fix: [#3078] Pointer lastWorldPosition updates when the camera does

CHANGELOG.md

@@ -151,6 +151,7 @@ are doing mtv adjustments during precollision.
 
 ### Fixed
 
+- Fixed issue where the pointer `lastWorldPos` was not updated when the current `Camera` moved
 - Fixed issue where `cancel()`'d events still bubbled to the top level input handlers
 - Fixed issue where unexpected html HTML content from an image would silently hang the loader
 - Fixed issue where Collision events ahd inconsistent targets, sometimes they were Colliders and sometimes they were Entities

src/engine/Camera.ts

@@ -9,11 +9,11 @@ import { PreUpdateEvent, PostUpdateEvent, InitializeEvent } from './Events';
 import { BoundingBox } from './Collision/BoundingBox';
 import { Logger } from './Util/Log';
 import { ExcaliburGraphicsContext } from './Graphics/Context/ExcaliburGraphicsContext';
-import { watchAny } from './Util/Watch';
 import { AffineMatrix } from './Math/affine-matrix';
 import { EventEmitter, EventKey, Handler, Subscription } from './EventEmitter';
 import { pixelSnapEpsilon } from './Graphics';
 import { sign } from './Math/util';
+import { WatchVector } from './Math/watch-vector';
 
 /**
  * Interface that describes a custom camera strategy for tracking targets
@@ -312,17 +312,28 @@ export class Camera implements CanUpdate, CanInitialize {
     this._angularVelocity = value;
   }
 
+  private _posChanged = false;
+  private _pos: Vector = new WatchVector(Vector.Zero, () => {
+    this._posChanged = true;
+  });
   /**
    * Get or set the camera's position
    */
-  private _posChanged = false;
-  private _pos: Vector = watchAny(Vector.Zero, () => (this._posChanged = true));
   public get pos(): Vector {
     return this._pos;
   }
   public set pos(vec: Vector) {
-    this._pos = watchAny(vec, () => (this._posChanged = true));
     this._posChanged = true;
+    this._pos = new WatchVector(vec, () => {
+      this._posChanged = true;
+    });
+  }
+
+  /**
+   * Has the position changed since the last update
+   */
+  public hasChanged(): boolean {
+    return this._posChanged;
   }
   /**
    * Interpolated camera position if more draws are running than updates
@@ -782,8 +793,8 @@ export class Camera implements CanUpdate, CanInitialize {
     // It's important to update the camera after strategies
     // This prevents jitter
     this.updateTransform(this.pos);
-
     this._postupdate(engine, elapsedMs);
+    this._posChanged = false;
   }
 
   private _snapPos = vec(0, 0);

src/engine/Input/PointerAbstraction.ts

@@ -2,6 +2,8 @@
 import { PointerEvent } from './PointerEvent';
 import { EventEmitter, EventKey, Handler, Subscription } from '../EventEmitter';
 import { PointerEvents } from './PointerEventReceiver';
+import { GlobalCoordinates } from '../Math/global-coordinates';
+import { Engine } from '../Engine';
 
 export class PointerAbstraction {
   public events = new EventEmitter<PointerEvents>();
@@ -50,6 +52,17 @@
     this.events.off(eventName, handler);
   }
 
+  /**
+   * Called internally by excalibur to keep pointers up to date
+   * @internal
+   * @param pos
+   */
+  public _updateWorldPosition(engine: Engine) {
+    const coord = GlobalCoordinates.fromPagePosition(this.lastPagePos, engine);
+    this.lastScreenPos = coord.screenPos;
+    this.lastWorldPos = coord.worldPos;
+  }
+
   private _onPointerMove = (ev: PointerEvent): void => {
     this.lastPagePos = new Vector(ev.pagePos.x, ev.pagePos.y);
     this.lastScreenPos = new Vector(ev.screenPos.x, ev.screenPos.y);

src/engine/Input/PointerEventReceiver.ts

@@ -202,6 +202,7 @@ export class PointerEventReceiver {
    * Updates the current frame pointer info and emits raw pointer events
    *
    * This does not emit events to entities, see PointerSystem
+   * @internal
    */
   public update() {
     this.lastFramePointerDown = new Map(this.currentFramePointerDown);
@@ -253,6 +254,12 @@ export class PointerEventReceiver {
       this.primary.emit('pointerwheel', event);
       this.primary.emit('wheel', event);
     }
+
+    if (this.engine.currentScene.camera.hasChanged()) {
+      for (const pointer of this._pointers) {
+        pointer._updateWorldPosition(this.engine);
+      }
+    }
   }
 
