From 86894cf58318e58481318b0cbf3df824c9850919 Mon Sep 17 00:00:00 2001
From: Nick Fisher <nick.fisher@avinium.com>
Date: Thu, 29 May 2025 22:26:42 +0800
Subject: [PATCH] add alpha/requireAlpha argument when decoding images remove
 size checks from setImage (we are assuming the caller knows the correct size)
 This also adds some monkey-patch methods to js_interop to convert Float32List
 to a UInt8List (but use this with care, because it will only work for
 emscripten-allocated objects)

---
 thermion_dart/lib/src/bindings/src/ffi.dart   |  7 +++
 .../lib/src/bindings/src/js_interop.dart      | 57 ++++++++++++++++---
 .../src/bindings/src/thermion_dart_ffi.g.dart |  5 +-
 .../src/thermion_dart_js_interop.g.dart       |  9 ++-
 .../src/implementation/ffi_filament_app.dart  | 25 +++++---
 .../src/implementation/ffi_texture.dart       | 13 ++---
 .../filament/src/interface/filament_app.dart  |  2 +-
 .../src/filament/src/interface/texture.dart   | 12 +++-
 thermion_dart/native/include/c_api/TTexture.h |  2 +-
 .../c_api/ThermionDartRenderThreadApi.h       |  2 +-
 thermion_dart/native/src/c_api/TTexture.cpp   | 38 +++++--------
 .../src/c_api/ThermionDartRenderThreadApi.cpp |  4 +-
 12 files changed, 115 insertions(+), 61 deletions(-)

diff --git a/thermion_dart/lib/src/bindings/src/ffi.dart b/thermion_dart/lib/src/bindings/src/ffi.dart
index c0af1e25..178ea93d 100644
--- a/thermion_dart/lib/src/bindings/src/ffi.dart
+++ b/thermion_dart/lib/src/bindings/src/ffi.dart
@@ -215,3 +215,10 @@ extension DartBigIntExtension on int {
     return this;
   }
 }
+
+extension Float32ListExtension on Float32List {
+
+  Uint8List asUint8List() {
+    return this.buffer.asUint8List(this.offsetInBytes);
+  }
+}
\ No newline at end of file
diff --git a/thermion_dart/lib/src/bindings/src/js_interop.dart b/thermion_dart/lib/src/bindings/src/js_interop.dart
index 1da5a373..8e06eac9 100644
--- a/thermion_dart/lib/src/bindings/src/js_interop.dart
+++ b/thermion_dart/lib/src/bindings/src/js_interop.dart
@@ -10,10 +10,22 @@ const FILAMENT_SINGLE_THREADED = true;
 const FILAMENT_WASM = true;
 const IS_WINDOWS = false;
 
+final _allocations = <TypedData>{};
+
 Int32List makeInt32List(int length) {
-  var ptr = malloc<Int32>(length * 4);
+  var ptr = stackAlloc<Int32>(length * 4);
   var buf = _NativeLibrary.instance._emscripten_make_int32_buffer(ptr, length);
-  return buf.toDart;
+  var int32List = buf.toDart;
+  _allocations.add(int32List);
+  return int32List;
+}
+
+Float32List makeFloat32List(int length) {
+  var ptr = stackAlloc<Float32>(length * 4);
+  var buf = _NativeLibrary.instance._emscripten_make_f32_buffer(ptr, length);
+  var f32List = buf.toDart;
+  _allocations.add(f32List);
+  return f32List;
 }
 
 extension type _NativeLibrary(JSObject _) implements JSObject {
@@ -34,6 +46,8 @@ extension type _NativeLibrary(JSObject _) implements JSObject {
       Pointer<Float64> ptr, int length);
   external Pointer _emscripten_get_byte_offset(JSObject obj);
 
+  external int _emscripten_stack_get_base();
+  external Pointer _emscripten_stack_get_current();
   external int _emscripten_stack_get_free();
 
   external void _execute_queue();
@@ -47,8 +61,8 @@ extension type _NativeLibrary(JSObject _) implements JSObject {
 
 extension FreeTypedData<T> on TypedData {
   void free() {
-    final ptr = Pointer<Void>(this.offsetInBytes);
-    ptr.free();
+    Pointer<Void>(this.offsetInBytes).free();
+    _allocations.remove(this);
   }
 }
 
