Add an action to forbid to jump again while in the air to the Platformer behavior. (#2872)

* This is useful if you want to allow to jump again in the air for a bit of time, and then forbid to jump again later (for example, to implement a "Coyote Time" feature to your player character)

Extensions/PlatformBehavior/Extension.cpp

@@ -5,8 +5,9 @@ Copyright (c) 2014-2016 Florian Rival (Florian.Rival@gmail.com)
 This project is released under the MIT License.
 */
 
-#include "GDCpp/Extensions/ExtensionBase.h"
 #include "PlatformBehavior.h"
+
+#include "GDCpp/Extensions/ExtensionBase.h"
 #include "PlatformRuntimeBehavior.h"
 #include "PlatformerObjectBehavior.h"
 #include "PlatformerObjectRuntimeBehavior.h"
@@ -381,6 +382,19 @@ void DeclarePlatformBehaviorExtension(gd::PlatformExtension& extension) {
         .SetFunctionName("SetCanJump")
         .SetIncludeFile("PlatformBehavior/PlatformerObjectRuntimeBehavior.h");
 
+    aut.AddScopedAction(
+           "SetCanNotAirJump",
+           _("Forbid jumping again in the air"),
+           _("This revokes the effect of \"Allow jumping again\". The object "
+             "is made unable to jump while in mid air. This has no effect if "
+             "the object is not in the air."),
+           _("Forbid _PARAM0_ to air jump"),
+           _("Options"),
+           "CppPlatform/Extensions/platformerobjecticon24.png",
+           "CppPlatform/Extensions/platformerobjecticon16.png")
+        .AddParameter("object", _("Object"))
+        .AddParameter("behavior", _("Behavior"), "PlatformerObjectBehavior");
+
     aut.AddCondition("CanJump",
                      _("Can jump"),
                      _("Check if the object can jump."),

Extensions/PlatformBehavior/JsExtension.cpp

@@ -119,6 +119,7 @@ class PlatformBehaviorJsExtension : public gd::PlatformExtension {
           "getCurrentJumpSpeed");
       autExpressions["CurrentJumpSpeed"].SetFunctionName("getCurrentJumpSpeed");
       autActions["PlatformBehavior::SetCanJump"].SetFunctionName("setCanJump");
+      autActions["PlatformBehavior::PlatformerObjectBehavior::SetCanNotAirJump"].SetFunctionName("setCanNotAirJump");
       autConditions["PlatformBehavior::CanJump"].SetFunctionName(
           "canJump");
       autActions["PlatformBehavior::SimulateLeftKey"].SetFunctionName(

Extensions/PlatformBehavior/platformerobjectruntimebehavior.ts

@@ -236,7 +236,9 @@ namespace gdjs {
       this._jumpKey = false;
 
       //5) Track the movement
-      this._hasReallyMoved = Math.abs(object.getX() - oldX) >= 1;
+      this._hasReallyMoved =
+        Math.abs(object.getX() - oldX) >= 1 ||
+        Math.abs(object.getY() - oldY) >= 1;
       this._lastDeltaY = object.getY() - oldY;
     }
 
@@ -999,6 +1001,15 @@ namespace gdjs {
       this._canJump = true;
     }
 
+    /**
+     * Forbid the Platformer Object to air jump.
+     */
+    setCanNotAirJump(): void {
+      if (this._state === this._jumping || this._state === this._falling) {
+        this._canJump = false;
+      }
+    }
+
     /**
      * Set if the Platformer Object can grab platforms.
      * @param enable Enable / Disable grabbing of platforms.
@@ -1135,7 +1146,8 @@ namespace gdjs {
      */
     isMoving(): boolean {
       return (
-        (this._hasReallyMoved && this._currentSpeed !== 0) ||
+        (this._hasReallyMoved &&
+          (this._currentSpeed !== 0 || this._state === this._onLadder)) ||
         this._jumping.getCurrentJumpSpeed() !== 0 ||
         this._currentFallSpeed !== 0
       );
@@ -1616,6 +1628,7 @@ namespace gdjs {
     beforeMovingY(timeDelta: float, oldX: float) {
       const behavior = this._behavior;
 
+      // TODO: we could consider supporting acceleration for ladder climbing in the future.
       if (behavior._upKey) {
         behavior._requestedDeltaY -= behavior._ladderClimbingSpeed * timeDelta;
       }

Extensions/PlatformBehavior/tests/platformerobjectruntimebehavior.spec.js

@@ -550,6 +550,11 @@ describe('gdjs.PlatformerObjectRuntimeBehavior', function () {
       );
       expect(object.getBehavior('auto1').isMoving()).to.be(false);
 
+      // Forbid to jump
+      object.getBehavior('auto1').setCanNotAirJump();
+      // It has no impact as the object is on a platform.
+      expect(object.getBehavior('auto1').canJump()).to.be(true);
+
       // Jump with sustaining as much as possible, and
       // even more (18 frames at 60fps is greater than 0.2s)
       for (let i = 0; i < 18; ++i) {
@@ -649,7 +654,7 @@ describe('gdjs.PlatformerObjectRuntimeBehavior', function () {
       );
       expect(object.getBehavior('auto1').isMoving()).to.be(false);
 