   /**

src/engine/Input/PointerSystem.ts

@@ -95,6 +95,11 @@ export class PointerSystem extends System {
   };
 
   public preupdate(): void {
+    if (this._scene.camera.hasChanged()) {
+      // if the camera has changed we want to force a transform update so pointers can be correctly calc'd
+      this._scene.camera.updateTransform(this._scene.camera.pos);
+    }
+
     // event receiver might change per frame
     this._receivers = [this._engine.input.pointers, this._scene.input.pointers];
     this._engineReceiver = this._engine.input.pointers;
@@ -142,8 +147,10 @@ export class PointerSystem extends System {
     // Dispatch pointer events on entities
     this._dispatchEvents(this._sortedEntities);
 
-    // Clear last frame's events
+    // Dispatch pointer events on top level pointers
     this._receivers.forEach((r) => r.update());
+
+    // Clear last frame's events
     this.lastFrameEntityToPointers.clear();
     this.lastFrameEntityToPointers = new Map<number, number[]>(this.currentFrameEntityToPointers);
     this.currentFrameEntityToPointers.clear();

src/engine/Math/watch-vector.ts

@@ -31,4 +31,9 @@ export class WatchVector extends Vector {
       this._y = this.original.y = newY;
     }
   }
+
+  override setTo(x: number, y: number): void {
+    this.x = x;
+    this.y = y;
+  }
 }

src/spec/CameraSpec.ts

@@ -325,7 +325,7 @@ describe('A camera', () => {
 
   it('can use built-in elastic around actor strategy', () => {
     engine.currentScene.camera = new ex.Camera();
-    engine.currentScene.camera.pos.setTo(0, 0);
+    engine.currentScene.camera.pos = ex.vec(0, 0);
     const actor = new ex.Actor();
 
     engine.currentScene.camera.strategy.elasticToActor(actor, 0.05, 0.1);

src/spec/PointerInputSpec.ts

@@ -229,6 +229,29 @@ describe('A pointer', () => {
     expect(spyTopLevelPointerWheel).not.toHaveBeenCalled();
   });
 
+  it('should update the pointer pos when the camera moves', () => {
+    const oldMargin = document.body.style.margin;
+    const oldPadding = document.body.style.padding;
+    document.body.style.margin = '0';
+    document.body.style.padding = '0';
+    executeMouseEvent('pointerdown', <any>document, null, 10, 10);
+    engine.currentScene.update(engine, 0);
+    expect(engine.input.pointers.primary.lastWorldPos).toEqual(ex.vec(10, 10));
+    expect(engine.input.pointers.primary.lastScreenPos).toEqual(ex.vec(10, 10));
+    expect(engine.input.pointers.primary.lastPagePos).toEqual(ex.vec(10, 10));
+
+    expect(engine.currentScene.camera.hasChanged()).toBe(false);
+    engine.currentScene.camera.pos = ex.vec(1000, 1000);
+    expect(engine.currentScene.camera.hasChanged()).toBe(true);
+    engine.currentScene.update(engine, 0);
+    expect(engine.input.pointers.primary.lastWorldPos).toEqual(ex.vec(760, 760));
+    expect(engine.input.pointers.primary.lastScreenPos).toEqual(ex.vec(10, 10));
+    expect(engine.input.pointers.primary.lastPagePos).toEqual(ex.vec(10, 10));
+
+    document.body.style.margin = oldMargin;
+    document.body.style.padding = oldPadding;
+  });
+
   it('should dispatch point events on screen elements', () => {
     const pointerDownSpy = jasmine.createSpy('pointerdown');
     const screenElement = new ex.ScreenElement({
@@ -307,9 +330,9 @@ describe('A pointer', () => {
     const actor1 = new ex.Actor({
       pos: ex.vec(50, 50),
       width: 100,
-      height: 100
+      height: 100,
+      coordPlane: ex.CoordPlane.Screen
     });
-    actor1.transform.coordPlane = ex.CoordPlane.Screen;
     actor1.on('pointerdown', clickSpy);
     engine.currentScene.camera.pos = ex.vec(1000, 1000);
     engine.currentScene.camera.draw(engine.graphicsContext);