriptor.cpp

@@ -21,14 +21,33 @@ void PropertyDescriptor::SerializeTo(SerializerElement& element) const {
     element.AddChild("unit").SetStringValue(measurementUnit.GetName());
   }
   element.AddChild("label").SetStringValue(label);
-  element.AddChild("description").SetStringValue(description);
-  element.AddChild("group").SetStringValue(group);
-  SerializerElement& extraInformationElement =
-      element.AddChild("extraInformation");
-  extraInformationElement.ConsiderAsArray();
-  for (const gd::String& information : extraInformation) {
-    extraInformationElement.AddChild("").SetStringValue(information);
+  if (!description.empty())
+    element.AddChild("description").SetStringValue(description);
+  if (!group.empty()) element.AddChild("group").SetStringValue(group);
+
+  if (!extraInformation.empty()) {
+    SerializerElement& extraInformationElement =
+        element.AddChild("extraInformation");
+    extraInformationElement.ConsiderAsArray();
+    for (const gd::String& information : extraInformation) {
+      extraInformationElement.AddChild("").SetStringValue(information);
+    }
   }
+
+  if (!choices.empty()
+      // Compatibility with GD <= 5.5.239
+      || !extraInformation.empty()
+      // end of compatibility code
+  ) {
+    SerializerElement &choicesElement = element.AddChild("choices");
+    choicesElement.ConsiderAsArrayOf("choice");
+    for (const auto &choice : choices) {
+      auto &choiceElement = choicesElement.AddChild("Choice");
+      choiceElement.SetStringAttribute("value", choice.GetValue());
+      choiceElement.SetStringAttribute("label", choice.GetLabel());
+    }
+  }
+
   if (hidden) {
     element.AddChild("hidden").SetBoolValue(hidden);
   }
@@ -59,16 +78,41 @@ void PropertyDescriptor::UnserializeFrom(const SerializerElement& element) {
             : gd::MeasurementUnit::GetUndefined();
   }
   label = element.GetChild("label").GetStringValue();
-  description = element.GetChild("description").GetStringValue();
-  group = element.GetChild("group").GetStringValue();
+  description = element.HasChild("description")
+                    ? element.GetChild("description").GetStringValue()
+                    : "";
+  group = element.HasChild("group") ? element.GetChild("group").GetStringValue()
+                                    : "";
 
   extraInformation.clear();
-  const SerializerElement& extraInformationElement =
-      element.GetChild("extraInformation");
-  extraInformationElement.ConsiderAsArray();
-  for (std::size_t i = 0; i < extraInformationElement.GetChildrenCount(); ++i)
-    extraInformation.push_back(
-        extraInformationElement.GetChild(i).GetStringValue());
+  if (element.HasChild("extraInformation")) {
+    const SerializerElement& extraInformationElement =
+        element.GetChild("extraInformation");
+    extraInformationElement.ConsiderAsArray();
+    for (std::size_t i = 0; i < extraInformationElement.GetChildrenCount(); ++i)
+      extraInformation.push_back(
+          extraInformationElement.GetChild(i).GetStringValue());
+  }
+
+  if (element.HasChild("choices")) {
+    choices.clear();
+    const SerializerElement &choicesElement = element.GetChild("choices");
+    choicesElement.ConsiderAsArrayOf("choice");
+    for (std::size_t i = 0; i < choicesElement.GetChildrenCount(); ++i) {
+      auto &choiceElement = choicesElement.GetChild(i);
+      AddChoice(choiceElement.GetStringAttribute("value"),
+                choiceElement.GetStringAttribute("label"));
+    }
+  }
+  // Compatibility with GD <= 5.5.239
+  else if (type == "Choice") {
+    choices.clear();
+    for (auto &choiceValue : extraInformation) {
+      AddChoice(choiceValue, choiceValue);
+    }
+    extraInformation.clear();
+  }
+  // end of compatibility code
 
   hidden = element.HasChild("hidden")
                ? element.GetChild("hidden").GetBoolValue()

Core/GDCore/Project/PropertyDescriptor.h

@@ -7,9 +7,9 @@
 #define GDCORE_PROPERTYDESCRIPTOR
 #include <vector>
 
-#include "GDCore/String.h"
 #include "GDCore/Project/MeasurementUnit.h"
 #include "GDCore/Project/QuickCustomization.h"
+#include "GDCore/String.h"
 
 namespace gd {
 class SerializerElement;
@@ -17,6 +17,19 @@ class SerializerElement;
 
 namespace gd {
 
+class GD_CORE_API PropertyDescriptorChoice {
+ public:
+  PropertyDescriptorChoice(const gd::String& value, const gd::String& label)
+      : value(value), label(label) {}
+
+  const gd::String& GetValue() const { return value; }
+  const gd::String& GetLabel() const { return label; }
+
+ private:
+  gd::String value;
+  gd::String label;
+};
+
 /**
  * \brief Used to describe a property shown in a property grid.
  * \see gd::Object
@@ -31,8 +44,12 @@ class GD_CORE_API PropertyDescriptor {
    * \param propertyValue The value of the property.
    */
   PropertyDescriptor(gd::String propertyValue)
-      : currentValue(propertyValue), type("string"), label(""), hidden(false),
-        deprecated(false), advanced(false),
+      : currentValue(propertyValue),
+        type("string"),
+        label(""),
+        hidden(false),
+        deprecated(false),
+        advanced(false),
         hasImpactOnOtherProperties(false),
         measurementUnit(gd::MeasurementUnit::GetUndefined()),
         quickCustomizationVisibility(QuickCustomization::Visibility::Default) {}
@@ -41,10 +58,13 @@ class GD_CORE_API PropertyDescriptor {
    * \brief Empty constructor creating an empty property to be displayed.
    */
   PropertyDescriptor()
-      : hidden(false), deprecated(false), advanced(false),
+      : hidden(false),
+        deprecated(false),
+        advanced(false),
         hasImpactOnOtherProperties(false),
         measurementUnit(gd::MeasurementUnit::GetUndefined()),
-        quickCustomizationVisibility(QuickCustomization::Visibility::Default){};
+        quickCustomizationVisibility(QuickCustomization::Visibility::Default) {
+        };
 
   /**
    * \brief Destructor
@@ -88,13 +108,25 @@ class GD_CORE_API PropertyDescriptor {
   }
 
   /**
-   * \brief Change the group where this property is displayed to the user, if any.
+   * \brief Change the group where this property is displayed to the user, if
+   * any.
    */
   PropertyDescriptor& SetGroup(gd::String group_) {
     group = group_;
     return *this;
   }
 
+  PropertyDescriptor& ClearChoices() {
+    choices.clear();
+    return *this;
+  }
+
+  PropertyDescriptor& AddChoice(const gd::String& value,
+                                const gd::String& label) {
+    choices.push_back(PropertyDescriptorChoice(value, label));
+    return *this;
+  }
+
   /**
    * \brief Set and replace the additional information for the property.
    */
@@ -118,7 +150,8 @@ class GD_CORE_API PropertyDescriptor {
   /**
    * \brief Change the unit of measurement of the property value.
    */
-  PropertyDescriptor& SetMeasurementUnit(const gd::MeasurementUnit &measurementUnit_) {
+  PropertyDescriptor& SetMeasurementUnit(
+      const gd::MeasurementUnit& measurementUnit_) {
     measurementUnit = measurementUnit_;
     return *this;
   }
@@ -128,14 +161,18 @@ class GD_CORE_API PropertyDescriptor {
   const gd::String& GetLabel() const { return label; }
   const gd::String& GetDescription() const { return description; }
   const gd::String& GetGroup() const { return group; }
-  const gd::MeasurementUnit& GetMeasurementUnit() const { return measurementUnit; }
+  const gd::MeasurementUnit& GetMeasurementUnit() const {
+    return measurementUnit;
+  }
 
   const std::vector<gd::String>& GetExtraInfo() const {
     return extraInformation;
   }
 
-  std::vector<gd::String>& GetExtraInfo() {
-    return extraInformation;
+  std::vector<gd::String>& GetExtraInfo() { return extraInformation; }
+
+  const std::vector<PropertyDescriptorChoice>& GetChoices() const {
+    return choices;
   }
 
   /**
@@ -178,23 +215,26 @@ class GD_CORE_API PropertyDescriptor {
   bool IsAdvanced() const { return advanced; }
 
   /**
-   * \brief Check if the property has impact on other properties - which means a change
-   * must re-render other properties.
+   * \brief Check if the property has impact on other properties - which means a
+   * change must re-render other properties.
    */
   bool HasImpactOnOtherProperties() const { return hasImpactOnOtherProperties; }
 
   /**
-   * \brief Set if the property has impact on other properties - which means a change
-   * must re-render other properties.
+   * \brief Set if the property has impact on other properties - which means a
+   * change must re-render other properties.
    */
   PropertyDescriptor& SetHasImpactOnOtherProperties(bool enable) {
     hasImpactOnOtherProperties = enable;
     return *this;
   }
 
-  QuickCustomization::Visibility GetQuickCustomizationVisibility() const { return quickCustomizationVisibility; }
+  QuickCustomization::Visibility GetQuickCustomizationVisibility() const {
+    return quickCustomizationVisibility;
+  }
 
-  PropertyDescriptor& SetQuickCustomizationVisibility(QuickCustomization::Visibility visibility) {
+  PropertyDescriptor& SetQuickCustomizationVisibility(
+      QuickCustomization::Visibility visibility) {
     quickCustomizationVisibility = visibility;
     return *this;
   }
@@ -231,15 +271,17 @@ class GD_CORE_API PropertyDescriptor {
   gd::String label;        //< The user-friendly property name
   gd::String description;  //< The user-friendly property description
   gd::String group;        //< The user-friendly property group
+  std::vector<PropertyDescriptorChoice>
+      choices;  //< The optional choices for the property.
   std::vector<gd::String>
-      extraInformation;  ///< Can be used to store for example the available
-                         ///< choices, if a property is a displayed as a combo
-                         ///< box.
+      extraInformation;  ///< Can be used to store an additional information
+                         ///< like an object type.
   bool hidden;
   bool deprecated;
   bool advanced;
   bool hasImpactOnOtherProperties;
-  gd::MeasurementUnit measurementUnit; //< The unit of measurement of the property vale.
+  gd::MeasurementUnit
+      measurementUnit;  //< The unit of measurement of the property vale.
   QuickCustomization::Visibility quickCustomizationVisibility;
 };
 

Core/tests/ArbitraryResourceWorker.cpp

@@ -764,129 +764,6 @@ TEST_CASE("ArbitraryResourceWorker", "[common][resources]") {
       REQUIRE(worker.audios[0] == "res4");
     }
 
