fixes for Windows

flutter_filament_federated/flutter_filament/lib/filament/widgets/filament_widget.dart

@@ -72,6 +72,14 @@ class _FilamentWidgetState extends State<FilamentWidget> {
 
   @override
   Widget build(BuildContext context) {
+
+    if (_texture?.usesBackingWindow == true) {
+      return Stack(children: [
+        Positioned.fill(child: CustomPaint(painter: TransparencyPainter()))
+      ]);
+    }
+
+
     if (_texture == null || _resizing) {
       return widget.initial ??
           Container(color: kIsWeb ? Colors.transparent : Colors.red);
@@ -79,7 +87,7 @@ class _FilamentWidgetState extends State<FilamentWidget> {
 
     var textureWidget = Texture(
       key: ObjectKey("texture_${_texture!.flutterTextureId}"),
-      textureId: _texture!.flutterTextureId,
+      textureId: _texture!.flutterTextureId!,
       filterQuality: FilterQuality.none,
       freeze: false,
     );
@@ -98,3 +106,19 @@ class _FilamentWidgetState extends State<FilamentWidget> {
         ]));
   }
 }
+
+
+class TransparencyPainter extends CustomPainter {
+  @override
+  void paint(Canvas canvas, Size size) {
+    canvas.drawRect(
+      Rect.fromLTWH(0, 0, size.width, size.height),
+      Paint()
+        ..blendMode = BlendMode.clear
+        ..color = const Color(0x00000000),
+    );
+  }
+
+  @override
+  bool shouldRepaint(covariant CustomPainter oldDelegate) => false;
+}

flutter_filament_federated/flutter_filament/windows/CMakeLists.txt

@@ -100,6 +100,12 @@ set(flutter_filament_bundled_libraries
   ${CMAKE_CURRENT_SOURCE_DIR}/lib/Debug/libc++.dll
   ${CMAKE_CURRENT_SOURCE_DIR}/lib/Debug/third_party_abseil-cpp_absl.dll
   ${CMAKE_CURRENT_SOURCE_DIR}/lib/Debug/third_party_zlib.dll
+  ${CMAKE_CURRENT_SOURCE_DIR}/dart_filament.dll
+  PARENT_SCOPE
+)
+else()
+set(flutter_filament_bundled_libraries
+  ${runner_BINARY_DIR}/../../../native_assets/windows/dart_filament.dll
   PARENT_SCOPE
 )
 endif()

flutter_filament_federated/flutter_filament/windows/flutter_filament_plugin.cpp

@@ -1,5 +1,6 @@
 #pragma comment(lib, "dxgi.lib")
 #pragma comment(lib, "d3d11.lib")
+#pragma comment(lib, "Shlwapi.lib")
 
 #include "flutter_filament_plugin.h"
 
@@ -35,8 +36,7 @@
 
 namespace flutter_filament {
 
-  using namespace std::chrono_literals;
-
+using namespace std::chrono_literals;
 
 void FlutterFilamentPlugin::RegisterWithRegistrar(
     flutter::PluginRegistrarWindows *registrar) {
@@ -123,6 +123,7 @@ void FlutterFilamentPlugin::freeResource(ResourceBuffer rbuf) {
 }
 
 static ResourceBuffer _loadResource(const char *path, void *const plugin) {
+  std::wcout << "Loading resource from path " << path << std::endl;
   return ((FlutterFilamentPlugin *)plugin)->loadResource(path);
 }
 
@@ -163,10 +164,10 @@ void FlutterFilamentPlugin::CreateTexture(
   const auto *args =
       std::get_if<flutter::EncodableList>(methodCall.arguments());
 
