add makeInt32List method (to create an Int32List actually backed by heap-allocated memory

thermion_dart/lib/src/bindings/src/ffi.dart

@@ -11,6 +11,10 @@ const FILAMENT_SINGLE_THREADED = false;
 const FILAMENT_WASM = false;
 bool get IS_WINDOWS => Platform.isWindows;
 
+Int32List makeInt32List(int length) {
+  return Int32List(length);
+}
+
 class NativeLibrary {
   static void initBindings(String name) {
     throw Exception();
@@ -93,8 +97,8 @@ void _voidCallbackHandler(int requestId) {
   _requests[requestId]!.complete();
 }
 
-late NativeCallable<Void Function(Int32)>
+late NativeCallable<Void Function(Int32)> _voidCallbackNativeCallable =
-    _voidCallbackNativeCallable = NativeCallable<Void Function(Int32)>.listener(_voidCallbackHandler);
+    NativeCallable<Void Function(Int32)>.listener(_voidCallbackHandler);
 
 Future<void> withVoidCallback(
     Function(int, Pointer<NativeFunction<Void Function(Int32)>>) func) async {
@@ -102,8 +106,9 @@ Future<void> withVoidCallback(
   _requestId++;
   final completer = Completer();
   _requests[requestId] = completer;
-  
+
-  _voidCallbackNativeCallable = NativeCallable<Void Function(Int32)>.listener(_voidCallbackHandler);
+  _voidCallbackNativeCallable =
+      NativeCallable<Void Function(Int32)>.listener(_voidCallbackHandler);
   func.call(requestId, _voidCallbackNativeCallable.nativeFunction.cast());
 
   await completer.future;

thermion_dart/lib/src/bindings/src/js_interop.dart

@@ -10,6 +10,12 @@ const FILAMENT_SINGLE_THREADED = true;
 const FILAMENT_WASM = true;
 const IS_WINDOWS = false;
 
+Int32List makeInt32List(int length) {
+  var ptr = malloc<Int32>(length * 4);
+  var buf = _NativeLibrary.instance._emscripten_make_int32_buffer(ptr, length);
+  return buf.toDart;
+}
+
 extension type _NativeLibrary(JSObject _) implements JSObject {
   static _NativeLibrary get instance =>
       NativeLibrary.instance as _NativeLibrary;
@@ -157,8 +163,9 @@ extension UInt32ListExtension on Uint32List {
       return nullptr;
     }
     final ptr = getPointer<Uint32>(this, this.toJS);
-    final bar = Uint32ArrayWrapper(NativeLibrary.instance.HEAPU8, ptr, length)
+    final bar =
-        as JSUint32Array;
+        Uint32ArrayWrapper(NativeLibrary.instance.HEAPU8.buffer, ptr, length)
+            as JSUint32Array;
     bar.toDart.setRange(0, length, this);
     return ptr;
   }
@@ -169,11 +176,17 @@ extension Int32ListExtension on Int32List {
     if (this.lengthInBytes == 0) {
       return nullptr;
     }
-    final ptr = getPointer<Int32>(this, this.toJS);
+    try {
-    final bar = Int32ArrayWrapper(NativeLibrary.instance.HEAPU8, ptr, length)
+      this.buffer.asUint8List(this.offsetInBytes);
-        as JSInt32Array;
+      final ptr = getPointer<Int32>(this, this.toJS);
-    bar.toDart.setRange(0, length, this);
+      final bar =
-    return ptr;
+          Int32ArrayWrapper(NativeLibrary.instance.HEAPU8.buffer, ptr, length)
+              as JSInt32Array;
+      bar.toDart.setRange(0, length, this);
+      return ptr;
+    } catch (_) {
+      return Pointer<Int32>(this.offsetInBytes);
+    }
   }
 }
 
@@ -242,7 +255,7 @@ class CallbackHolder<T extends Function> {
 
 extension DPCF on DartPickCallbackFunction {
   CallbackHolder<DartPickCallbackFunction> asCallback() {
-    final ptr = addFunction<DartPickCallbackFunction>(this.toJS, "viidddd");
+    final ptr = addFunction<DartPickCallbackFunction>(this.toJS, "viiffff");
     final cbh = CallbackHolder(ptr);
     return cbh;
   }
@@ -270,8 +283,7 @@ void Function(int) _voidCallback = (int requestId) {
 
 final _voidCallbackPtr = _voidCallback.addFunction();
 
-
+Future<void> withVoidCallback(
-  Future<void> withVoidCallback(
     Function(int, Pointer<NativeFunction<Void Function(int)>>) func) async {
   final completer = Completer();
   final requestId = _completers.length;

thermion_dart/lib/src/filament/src/implementation/ffi_asset.dart

@@ -1,5 +1,6 @@
 import 'package:animation_tools_dart/animation_tools_dart.dart';
 import 'package:logging/logging.dart';
+import 'package:thermion_dart/src/bindings/src/js_interop.dart';
 import 'package:thermion_dart/src/utils/src/matrix.dart';
 import 'package:thermion_dart/src/filament/src/implementation/ffi_filament_app.dart';
 import 'package:thermion_dart/src/filament/src/implementation/ffi_material.dart';
@@ -56,10 +57,10 @@ class FFIAsset extends ThermionAsset {
   Future<List<ThermionEntity>> getChildEntities() async {
     if (_childEntities == null) {
       var count = SceneAsset_getChildEntityCount(asset);
-      var childEntities = Int32List(count);
+      var childEntities = makeInt32List(count);
       late Pointer stackPtr;
       if (FILAMENT_WASM) {
-        //stackPtr = stackSave();
+        stackPtr = stackSave();
       }
       if (count > 0) {
         SceneAsset_getChildEntities(asset, childEntities.address);
@@ -67,7 +68,7 @@ class FFIAsset extends ThermionAsset {
       _childEntities = Int32List.fromList(childEntities);
       childEntities.free();
       if (FILAMENT_WASM) {
-        //stackRestore(stackPtr);
+        stackRestore(stackPtr);
       }
     }