-    SECTION("Can find resource usages in event-based functions") {
-      gd::Project project;
-      gd::Platform platform;
-      SetupProjectWithDummyPlatform(project, platform);
-
-      project.GetResourcesManager().AddResource(
-          "res1", "path/to/file1.png", "image");
-      project.GetResourcesManager().AddResource(
-          "res2", "path/to/file2.png", "image");
-      project.GetResourcesManager().AddResource(
-          "res3", "path/to/file3.png", "image");
-      ArbitraryResourceWorkerTest worker(project.GetResourcesManager());
-
-      auto& extension = project.InsertNewEventsFunctionsExtension("MyEventExtension", 0);
-      auto &function = extension.GetEventsFunctions().InsertNewEventsFunction(
-          "MyFreeFunction", 0);
-
-      gd::StandardEvent standardEvent;
-      gd::Instruction instruction;
-      instruction.SetType("MyExtension::DoSomethingWithResources");
-      instruction.SetParametersCount(3);
-      instruction.SetParameter(0, "res3");
-      instruction.SetParameter(1, "res1");
-      instruction.SetParameter(2, "res4");
-      standardEvent.GetActions().Insert(instruction);
-      function.GetEvents().InsertEvent(standardEvent);
-
-      auto& layout = project.InsertNewLayout("MyScene", 0);
-
-      // MyEventExtension::MyFreeFunction doesn't need to be actually used in
-      // events because the implementation is naive.
-
-      gd::ResourceExposer::ExposeLayoutResources(project, layout, worker);
-      REQUIRE(worker.bitmapFonts.size() == 1);
-      REQUIRE(worker.bitmapFonts[0] == "res3");
-      REQUIRE(worker.images.size() == 1);
-      REQUIRE(worker.images[0] == "res1");
-      REQUIRE(worker.audios.size() == 1);
-      REQUIRE(worker.audios[0] == "res4");
-    }
-
-    SECTION("Can find resource usages in event-based behavior functions") {
-      gd::Project project;
-      gd::Platform platform;
-      SetupProjectWithDummyPlatform(project, platform);
-
-      project.GetResourcesManager().AddResource(
-          "res1", "path/to/file1.png", "image");
-      project.GetResourcesManager().AddResource(
-          "res2", "path/to/file2.png", "image");
-      project.GetResourcesManager().AddResource(
-          "res3", "path/to/file3.png", "image");
-      ArbitraryResourceWorkerTest worker(project.GetResourcesManager());
-
-      auto& extension = project.InsertNewEventsFunctionsExtension("MyEventExtension", 0);
-      auto& behavior = extension.GetEventsBasedBehaviors().InsertNew("MyBehavior", 0);
-      auto& function = behavior.GetEventsFunctions().InsertNewEventsFunction("MyFunction", 0);
-      
-      gd::StandardEvent standardEvent;
-      gd::Instruction instruction;
-      instruction.SetType("MyExtension::DoSomethingWithResources");
-      instruction.SetParametersCount(3);
-      instruction.SetParameter(0, "res3");
-      instruction.SetParameter(1, "res1");
-      instruction.SetParameter(2, "res4");
-      standardEvent.GetActions().Insert(instruction);
-      function.GetEvents().InsertEvent(standardEvent);
-
-      auto& layout = project.InsertNewLayout("MyScene", 0);
-
-      // MyEventExtension::MyBehavior::MyFunction doesn't need to be actually used in
-      // events because the implementation is naive.
-
-      gd::ResourceExposer::ExposeLayoutResources(project, layout, worker);
-      REQUIRE(worker.bitmapFonts.size() == 1);
-      REQUIRE(worker.bitmapFonts[0] == "res3");
-      REQUIRE(worker.images.size() == 1);
-      REQUIRE(worker.images[0] == "res1");
-      REQUIRE(worker.audios.size() == 1);
-      REQUIRE(worker.audios[0] == "res4");
-    }
-
-    SECTION("Can find resource usages in event-based object functions") {
-      gd::Project project;
-      gd::Platform platform;
-      SetupProjectWithDummyPlatform(project, platform);
-
-      project.GetResourcesManager().AddResource(
-          "res1", "path/to/file1.png", "image");
-      project.GetResourcesManager().AddResource(
-          "res2", "path/to/file2.png", "image");
-      project.GetResourcesManager().AddResource(
-          "res3", "path/to/file3.png", "image");
-      ArbitraryResourceWorkerTest worker(project.GetResourcesManager());
-
-      auto& extension = project.InsertNewEventsFunctionsExtension("MyEventExtension", 0);
-      auto& object = extension.GetEventsBasedObjects().InsertNew("MyObject", 0);
-      auto& function = object.GetEventsFunctions().InsertNewEventsFunction("MyFunction", 0);
-      
-      gd::StandardEvent standardEvent;
-      gd::Instruction instruction;
-      instruction.SetType("MyExtension::DoSomethingWithResources");
-      instruction.SetParametersCount(3);
-      instruction.SetParameter(0, "res3");
-      instruction.SetParameter(1, "res1");
-      instruction.SetParameter(2, "res4");
-      standardEvent.GetActions().Insert(instruction);
-      function.GetEvents().InsertEvent(standardEvent);
-
-      auto& layout = project.InsertNewLayout("MyScene", 0);
-
-      // MyEventExtension::MyObject::MyFunction doesn't need to be actually used in
-      // events because the implementation is naive.
-
-      gd::ResourceExposer::ExposeLayoutResources(project, layout, worker);
-      REQUIRE(worker.bitmapFonts.size() == 1);
-      REQUIRE(worker.bitmapFonts[0] == "res3");
-      REQUIRE(worker.images.size() == 1);
-      REQUIRE(worker.images[0] == "res1");
-      REQUIRE(worker.audios.size() == 1);
-      REQUIRE(worker.audios[0] == "res4");
-    }
-
     SECTION("Can find resource usages in layer effects") {
       gd::Project project;
       gd::Platform platform;

Core/tests/EventsBasedObjectVariantHelper.cpp

@@ -0,0 +1,522 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+/**
+ * @file Tests covering events of GDevelop Core.
+ */
+#include "catch.hpp"
+
+#include <algorithm>
+#include <initializer_list>
+#include <map>
+
+#include "GDCore/CommonTools.h"
+#include "GDCore/IDE/EventsBasedObjectVariantHelper.h"
+
+#include "DummyPlatform.h"
+#include "GDCore/Extensions/Platform.h"
+#include "GDCore/Extensions/PlatformExtension.h"
+#include "GDCore/Project/Behavior.h"
+#include "GDCore/Project/EventsFunctionsExtension.h"
+#include "GDCore/Project/Object.h"
+#include "GDCore/Project/Project.h"
+#include "GDCore/Project/ProjectScopedContainers.h"
+#include "GDCore/Project/Variable.h"
+#include "catch.hpp"
+
+gd::InitialInstance *
+GetFirstInstanceOf(const gd::String objectName,
+                   gd::InitialInstancesContainer &initialInstances) {
+  gd::InitialInstance *variantInstance = nullptr;
+  initialInstances.IterateOverInstances(
+      [&variantInstance, &objectName](gd::InitialInstance &instance) {
+        if (instance.GetObjectName() == objectName) {
+          variantInstance = &instance;
+          return true;
+        }
+        return false;
+      });
+  return variantInstance;
+}
+
+gd::EventsBasedObject &SetupEventsBasedObject(gd::Project &project) {
+  auto &eventsExtension =
+      project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+  auto &eventsBasedObject = eventsExtension.GetEventsBasedObjects().InsertNew(
+      "MyEventsBasedObject", 0);
+  auto &object = eventsBasedObject.GetObjects().InsertNewObject(
+      project, "MyExtension::Sprite", "MyChildObject", 0);
+  object.GetVariables().InsertNew("MyVariable").SetValue(123);
+  object.AddNewBehavior(project, "MyExtension::MyBehavior", "MyBehavior");
+  auto &instance =
+      eventsBasedObject.GetInitialInstances().InsertNewInitialInstance();
+  instance.SetObjectName("MyChildObject");
+  instance.GetVariables().InsertNew("MyVariable").SetValue(111);
+  auto &objectGroup =
+      eventsBasedObject.GetObjects().GetObjectGroups().InsertNew(
+          "MyObjectGroup");
+  objectGroup.AddObject("MyChildObject");
+  return eventsBasedObject;
+}
+
+TEST_CASE("EventsBasedObjectVariantHelper", "[common]") {
+  SECTION("Can add missing objects") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChildObject2", 0);
+    eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChildObject3", 0);
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject2"));
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject3"));
+  }
+
+  SECTION("Can remove objects") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+
+    eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChildObject2", 0);
+    eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChildObject3", 0);
+
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+    variant.GetInitialInstances().InsertNewInitialInstance().SetObjectName(
+        "MyChildObject2");
+    REQUIRE(variant.GetInitialInstances().HasInstancesOfObject(
+                "MyChildObject2") == true);
+
+    // Do the changes and launch the refactoring.
+    eventsBasedObject.GetObjects().RemoveObject("MyChildObject2");
+    eventsBasedObject.GetObjects().RemoveObject("MyChildObject3");
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject2") == false);
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject3") == false);
+    REQUIRE(variant.GetInitialInstances().HasInstancesOfObject(
+                "MyChildObject2") == false);
+  }
+
+  SECTION("Can change object type") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    eventsBasedObject.GetObjects().RemoveObject("MyChildObject");
+    eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::FakeObjectWithDefaultBehavior", "MyChildObject",
+        0);
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    REQUIRE(variant.GetObjects().GetObject("MyChildObject").GetType() ==
+            "MyExtension::FakeObjectWithDefaultBehavior");
+    REQUIRE(variant.GetInitialInstances().GetInstancesCount() == 1);
+  }
+
+  SECTION("Can add missing object groups") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    eventsBasedObject.GetObjects().GetObjectGroups().InsertNew("MyObjectGroup2",
+                                                               0);
+    eventsBasedObject.GetObjects()
+        .GetObjectGroups()
+        .InsertNew("MyObjectGroup3", 0)
+        .AddObject("MyChildObject");
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    auto &variantObjectGroups = variant.GetObjects().GetObjectGroups();
+    REQUIRE(variantObjectGroups.Has("MyObjectGroup"));
+    REQUIRE(variantObjectGroups.Has("MyObjectGroup2"));
+    REQUIRE(variantObjectGroups.Has("MyObjectGroup3"));
+    REQUIRE(
+        variantObjectGroups.Get("MyObjectGroup").GetAllObjectsNames().size() ==
+        1);
+    REQUIRE(
+        variantObjectGroups.Get("MyObjectGroup2").GetAllObjectsNames().size() ==
+        0);
+    REQUIRE(
+        variantObjectGroups.Get("MyObjectGroup3").GetAllObjectsNames().size() ==
+        1);
+  }
+
+  SECTION("Can remove object groups") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+
+    // Do the changes and launch the refactoring.
+    eventsBasedObject.GetObjects().GetObjectGroups().InsertNew("MyObjectGroup2",
+                                                               0);
+    eventsBasedObject.GetObjects().GetObjectGroups().InsertNew("MyObjectGroup3",
+                                                               0);
+
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    eventsBasedObject.GetObjects().GetObjectGroups().Remove("MyObjectGroup2");
+    eventsBasedObject.GetObjects().GetObjectGroups().Remove("MyObjectGroup3");
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    auto &variantObjectGroups = variant.GetObjects().GetObjectGroups();
+    REQUIRE(variantObjectGroups.Has("MyObjectGroup"));
+    REQUIRE(variantObjectGroups.Has("MyObjectGroup2") == false);
+    REQUIRE(variantObjectGroups.Has("MyObjectGroup3") == false);
+  }
+
+  SECTION("Can add objects to groups") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChildObject2", 0);
+    eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChildObject3", 0);
+
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    auto &objectGroup =
+        eventsBasedObject.GetObjects().GetObjectGroups().Get("MyObjectGroup");
+    objectGroup.AddObject("MyChildObject2");
+    objectGroup.AddObject("MyChildObject3");
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    auto &variantObjectGroups = variant.GetObjects().GetObjectGroups();
+    REQUIRE(variantObjectGroups.Has("MyObjectGroup"));
+    REQUIRE(
+        variantObjectGroups.Get("MyObjectGroup").GetAllObjectsNames().size() ==
+        3);
+  }
+
+  SECTION("Can remove objects from groups") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChildObject2", 0);
+    eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChildObject3", 0);
+    auto &objectGroup =
+        eventsBasedObject.GetObjects().GetObjectGroups().Get("MyObjectGroup");
+    objectGroup.AddObject("MyChildObject2");
+    objectGroup.AddObject("MyChildObject3");
+
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    objectGroup.RemoveObject("MyChildObject2");
+    objectGroup.RemoveObject("MyChildObject3");
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    auto &variantObjectGroups = variant.GetObjects().GetObjectGroups();
+    REQUIRE(variantObjectGroups.Has("MyObjectGroup"));
+    REQUIRE(
+        variantObjectGroups.Get("MyObjectGroup").GetAllObjectsNames().size() ==
+        1);
+  }
+
+  SECTION("Can add missing behaviors") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    auto &object = eventsBasedObject.GetObjects().GetObject("MyChildObject");
+    object.AddNewBehavior(project, "MyExtension::MyBehavior", "MyBehavior2");
+    object.AddNewBehavior(project, "MyExtension::MyBehavior", "MyBehavior3");
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    auto &variantObject = variant.GetObjects().GetObject("MyChildObject");
+    REQUIRE(variantObject.HasBehaviorNamed("MyBehavior"));
+    REQUIRE(variantObject.HasBehaviorNamed("MyBehavior2"));
+    REQUIRE(variantObject.HasBehaviorNamed("MyBehavior3"));
+  }
+
+  SECTION("Can remove missing behaviors") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+
+    auto &object = eventsBasedObject.GetObjects().GetObject("MyChildObject");
+    object.AddNewBehavior(project, "MyExtension::MyBehavior", "MyBehavior2");
+    object.AddNewBehavior(project, "MyExtension::MyBehavior", "MyBehavior3");
+
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    object.RemoveBehavior("MyBehavior2");
+    object.RemoveBehavior("MyBehavior3");
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    auto &variantObject = variant.GetObjects().GetObject("MyChildObject");
+    REQUIRE(variantObject.HasBehaviorNamed("MyBehavior"));
+    REQUIRE(variantObject.HasBehaviorNamed("MyBehavior2") == false);
+    REQUIRE(variantObject.HasBehaviorNamed("MyBehavior3") == false);
+  }
+
+  SECTION("Can change behavior type") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    auto &object = eventsBasedObject.GetObjects().GetObject("MyChildObject");
+    object.RemoveBehavior("MyBehavior");
+    object.AddNewBehavior(project, "MyExtension::MyOtherBehavior",
+                          "MyBehavior");
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    auto &variantObject = variant.GetObjects().GetObject("MyChildObject");
+    REQUIRE(variantObject.HasBehaviorNamed("MyBehavior"));
+    REQUIRE(variantObject.GetBehavior("MyBehavior").GetTypeName() ==
+            "MyExtension::MyOtherBehavior");
+  }
+
+  SECTION("Can add missing variables") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    auto &object = eventsBasedObject.GetObjects().GetObject("MyChildObject");
+    object.GetVariables().InsertNew("MyVariable2", 1).SetValue(456);
+    object.GetVariables().InsertNew("MyVariable3", 2).SetValue(789);
+
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    auto &variantObject = variant.GetObjects().GetObject("MyChildObject");
+    REQUIRE(variantObject.GetVariables().Get("MyVariable").GetValue() == 123);
+    REQUIRE(variantObject.GetVariables().Get("MyVariable2").GetValue() == 456);
+    REQUIRE(variantObject.GetVariables().Get("MyVariable3").GetValue() == 789);
+    {
+      auto *objectInstance =
+          GetFirstInstanceOf("MyChildObject", variant.GetInitialInstances());
+      REQUIRE(objectInstance != nullptr);
+      REQUIRE(objectInstance->GetVariables().Has("MyVariable"));
+      REQUIRE(objectInstance->GetVariables().Has("MyVariable2") == false);
+      REQUIRE(objectInstance->GetVariables().Has("MyVariable3") == false);
+    }
+  }
+
+  SECTION("Can keep variable value") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+    auto &object = eventsBasedObject.GetObjects().GetObject("MyChildObject");
+
+    // Do the changes and launch the refactoring.
+    object.GetVariables().Get("MyVariable").SetValue(456);
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    auto &variantObject = variant.GetObjects().GetObject("MyChildObject");
+    REQUIRE(variantObject.GetVariables().Get("MyVariable").GetValue() == 123);
+    {
+      auto *objectInstance =
+          GetFirstInstanceOf("MyChildObject", variant.GetInitialInstances());
+      REQUIRE(objectInstance != nullptr);
+      REQUIRE(objectInstance->GetVariables().Get("MyVariable").GetValue() ==
+              111);
+    }
+  }
+
+  SECTION("Must not propagate instance variable value changes") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    {
+      auto *objectInstance = GetFirstInstanceOf(
+          "MyChildObject", eventsBasedObject.GetInitialInstances());
+      REQUIRE(objectInstance != nullptr);
+      objectInstance->GetVariables().Get("MyVariable").SetValue(222);
+    }
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    {
+      auto *objectInstance =
+          GetFirstInstanceOf("MyChildObject", variant.GetInitialInstances());
+      REQUIRE(objectInstance != nullptr);
+      REQUIRE(objectInstance->GetVariables().Get("MyVariable").GetValue() ==
+              111);
+    }
+  }
+
+  SECTION("Can move variables") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &object = eventsBasedObject.GetObjects().GetObject("MyChildObject");
+    object.GetVariables().InsertNew("MyVariable2", 1).SetValue(456);
+    object.GetVariables().InsertNew("MyVariable3", 2).SetValue(789);
+    {
+      auto *objectInstance = GetFirstInstanceOf(
+          "MyChildObject", eventsBasedObject.GetInitialInstances());
+      REQUIRE(objectInstance != nullptr);
+      objectInstance->GetVariables().Get("MyVariable2").SetValue(222);
+      objectInstance->GetVariables().Get("MyVariable3").SetValue(333);
+    }
+
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+
+    // Do the changes and launch the refactoring.
+    object.GetVariables().Move(2, 0);
+    object.GetVariables().Get("MyVariable").SetValue(111);
+    object.GetVariables().Get("MyVariable2").SetValue(222);
+    object.GetVariables().Get("MyVariable3").SetValue(333);
+    REQUIRE(object.GetVariables().GetNameAt(0) == "MyVariable3");
+    REQUIRE(object.GetVariables().GetNameAt(1) == "MyVariable");
+    REQUIRE(object.GetVariables().GetNameAt(2) == "MyVariable2");
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    auto &variantObject = variant.GetObjects().GetObject("MyChildObject");
+    REQUIRE(variantObject.GetVariables().Get("MyVariable").GetValue() == 123);
+    REQUIRE(variantObject.GetVariables().Get("MyVariable2").GetValue() == 456);
+    REQUIRE(variantObject.GetVariables().Get("MyVariable3").GetValue() == 789);
+    REQUIRE(variantObject.GetVariables().GetNameAt(0) == "MyVariable3");
+    REQUIRE(variantObject.GetVariables().GetNameAt(1) == "MyVariable");
+    REQUIRE(variantObject.GetVariables().GetNameAt(2) == "MyVariable2");
+  }
+
+  SECTION("Can remove variables") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+    auto &object = eventsBasedObject.GetObjects().GetObject("MyChildObject");
+    object.GetVariables().InsertNew("MyVariable2", 1).SetValue(456);
+    object.GetVariables().InsertNew("MyVariable3", 2).SetValue(789);
+    {
+      auto *objectInstance = GetFirstInstanceOf(
+          "MyChildObject", eventsBasedObject.GetInitialInstances());
+      REQUIRE(objectInstance != nullptr);
+      objectInstance->GetVariables().Get("MyVariable2").SetValue(222);
+      objectInstance->GetVariables().Get("MyVariable3").SetValue(333);
+    }
+
+    // Do the changes and launch the refactoring.
+    object.GetVariables().Remove("MyVariable2");
+    object.GetVariables().Remove("MyVariable3");
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    auto &variantObject = variant.GetObjects().GetObject("MyChildObject");
+    REQUIRE(variantObject.GetVariables().Has("MyVariable"));
+    REQUIRE(variantObject.GetVariables().Has("MyVariable2") == false);
+    REQUIRE(variantObject.GetVariables().Has("MyVariable3") == false);
+    {
+      auto *objectInstance =
+          GetFirstInstanceOf("MyChildObject", variant.GetInitialInstances());
+      REQUIRE(objectInstance != nullptr);
+      REQUIRE(objectInstance->GetVariables().Has("MyVariable"));
+      REQUIRE(objectInstance->GetVariables().Has("MyVariable2") == false);
+      REQUIRE(objectInstance->GetVariables().Has("MyVariable3") == false);
+    }
+  }
+
+  SECTION("Can change variable type") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsBasedObject = SetupEventsBasedObject(project);
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+    auto &object = eventsBasedObject.GetObjects().GetObject("MyChildObject");
+
+    // Do the changes and launch the refactoring.
+    object.GetVariables().Get("MyVariable").SetString("abc");
+    gd::EventsBasedObjectVariantHelper::ComplyVariantsToEventsBasedObject(
+        project, eventsBasedObject);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    auto &variantObject = variant.GetObjects().GetObject("MyChildObject");
+    REQUIRE(variantObject.GetVariables().Get("MyVariable").GetString() ==
+            "abc");
+    REQUIRE(variant.GetInitialInstances().HasInstancesOfObject("MyVariable") ==
+            false);
+  }
+}