@@ -64,7 +78,12 @@ Pointer<T> getPointer<T extends NativeType>(TypedData data, JSObject obj) {
   return ptr;
 }
 
-extension JSBackingBuffer on JSUint8Array {
+extension JSUint8BackingBuffer on JSUint8Array {
+  @JS('buffer')
+  external JSObject buffer;
+}
+
+extension JSFloat32BackingBuffer on JSFloat32Array {
   @JS('buffer')
   external JSObject buffer;
 }
@@ -117,7 +136,11 @@ extension Uint8ListExtension on Uint8List {
     final bar =
         Uint8ArrayWrapper(NativeLibrary.instance.HEAPU8.buffer, ptr, length)
             as JSUint8Array;
+    var now = DateTime.now();
     bar.toDart.setRange(0, length, this);
+    var finished = DateTime.now();
+    print(
+        "uint8list copy finished in ${finished.millisecondsSinceEpoch - now.millisecondsSinceEpoch}ms");
     return ptr;
   }
 }
@@ -131,6 +154,11 @@ extension Float32ListExtension on Float32List {
     bar.toDart.setRange(0, length, this);
     return ptr;
   }
+
+  Uint8List asUint8List() {
+    var ptr = Pointer<Uint8>(_NativeLibrary.instance._emscripten_get_byte_offset(this.toJS));
+    return ptr.asTypedList(length * 4);
+  }
 }
 
 extension Int16ListExtension on Int16List {
@@ -176,6 +204,10 @@ extension Int32ListExtension on Int32List {
     if (this.lengthInBytes == 0) {
       return nullptr;
     }
+    if (_allocations.contains(this)) {
+      return Pointer<Int32>(
+          _NativeLibrary.instance._emscripten_get_byte_offset(this.toJS));
+    }
     try {
       this.buffer.asUint8List(this.offsetInBytes);
       final ptr = getPointer<Int32>(this, this.toJS);
@@ -214,12 +246,21 @@ extension Float64ListExtension on Float64List {
   }
 }
 
+extension AsUint8List on Pointer<Uint8> {
+  Uint8List asTypedList(int length) {
+    final start = addr;
+    final wrapper =
+        Uint8ArrayWrapper(NativeLibrary.instance.HEAPU8.buffer, start, length)
+            as JSUint8Array;
+    return wrapper.toDart;
+  }
+}
+
 extension AsFloat32List on Pointer<Float> {
   Float32List asTypedList(int length) {
     final start = addr;
-    final wrapper =
-        Float32ArrayWrapper(NativeLibrary.instance.HEAPU8.buffer, start, length)
-            as JSFloat32Array;
+    final wrapper = Float32ArrayWrapper(
+        NativeLibrary.instance.HEAPF32.buffer, start, length) as JSFloat32Array;
     return wrapper.toDart;
   }
 }
diff --git a/thermion_dart/lib/src/bindings/src/thermion_dart_ffi.g.dart b/thermion_dart/lib/src/bindings/src/thermion_dart_ffi.g.dart
index 44f0d235..b37c00cf 100644
--- a/thermion_dart/lib/src/bindings/src/thermion_dart_ffi.g.dart
+++ b/thermion_dart/lib/src/bindings/src/thermion_dart_ffi.g.dart
@@ -738,11 +738,12 @@ external ffi.Pointer<TLinearImage> Image_createEmpty(
 
 @ffi.Native<
     ffi.Pointer<TLinearImage> Function(
-        ffi.Pointer<ffi.Uint8>, ffi.Size, ffi.Pointer<ffi.Char>)>(isLeaf: true)
+        ffi.Pointer<ffi.Uint8>, ffi.Size, ffi.Pointer<ffi.Char>, ffi.Bool alpha)>(isLeaf: true)
 external ffi.Pointer<TLinearImage> Image_decode(
   ffi.Pointer<ffi.Uint8> data,
   int length,
   ffi.Pointer<ffi.Char> name,
+  bool alpha
 );
 
