Fixes for Furfur Rig

- Stop all sounds on destroyed clones
- Fix redraws being requested on invisible sprites
- Fix the "stop all" block and rename Interpreter#stopAll to
  Interpreter#stopAllThreads to prevent further footguns and guide
  towards Runtime#stopAll instead
- Stop the project before unloading it

src/blocks.ts

@@ -2084,6 +2084,7 @@ export const pen_clear = new ProtoBlock({
     inputs: {},
     execute: function* (_, ctx) {
         ctx.renderer?.penLayer.clear();
+        ctx.target.runtime.requestRedraw();
     },
 });
 
@@ -2092,6 +2093,7 @@ export const pen_stamp = new ProtoBlock({
     inputs: {},
     execute: function* (_, ctx) {
         ctx.renderer?.stamp(ctx.target);
+        ctx.target.runtime.requestRedraw();
     },
 });
 

src/interpreter/block-context.ts

@@ -105,7 +105,7 @@ export default class BlockContext {
     }
 
     *stopAll() {
-        this.interpreter.stopAll();
+        this.target.runtime.stopAll();
         // We will never resume from this yield.
         yield;
     }

src/interpreter/interpreter.ts

@@ -23,7 +23,7 @@ export default class Interpreter {
     }
 
     public setProject(project: Project | null) {
-        this.stopAll();
+        this.stopAllThreads();
         this.project = project;
 
         // This is obviously a lie, but with no project, blocks should not be executing anyway
@@ -62,7 +62,7 @@ export default class Interpreter {
         return thread;
     }
 
-    public stopAll() {
+    public stopAllThreads() {
         for (const thread of this.threads) {
             thread.retire();
         }

src/interpreter/thread.ts

@@ -280,7 +280,8 @@ export default class Thread {
      * Scratch does.
      */
     isRecursiveCall(procedure: ProtoBlock) {
-        for (let i = this.callStack.length - 1, j = 5; i >= 0 && j > 0; i--, j--) {
+        // We just pushed the procedure we're testing against to the stack, so skip over it
+        for (let i = this.callStack.length - 2, j = 5; i >= 0 && j > 0; i--, j--) {
             if (this.callStack[i].procedure === procedure) return true;
         }
         return false;

src/runtime.ts

@@ -297,7 +297,7 @@ export default class Runtime {
     }
 
     public stopAll() {
-        this.interpreter.stopAll();
+        this.interpreter.stopAllThreads();
         this.project?.stopAll();
     }
 

src/target.ts

@@ -259,6 +259,7 @@ export default class Target {
     }
 
     public destroy() {
+        this.reset();
         this.scriptListenerCleanup();
         this.runtime.stopTargetThreads(this);
     }
@@ -290,7 +291,9 @@ export default class Target {
             y = Math.floor(this._position.y + (stageTop - fenceBounds.bottom));
         }
 
-        if (this.penState.down && !fromDrag) {
+        const shouldDrawPenLine = this.penState.down && !fromDrag;
+
+        if (shouldDrawPenLine) {
             this.runtime.penLayer?.penLine(
                 this._position.x,
                 this._position.y,
@@ -307,7 +310,7 @@ export default class Target {
             this.drawable.setTransformDirty();
         }
 
-        this.runtime.requestRedraw();
+        if (this.visible || shouldDrawPenLine) this.runtime.requestRedraw();
     }
 
     /**
@@ -359,7 +362,7 @@ export default class Target {
         if (this.drawable) {
             this.drawable.setTransformDirty();
         }
-        this.runtime.requestRedraw();
+        if (this.visible) this.runtime.requestRedraw();
     }
 
     get size(): number {
@@ -372,7 +375,7 @@ export default class Target {
         if (this.drawable) {
             this.drawable.setTransformDirty();
         }
-        this.runtime.requestRedraw();
+        if (this.visible) this.runtime.requestRedraw();
     }
 
     get rotationStyle(): RotationStyle {
@@ -385,7 +388,7 @@ export default class Target {
         if (this.drawable) {
             this.drawable.setTransformDirty();
         }
-        this.runtime.requestRedraw();
+        if (this.visible) this.runtime.requestRedraw();
     }
 
     get currentCostume(): number {
@@ -405,7 +408,7 @@ export default class Target {
         if (this.drawable) {
             this.drawable.setCostume(this.sprite.costumes[index]);
         }
-        this.runtime.requestRedraw();
+        if (this.visible) this.runtime.requestRedraw();
     }
 
     get visible(): boolean {
@@ -415,7 +418,7 @@ export default class Target {
     set visible(visible: boolean) {
         if (this.sprite.isStage) return;
         this._visible = visible;
-        this.runtime.requestRedraw();
+        if (visible) this.runtime.requestRedraw();
     }
 
     public isTouchingEdge(): boolean {