Core/tests/ObjectAssetSerializer.cpp

@@ -33,7 +33,132 @@ using namespace gd;
 
 TEST_CASE("ObjectAssetSerializer", "[common]") {
 
-  SECTION("Can serialize custom objects as assets") {
+  SECTION("Can serialize custom objects as assets with variant") {
+    gd::Platform platform;
+    gd::Project project;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &eventsExtension =
+        project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+    auto &eventsBasedObject = eventsExtension.GetEventsBasedObjects().InsertNew(
+        "MyEventsBasedObject", 0);
+    eventsBasedObject.SetFullName("My events based object");
+    eventsBasedObject.SetDescription("An events based object for test");
+    auto &childObject = eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChild", 0);
+    auto &childInstance =
+        eventsBasedObject.GetInitialInstances().InsertNewInitialInstance();
+    childInstance.SetObjectName("MyChild");
+
+    auto &resourceManager = project.GetResourcesManager();
+    gd::ImageResource imageResource;
+    imageResource.SetName("assets/Idle.png");
+    imageResource.SetFile("assets/Idle.png");
+    imageResource.SetSmooth(true);
+    resourceManager.AddResource(imageResource);
+
+    gd::Layout &layout = project.InsertNewLayout("Scene", 0);
+    gd::Object &object = layout.GetObjects().InsertNewObject(
+        project, "MyEventsExtension::MyEventsBasedObject", "MyObject", 0);
+    auto *spriteConfiguration =
+        dynamic_cast<gd::SpriteObject *>(&childObject.GetConfiguration());
+    REQUIRE(spriteConfiguration != nullptr);
+    {
+      gd::Animation animation;
+      animation.SetName("Idle");
+      animation.SetDirectionsCount(1);
+      auto &direction = animation.GetDirection(0);
+      gd::Sprite frame;
+      frame.SetImageName("assets/Idle.png");
+      direction.AddSprite(frame);
+
+      spriteConfiguration->GetAnimations().AddAnimation(animation);
+    }
+
+    SerializerElement assetElement;
+    std::vector<gd::String> usedResourceNames;
+    ObjectAssetSerializer::SerializeTo(project, object, "My Object",
+                                       assetElement, usedResourceNames);
+
+    // This list is used to copy resource files.
+    REQUIRE(usedResourceNames.size() == 1);
+    REQUIRE(usedResourceNames[0] == "assets/Idle.png");
+
+    // Check that the project is left untouched.
+    REQUIRE(resourceManager.HasResource("assets/Idle.png"));
+    REQUIRE(resourceManager.GetResource("assets/Idle.png").GetFile() ==
+            "assets/Idle.png");
+    REQUIRE(!resourceManager.HasResource("Idle.png"));
+
+    REQUIRE(assetElement.HasChild("objectAssets"));
+    auto &objectAssetsElement = assetElement.GetChild("objectAssets");
+    objectAssetsElement.ConsiderAsArrayOf("objectAsset");
+    REQUIRE(objectAssetsElement.GetChildrenCount() == 1);
+    auto &objectAssetElement = objectAssetsElement.GetChild(0);
+
+    REQUIRE(objectAssetElement.HasChild("variants"));
+    auto &variantsElement = objectAssetElement.GetChild("variants");
+    variantsElement.ConsiderAsArrayOf("variant");
+    REQUIRE(variantsElement.GetChildrenCount() == 1);
+    auto &variantPairElement = variantsElement.GetChild(0);
+    REQUIRE(variantPairElement.GetStringAttribute("objectType") ==
+            "MyEventsExtension::MyEventsBasedObject");
+    REQUIRE(variantPairElement.HasChild("variant"));
+    auto &variantElement = variantPairElement.GetChild("variant");
+    REQUIRE(variantElement.GetStringAttribute("name") == "");
+    REQUIRE(variantElement.HasChild("objects"));
+    auto &objectsElement = variantElement.GetChild("objects");
+    objectsElement.ConsiderAsArrayOf("object");
+    REQUIRE(objectsElement.GetChildrenCount() == 1);
+    auto &childElement = objectsElement.GetChild(0);
+
+    REQUIRE(childElement.HasChild("animations"));
+    auto &animationsElement = childElement.GetChild("animations");
+    animationsElement.ConsiderAsArrayOf("animation");
+    REQUIRE(animationsElement.GetChildrenCount() == 1);
+    auto &animationElement = animationsElement.GetChild(0);
+
+    REQUIRE(animationElement.GetStringAttribute("name") == "Idle");
+    auto &directionsElement = animationElement.GetChild("directions");
+    directionsElement.ConsiderAsArrayOf("direction");
+    REQUIRE(directionsElement.GetChildrenCount() == 1);
+    auto &directionElement = directionsElement.GetChild(0);
+    auto &spritesElement = directionElement.GetChild("sprites");
+    spritesElement.ConsiderAsArrayOf("sprite");
+    REQUIRE(spritesElement.GetChildrenCount() == 1);
+    auto &spriteElement = spritesElement.GetChild(0);
+    REQUIRE(spriteElement.GetStringAttribute("image") == "assets/Idle.png");
+
+    REQUIRE(objectAssetElement.HasChild("requiredExtensions"));
+    auto &requiredExtensionsElement =
+        objectAssetElement.GetChild("requiredExtensions");
+    requiredExtensionsElement.ConsiderAsArrayOf("requiredExtension");
+    REQUIRE(requiredExtensionsElement.GetChildrenCount() == 1);
+    auto &requiredExtensionElement = requiredExtensionsElement.GetChild(0);
+    REQUIRE(requiredExtensionElement.GetStringAttribute("extensionName") ==
+            "MyEventsExtension");
+
+    // Resources are renamed according to asset script naming conventions.
+    REQUIRE(objectAssetElement.HasChild("resources"));
+    auto &resourcesElement = objectAssetElement.GetChild("resources");
+    resourcesElement.ConsiderAsArrayOf("resource");
+    REQUIRE(resourcesElement.GetChildrenCount() == 1);
+    {
+      auto &resourceElement = resourcesElement.GetChild(0);
+      REQUIRE(resourceElement.GetStringAttribute("name") == "assets/Idle.png");
+      REQUIRE(resourceElement.GetStringAttribute("file") == "assets/Idle.png");
+      REQUIRE(resourceElement.GetStringAttribute("kind") == "image");
+      REQUIRE(resourceElement.GetBoolAttribute("smoothed") == true);
+    }
+
+    // Resources used in object configuration are updated.
+    REQUIRE(objectAssetElement.HasChild("object"));
+    auto &objectElement = objectAssetElement.GetChild("object");
+    REQUIRE(objectElement.GetStringAttribute("name") == "MyObject");
+    REQUIRE(objectElement.GetStringAttribute("type") ==
+            "MyEventsExtension::MyEventsBasedObject");
+  }
+
+  SECTION("Can serialize custom objects as assets with children overriding") {
     gd::Platform platform;
     gd::Project project;
     SetupProjectWithDummyPlatform(project, platform);
@@ -59,6 +184,8 @@ TEST_CASE("ObjectAssetSerializer", "[common]") {
     auto &configuration = object.GetConfiguration();
     auto *customObjectConfiguration =
         dynamic_cast<gd::CustomObjectConfiguration *>(&configuration);
+    customObjectConfiguration
+        ->SetMarkedAsOverridingEventsBasedObjectChildrenConfiguration(true);
     auto *spriteConfiguration = dynamic_cast<gd::SpriteObject *>(
         &customObjectConfiguration->GetChildObjectConfiguration("MyChild"));
     REQUIRE(spriteConfiguration != nullptr);

