add support for multiple bone animations using quaternions

lib/animations/animation_data.dart

@@ -1,5 +1,7 @@
 import 'dart:typed_data';
 
+import 'package:vector_math/vector_math_64.dart';
+
 ///
 /// Specifies frame data (i.e. weights) to animate the morph targets contained in [morphTargets] under a mesh named [mesh].
 /// [data] is laid out as numFrames x numMorphTargets.
@@ -40,7 +42,7 @@ class MorphAnimationData {
 class BoneAnimationData {
   final String boneName;
   final List<String> meshNames;
-  final Float32List frameData;
+  final List<Quaternion> frameData;
   double frameLengthInMs;
   BoneAnimationData(
       this.boneName, this.meshNames, this.frameData, this.frameLengthInMs);

lib/filament_controller.dart

@@ -272,12 +272,9 @@ abstract class FilamentController {
       FilamentEntity entity, MorphAnimationData animation);
 
   ///
-  /// Animates morph target weights/bone transforms (where each frame requires a duration of [frameLengthInMs].
-  /// [morphWeights] is a list of doubles in frame-major format.
-  /// Each frame is [numWeights] in length, and each entry is the weight to be applied to the morph target located at that index in the mesh primitive at that frame.
-  /// for now we only allow animating a single bone (though multiple skinned targets are supported)
+  /// Starts animating a bone (joint) according to the specified [animation].
   ///
-  Future setBoneAnimation(FilamentEntity entity, BoneAnimationData animation);
+  Future addBoneAnimation(FilamentEntity entity, BoneAnimationData animation);
 
   ///
   /// Sets the local joint transform for the bone at the given index in [entity] for the mesh under [meshName].

lib/filament_controller_ffi.dart

@@ -691,41 +691,40 @@ class FilamentControllerFFI extends FilamentController {
   }
 
   @override
-  Future setBoneAnimation(
+  Future addBoneAnimation(
       FilamentEntity entity, BoneAnimationData animation) async {
     if (_viewer == null) {
       throw Exception("No viewer available, ignoring");
     }
-    // var data = calloc<Float>(animation.frameData.length);
-    // int offset = 0;
-    // var numFrames = animation.frameData.length ~/ 7;
-    // var boneNames = calloc<Pointer<Char>>(1);
-    // boneNames.elementAt(0).value =
-    //     animation.boneName.toNativeUtf8().cast<Char>();
 
-    // var meshNames = calloc<Pointer<Char>>(animation.meshNames.length);
-    // for (int i = 0; i < animation.meshNames.length; i++) {
-    //   meshNames.elementAt(i).value =
-    //       animation.meshNames[i].toNativeUtf8().cast<Char>();
-    // }
+    var numFrames = animation.frameData.length;
 
-    // for (int i = 0; i < animation.frameData.length; i++) {
-    //   data.elementAt(offset).value = animation.frameData[i];
-    //   offset += 1;
-    // }
+    var meshNames = calloc<Pointer<Char>>(animation.meshNames.length);
+    for (int i = 0; i < animation.meshNames.length; i++) {
+      meshNames.elementAt(i).value =
+          animation.meshNames[i].toNativeUtf8().cast<Char>();
+    }
 
-    // await _channel.invokeMethod("setBoneAnimation", [
-    //   _assetManager!,
-    //   asset,
-    //   data,
-    //   numFrames,
-    //   1,
-    //   boneNames,
-    //   meshNames,
-    //   animation.meshNames.length,
-    //   animation.frameLengthInMs
-    // ]);
-    // calloc.free(data);
+    var data = calloc<Float>(numFrames * 4);
+
+    for (int i = 0; i < numFrames; i++) {
+      data.elementAt(i * 4).value = animation.frameData[i].w;
+      data.elementAt((i * 4) + 1).value = animation.frameData[i].x;
+      data.elementAt((i * 4) + 2).value = animation.frameData[i].y;
+      data.elementAt((i * 4) + 3).value = animation.frameData[i].z;
+    }
+
+    add_bone_animation(
+        _assetManager!,
+        entity,
+        data,
+        numFrames,
+        animation.boneName.toNativeUtf8().cast<Char>(),
+        meshNames,
+        animation.meshNames.length,
+        animation.frameLengthInMs);
+    calloc.free(data);
+    calloc.free(meshNames);
   }
 
   @override

lib/generated_bindings.dart

@@ -370,20 +370,18 @@ external bool set_morph_animation(
             EntityId,
             ffi.Pointer<ffi.Float>,
             ffi.Int,
-            ffi.Int,
-            ffi.Pointer<ffi.Pointer<ffi.Char>>,
+            ffi.Pointer<ffi.Char>,
             ffi.Pointer<ffi.Pointer<ffi.Char>>,
             ffi.Int,
             ffi.Float)>(
-    symbol: 'set_bone_animation', assetId: 'flutter_filament_plugin')
-external void set_bone_animation(
+    symbol: 'add_bone_animation', assetId: 'flutter_filament_plugin')
+external void add_bone_animation(
   ffi.Pointer<ffi.Void> assetManager,
   int asset,
   ffi.Pointer<ffi.Float> frameData,
   int numFrames,
-  int numBones,
-  ffi.Pointer<ffi.Pointer<ffi.Char>> boneNames,
-  ffi.Pointer<ffi.Pointer<ffi.Char>> meshName,
+  ffi.Pointer<ffi.Char> boneName,
+  ffi.Pointer<ffi.Pointer<ffi.Char>> meshNames,
   int numMeshTargets,
   double frameLengthInMs,
 );