 @ffi.Native<ffi.Pointer<ffi.Float> Function(ffi.Pointer<TLinearImage>)>(
@@ -2367,6 +2368,7 @@ external void Image_createEmptyRenderThread(
         ffi.Pointer<ffi.Uint8>,
         ffi.Size,
         ffi.Pointer<ffi.Char>,
+        ffi.Bool,
         ffi.Pointer<
             ffi.NativeFunction<
                 ffi.Void Function(ffi.Pointer<TLinearImage>)>>)>(isLeaf: true)
@@ -2374,6 +2376,7 @@ external void Image_decodeRenderThread(
   ffi.Pointer<ffi.Uint8> data,
   int length,
   ffi.Pointer<ffi.Char> name,
+  bool alpha,
   ffi.Pointer<ffi.NativeFunction<ffi.Void Function(ffi.Pointer<TLinearImage>)>>
       onComplete,
 );
diff --git a/thermion_dart/lib/src/bindings/src/thermion_dart_js_interop.g.dart b/thermion_dart/lib/src/bindings/src/thermion_dart_js_interop.g.dart
index ef592057..4456a072 100644
--- a/thermion_dart/lib/src/bindings/src/thermion_dart_js_interop.g.dart
+++ b/thermion_dart/lib/src/bindings/src/thermion_dart_js_interop.g.dart
@@ -393,6 +393,7 @@ extension type NativeLibrary(JSObject _) implements JSObject {
       JSFunction f, String signature);
   external void removeFunction<T>(Pointer<NativeFunction<T>> f);
   external JSUint8Array get HEAPU8;
+  external JSFloat32Array get HEAPF32;
 
   external void _Thermion_resizeCanvas(
     int width,
@@ -812,6 +813,7 @@ extension type NativeLibrary(JSObject _) implements JSObject {
     Pointer<Uint8> data,
     size_t length,
     Pointer<Char> name,
+    bool alpha
   );
   external Pointer<Float32> _Image_getBytes(
     Pointer<TLinearImage> tLinearImage,
@@ -1670,6 +1672,7 @@ extension type NativeLibrary(JSObject _) implements JSObject {
     Pointer<Uint8> data,
     size_t length,
     Pointer<Char> name,
+    bool alpha,
     Pointer<self.NativeFunction<void Function(PointerClass<TLinearImage>)>>
         onComplete,
   );
@@ -3071,8 +3074,9 @@ self.Pointer<TLinearImage> Image_decode(
   self.Pointer<Uint8> data,
   Dart__darwin_size_t length,
   self.Pointer<Char> name,
+  bool alpha
 ) {
-  final result = _lib._Image_decode(data, length, name);
+  final result = _lib._Image_decode(data, length, name, alpha);
   return self.Pointer<TLinearImage>(result);
 }
 
@@ -4839,11 +4843,12 @@ void Image_decodeRenderThread(
   self.Pointer<Uint8> data,
   Dart__darwin_size_t length,
   self.Pointer<Char> name,
+  bool alpha,
   self.Pointer<self.NativeFunction<void Function(Pointer<TLinearImage>)>>
       onComplete,
 ) {
   final result =
-      _lib._Image_decodeRenderThread(data, length, name, onComplete.cast());
+      _lib._Image_decodeRenderThread(data, length, name, alpha, onComplete.cast());
   return result;
 }
 
diff --git a/thermion_dart/lib/src/filament/src/implementation/ffi_filament_app.dart b/thermion_dart/lib/src/filament/src/implementation/ffi_filament_app.dart
index 793cb84a..58f3f455 100644
--- a/thermion_dart/lib/src/filament/src/implementation/ffi_filament_app.dart
+++ b/thermion_dart/lib/src/filament/src/implementation/ffi_filament_app.dart
@@ -310,6 +310,7 @@ class FFIFilamentApp extends FilamentApp<Pointer> {
       TextureSamplerType textureSamplerType = TextureSamplerType.SAMPLER_2D,
       TextureFormat textureFormat = TextureFormat.RGBA16F,
       int? importedTextureHandle}) async {
+    
     var bitmask = flags.fold(0, (a, b) => a | b.value);
 
     final texturePtr = await withPointerCallback<TTexture>((cb) {
@@ -362,19 +363,28 @@ class FFIFilamentApp extends FilamentApp<Pointer> {
     return FFITextureSampler(samplerPtr);
   }
 