Core/tests/ObjectsContainersList.cpp

@@ -150,7 +150,7 @@ TEST_CASE("ObjectContainersList (GetTypeOfObject)", "[common]") {
     gd::Object &object1 = layout.GetObjects().InsertNewObject(
         project, "MyExtension::Sprite", "MyObject1", 0);
     gd::Object &object2 = layout.GetObjects().InsertNewObject(
-        project, "FakeObjectWithDefaultBehavior", "MyObject2", 0);
+        project, "MyExtension::FakeObjectWithDefaultBehavior", "MyObject2", 0);
 
     auto &group = layout.GetObjects().GetObjectGroups().InsertNew("MyGroup", 0);
     group.AddObject(object1.GetName());

Core/tests/PropertyFunctionGenerator.cpp

@@ -139,8 +139,8 @@ TEST_CASE("PropertyFunctionGenerator", "[common]") {
         .SetLabel("Dot shape")
         .SetDescription("The shape is used for collision.")
         .SetGroup("Movement");
-    property.GetExtraInfo().push_back("Dot shape");
-    property.GetExtraInfo().push_back("Bounding disk");
+    property.AddChoice("DotShape", "Dot shape");
+    property.AddChoice("BoundingDisk", "Bounding disk");
 
     gd::PropertyFunctionGenerator::GenerateBehaviorGetterAndSetter(
         project, extension, behavior, property, false);
@@ -157,7 +157,7 @@ TEST_CASE("PropertyFunctionGenerator", "[common]") {
             gd::EventsFunction::ExpressionAndCondition);
     REQUIRE(getter.GetExpressionType().GetName() == "stringWithSelector");
     REQUIRE(getter.GetExpressionType().GetExtraInfo() ==
-            "[\"Dot shape\",\"Bounding disk\"]");
+            "[\"DotShape\",\"BoundingDisk\"]");
   }
 
   SECTION("Can generate functions for a boolean property in a behavior") {
@@ -386,8 +386,8 @@ TEST_CASE("PropertyFunctionGenerator", "[common]") {
         .SetLabel("Dot shape")
         .SetDescription("The shape is used for collision.")
         .SetGroup("Movement");
-    property.GetExtraInfo().push_back("Dot shape");
-    property.GetExtraInfo().push_back("Bounding disk");
+    property.AddChoice("DotShape", "Dot shape");
+    property.AddChoice("BoundingDisk", "Bounding disk");
 
     gd::PropertyFunctionGenerator::GenerateObjectGetterAndSetter(
         project, extension, object, property);
@@ -404,7 +404,7 @@ TEST_CASE("PropertyFunctionGenerator", "[common]") {
             gd::EventsFunction::ExpressionAndCondition);
     REQUIRE(getter.GetExpressionType().GetName() == "stringWithSelector");
     REQUIRE(getter.GetExpressionType().GetExtraInfo() ==
-            "[\"Dot shape\",\"Bounding disk\"]");
+            "[\"DotShape\",\"BoundingDisk\"]");
   }
 
   SECTION("Can generate functions for a boolean property in an object") {

Core/tests/WholeProjectRefactorer-ApplyRefactoringForVariablesContainer.cpp

@@ -1072,6 +1072,99 @@ TEST_CASE("WholeProjectRefactorer::ApplyRefactoringForVariablesContainer",
     REQUIRE(instance.GetVariables().Get("MyRenamedVariable").GetValue() == 456);
   }
 
+  SECTION("Can rename an object variable (in events-based object)") {
+    gd::Project project;
+    gd::Platform platform;
+    SetupProjectWithDummyPlatform(project, platform);
+
+    auto &eventsExtension =
+        project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+    auto &eventsBasedObject = eventsExtension.GetEventsBasedObjects().InsertNew(
+        "MyEventsBasedObject", 0);
+    auto &object = eventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyExtension::Sprite", "MyChildObject", 0);
+    object.GetVariables().InsertNew("MyVariable").SetValue(123);
+    auto &instance =
+        eventsBasedObject.GetInitialInstances().InsertNewInitialInstance();
+    instance.SetObjectName("MyChildObject");
+    instance.GetVariables().InsertNew("MyVariable").SetValue(456);
+
+    auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+        eventsBasedObject.GetDefaultVariant(), 0);
+    gd::InitialInstance *variantInstance = nullptr;
+    variant.GetInitialInstances().IterateOverInstances(
+        [&variantInstance](gd::InitialInstance &instance) {
+          variantInstance = &instance;
+          return true;
+        });
+    REQUIRE(variantInstance != nullptr);
+    variant.GetObjects()
+        .GetObject("MyChildObject")
+        .GetVariables()
+        .Get("MyVariable")
+        .SetValue(111);
+    variantInstance->GetVariables().Get("MyVariable").SetValue(222);
+
+    auto &objectFunction =
+        eventsBasedObject.GetEventsFunctions().InsertNewEventsFunction(
+            "MyObjectEventsFunction", 0);
+    gd::StandardEvent &event = dynamic_cast<gd::StandardEvent &>(
+        objectFunction.GetEvents().InsertNewEvent(
+            project, "BuiltinCommonInstructions::Standard"));
+
+    {
+      gd::Instruction action;
+      action.SetType("SetNumberObjectVariable");
+      action.SetParametersCount(4);
+      action.SetParameter(0, gd::Expression("MyChildObject"));
+      action.SetParameter(1, gd::Expression("MyVariable"));
+      action.SetParameter(2, gd::Expression("="));
+      action.SetParameter(3, gd::Expression("MyChildObject.MyVariable"));
+      event.GetActions().Insert(action);
+    }
+
+    // Do the changes and launch the refactoring.
+    object.GetVariables().ResetPersistentUuid();
+    gd::SerializerElement originalSerializedVariables;
+    object.GetVariables().SerializeTo(originalSerializedVariables);
+
+    object.GetVariables().Rename("MyVariable", "MyRenamedVariable");
+    auto changeset =
+        gd::WholeProjectRefactorer::ComputeChangesetForVariablesContainer(
+            originalSerializedVariables, object.GetVariables());
+
+    REQUIRE(changeset.oldToNewVariableNames.size() == 1);
+
+    gd::WholeProjectRefactorer::ApplyRefactoringForObjectVariablesContainer(
+        project, object.GetVariables(), eventsBasedObject.GetInitialInstances(),
+        object.GetName(), changeset, originalSerializedVariables);
+    gd::ObjectVariableHelper::ApplyChangesToVariants(
+        eventsBasedObject, "MyChildObject", changeset);
+
+    REQUIRE(event.GetActions()[0].GetParameter(1).GetPlainString() ==
+            "MyRenamedVariable");
+    REQUIRE(event.GetActions()[0].GetParameter(3).GetPlainString() ==
+            "MyChildObject.MyRenamedVariable");
+
+    REQUIRE(eventsBasedObject.GetObjects().HasObjectNamed("MyChildObject"));
+    REQUIRE(eventsBasedObject.GetObjects()
+                .GetObject("MyChildObject")
+                .GetVariables()
+                .Get("MyRenamedVariable")
+                .GetValue() == 123);
+    REQUIRE(instance.GetVariables().Get("MyRenamedVariable").GetValue() == 456);
+
+    REQUIRE(variant.GetObjects().HasObjectNamed("MyChildObject"));
+    REQUIRE(variant.GetObjects()
+                .GetObject("MyChildObject")
+                .GetVariables()
+                .Get("MyRenamedVariable")
+                .GetValue() == 111);
+    REQUIRE(
+        variantInstance->GetVariables().Get("MyRenamedVariable").GetValue() ==
+        222);
+  }
+
   SECTION("Can delete an object variable") {
     gd::Project project;
     gd::Platform platform;

Core/tests/WholeProjectRefactorer.cpp

@@ -1754,6 +1754,9 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
       eventsBasedObject.GetObjects().InsertNewObject(
           project, "MyExtension::Sprite", "Object2", 0);
 
+      auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+          eventsBasedObject.GetDefaultVariant(), 0);
+
       // Create the objects container for the events function
       gd::ObjectsContainer parametersObjectsContainer(
           gd::ObjectsContainer::SourceType::Function);
@@ -1765,6 +1768,10 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
       gd::WholeProjectRefactorer::ObjectOrGroupRenamedInEventsBasedObject(
           project, projectScopedContainers, eventsBasedObject, "Object1",
           "Object3", /* isObjectGroup =*/false);
+
+      REQUIRE(variant.GetObjects().HasObjectNamed("Object1") == false);
+      REQUIRE(variant.GetObjects().HasObjectNamed("Object2") == true);
+      REQUIRE(variant.GetObjects().HasObjectNamed("Object3") == true);
       REQUIRE(eventsBasedObject.GetObjects().GetObjectGroups().size() == 1);
       REQUIRE(eventsBasedObject.GetObjects().GetObjectGroups()[0].Find(
                   "Object1") == false);
@@ -1772,6 +1779,17 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
                   "Object2") == true);
       REQUIRE(eventsBasedObject.GetObjects().GetObjectGroups()[0].Find(
                   "Object3") == true);
+
+      REQUIRE(variant.GetObjects().HasObjectNamed("Object1") == false);
+      REQUIRE(variant.GetObjects().HasObjectNamed("Object2") == true);
+      REQUIRE(variant.GetObjects().HasObjectNamed("Object3") == true);
+      REQUIRE(variant.GetObjects().GetObjectGroups().size() == 1);
+      REQUIRE(variant.GetObjects().GetObjectGroups()[0].Find("Object1") ==
+              false);
+      REQUIRE(variant.GetObjects().GetObjectGroups()[0].Find("Object2") ==
+              true);
+      REQUIRE(variant.GetObjects().GetObjectGroups()[0].Find("Object3") ==
+              true);
     }
 
     SECTION("Initial instances") {
@@ -1796,6 +1814,9 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
       eventsBasedObject.GetInitialInstances().InsertInitialInstance(instance1);
       eventsBasedObject.GetInitialInstances().InsertInitialInstance(instance2);
 
+      auto &variant = eventsBasedObject.GetVariants().InsertVariant(
+          eventsBasedObject.GetDefaultVariant(), 0);
+
       // Create the objects container for the events function
       gd::ObjectsContainer parametersObjectsContainer(
           gd::ObjectsContainer::SourceType::Function);
@@ -1807,10 +1828,16 @@ TEST_CASE("WholeProjectRefactorer", "[common]") {
       gd::WholeProjectRefactorer::ObjectOrGroupRenamedInEventsBasedObject(
           project, projectScopedContainers, eventsBasedObject, "Object1",
           "Object3", /* isObjectGroup =*/false);
+
       REQUIRE(eventsBasedObject.GetInitialInstances().HasInstancesOfObject(
                   "Object1") == false);
       REQUIRE(eventsBasedObject.GetInitialInstances().HasInstancesOfObject(
                   "Object3") == true);
+
+      REQUIRE(variant.GetInitialInstances().HasInstancesOfObject("Object1") ==
+              false);
+      REQUIRE(variant.GetInitialInstances().HasInstancesOfObject("Object3") ==
+              true);
     }
 
     SECTION("Events") {

Extensions/3D/A_RuntimeObject3D.ts

@@ -5,8 +5,6 @@ namespace gdjs {
   type Object3DNetworkSyncDataType = {
     // z is position on the Z axis, different from zo, which is Z order
     z: number;
-    w: number;
-    h: number;
     d: number;
     rx: number;
     ry: number;
@@ -116,8 +114,6 @@ namespace gdjs {
       return {
         ...super.getNetworkSyncData(),
         z: this.getZ(),
-        w: this.getWidth(),
-        h: this.getHeight(),
         d: this.getDepth(),
         rx: this.getRotationX(),
         ry: this.getRotationY(),
@@ -130,8 +126,6 @@ namespace gdjs {
     updateFromNetworkSyncData(networkSyncData: Object3DNetworkSyncData) {
       super.updateFromNetworkSyncData(networkSyncData);
       if (networkSyncData.z !== undefined) this.setZ(networkSyncData.z);
-      if (networkSyncData.w !== undefined) this.setWidth(networkSyncData.w);
-      if (networkSyncData.h !== undefined) this.setHeight(networkSyncData.h);
       if (networkSyncData.d !== undefined) this.setDepth(networkSyncData.d);
       if (networkSyncData.rx !== undefined)
         this.setRotationX(networkSyncData.rx);