-      // Fell from the platform
+      // Fall from the platform
       for (let i = 0; i < 35; ++i) {
         object.getBehavior('auto1').simulateLeftKey();
         runtimeScene.renderAndStep(1000 / 60);
@@ -663,6 +668,96 @@ describe('gdjs.PlatformerObjectRuntimeBehavior', function () {
       expect(object.getBehavior('auto1').isFallingWithoutJumping()).to.be(true);
     });
 
+    it('can be allowed to jump in mid air', function () {
+      // Ensure the object falls on the platform
+      for (let i = 0; i < 10; ++i) {
+        runtimeScene.renderAndStep(1000 / 60);
+      }
+
+      // Check the object is on the platform
+      expect(object.getY()).to.be(-30); // -30 = -10 (platform y) + -20 (object height)
+      expect(object.getBehavior('auto1').isFalling()).to.be(false);
+      expect(object.getBehavior('auto1').isFallingWithoutJumping()).to.be(
+        false
+      );
+      expect(object.getBehavior('auto1').isMoving()).to.be(false);
+
+      // Fall from the platform
+      for (let i = 0; i < 20; ++i) {
+        object.getBehavior('auto1').simulateLeftKey();
+        runtimeScene.renderAndStep(1000 / 60);
+      }
+      // Allow to jump in mid air
+      expect(object.getBehavior('auto1').isFalling()).to.be(true);
+      object.getBehavior('auto1').setCanJump();
+      expect(object.getBehavior('auto1').canJump()).to.be(true);
+
+      // Can jump in the air
+      object.getBehavior('auto1').simulateJumpKey();
+      runtimeScene.renderAndStep(1000 / 60);
+      expect(object.getBehavior('auto1').isJumping()).to.be(true);
+      expect(object.getBehavior('auto1').isFalling()).to.be(false);
+      expect(object.getBehavior('auto1').isFallingWithoutJumping()).to.be(
+        false
+      );
+
+      for (let i = 0; i < 40; ++i) {
+        object.getBehavior('auto1').simulateLeftKey();
+        runtimeScene.renderAndStep(1000 / 60);
+      }
+      expect(object.getBehavior('auto1').isJumping()).to.be(false);
+
+      // Can no longer to jump
+      object.getBehavior('auto1').simulateJumpKey();
+      runtimeScene.renderAndStep(1000 / 60);
+      expect(object.getBehavior('auto1').isJumping()).to.be(false);
+      expect(object.getBehavior('auto1').isFalling()).to.be(true);
+      expect(object.getBehavior('auto1').isFallingWithoutJumping()).to.be(true);
+    });
+
+    it('can allow coyote time', function () {
+      // Ensure the object falls on the platform
+      for (let i = 0; i < 10; ++i) {
+        runtimeScene.renderAndStep(1000 / 60);
+      }
+
+      // Check the object is on the platform
+      expect(object.getY()).to.be(-30); // -30 = -10 (platform y) + -20 (object height)
+      expect(object.getBehavior('auto1').isFalling()).to.be(false);
+      expect(object.getBehavior('auto1').isFallingWithoutJumping()).to.be(
+        false
+      );
+      expect(object.getBehavior('auto1').isMoving()).to.be(false);
+
+      // Fall from the platform
+      for (let i = 0; i < 20; ++i) {
+        object.getBehavior('auto1').simulateLeftKey();
+        runtimeScene.renderAndStep(1000 / 60);
+      }
+      // Allow to jump
+      expect(object.getBehavior('auto1').isFalling()).to.be(true);
+      object.getBehavior('auto1').setCanJump();
+      expect(object.getBehavior('auto1').canJump()).to.be(true);
+
+      // Still falling from the platform
+      for (let i = 0; i < 4; ++i) {
+        object.getBehavior('auto1').simulateLeftKey();
+        runtimeScene.renderAndStep(1000 / 60);
+      }
+
+      // Suppose that we miss an eventual time frame or some condition.
+      // So we forbid to jump again:
+      object.getBehavior('auto1').setCanNotAirJump();
+      expect(object.getBehavior('auto1').canJump()).to.be(false);
+
+      // Can no longer to jump in mid air
+      object.getBehavior('auto1').simulateJumpKey();
+      runtimeScene.renderAndStep(1000 / 60);
+      expect(object.getBehavior('auto1').isJumping()).to.be(false);
+      expect(object.getBehavior('auto1').isFalling()).to.be(true);
+      expect(object.getBehavior('auto1').isFallingWithoutJumping()).to.be(true);
+    });
+
     it('should not grab a platform while in the ascending phase of a jump', function () {
       const topPlatform = addPlatformObject(runtimeScene);
       topPlatform.setPosition(12, -80);
@@ -1532,8 +1627,7 @@ describe('gdjs.PlatformerObjectRuntimeBehavior', function () {
         object.getBehavior('auto1').simulateUpKey();
         runtimeScene.renderAndStep(1000 / 60);
         expect(object.getBehavior('auto1').isOnLadder()).to.be(true);
-        //TODO Probably a bug, uncomment it after it's fixed
-        //expect(object.getBehavior('auto1').isMoving()).to.be(true);
+        expect(object.getBehavior('auto1').isMoving()).to.be(true);
         expect(object.getY()).to.be.below(lastY);
       }
     };