+  /// Decodes the image data into a native LinearImage (floating point).
+  /// If [requireAlpha] is true, the decoded image will always contain an 
+  /// alpha channel (even if the original image did not contain one). 
   ///
-  ///
-  ///
-  Future<LinearImage> decodeImage(Uint8List data) async {
-    final name = "image";
+  Future<LinearImage> decodeImage(Uint8List data, { String name = "image", bool requireAlpha = false}) async {
+    
     late Pointer stackPtr;
     if (FILAMENT_WASM) {
       //stackPtr = stackSave();
     }
+    var now = DateTime.now();
+
     var ptr = Image_decode(
       data.address,
       data.length,
       name.toNativeUtf8().cast<Char>(),
+      requireAlpha
+    );
+
+    var finished = DateTime.now();
+    print(
+      "Image_decode (render thread) finished in ${finished.millisecondsSinceEpoch - now.millisecondsSinceEpoch}ms",
     );
 
     if (FILAMENT_WASM) {
@@ -1114,11 +1124,11 @@ class FFIFilamentApp extends FilamentApp<Pointer> {
     if (FILAMENT_WASM) {
       stackPtr = stackSave();
     }
-    TransformManager_setTransform(transformManager, entity, matrix4ToDouble4x4(transform));
+    TransformManager_setTransform(
+        transformManager, entity, matrix4ToDouble4x4(transform));
     if (FILAMENT_WASM) {
       stackRestore(stackPtr);
     }
-    
   }
 
   ///
@@ -1129,7 +1139,7 @@ class FFIFilamentApp extends FilamentApp<Pointer> {
     if (FILAMENT_WASM) {
       stackPtr = stackSave();
     }
-    
+
     var transform = double4x4ToMatrix4(
         TransformManager_getWorldTransform(transformManager, entity));
     if (FILAMENT_WASM) {
@@ -1137,5 +1147,4 @@ class FFIFilamentApp extends FilamentApp<Pointer> {
     }
     return transform;
   }
-
 }
diff --git a/thermion_dart/lib/src/filament/src/implementation/ffi_texture.dart b/thermion_dart/lib/src/filament/src/implementation/ffi_texture.dart
index 2d5bc51e..96adb51e 100644
--- a/thermion_dart/lib/src/filament/src/implementation/ffi_texture.dart
+++ b/thermion_dart/lib/src/filament/src/implementation/ffi_texture.dart
@@ -165,15 +165,10 @@ class FFILinearImage extends LinearImage {
   }
 
   static Future<FFILinearImage> decode(Uint8List data,
-      [String name = "image"]) async {
-    final namePtr = name.toNativeUtf8();
-
-    final imagePtr = await withPointerCallback<TLinearImage>((cb) {
-      Image_decodeRenderThread(
-          data.address, data.lengthInBytes, namePtr.cast(), cb);
-    });
-
-    return FFILinearImage(imagePtr);
+      {String name = "image", bool requireAlpha = false}) async {
+    final image = await FilamentApp.instance!
+        .decodeImage(data, name: name, requireAlpha: requireAlpha);
+    return image as FFILinearImage;
   }
 
   Future<void> destroy() async {
diff --git a/thermion_dart/lib/src/filament/src/interface/filament_app.dart b/thermion_dart/lib/src/filament/src/interface/filament_app.dart
index a66a1485..ad0eef14 100644
--- a/thermion_dart/lib/src/filament/src/interface/filament_app.dart
+++ b/thermion_dart/lib/src/filament/src/interface/filament_app.dart
@@ -133,7 +133,7 @@ abstract class FilamentApp<T> {
   ///
   /// Decodes the specified image data.
   ///
-  Future<LinearImage> decodeImage(Uint8List data);
+  Future<LinearImage> decodeImage(Uint8List data, { String name = "image", bool requireAlpha = false});
 