Extensions/3D/Cube3DRuntimeObject.ts

@@ -25,6 +25,8 @@ namespace gdjs {
       topFaceVisible: boolean;
       bottomFaceVisible: boolean;
       tint: string | undefined;
+      isCastingShadow: boolean;
+      isReceivingShadow: boolean;
       materialType: 'Basic' | 'StandardWithoutMetalness';
     };
   }
@@ -71,8 +73,10 @@ namespace gdjs {
       string,
     ];
     _materialType: gdjs.Cube3DRuntimeObject.MaterialType =
-      gdjs.Cube3DRuntimeObject.MaterialType.Basic;
+      gdjs.Cube3DRuntimeObject.MaterialType.StandardWithoutMetalness;
     _tint: string;
+    _isCastingShadow: boolean = true;
+    _isReceivingShadow: boolean = true;
 
     constructor(
       instanceContainer: gdjs.RuntimeInstanceContainer,
@@ -121,6 +125,8 @@ namespace gdjs {
       ];
 
       this._tint = objectData.content.tint || '255;255;255';
+      this._isCastingShadow = objectData.content.isCastingShadow || false;
+      this._isReceivingShadow = objectData.content.isReceivingShadow || false;
 
       this._materialType = this._convertMaterialType(
         objectData.content.materialType
@@ -430,6 +436,18 @@ namespace gdjs {
       ) {
         this.setMaterialType(newObjectData.content.materialType);
       }
+      if (
+        oldObjectData.content.isCastingShadow !==
+        newObjectData.content.isCastingShadow
+      ) {
+        this.updateShadowCasting(newObjectData.content.isCastingShadow);
+      }
+      if (
+        oldObjectData.content.isReceivingShadow !==
+        newObjectData.content.isReceivingShadow
+      ) {
+        this.updateShadowReceiving(newObjectData.content.isReceivingShadow);
+      }
 
       return true;
     }
@@ -531,6 +549,14 @@ namespace gdjs {
       this._materialType = newMaterialType;
       this._renderer._updateMaterials();
     }
+    updateShadowCasting(value: boolean) {
+      this._isCastingShadow = value;
+      this._renderer.updateShadowCasting();
+    }
+    updateShadowReceiving(value: boolean) {
+      this._isReceivingShadow = value;
+      this._renderer.updateShadowReceiving();
+    }
   }
 
   export namespace Cube3DRuntimeObject {

Extensions/3D/Cube3DRuntimeObjectPixiRenderer.ts

@@ -81,13 +81,14 @@ namespace gdjs {
         .map((_, index) =>
           getFaceMaterial(runtimeObject, materialIndexToFaceIndex[index])
         );
-
       const boxMesh = new THREE.Mesh(geometry, materials);
 
       super(runtimeObject, instanceContainer, boxMesh);
       this._boxMesh = boxMesh;
       this._cube3DRuntimeObject = runtimeObject;
 
+      boxMesh.receiveShadow = this._cube3DRuntimeObject._isReceivingShadow;
+      boxMesh.castShadow = this._cube3DRuntimeObject._isCastingShadow;
       this.updateSize();
       this.updatePosition();
       this.updateRotation();
@@ -114,6 +115,13 @@ namespace gdjs {
         new THREE.BufferAttribute(new Float32Array(tints), 3)
       );
     }
+    updateShadowCasting() {
+      this._boxMesh.castShadow = this._cube3DRuntimeObject._isCastingShadow;
+    }
+    updateShadowReceiving() {
+      this._boxMesh.receiveShadow =
+        this._cube3DRuntimeObject._isReceivingShadow;
+    }
 
     updateFace(faceIndex: integer) {
       const materialIndex = faceIndexToMaterialIndex[faceIndex];

Extensions/3D/CustomRuntimeObject3D.ts

@@ -1,4 +1,12 @@
 namespace gdjs {
+  type CustomObject3DNetworkSyncDataType = CustomObjectNetworkSyncDataType & {
+    z: float;
+    d: float;
+    rx: float;
+    ry: float;
+    ifz: boolean;
+  };
+
   /**
    * Base class for 3D custom objects.
    */
@@ -34,7 +42,6 @@ namespace gdjs {
       objectData: gdjs.Object3DData & gdjs.CustomObjectConfiguration
     ) {
       super(parent, objectData);
-      this._renderer.reinitialize(this, parent);
     }
 
     protected override _createRender() {
@@ -78,6 +85,30 @@ namespace gdjs {
       }
     }
 
+    getNetworkSyncData(): CustomObject3DNetworkSyncDataType {
+      return {
+        ...super.getNetworkSyncData(),
+        z: this.getZ(),
+        d: this.getDepth(),
+        rx: this.getRotationX(),
+        ry: this.getRotationY(),
+        ifz: this.isFlippedZ(),
+      };
+    }
+
+    updateFromNetworkSyncData(
+      networkSyncData: CustomObject3DNetworkSyncDataType
+    ): void {
+      super.updateFromNetworkSyncData(networkSyncData);
+      if (networkSyncData.z !== undefined) this.setZ(networkSyncData.z);
+      if (networkSyncData.d !== undefined) this.setDepth(networkSyncData.d);
+      if (networkSyncData.rx !== undefined)
+        this.setRotationX(networkSyncData.rx);
+      if (networkSyncData.ry !== undefined)
+        this.setRotationY(networkSyncData.ry);
+      if (networkSyncData.ifz !== undefined) this.flipZ(networkSyncData.ifz);
+    }
+
     /**
      * Set the object position on the Z axis.
      */

Extensions/3D/CustomRuntimeObject3DRenderer.ts

@@ -44,10 +44,7 @@ namespace gdjs {
     ) {
       this._object = object;
       this._isContainerDirty = true;
-      const layer = parent.getLayer('');
-      if (layer) {
-        layer.getRenderer().add3DRendererObject(this._threeGroup);
-      }
+      this._threeGroup.clear();
     }
 
     _updateThreeGroup() {

Extensions/3D/DirectionalLight.ts

@@ -6,6 +6,7 @@ namespace gdjs {
     r: number;
     t: string;
   }
+  const shadowHelper = false;
   gdjs.PixiFiltersTools.registerFilterCreator(
     'Scene3D::DirectionalLight',
     new (class implements gdjs.PixiFiltersTools.FilterCreator {
@@ -17,19 +18,63 @@ namespace gdjs {
           return new gdjs.PixiFiltersTools.EmptyFilter();
         }
         return new (class implements gdjs.PixiFiltersTools.Filter {
-          light: THREE.DirectionalLight;
-          rotationObject: THREE.Group;
-          _isEnabled: boolean = false;
-          top: string = 'Y-';
-          elevation: float = 45;
-          rotation: float = 0;
+          private _top: string = 'Z+';
+          private _elevation: float = 45;
+          private _rotation: float = 0;
+          private _shadowMapSize: float = 1024;
+          private _minimumShadowBias: float = 0;
+          private _distanceFromCamera: float = 1500;
+          private _frustumSize: float = 4000;
+
+          private _isEnabled: boolean = false;
+          private _light: THREE.DirectionalLight;
+          private _shadowMapDirty = true;
+          private _shadowCameraDirty = true;
+          private _shadowCameraHelper: THREE.CameraHelper | null;
 
           constructor() {
-            this.light = new THREE.DirectionalLight();
-            this.light.position.set(1, 0, 0);
-            this.rotationObject = new THREE.Group();
-            this.rotationObject.add(this.light);
-            this.updateRotation();
+            this._light = new THREE.DirectionalLight();
+
+            if (shadowHelper) {
+              this._shadowCameraHelper = new THREE.CameraHelper(
+                this._light.shadow.camera
+              );
+            } else {
+              this._shadowCameraHelper = null;
+            }
+
+            this._light.shadow.camera.updateProjectionMatrix();
+          }
+
+          private _updateShadowCamera(): void {
+            if (!this._shadowCameraDirty) {
+              return;
+            }
+            this._shadowCameraDirty = false;
+
+            this._light.shadow.camera.near = 1;
+            this._light.shadow.camera.far = this._distanceFromCamera + 10000;
+            this._light.shadow.camera.right = this._frustumSize / 2;
+            this._light.shadow.camera.left = -this._frustumSize / 2;
+            this._light.shadow.camera.top = this._frustumSize / 2;
+            this._light.shadow.camera.bottom = -this._frustumSize / 2;
+          }
+
+          private _updateShadowMapSize(): void {
+            if (!this._shadowMapDirty) {
+              return;
+            }
+            this._shadowMapDirty = false;
+
+            this._light.shadow.mapSize.set(
+              this._shadowMapSize,
+              this._shadowMapSize
+            );
+
+            // Force the recreation of the shadow map texture:
+            this._light.shadow.map?.dispose();
+            this._light.shadow.map = null;
+            this._light.shadow.needsUpdate = true;
           }
 
