avoid multiple 3D button pointer events with multitouch

dist/preview release/what's new.md

@@ -228,7 +228,7 @@
 - Fix ArcRotateCamera rebuildAnglesAndRadius when upVector modified ([sable](https://github.com/thscott))
 - Fix code branch, that does not try to (re)load an `EquiRectangularCubeTexture`/`HDRCubeTexture` when the caching returns an empty or corrupt `InternalTexture` ([Dennis Dervisis](https://github.com/ddervisis))
 - Add error eventlistener (bubbling up the onError callback chain) in case an `EquiRectangularCubeTexture` cannot be loaded, because of a wrong path or IO problems ([Dennis Dervisis](https://github.com/ddervisis))
-- 3D GUI buttons no longer will scale up when pressing with multitouch devices ([TrevorDev](https://github.com/TrevorDev))
+- 3D GUI buttons no longer will scale up when pressing with a multitouch device ([TrevorDev](https://github.com/TrevorDev))
 
 ### Core Engine
 - Fixed a bug with `mesh.alwaysSelectAsActiveMesh` preventing layerMask to be taken in account ([Deltakosh](https://github.com/deltakosh))

gui/src/3D/controls/button3D.ts

@@ -22,7 +22,6 @@ export class Button3D extends AbstractButton3D {
     private _content: Control;
     private _contentResolution = 512;
     private _contentScaleRatio = 2;
-    private _pressed = false;
 
     /**
      * Gets or sets the texture resolution used to render content (512 by default)
@@ -92,10 +91,8 @@ export class Button3D extends AbstractButton3D {
             if (!this.mesh) {
                 return;
             }
-            if (!this._pressed) {
-                this.mesh.scaling.scaleInPlace(0.95);
-                this._pressed = true;
-            }
+
+            this.mesh.scaling.scaleInPlace(0.95);
         };
 
         this.pointerUpAnimation = () => {
@@ -103,10 +100,7 @@ export class Button3D extends AbstractButton3D {
                 return;
             }
 
-            if (this._pressed) {
-                this.mesh.scaling.scaleInPlace(1.0 / 0.95);
-                this._pressed = false;
-            }
+            this.mesh.scaling.scaleInPlace(1.0 / 0.95);
         };
     }
 

gui/src/3D/controls/control3D.ts

@@ -333,6 +333,7 @@ export class Control3D implements IDisposable, IBehaviorAware<Control3D> {
     /** @hidden */
     public _onPointerDown(target: Control3D, coordinates: Vector3, pointerId: number, buttonIndex: number): boolean {
         if (this._downCount !== 0) {
+            this._downCount++;
             return false;
         }
 
@@ -351,17 +352,24 @@ export class Control3D implements IDisposable, IBehaviorAware<Control3D> {
 
     /** @hidden */
     public _onPointerUp(target: Control3D, coordinates: Vector3, pointerId: number, buttonIndex: number, notifyClick: boolean): void {
-        this._downCount = 0;
-
+        this._downCount--;
         delete this._downPointerIds[pointerId];
 
-        if (notifyClick && (this._enterCount > 0 || this._enterCount === -1)) {
-            this.onPointerClickObservable.notifyObservers(new Vector3WithInfo(coordinates, buttonIndex), -1, target, this);
+        if (this._downCount < 0) {
+            // Handle if forcePointerUp was called prior to this
+            this._downCount = 0;
+            return;
         }
-        this.onPointerUpObservable.notifyObservers(new Vector3WithInfo(coordinates, buttonIndex), -1, target, this);
 
-        if (this.pointerUpAnimation) {
-            this.pointerUpAnimation();
+        if (this._downCount == 0) {
+            if (notifyClick && (this._enterCount > 0 || this._enterCount === -1)) {
+                this.onPointerClickObservable.notifyObservers(new Vector3WithInfo(coordinates, buttonIndex), -1, target, this);
+            }
+            this.onPointerUpObservable.notifyObservers(new Vector3WithInfo(coordinates, buttonIndex), -1, target, this);
+
+            if (this.pointerUpAnimation) {
+                this.pointerUpAnimation();
+            }
         }
     }
 
@@ -373,6 +381,11 @@ export class Control3D implements IDisposable, IBehaviorAware<Control3D> {
             for (var key in this._downPointerIds) {
                 this._onPointerUp(this, Vector3.Zero(), +key as number, 0, true);
             }
+            if (this._downCount > 0) {
+                this._downCount = 1;
+                this._onPointerUp(this, Vector3.Zero(), 0, 0, true);
+            }
+
         }
     }