   ///
   /// Creates an (empty) imge with the given dimensions.
diff --git a/thermion_dart/lib/src/filament/src/interface/texture.dart b/thermion_dart/lib/src/filament/src/interface/texture.dart
index a19ced43..f37f7658 100644
--- a/thermion_dart/lib/src/filament/src/interface/texture.dart
+++ b/thermion_dart/lib/src/filament/src/interface/texture.dart
@@ -484,11 +484,17 @@ abstract class LinearImage {
   Future<int> getHeight();
   Future<int> getChannels();
   
+  /// Decodes the image contained in [data] and returns a texture of 
+  /// the corresponding size with the image set as mip-level 0. 
   ///
   ///
-  ///
-  static Future<Texture> decodeToTexture(Uint8List data, { TextureFormat textureFormat = TextureFormat.RGB32F, PixelDataFormat pixelDataFormat = PixelDataFormat.RGB, PixelDataType pixelDataType = PixelDataType.FLOAT, int levels = 1}) async {
-    final decodedImage = await FilamentApp.instance!.decodeImage(data);
+  static Future<Texture> decodeToTexture(Uint8List data, { 
+    TextureFormat textureFormat = TextureFormat.RGB32F,
+    PixelDataFormat pixelDataFormat = PixelDataFormat.RGB,
+    PixelDataType pixelDataType = PixelDataType.FLOAT,
+    int levels = 1, 
+    bool requireAlpha = false}) async {
+    final decodedImage = await FilamentApp.instance!.decodeImage(data, requireAlpha: requireAlpha);
     
     final texture = await FilamentApp.instance!.createTexture(
       await decodedImage.getWidth(),
diff --git a/thermion_dart/native/include/c_api/TTexture.h b/thermion_dart/native/include/c_api/TTexture.h
index 76991a01..360d3beb 100644
--- a/thermion_dart/native/include/c_api/TTexture.h
+++ b/thermion_dart/native/include/c_api/TTexture.h
@@ -262,7 +262,7 @@ EMSCRIPTEN_KEEPALIVE TTextureUsage Texture_getUsage(TTexture *tTexture, uint32_t
 EMSCRIPTEN_KEEPALIVE void Texture_generateMipMaps(TTexture *tTexture, TEngine *tEngine);
 
 EMSCRIPTEN_KEEPALIVE TLinearImage *Image_createEmpty(uint32_t width,uint32_t height,uint32_t channel);
-EMSCRIPTEN_KEEPALIVE TLinearImage *Image_decode(uint8_t* data, size_t length, const char* name);
+EMSCRIPTEN_KEEPALIVE TLinearImage *Image_decode(uint8_t* data, size_t length, const char* name, bool alpha);
 EMSCRIPTEN_KEEPALIVE float *Image_getBytes(TLinearImage *tLinearImage);
 EMSCRIPTEN_KEEPALIVE void Image_destroy(TLinearImage *tLinearImage);
 EMSCRIPTEN_KEEPALIVE uint32_t Image_getWidth(TLinearImage *tLinearImage);
diff --git a/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h b/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h
index 4a1f3e23..d36c0daf 100644
--- a/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h
+++ b/thermion_dart/native/include/c_api/ThermionDartRenderThreadApi.h
@@ -172,7 +172,7 @@ namespace thermion
 
         // Image methods
         void Image_createEmptyRenderThread(uint32_t width, uint32_t height, uint32_t channel, void (*onComplete)(TLinearImage *));
-        void Image_decodeRenderThread(uint8_t* data, size_t length, const char* name, void (*onComplete)(TLinearImage *));
+        void Image_decodeRenderThread(uint8_t* data, size_t length, const char* name, bool alpha, void (*onComplete)(TLinearImage *));
         void Image_getBytesRenderThread(TLinearImage *tLinearImage, void (*onComplete)(float *));
         void Image_destroyRenderThread(TLinearImage *tLinearImage, uint32_t requestId, VoidCallback onComplete);
         void Image_getWidthRenderThread(TLinearImage *tLinearImage, void (*onComplete)(uint32_t));
diff --git a/thermion_dart/native/src/c_api/TTexture.cpp b/thermion_dart/native/src/c_api/TTexture.cpp
index fce288c3..f43870d8 100644
--- a/thermion_dart/native/src/c_api/TTexture.cpp
+++ b/thermion_dart/native/src/c_api/TTexture.cpp
@@ -40,14 +40,16 @@ namespace thermion
     }
 