           isEnabled(target: EffectsTarget): boolean {
@@ -53,7 +98,12 @@ namespace gdjs {
             if (!scene) {
               return false;
             }
-            scene.add(this.rotationObject);
+            scene.add(this._light);
+            scene.add(this._light.target);
+            if (this._shadowCameraHelper) {
+              scene.add(this._shadowCameraHelper);
+            }
+
             this._isEnabled = true;
             return true;
           }
@@ -65,82 +115,164 @@ namespace gdjs {
             if (!scene) {
               return false;
             }
-            scene.remove(this.rotationObject);
+            scene.remove(this._light);
+            scene.remove(this._light.target);
+            if (this._shadowCameraHelper) {
+              scene.remove(this._shadowCameraHelper);
+            }
             this._isEnabled = false;
             return true;
           }
-          updatePreRender(target: gdjs.EffectsTarget): any {}
+          updatePreRender(target: gdjs.EffectsTarget): any {
+            // Apply any update to the camera or shadow map size.
+            this._updateShadowCamera();
+            this._updateShadowMapSize();
+
+            // Avoid shadow acne due to depth buffer precision.
+            const biasMultiplier =
+              this._shadowMapSize < 1024
+                ? 2
+                : this._shadowMapSize < 2048
+                  ? 1.25
+                  : 1;
+            this._light.shadow.bias = -this._minimumShadowBias * biasMultiplier;
+
+            // Apply update to the light position and its target.
+            // By doing this, the shadows are "following" the GDevelop camera.
+            if (!target.getRuntimeLayer) {
+              return;
+            }
+            const layer = target.getRuntimeLayer();
+            const x = layer.getCameraX();
+            const y = layer.getCameraY();
+            const z = layer.getCameraZ(layer.getInitialCamera3DFieldOfView());
+
+            const roundedX = Math.floor(x / 100) * 100;
+            const roundedY = Math.floor(y / 100) * 100;
+            const roundedZ = Math.floor(z / 100) * 100;
+            if (this._top === 'Y-') {
+              const posLightX =
+                roundedX +
+                this._distanceFromCamera *
+                  Math.cos(gdjs.toRad(-this._rotation + 90)) *
+                  Math.cos(gdjs.toRad(this._elevation));
+              const posLightY =
+                roundedY -
+                this._distanceFromCamera *
+                  Math.sin(gdjs.toRad(this._elevation));
+              const posLightZ =
+                roundedZ +
+                this._distanceFromCamera *
+                  Math.sin(gdjs.toRad(-this._rotation + 90)) *
+                  Math.cos(gdjs.toRad(this._elevation));
+              this._light.position.set(posLightX, posLightY, posLightZ);
+              this._light.target.position.set(roundedX, roundedY, roundedZ);
+            } else {
+              const posLightX =
+                roundedX +
+                this._distanceFromCamera *
+                  Math.cos(gdjs.toRad(this._rotation)) *
+                  Math.cos(gdjs.toRad(this._elevation));
+              const posLightY =
+                roundedY +
+                this._distanceFromCamera *
+                  Math.sin(gdjs.toRad(this._rotation)) *
+                  Math.cos(gdjs.toRad(this._elevation));
+              const posLightZ =
+                roundedZ +
+                this._distanceFromCamera *
+                  Math.sin(gdjs.toRad(this._elevation));
+
+              this._light.position.set(posLightX, posLightY, posLightZ);
+              this._light.target.position.set(roundedX, roundedY, roundedZ);
+            }
+          }
           updateDoubleParameter(parameterName: string, value: number): void {
             if (parameterName === 'intensity') {
-              this.light.intensity = value;
+              this._light.intensity = value;
             } else if (parameterName === 'elevation') {
-              this.elevation = value;
-              this.updateRotation();
+              this._elevation = value;
             } else if (parameterName === 'rotation') {
-              this.rotation = value;
-              this.updateRotation();
+              this._rotation = value;
+            } else if (parameterName === 'distanceFromCamera') {
+              this._distanceFromCamera = value;
+            } else if (parameterName === 'frustumSize') {
+              this._frustumSize = value;
+            } else if (parameterName === 'minimumShadowBias') {
+              this._minimumShadowBias = value;
             }
           }
           getDoubleParameter(parameterName: string): number {
             if (parameterName === 'intensity') {
-              return this.light.intensity;
+              return this._light.intensity;
             } else if (parameterName === 'elevation') {
-              return this.elevation;
+              return this._elevation;
             } else if (parameterName === 'rotation') {
-              return this.rotation;
+              return this._rotation;
+            } else if (parameterName === 'distanceFromCamera') {
+              return this._distanceFromCamera;
+            } else if (parameterName === 'frustumSize') {
+              return this._frustumSize;
+            } else if (parameterName === 'minimumShadowBias') {
+              return this._minimumShadowBias;
             }
             return 0;
           }
           updateStringParameter(parameterName: string, value: string): void {
             if (parameterName === 'color') {
-              this.light.color = new THREE.Color(
+              this._light.color = new THREE.Color(
                 gdjs.rgbOrHexStringToNumber(value)
               );
             }
             if (parameterName === 'top') {
-              this.top = value;
-              this.updateRotation();
+              this._top = value;
+            }
+            if (parameterName === 'shadowQuality') {
+              if (value === 'low' && this._shadowMapSize !== 512) {
+                this._shadowMapSize = 512;
+                this._shadowMapDirty = true;
+              }
+              if (value === 'medium' && this._shadowMapSize !== 1024) {
+                this._shadowMapSize = 1024;
+                this._shadowMapDirty = true;
+              }
+              if (value === 'high' && this._shadowMapSize !== 2048) {
+                this._shadowMapSize = 2048;
+                this._shadowMapDirty = true;
+              }
             }
           }
           updateColorParameter(parameterName: string, value: number): void {
             if (parameterName === 'color') {
-              this.light.color.setHex(value);
+              this._light.color.setHex(value);
             }
           }
           getColorParameter(parameterName: string): number {
             if (parameterName === 'color') {
-              return this.light.color.getHex();
+              return this._light.color.getHex();
             }
             return 0;
           }
-          updateBooleanParameter(parameterName: string, value: boolean): void {}
-          updateRotation() {
-            if (this.top === 'Z+') {
-              // 0° is a light from the right of the screen.
-              this.rotationObject.rotation.z = gdjs.toRad(this.rotation);
-              this.rotationObject.rotation.y = -gdjs.toRad(this.elevation);
-            } else {
-              // 0° becomes a light from Z+.
-              this.rotationObject.rotation.y = gdjs.toRad(this.rotation - 90);
-              this.rotationObject.rotation.z = -gdjs.toRad(this.elevation);
+          updateBooleanParameter(parameterName: string, value: boolean): void {
+            if (parameterName === 'isCastingShadow') {
+              this._light.castShadow = value;
             }
           }
           getNetworkSyncData(): DirectionalLightFilterNetworkSyncData {
             return {
-              i: this.light.intensity,
-              c: this.light.color.getHex(),
-              e: this.elevation,
-              r: this.rotation,
-              t: this.top,
+              i: this._light.intensity,
+              c: this._light.color.getHex(),
+              e: this._elevation,
+              r: this._rotation,
+              t: this._top,
             };
           }
           updateFromNetworkSyncData(syncData: any): void {
-            this.light.intensity = syncData.i;
-            this.light.color.setHex(syncData.c);
-            this.elevation = syncData.e;
-            this.rotation = syncData.r;
-            this.top = syncData.t;
-            this.updateRotation();
+            this._light.intensity = syncData.i;
+            this._light.color.setHex(syncData.c);
+            this._elevation = syncData.e;
+            this._rotation = syncData.r;
+            this._top = syncData.t;
           }
         })();
       }

Extensions/3D/HemisphereLight.ts

@@ -18,18 +18,15 @@ namespace gdjs {
           return new gdjs.PixiFiltersTools.EmptyFilter();
         }
         return new (class implements gdjs.PixiFiltersTools.Filter {
-          light: THREE.HemisphereLight;
-          rotationObject: THREE.Group;
+          _top: string = 'Z+';
+          _elevation: float = 90;
+          _rotation: float = 0;
+
           _isEnabled: boolean = false;
-          top: string = 'Y-';
-          elevation: float = 45;
-          rotation: float = 0;
+          _light: THREE.HemisphereLight;
 
           constructor() {
-            this.light = new THREE.HemisphereLight();
-            this.light.position.set(1, 0, 0);
-            this.rotationObject = new THREE.Group();
-            this.rotationObject.add(this.light);
+            this._light = new THREE.HemisphereLight();
             this.updateRotation();
           }
 
@@ -54,7 +51,7 @@ namespace gdjs {
             if (!scene) {
               return false;
             }
-            scene.add(this.rotationObject);
+            scene.add(this._light);
             this._isEnabled = true;
             return true;
           }
@@ -66,96 +63,106 @@ namespace gdjs {
             if (!scene) {
               return false;
             }
-            scene.remove(this.rotationObject);
+            scene.remove(this._light);
             this._isEnabled = false;
             return true;
           }
           updatePreRender(target: gdjs.EffectsTarget): any {}
           updateDoubleParameter(parameterName: string, value: number): void {
             if (parameterName === 'intensity') {
-              this.light.intensity = value;
+              this._light.intensity = value;
             } else if (parameterName === 'elevation') {
-              this.elevation = value;
+              this._elevation = value;
               this.updateRotation();
             } else if (parameterName === 'rotation') {
-              this.rotation = value;
+              this._rotation = value;
               this.updateRotation();
             }
           }
           getDoubleParameter(parameterName: string): number {
             if (parameterName === 'intensity') {
-              return this.light.intensity;
+              return this._light.intensity;
             } else if (parameterName === 'elevation') {
-              return this.elevation;
+              return this._elevation;
             } else if (parameterName === 'rotation') {
-              return this.rotation;
+              return this._rotation;
             }
             return 0;
           }
           updateStringParameter(parameterName: string, value: string): void {
             if (parameterName === 'skyColor') {
-              this.light.color = new THREE.Color(
+              this._light.color = new THREE.Color(
                 gdjs.rgbOrHexStringToNumber(value)
               );
             }
             if (parameterName === 'groundColor') {
-              this.light.groundColor = new THREE.Color(
+              this._light.groundColor = new THREE.Color(
                 gdjs.rgbOrHexStringToNumber(value)
               );
             }
             if (parameterName === 'top') {
-              this.top = value;
+              this._top = value;
               this.updateRotation();
             }
           }
           updateColorParameter(parameterName: string, value: number): void {
             if (parameterName === 'skyColor') {
-              this.light.color.setHex(value);
+              this._light.color.setHex(value);
             }
             if (parameterName === 'groundColor') {
-              this.light.groundColor.setHex(value);
+              this._light.groundColor.setHex(value);
             }
           }
           getColorParameter(parameterName: string): number {
             if (parameterName === 'skyColor') {
-              return this.light.color.getHex();
+              return this._light.color.getHex();
             }
             if (parameterName === 'groundColor') {
-              return this.light.groundColor.getHex();
+              return this._light.groundColor.getHex();
             }
             return 0;
           }
           updateBooleanParameter(parameterName: string, value: boolean): void {}
           updateRotation() {
-            if (this.top === 'Z+') {
-              // 0° is a light from the right of the screen.
-              this.rotationObject.rotation.z = gdjs.toRad(this.rotation);
-              this.rotationObject.rotation.y = -gdjs.toRad(this.elevation);
+            if (this._top === 'Y-') {
+              // `rotation` at 0° becomes a light from Z+.
+              this._light.position.set(
+                Math.cos(gdjs.toRad(-this._rotation + 90)) *
+                  Math.cos(gdjs.toRad(this._elevation)),
+                -Math.sin(gdjs.toRad(this._elevation)),
+                Math.sin(gdjs.toRad(-this._rotation + 90)) *
+                  Math.cos(gdjs.toRad(this._elevation))
+              );
             } else {
-              // 0° becomes a light from Z+.
-              this.rotationObject.rotation.y = gdjs.toRad(this.rotation - 90);
-              this.rotationObject.rotation.z = -gdjs.toRad(this.elevation);
+              // `rotation` at 0° is a light from the right of the screen.
+              this._light.position.set(
+                Math.cos(gdjs.toRad(this._rotation)) *
+                  Math.cos(gdjs.toRad(this._elevation)),
+                Math.sin(gdjs.toRad(this._rotation)) *
+                  Math.cos(gdjs.toRad(this._elevation)),
+                Math.sin(gdjs.toRad(this._elevation))
+              );
             }
           }
           getNetworkSyncData(): HemisphereLightFilterNetworkSyncData {
             return {
-              i: this.light.intensity,
-              sc: this.light.color.getHex(),
-              gc: this.light.groundColor.getHex(),
-              e: this.elevation,
-              r: this.rotation,
-              t: this.top,
+              i: this._light.intensity,
+              sc: this._light.color.getHex(),
+              gc: this._light.groundColor.getHex(),
+              e: this._elevation,
+              r: this._rotation,
+              t: this._top,
             };
           }
           updateFromNetworkSyncData(
             syncData: HemisphereLightFilterNetworkSyncData
           ): void {
-            this.light.intensity = syncData.i;
-            this.light.color.setHex(syncData.sc);
-            this.light.groundColor.setHex(syncData.gc);
-            this.elevation = syncData.e;
-            this.rotation = syncData.r;
-            this.top = syncData.t;
+            this._light.intensity = syncData.i;
+            this._light.color.setHex(syncData.sc);
+            this._light.groundColor.setHex(syncData.gc);
+            this._elevation = syncData.e;
+            this._rotation = syncData.r;
+            this._top = syncData.t;
             this.updateRotation();
           }
         })();

Extensions/3D/JsExtension.js

@@ -21,7 +21,9 @@ module.exports = {
       .setExtensionInformation(
         'Scene3D',
         _('3D'),
-        _('Support for 3D in GDevelop.'),
+        _(
+          'Support for 3D in GDevelop: this provides 3D objects and the common features for all 3D objects.'
+        ),
         'Florian Rival',
         'MIT'
       )
@@ -36,7 +38,9 @@ module.exports = {
           'Base3DBehavior',
           _('3D capability'),
           'Object3D',
-          _('Move the object in 3D space.'),
+          _(
+            'Common features for all 3D objects: position in 3D space (including the Z axis, in addition to X and Y), size (including depth, in addition to width and height), rotation (on X and Y axis, in addition to the Z axis), scale (including Z axis, in addition to X and Y), flipping (on Z axis, in addition to horizontal (Y)/vertical (X) flipping).'
+          ),
           '',
           'res/conditions/3d_box.svg',
           'Base3DBehavior',
@@ -158,7 +162,12 @@ module.exports = {
         )
         .addParameter('object', _('3D object'), '', false)
         .addParameter('behavior', _('Behavior'), 'Base3DBehavior')
-        .useStandardParameters('number', gd.ParameterOptions.makeNewOptions())
+        .useStandardParameters(
+          'number',
+          gd.ParameterOptions.makeNewOptions().setDescription(
+            _('Angle (in degrees)')
+          )
+        )
         .setFunctionName('setRotationX')
         .setGetter('getRotationX');
 
@@ -174,7 +183,12 @@ module.exports = {
         )
         .addParameter('object', _('3D object'), '', false)
         .addParameter('behavior', _('Behavior'), 'Base3DBehavior')
-        .useStandardParameters('number', gd.ParameterOptions.makeNewOptions())
+        .useStandardParameters(
+          'number',
+          gd.ParameterOptions.makeNewOptions().setDescription(
+            _('Angle (in degrees)')
+          )
+        )
         .setFunctionName('setRotationY')
         .setGetter('getRotationY');
 
@@ -192,7 +206,7 @@ module.exports = {
         )
         .addParameter('object', _('3D object'), '', false)
         .addParameter('behavior', _('Behavior'), 'Base3DBehavior')
-        .addParameter('number', _('Rotation angle'), '', false)
+        .addParameter('number', _('Angle to add (in degrees)'), '', false)
         .markAsAdvanced()
         .setFunctionName('turnAroundX');
 
@@ -210,7 +224,7 @@ module.exports = {
         )
         .addParameter('object', _('3D object'), '', false)
         .addParameter('behavior', _('Behavior'), 'Base3DBehavior')
-        .addParameter('number', _('Rotation angle'), '', false)
+        .addParameter('number', _('Angle to add (in degrees)'), '', false)
         .markAsAdvanced()
         .setFunctionName('turnAroundY');
 
