Fix NavMesh memory leaks (#9175)

Extensions/NavMeshPathfinding/JsExtension.js

@@ -389,7 +389,7 @@ module.exports = {
         .addIncludeFile(
           'Extensions/NavMeshPathfinding/NavMeshObstacleRuntimeBehavior.js'
         )
-        .addIncludeFile(
+        .addRequiredFile(
           'Extensions/NavMeshPathfinding/recast-navigation.wasm.js'
         )
         .addRequiredFile(
@@ -858,7 +858,7 @@ module.exports = {
         .addIncludeFile(
           'Extensions/NavMeshPathfinding/NavMeshObstacleRuntimeBehavior.js'
         )
-        .addIncludeFile(
+        .addRequiredFile(
           'Extensions/NavMeshPathfinding/recast-navigation.wasm.js'
         )
         .addRequiredFile(
@@ -886,7 +886,9 @@ module.exports = {
       .addIncludeFile(
         'Extensions/NavMeshPathfinding/NavMeshObstacleRuntimeBehavior.js'
       )
-      .addIncludeFile('Extensions/NavMeshPathfinding/recast-navigation.wasm.js')
+      // `recast-navigation.wasm.js` is an ES module loaded with `import()` by
+      // NavMeshCharacterRuntimeBehavior.js: it's a required file of the
+      // behaviors and must not be included as a classic script.
       .addIncludeFile(
         'Extensions/NavMeshPathfinding/recast-navigation-generators.js'
       )

Extensions/NavMeshPathfinding/NavMeshCharacterRuntimeBehavior.ts

@@ -1,17 +1,31 @@
 namespace gdjs {
   const loadRecast = async () => {
     try {
-      const module = await import('./recast-navigation.wasm.js');
-      const initializeRecast = module.default;
-      if (!initializeRecast) {
-        throw new Error('No default export found in Recast.');
-      }
-
-      const Recast = await initializeRecast();
-
-      await RecastNav.init();
-      //@ts-ignore
-      window.Recast = Recast;
+      // Give the module instantiated from `recast-navigation.wasm.wasm` to
+      // RecastNav. Without an implementation, `RecastNav.init` instantiates
+      // the "compat" build embedded (in base64) in
+      // `recast-navigation-generators.js`, so each game would create 2
+      // WebAssembly instances (each with its own memory) instead of 1.
+      // Previews of the in-game editor and gameplay tests run in the editor
+      // process: this halves the WebAssembly memory reserved by each preview.
+      // `RecastNav.init` does nothing (and doesn't instantiate anything) if
+      // Recast is already initialized, for instance if this script is
+      // reloaded by the hot-reloader.
+      // The vendored `init` expects a function returning the module, but the
+      // typings of `@recast-navigation/core` declare the module itself.
+      const instantiateRecastModule = async () => {
+        const module = await import('./recast-navigation.wasm.js');
+        const initializeRecast = module.default;
+        if (!initializeRecast) {
+          throw new Error('No default export found in Recast.');
+        }
+        return initializeRecast();
+      };
+      await RecastNav.init(
+        instantiateRecastModule as unknown as Parameters<
+          typeof RecastNav.init
+        >[0]
+      );
     } catch (err) {
       console.error('Unable to load Recast navigation mesh library.', err);
       throw err;

Extensions/NavMeshPathfinding/NavMeshDebugPixiRenderer.ts

@@ -116,6 +116,17 @@ namespace gdjs {
       this.meshes.length = 0;
     }
 
+    /**
+     * Free the debug drawer from the WebAssembly memory.
+     */
+    dispose() {
+      this.removeFor3D();
+      if (this.debugDrawerUtils) {
+        this.debugDrawerUtils.dispose();
+        this.debugDrawerUtils = null;
+      }
+    }
+
     renderFor3D() {
       this.removeFor3D();
       if (!this.enabled || !this.obstaclesManager.is3D) {

