fix: [#3083] Actors inherit opacity from parents

Closes #3083

CHANGELOG.md

@@ -64,6 +64,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+- Child `ex.Actor` inherits opacity of parents
 - `ex.Engine.timeScale` values of 0 are now supported
 - `ex.Trigger` now supports all valid actor constructor parameters from `ex.ActorArgs` in addition to `ex.TriggerOptions`
 - `ex.Gif` can now handle default embedded GIF frame timings

src/engine/Graphics/GraphicsSystem.ts

@@ -141,7 +141,8 @@ export class GraphicsSystem extends System {
       }
       entity.events.emit('predraw', new PreDrawEvent(this._graphicsContext, elapsedMs, entity));
 
-      this._graphicsContext.opacity *= graphics.opacity;
+      // this._graphicsContext.opacity *= graphics.opacity;
+      this._applyOpacity(entity);
 
       // Draw the graphics component
       this._drawGraphicsComponent(graphics, transform);
@@ -269,4 +270,12 @@ export class GraphicsSystem extends System {
       }
     }
   }
+
+  private _applyOpacity(entity: Entity): void {
+    const ancestors = entity.getAncestors();
+    for (const ancestor of ancestors) {
+      const maybeGraphics = ancestor?.get(GraphicsComponent);
+      this._graphicsContext.opacity *= maybeGraphics?.opacity ?? 1;
+    }
+  }
 }