@@ -228,7 +242,7 @@ module.exports = {
         )
         .addParameter('object', _('3D object'), '', false)
         .addParameter('behavior', _('Behavior'), 'Base3DBehavior')
-        .addParameter('number', _('Rotation angle'), '', false)
+        .addParameter('number', _('Angle to add (in degrees)'), '', false)
         .markAsAdvanced()
         .setFunctionName('turnAroundZ');
     }
@@ -238,7 +252,7 @@ module.exports = {
         .addObject(
           'Model3DObject',
           _('3D Model'),
-          _('An animated 3D model.'),
+          _('An animated 3D model, useful for most elements of a 3D game.'),
           'JsPlatform/Extensions/3d_model.svg',
           new gd.Model3DObjectConfiguration()
         )
@@ -590,7 +604,12 @@ module.exports = {
           'res/conditions/3d_box.svg'
         )
         .addParameter('object', _('3D model'), 'Model3DObject', false)
-        .useStandardParameters('number', gd.ParameterOptions.makeNewOptions())
+        .useStandardParameters(
+          'number',
+          gd.ParameterOptions.makeNewOptions().setDescription(
+            _('Angle (in degrees)')
+          )
+        )
         .setHidden()
         .setFunctionName('setRotationX')
         .setGetter('getRotationX');
@@ -607,7 +626,12 @@ module.exports = {
           'res/conditions/3d_box.svg'
         )
         .addParameter('object', _('3D model'), 'Model3DObject', false)
-        .useStandardParameters('number', gd.ParameterOptions.makeNewOptions())
+        .useStandardParameters(
+          'number',
+          gd.ParameterOptions.makeNewOptions().setDescription(
+            _('Angle (in degrees)')
+          )
+        )
         .setHidden()
         .setFunctionName('setRotationY')
         .setGetter('getRotationY');
@@ -626,7 +650,7 @@ module.exports = {
           'res/conditions/3d_box.svg'
         )
         .addParameter('object', _('3D model'), 'Model3DObject', false)
-        .addParameter('number', _('Rotation angle'), '', false)
+        .addParameter('number', _('Angle to add (in degrees)'), '', false)
         .markAsAdvanced()
         .setHidden()
         .setFunctionName('turnAroundX');
@@ -645,7 +669,7 @@ module.exports = {
           'res/conditions/3d_box.svg'
         )
         .addParameter('object', _('3D model'), 'Model3DObject', false)
-        .addParameter('number', _('Rotation angle'), '', false)
+        .addParameter('number', _('Angle to add (in degrees)'), '', false)
         .markAsAdvanced()
         .setHidden()
         .setFunctionName('turnAroundY');
@@ -664,7 +688,7 @@ module.exports = {
           'res/conditions/3d_box.svg'
         )
         .addParameter('object', _('3D model'), 'Model3DObject', false)
-        .addParameter('number', _('Rotation angle'), '', false)
+        .addParameter('number', _('Angle to add (in degrees)'), '', false)
         .markAsAdvanced()
         .setHidden()
         .setFunctionName('turnAroundZ');
@@ -855,7 +879,9 @@ module.exports = {
         propertyName === 'rightFaceResourceRepeat' ||
         propertyName === 'topFaceResourceRepeat' ||
         propertyName === 'bottomFaceResourceRepeat' ||
-        propertyName === 'enableTextureTransparency'
+        propertyName === 'enableTextureTransparency' ||
+        propertyName === 'isCastingShadow' ||
+        propertyName === 'isReceivingShadow'
       ) {
         objectContent[propertyName] = newValue === '1';
         return true;
@@ -883,8 +909,8 @@ module.exports = {
         .getOrCreate('facesOrientation')
         .setValue(objectContent.facesOrientation || 'Y')
         .setType('choice')
-        .addExtraInfo('Y')
-        .addExtraInfo('Z')
+        .addChoice('Y', 'Y')
+        .addChoice('Z', 'Z')
         .setLabel(_('Faces orientation'))
         .setDescription(
           _(
@@ -944,8 +970,8 @@ module.exports = {
         .getOrCreate('backFaceUpThroughWhichAxisRotation')
         .setValue(objectContent.backFaceUpThroughWhichAxisRotation || 'X')
         .setType('choice')
-        .addExtraInfo('X')
-        .addExtraInfo('Y')
+        .addChoice('X', 'X')
+        .addChoice('Y', 'Y')
         .setLabel(_('Back face orientation'))
         .setDescription(
           _(
@@ -1079,11 +1105,29 @@ module.exports = {
 
       objectProperties
         .getOrCreate('materialType')
-        .setValue(objectContent.materialType || 'Basic')
+        .setValue(objectContent.materialType || 'StandardWithoutMetalness')
         .setType('choice')
-        .addExtraInfo('Basic')
-        .addExtraInfo('StandardWithoutMetalness')
-        .setLabel(_('Material type'));
+        .addChoice('Basic', _('Basic (no lighting, no shadows)'))
+        .addChoice(
+          'StandardWithoutMetalness',
+          _('Standard (without metalness)')
+        )
+        .setLabel(_('Material type'))
+        .setGroup(_('Lighting'));
+
+      objectProperties
+        .getOrCreate('isCastingShadow')
+        .setValue(objectContent.isCastingShadow ? 'true' : 'false')
+        .setType('boolean')
+        .setLabel(_('Shadow casting'))
+        .setGroup(_('Lighting'));
+
+      objectProperties
+        .getOrCreate('isReceivingShadow')
+        .setValue(objectContent.isReceivingShadow ? 'true' : 'false')
+        .setType('boolean')
+        .setLabel(_('Shadow receiving'))
+        .setGroup(_('Lighting'));
 
       return objectProperties;
     };
@@ -1101,7 +1145,7 @@ module.exports = {
       topFaceResourceName: '',
       bottomFaceResourceName: '',
       frontFaceVisible: true,
-      backFaceVisible: false,
+      backFaceVisible: true,
       leftFaceVisible: true,
       rightFaceVisible: true,
       topFaceVisible: true,
@@ -1112,8 +1156,10 @@ module.exports = {
       rightFaceResourceRepeat: false,
       topFaceResourceRepeat: false,
       bottomFaceResourceRepeat: false,
-      materialType: 'Basic',
+      materialType: 'StandardWithoutMetalness',
       tint: '255;255;255',
+      isCastingShadow: true,
+      isReceivingShadow: true,
     };
 
     Cube3DObject.updateInitialInstanceProperty = function (
@@ -1467,7 +1513,12 @@ module.exports = {
         'res/conditions/3d_box.svg'
       )
       .addParameter('object', _('3D cube'), 'Cube3DObject', false)
-      .useStandardParameters('number', gd.ParameterOptions.makeNewOptions())
+      .useStandardParameters(
+        'number',
+        gd.ParameterOptions.makeNewOptions().setDescription(
+          _('Angle (in degrees)')
+        )
+      )
       .setFunctionName('setRotationX')
       .setHidden()
       .setGetter('getRotationX');
@@ -1484,7 +1535,12 @@ module.exports = {
         'res/conditions/3d_box.svg'
       )
       .addParameter('object', _('3D cube'), 'Cube3DObject', false)
-      .useStandardParameters('number', gd.ParameterOptions.makeNewOptions())
+      .useStandardParameters(
+        'number',
+        gd.ParameterOptions.makeNewOptions().setDescription(
+          _('Angle (in degrees)')
+        )
+      )
       .setFunctionName('setRotationY')
       .setHidden()
       .setGetter('getRotationY');
@@ -1852,7 +1908,9 @@ module.exports = {
         .addEffect('AmbientLight')
         .setFullName(_('Ambient light'))
         .setDescription(
-          _('A light that illuminates all objects from every direction.')
+          _(
+            'A light that illuminates all objects from every direction. Often used along with a Directional light (though a Hemisphere light can be used instead of an Ambient light).'
+          )
         )
         .markAsNotWorkingForObjects()
         .markAsOnlyWorkingFor3D()
@@ -1873,7 +1931,11 @@ module.exports = {
       const effect = extension
         .addEffect('DirectionalLight')
         .setFullName(_('Directional light'))
-        .setDescription(_('A very far light source like the sun.'))
+        .setDescription(
+          _(
+            "A very far light source like the sun. This is the light to use for casting shadows for 3D objects (other lights won't emit shadows). Often used along with a Hemisphere light."
+          )
+        )
         .markAsNotWorkingForObjects()
         .markAsOnlyWorkingFor3D()
         .addIncludeFile('Extensions/3D/DirectionalLight.js');
@@ -1890,11 +1952,11 @@ module.exports = {
         .setType('number');
       properties
         .getOrCreate('top')
-        .setValue('Y-')
+        .setValue('Z+')
         .setLabel(_('3D world top'))
         .setType('choice')
-        .addExtraInfo('Y-')
         .addExtraInfo('Z+')
+        .addExtraInfo('Y-')
         .setGroup(_('Orientation'));
       properties
         .getOrCreate('elevation')
@@ -1909,6 +1971,47 @@ module.exports = {
         .setLabel(_('Rotation (in degrees)'))
         .setType('number')
         .setGroup(_('Orientation'));
+      properties
+        .getOrCreate('isCastingShadow')
+        .setValue('false')
+        .setLabel(_('Shadow casting'))
+        .setType('boolean')
+        .setGroup(_('Shadows'));
+      properties
+        .getOrCreate('shadowQuality')
+        .setValue('medium')
+        .addChoice('low', _('Low quality'))
+        .addChoice('medium', _('Medium quality'))
+        .addChoice('high', _('High quality'))
+        .setLabel(_('Shadow quality'))
+        .setType('choice')
+        .setGroup(_('Shadows'));
+      properties
+        .getOrCreate('minimumShadowBias')
+        .setValue('0')
+        .setLabel(_('Shadow bias'))
+        .setDescription(
+          _(
+            'Use this to avoid "shadow acne" due to depth buffer precision. Choose a value small enough like 0.001 to avoid creating distance between shadows and objects but not too small to avoid shadow glitches on low/medium quality. This value is used for high quality, and multiplied by 1.25 for medium quality and 2 for low quality.'
+          )
+        )
+        .setType('number')
+        .setGroup(_('Shadows'))
+        .setAdvanced(true);
+      properties
+        .getOrCreate('frustumSize')
+        .setValue('4000')
+        .setLabel(_('Shadow frustum size'))
+        .setType('number')
+        .setGroup(_('Shadows'))
+        .setAdvanced(true);
+      properties
+        .getOrCreate('distanceFromCamera')
+        .setValue('1500')
+        .setLabel(_("Distance from layer's camera"))
+        .setType('number')
+        .setGroup(_('Shadows'))
+        .setAdvanced(true);
     }
     {
       const effect = extension
@@ -1916,7 +2019,7 @@ module.exports = {
         .setFullName(_('Hemisphere light'))
         .setDescription(
           _(
-            'A light that illuminates objects from every direction with a gradient.'
+            'A light that illuminates objects from every direction with a gradient. Often used along with a Directional light.'
           )
         )
         .markAsNotWorkingForObjects()
@@ -1940,11 +2043,11 @@ module.exports = {
         .setType('number');
       properties
         .getOrCreate('top')
-        .setValue('Y-')
+        .setValue('Z+')
         .setLabel(_('3D world top'))
         .setType('choice')
-        .addExtraInfo('Y-')
         .addExtraInfo('Z+')
+        .addExtraInfo('Y-')
         .setGroup(_('Orientation'));
       properties
         .getOrCreate('elevation')
@@ -1960,6 +2063,48 @@ module.exports = {
         .setType('number')
         .setGroup(_('Orientation'));
     }
+    {
+      const effect = extension
+        .addEffect('Skybox')
+        .setFullName(_('Skybox'))
+        .setDescription(
+          _('Display a background on a cube surrounding the scene.')
+        )
+        .markAsNotWorkingForObjects()
+        .markAsOnlyWorkingFor3D()
+        .addIncludeFile('Extensions/3D/Skybox.js');
+      const properties = effect.getProperties();
+      properties
+        .getOrCreate('rightFaceResourceName')
+        .setType('resource')
+        .addExtraInfo('image')
+        .setLabel(_('Right face (X+)'));
+      properties
+        .getOrCreate('leftFaceResourceName')
+        .setType('resource')
+        .addExtraInfo('image')
+        .setLabel(_('Left face (X-)'));
+      properties
+        .getOrCreate('bottomFaceResourceName')
+        .setType('resource')
+        .addExtraInfo('image')
+        .setLabel(_('Bottom face (Y+)'));
+      properties
+        .getOrCreate('topFaceResourceName')
+        .setType('resource')
+        .addExtraInfo('image')
+        .setLabel(_('Top face (Y-)'));
+      properties
+        .getOrCreate('frontFaceResourceName')
+        .setType('resource')
+        .addExtraInfo('image')
+        .setLabel(_('Front face (Z+)'));
+      properties
+        .getOrCreate('backFaceResourceName')
+        .setType('resource')
+        .addExtraInfo('image')
+        .setLabel(_('Back face (Z-)'));
+    }
     {
       const effect = extension
         .addEffect('HueAndSaturation')
@@ -3206,6 +3351,8 @@ module.exports = {
 
         this._threeObject = new THREE.Group();
         this._threeObject.rotation.order = 'ZYX';
+        this._threeObject.castShadow = true;
+        this._threeObject.receiveShadow = true;
         this._threeGroup.add(this._threeObject);
       }
 