 
-    EMSCRIPTEN_KEEPALIVE TLinearImage *Image_decode(uint8_t *data, size_t length, const char *name = "image")
+    EMSCRIPTEN_KEEPALIVE TLinearImage *Image_decode(uint8_t *data, size_t length, const char *name = "image", bool alpha = true)
     {
 
         auto start = std::chrono::high_resolution_clock::now();
 
         int width, height, channels;
+
+        TRACE("Loading image from buffer of length %lu bytes (alpha : %s)", length, alpha ? "true" : "false");
         
-        uint8_t *imgData = stbi_load_from_memory(data, length, &width, &height, &channels, 0);
+        uint8_t *imgData = stbi_load_from_memory(data, length, &width, &height, &channels, alpha ? 4 : 3);
         
         if (!imgData) {
             ERROR("Failed to decode image");
@@ -56,7 +58,7 @@ namespace thermion
         
         LinearImage *linearImage;
         
-        if(channels == 4) {
+        if(alpha) {
             linearImage = new LinearImage(toLinearWithAlpha<uint8_t>(
                 width,
                 height, 
@@ -75,7 +77,7 @@ namespace thermion
         auto end = std::chrono::high_resolution_clock::now();
         auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
 
-        TRACE("Image decoded successfully in %lld ms", duration.count());        
+        TRACE("Image decoded successfully in %lld ms (%dx%dx%d)", duration.count(), width, height, channels);        
         
         if (!linearImage->isValid())
         {
@@ -383,28 +385,14 @@ namespace thermion
 
             switch (bufferFormat)
             {
-            case PixelBufferDescriptor::PixelDataFormat::RGB:
-            case PixelBufferDescriptor::PixelDataFormat::RGBA:
-            {
-                size_t expectedSize = width * height * channels * sizeof(float);
-                if (size != expectedSize)
-                {
-                    Log("Size mismatch (expected %lu, got %lu)", expectedSize, size);
+                case PixelBufferDescriptor::PixelDataFormat::RGB:
+                case PixelBufferDescriptor::PixelDataFormat::RGBA:
+                case PixelBufferDescriptor::PixelDataFormat::RGB_INTEGER:
+                case PixelBufferDescriptor::PixelDataFormat::RGBA_INTEGER:
+                    break;
+                default:
+                    Log("Unsupported buffer format type : %d", bufferFormat);
                     return false;
-                }
-                break;
-            }
-            case PixelBufferDescriptor::PixelDataFormat::RGB_INTEGER:
-            case PixelBufferDescriptor::PixelDataFormat::RGBA_INTEGER:
-                if (size != width * height * channels * sizeof(uint8_t))
-                {
-                    Log("Size mismatch");
-                    // return false;
-                }
-                break;
-            default:
-                Log("Unsupported buffer format type : %d", bufferFormat);
-                return false;
             }
 
             // the texture upload is async, so we need to copy the buffer
diff --git a/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp b/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp
index a4548e8e..5f1373cc 100644
--- a/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp
+++ b/thermion_dart/native/src/c_api/ThermionDartRenderThreadApi.cpp
@@ -755,12 +755,12 @@ extern "C"
     auto fut = _renderThread->add_task(lambda);
   }
 
-  EMSCRIPTEN_KEEPALIVE void Image_decodeRenderThread(uint8_t *data, size_t length, const char *name, void (*onComplete)(TLinearImage *))
+  EMSCRIPTEN_KEEPALIVE void Image_decodeRenderThread(uint8_t *data, size_t length, const char *name, bool alpha, void (*onComplete)(TLinearImage *))
   {
     std::packaged_task<void()> lambda(
         [=]() mutable
         {
-          auto image = Image_decode(data, length, name);
+          auto image = Image_decode(data, length, name, alpha);
           PROXY(onComplete(image));
         });
     auto fut = _renderThread->add_task(lambda);