Extensions/NavMeshPathfinding/NavMeshObstacleRuntimeBehavior.ts

@@ -582,8 +582,43 @@ namespace gdjs {
         character._agent = null;
       }
     }
+
+    /**
+     * Free the navigation mesh and the crowd from the WebAssembly memory.
+     * The manager must not be used after this.
+     */
+    dispose(): void {
+      for (const character of this.characters) {
+        character._agent = null;
+      }
+      this.characters.clear();
+      this.obstacles.clear();
+      if (this.crowd) {
+        this.crowd.destroy();
+        this.crowd = null;
+      }
+      if (this.navMesh) {
+        this.navMesh.destroy();
+        this.navMesh = null;
+      }
+      if (this.debuggerRenderer) {
+        this.debuggerRenderer.dispose();
+        this.debuggerRenderer = null;
+      }
+    }
   }
 
+  gdjs.registerRuntimeSceneUnloadedCallback(function (runtimeScene) {
+    // Without this, the navigation mesh and the crowd of each unloaded scene
+    // would stay allocated in the WebAssembly memory.
+    const navMeshObstaclesManager = runtimeScene.navMeshObstaclesManager;
+    if (navMeshObstaclesManager) {
+      navMeshObstaclesManager.dispose();
+      // @ts-ignore The manager is set back to undefined like before its creation.
+      runtimeScene.navMeshObstaclesManager = undefined;
+    }
+  });
+
   /** @category Behaviors > NavMesh pathfinding */
   export namespace NavMeshObstaclesManager {
     /**

Extensions/NavMeshPathfinding/tests/navmeshcharacterruntimebehavior.spec.js

@@ -315,6 +315,24 @@ describe('gdjs.NavMeshCharacterRuntimeBehavior', function () {
     expect(getPathLength(character)).to.be.within(180, 220);
   });
 
+  it('frees the navigation mesh and the crowd when the scene is unloaded', function () {
+    character.setPosition(400, 300);
+    runtimeScene.renderAndStep(1000 / 60);
+    getCharacterBehavior(character).moveTo(600, 300, 0);
+    runtimeScene.renderAndStep(1000 / 60);
+
+    const navMeshObstaclesManager = runtimeScene.navMeshObstaclesManager;
+    expect(navMeshObstaclesManager.navMesh).not.to.be(null);
+    expect(navMeshObstaclesManager.crowd).not.to.be(null);
+
+    runtimeScene.unloadScene();
+
+    expect(navMeshObstaclesManager.navMesh).to.be(null);
+    expect(navMeshObstaclesManager.crowd).to.be(null);
+    expect(navMeshObstaclesManager.characters.size).to.be(0);
+    expect(runtimeScene.navMeshObstaclesManager).to.be(undefined);
+  });
+
   describe('(network synchronization)', function () {
     it('can sync an idle character over an idle character without error', function () {
       const otherCharacter = addCharacter(runtimeScene);

GDJS/Runtime/debugger-client/hot-reloader.ts

@@ -116,6 +116,9 @@ namespace gdjs {
         if (
           // Don't reload Box2d as it would confuse and crash the asm.js library.
           endsWith(srcFilename, 'box2d.js') ||
+          // Don't reload the Recast navigation library as it would lose
+          // its initialized WebAssembly module.
+          endsWith(srcFilename, 'recast-navigation-generators.js') ||
           // Don't reload sha256.js library.
           endsWith(srcFilename, 'sha256.js') ||
           // Don't reload shopify-buy library.

newIDE/app/src/Utils/Analytics/EventSender.js

@@ -198,6 +198,11 @@ export const installAnalyticsEvents = () => {
       posthogLoaded = true;
     },
     autocapture: false, // we disable autocapture because we want to control which events we send.
+    session_recording: {
+      // Iframes (in-game editor, gameplay tests) are not recorded: the recording would
+      // keep a reference to every document loaded in them (including game WebAssembly memories).
+      blockSelector: 'iframe',
+    },
   });
 };