Extensions/3D/Model3DObjectConfiguration.cpp

@@ -23,7 +23,7 @@ Model3DObjectConfiguration::Model3DObjectConfiguration()
     : width(100), height(100), depth(100), rotationX(0), rotationY(0),
       rotationZ(0), modelResourceName(""), materialType("StandardWithoutMetalness"),
       originLocation("ModelOrigin"), centerLocation("ModelOrigin"),
-      keepAspectRatio(true), crossfadeDuration(0.1f) {}
+      keepAspectRatio(true), crossfadeDuration(0.1f), isCastingShadow(true), isReceivingShadow(true) {}
 
 bool Model3DObjectConfiguration::UpdateProperty(const gd::String &propertyName,
                                                 const gd::String &newValue) {
@@ -75,6 +75,16 @@ bool Model3DObjectConfiguration::UpdateProperty(const gd::String &propertyName,
     crossfadeDuration = newValue.To<double>();
     return true;
   }
+  if(propertyName == "isCastingShadow")
+  {
+    isCastingShadow = newValue == "1";
+    return true;
+  }
+  if(propertyName == "isReceivingShadow")
+  {
+    isReceivingShadow = newValue == "1";
+    return true;
+  }
 
   return false;
 }
@@ -143,19 +153,20 @@ Model3DObjectConfiguration::GetProperties() const {
   objectProperties["materialType"]
       .SetValue(materialType.empty() ? "Basic" : materialType)
       .SetType("choice")
-      .AddExtraInfo("Basic")
-      .AddExtraInfo("StandardWithoutMetalness")
-      .AddExtraInfo("KeepOriginal")
-      .SetLabel(_("Material"));
+      .AddChoice("Basic", _("Basic (no lighting, no shadows)"))
+      .AddChoice("StandardWithoutMetalness", _("Standard (without metalness)"))
+      .AddChoice("KeepOriginal", _("Keep original"))
+      .SetLabel(_("Material"))
+      .SetGroup(_("Lighting"));
 
   objectProperties["originLocation"]
       .SetValue(originLocation.empty() ? "TopLeft" : originLocation)
       .SetType("choice")
-      .AddExtraInfo("ModelOrigin")
-      .AddExtraInfo("TopLeft")
-      .AddExtraInfo("ObjectCenter")
-      .AddExtraInfo("BottomCenterZ")
-      .AddExtraInfo("BottomCenterY")
+      .AddChoice("ModelOrigin", _("Model origin"))
+      .AddChoice("TopLeft", _("Top left"))
+      .AddChoice("ObjectCenter", _("Object center"))
+      .AddChoice("BottomCenterZ", _("Bottom center (Z)"))
+      .AddChoice("BottomCenterY", _("Bottom center (Y)"))
       .SetLabel(_("Origin point"))
       .SetGroup(_("Points"))
       .SetAdvanced(true);
@@ -163,10 +174,10 @@ Model3DObjectConfiguration::GetProperties() const {
   objectProperties["centerLocation"]
       .SetValue(centerLocation.empty() ? "ObjectCenter" : centerLocation)
       .SetType("choice")
-      .AddExtraInfo("ModelOrigin")
-      .AddExtraInfo("ObjectCenter")
-      .AddExtraInfo("BottomCenterZ")
-      .AddExtraInfo("BottomCenterY")
+      .AddChoice("ModelOrigin", _("Model origin"))
+      .AddChoice("ObjectCenter", _("Object center"))
+      .AddChoice("BottomCenterZ", _("Bottom center (Z)"))
+      .AddChoice("BottomCenterY", _("Bottom center (Y)"))
       .SetLabel(_("Center point"))
       .SetGroup(_("Points"))
       .SetAdvanced(true);
@@ -178,6 +189,20 @@ Model3DObjectConfiguration::GetProperties() const {
       .SetGroup(_("Animations"))
       .SetMeasurementUnit(gd::MeasurementUnit::GetSecond());
 
+  objectProperties["isCastingShadow"]
+      .SetValue(isCastingShadow ? "true" : "false")
+      .SetType("boolean")
+      .SetLabel(_("Shadow casting"))
+      .SetGroup(_("Lighting"));
+
+  objectProperties["isReceivingShadow"]
+      .SetValue(isReceivingShadow ? "true" : "false")
+      .SetType("boolean")
+      .SetLabel(_("Shadow receiving"))
+      .SetGroup(_("Lighting"));
+
+
+
   return objectProperties;
 }
 
@@ -210,6 +235,8 @@ void Model3DObjectConfiguration::DoUnserializeFrom(
   centerLocation = content.GetStringAttribute("centerLocation");
   keepAspectRatio = content.GetBoolAttribute("keepAspectRatio");
   crossfadeDuration = content.GetDoubleAttribute("crossfadeDuration");
+  isCastingShadow = content.GetBoolAttribute("isCastingShadow");
+  isReceivingShadow = content.GetBoolAttribute("isReceivingShadow");
 
   RemoveAllAnimations();
   auto &animationsElement = content.GetChild("animations");
@@ -239,6 +266,8 @@ void Model3DObjectConfiguration::DoSerializeTo(
   content.SetAttribute("centerLocation", centerLocation);
   content.SetAttribute("keepAspectRatio", keepAspectRatio);
   content.SetAttribute("crossfadeDuration", crossfadeDuration);
+  content.SetAttribute("isCastingShadow", isCastingShadow);
+  content.SetAttribute("isReceivingShadow", isReceivingShadow);
 
   auto &animationsElement = content.AddChild("animations");
   animationsElement.ConsiderAsArrayOf("animation");

Extensions/3D/Model3DObjectConfiguration.h

@@ -160,6 +160,8 @@ public:
   const gd::String& GetCenterLocation() const { return centerLocation; };
 
   bool shouldKeepAspectRatio() const { return keepAspectRatio; };
+  bool shouldCastShadow() const { return isCastingShadow; };
+  bool shouldReceiveShadow() const { return isReceivingShadow; };
   ///@}
 
 protected:
@@ -182,6 +184,8 @@ private:
   gd::String centerLocation;
 
   bool keepAspectRatio;
+  bool isCastingShadow;
+  bool isReceivingShadow;
 
   std::vector<Model3DAnimation> animations;
   static Model3DAnimation badAnimation; //< Bad animation when an out of bound

Extensions/3D/Model3DRuntimeObject.ts

@@ -38,6 +38,8 @@ namespace gdjs {
         | 'BottomCenterY';
       animations: Model3DAnimation[];
       crossfadeDuration: float;
+      isCastingShadow: boolean;
+      isReceivingShadow: boolean;
     };
   }
 
@@ -101,6 +103,8 @@ namespace gdjs {
     _animationSpeedScale: float = 1;
     _animationPaused: boolean = false;
     _crossfadeDuration: float = 0;
+    _isCastingShadow: boolean = true;
+    _isReceivingShadow: boolean = true;
 
     constructor(
       instanceContainer: gdjs.RuntimeInstanceContainer,
@@ -123,6 +127,8 @@ namespace gdjs {
         objectData.content.materialType
       );
 
+      this.setIsCastingShadow(objectData.content.isCastingShadow);
+      this.setIsReceivingShadow(objectData.content.isReceivingShadow);
       this.onModelChanged(objectData);
 
       this._crossfadeDuration = objectData.content.crossfadeDuration || 0;
@@ -195,6 +201,18 @@ namespace gdjs {
           newObjectData.content.centerLocation
         );
       }
+      if (
+        oldObjectData.content.isCastingShadow !==
+        newObjectData.content.isCastingShadow
+      ) {
+        this.setIsCastingShadow(newObjectData.content.isCastingShadow);
+      }
+      if (
+        oldObjectData.content.isReceivingShadow !==
+        newObjectData.content.isReceivingShadow
+      ) {
+        this.setIsReceivingShadow(newObjectData.content.isReceivingShadow);
+      }
       return true;
     }
 
@@ -358,6 +376,16 @@ namespace gdjs {
       return this._renderer.hasAnimationEnded();
     }
 
+    setIsCastingShadow(value: boolean): void {
+      this._isCastingShadow = value;
+      this._renderer._updateShadow();
+    }
+
+    setIsReceivingShadow(value: boolean): void {
+      this._isReceivingShadow = value;
+      this._renderer._updateShadow();
+    }
+
     setCrossfadeDuration(duration: number): void {
       if (this._crossfadeDuration === duration) return;
       this._crossfadeDuration = duration;

Extensions/3D/Model3DRuntimeObject3DRenderer.ts

@@ -286,6 +286,7 @@ namespace gdjs {
       this.get3DRendererObject().remove(this._threeObject);
       this.get3DRendererObject().add(threeObject);
       this._threeObject = threeObject;
+      this._updateShadow();
 
       // Start the current animation on the new 3D object.
       this._animationMixer = new THREE.AnimationMixer(root);
@@ -323,6 +324,13 @@ namespace gdjs {
       return this._originalModel.animations[animationIndex].name;
     }
 
+    _updateShadow() {
+      this._threeObject.traverse((child) => {
+        child.castShadow = this._model3DRuntimeObject._isCastingShadow;
+        child.receiveShadow = this._model3DRuntimeObject._isReceivingShadow;
+      });
+    }
+
     /**
      * Return true if animation has ended.
      * The animation had ended if:

Extensions/3D/Skybox.ts

@@ -0,0 +1,102 @@
+namespace gdjs {
+  interface SkyboxFilterNetworkSyncData {}
+  gdjs.PixiFiltersTools.registerFilterCreator(
+    'Scene3D::Skybox',
+    new (class implements gdjs.PixiFiltersTools.FilterCreator {
+      makeFilter(
+        target: EffectsTarget,
+        effectData: EffectData
+      ): gdjs.PixiFiltersTools.Filter {
+        if (typeof THREE === 'undefined') {
+          return new gdjs.PixiFiltersTools.EmptyFilter();
+        }
+        return new (class implements gdjs.PixiFiltersTools.Filter {
+          _cubeTexture: THREE.CubeTexture;
+          _oldBackground:
+            | THREE.CubeTexture
+            | THREE.Texture
+            | THREE.Color
+            | null = null;
+          _isEnabled: boolean = false;
+
+          constructor() {
+            this._cubeTexture = target
+              .getRuntimeScene()
+              .getGame()
+              .getImageManager()
+              .getThreeCubeTexture(
+                effectData.stringParameters.rightFaceResourceName,
+                effectData.stringParameters.leftFaceResourceName,
+                effectData.stringParameters.topFaceResourceName,
+                effectData.stringParameters.bottomFaceResourceName,
+                effectData.stringParameters.frontFaceResourceName,
+                effectData.stringParameters.backFaceResourceName
+              );
+          }
+
+          isEnabled(target: EffectsTarget): boolean {
+            return this._isEnabled;
+          }
+          setEnabled(target: EffectsTarget, enabled: boolean): boolean {
+            if (this._isEnabled === enabled) {
+              return true;
+            }
+            if (enabled) {
+              return this.applyEffect(target);
+            } else {
+              return this.removeEffect(target);
+            }
+          }
+          applyEffect(target: EffectsTarget): boolean {
+            const scene = target.get3DRendererObject() as
+              | THREE.Scene
+              | null
+              | undefined;
+            if (!scene) {
+              return false;
+            }
+            // TODO Add a background stack in LayerPixiRenderer to allow
+            // filters to stack them.
+            this._oldBackground = scene.background;
+            scene.background = this._cubeTexture;
+            if (!scene.environment) {
+              scene.environment = this._cubeTexture;
+            }
+            this._isEnabled = true;
+            return true;
+          }
+          removeEffect(target: EffectsTarget): boolean {
+            const scene = target.get3DRendererObject() as
+              | THREE.Scene
+              | null
+              | undefined;
+            if (!scene) {
+              return false;
+            }
+            scene.background = this._oldBackground;
+            scene.environment = null;
+            this._isEnabled = false;
+            return true;
+          }
+          updatePreRender(target: gdjs.EffectsTarget): any {}
+          updateDoubleParameter(parameterName: string, value: number): void {}
+          getDoubleParameter(parameterName: string): number {
+            return 0;
+          }
+          updateStringParameter(parameterName: string, value: string): void {}
+          updateColorParameter(parameterName: string, value: number): void {}
+          getColorParameter(parameterName: string): number {
+            return 0;
+          }
+          updateBooleanParameter(parameterName: string, value: boolean): void {}
+          getNetworkSyncData(): SkyboxFilterNetworkSyncData {
+            return {};
+          }
+          updateFromNetworkSyncData(
+            syncData: SkyboxFilterNetworkSyncData
+          ): void {}
+        })();
+      }
+    })()
+  );
+}