-  double dWidth = *(std::get_if<double>(&(args->at(0))));
-  double dHeight = *(std::get_if<double>(&(args->at(1))));
-  double dLeft = *(std::get_if<double>(&(args->at(2))));
-  double dTop = *(std::get_if<double>(&(args->at(3))));
+  int dWidth = *(std::get_if<int>(&(args->at(0))));
+  int dHeight = *(std::get_if<int>(&(args->at(1))));
+  int dLeft = *(std::get_if<int>(&(args->at(2))));
+  int dTop = *(std::get_if<int>(&(args->at(3))));
   auto width = (uint32_t)round(dWidth );
   auto height = (uint32_t)round(dHeight );
   auto left = (uint32_t)round(dLeft );
@@ -233,10 +234,11 @@ void FlutterFilamentPlugin::HandleMethodCall(
     #if WGL_USE_BACKING_WINDOW
       const auto *args =
       std::get_if<flutter::EncodableList>(methodCall.arguments());
-      double dWidth = *(std::get_if<double>(&(args->at(0))));
-      double dHeight = *(std::get_if<double>(&(args->at(1))));
-      double dLeft = *(std::get_if<double>(&(args->at(2))));
-      double dTop = *(std::get_if<double>(&(args->at(3))));
+    
+      int dWidth = *(std::get_if<int>(&(args->at(0))));
+      int dHeight = *(std::get_if<int>(&(args->at(1))));
+      int dLeft = *(std::get_if<int>(&(args->at(2))));
+      int dTop = *(std::get_if<int>(&(args->at(3))));
       auto width = (uint32_t)round(dWidth );
       auto height = (uint32_t)round(dHeight );
       auto left = (uint32_t)round(dLeft );

flutter_filament_federated/flutter_filament/windows/wgl_context.cpp

@@ -118,11 +118,10 @@ void WGLContext::CreateRenderingSurface(
     ResizeRenderingSurface(width, height, left, top);
   }
   std::vector<flutter::EncodableValue> resultList;
-  resultList.push_back(flutter::EncodableValue((int64_t) nullptr));
+  resultList.push_back(flutter::EncodableValue()); // return null for Flutter texture ID
+  resultList.push_back(flutter::EncodableValue()); // return null for hardware texture ID
   resultList.push_back(
-      flutter::EncodableValue((int64_t)_backingWindow->GetHandle()));
-  resultList.push_back(flutter::EncodableValue((int64_t) nullptr));
-  resultList.push_back(flutter::EncodableValue((int64_t)_context));
+      flutter::EncodableValue((int64_t)_backingWindow->GetHandle())); // return the HWND handle for the native window 
   result->Success(resultList);
 #else
   if(left != 0 || top != 0) {

flutter_filament_federated/flutter_filament_ffi/lib/flutter_filament_ffi.dart

@@ -115,10 +115,10 @@ class FlutterFilamentFFI extends FlutterFilamentPlatform {
     var result = await _channel
         .invokeMethod("createTexture", [width, height, offsetLeft, offsetLeft]);
 
-    if (result == null || result[0] == -1) {
+    if (result == null || (result[0] == -1)) {
       throw Exception("Failed to create texture");
     }
-    final flutterTextureId = result[0] as int;
+    final flutterTextureId = result[0] as int?;
     final hardwareTextureId = result[1] as int?;
     final surfaceAddress = result[2] as int?;
 
@@ -126,23 +126,28 @@ class FlutterFilamentFFI extends FlutterFilamentPlatform {
         "Created texture with flutter texture id ${flutterTextureId}, hardwareTextureId $hardwareTextureId and surfaceAddress $surfaceAddress");
 
     viewer.viewportDimensions = (width.toDouble(), height.toDouble());
-    var texture = FlutterFilamentTexture(
-        flutterTextureId, hardwareTextureId, width, height, surfaceAddress);
+
+    final texture = FlutterFilamentTexture(
+      flutterTextureId, hardwareTextureId, width, height, surfaceAddress);
 
     await viewer.createSwapChain(width.toDouble(), height.toDouble(),
-        surface: texture.surfaceAddress == null
-            ? nullptr
-            : Pointer<Void>.fromAddress(texture.surfaceAddress!));
+      surface: texture.surfaceAddress == null
+          ? nullptr
+          : Pointer<Void>.fromAddress(texture.surfaceAddress!));
 
     if (texture.hardwareTextureId != null) {
+      print("Creating render target");
       var renderTarget = await viewer.createRenderTarget(
-          width.toDouble(), height.toDouble(), texture.hardwareTextureId!);
+        width.toDouble(), height.toDouble(), texture.hardwareTextureId!);
     }
+    
     await viewer.updateViewportAndCameraProjection(
         width.toDouble(), height.toDouble());
     viewer.render();
     _creatingTexture = false;
+    
     _textures.add(texture);
+    
     return texture;
   }