[flutter] skeleton drawable, vertices creation

spine-cpp/spine-cpp/include/spine/Atlas.h

@@ -84,11 +84,12 @@ namespace spine {
 		TextureWrap vWrap;
 		int width, height;
 		bool pma;
+        int index;
 
 		explicit AtlasPage(const String &inName) : name(inName), format(Format_RGBA8888),
 												   minFilter(TextureFilter_Nearest),
 												   magFilter(TextureFilter_Nearest), uWrap(TextureWrap_ClampToEdge),
-												   vWrap(TextureWrap_ClampToEdge), width(0), height(0), pma(false) {
+												   vWrap(TextureWrap_ClampToEdge), width(0), height(0), pma(false), index(0) {
 		}
 	};
 

spine-cpp/spine-cpp/src/spine/Atlas.cpp

@@ -286,6 +286,7 @@ void Atlas::load(const char *begin, int length, const char *dir, bool createText
 			} else {
 				page->texturePath = String(path, true);
 			}
+            page->index = _pages.size();
 			_pages.add(page);
 		} else {
 			AtlasRegion *region = new (__FILE__, __LINE__) AtlasRegion();

spine-flutter/example/assets/skeleton.atlas

@@ -0,0 +1,6 @@
+skeleton.png
+size:188,198
+filter:Linear,Linear
+pma:true
+Screenshot 2022-08-19 at 13.45.53
+bounds:2,2,184,194

spine-flutter/example/assets/skeleton.json

@@ -0,0 +1,40 @@
+{
+  "skeleton": {
+    "hash": "EzIWQLMq9sw",
+    "spine": "4.1.08",
+    "x": -92,
+    "y": -97,
+    "width": 184,
+    "height": 194,
+    "images": "",
+    "audio": ""
+  },
+  "bones": [
+    {
+      "name": "root"
+    }
+  ],
+  "slots": [
+    {
+      "name": "image",
+      "bone": "root",
+      "attachment": "Screenshot 2022-08-19 at 13.45.53"
+    }
+  ],
+  "skins": [
+    {
+      "name": "default",
+      "attachments": {
+        "image": {
+          "Screenshot 2022-08-19 at 13.45.53": {
+            "width": 184,
+            "height": 194
+          }
+        }
+      }
+    }
+  ],
+  "animations": {
+    "animation": {}
+  }
+}

spine-flutter/example/lib/main.dart

@@ -27,9 +27,13 @@ class _MyAppState extends State<MyApp> {
   }
   
   void loadSkeleton() async {
-    final atlas = await spine_flutter.loadAtlas(rootBundle, "assets/spineboy.atlas");
-    final skeletonData = spine_flutter.loadSkeletonDataJson(atlas, await rootBundle.loadString("assets/spineboy-pro.json"));
-    final skeletonDataBinary = spine_flutter.loadSkeletonDataBinary(atlas, await rootBundle.load("assets/spineboy-pro.skel"));
+    final atlas = await spine_flutter.loadAtlas(rootBundle, "assets/skeleton.atlas");
+    final skeletonData = spine_flutter.loadSkeletonDataJson(atlas, await rootBundle.loadString("assets/skeleton.json"));
+    // final skeletonDataBinary = spine_flutter.loadSkeletonDataBinary(atlas, await rootBundle.load("assets/spineboy-pro.skel"));
+    final skeletonDrawable = spine_flutter.createSkeletonDrawable(skeletonData);
+    spine_flutter.updateSkeletonDrawable(skeletonDrawable, 0.016);
+    final renderCommands = spine_flutter.renderSkeletonDrawable(skeletonDrawable);
+    print(renderCommands[0].vertices);
   }
 
   @override

spine-flutter/lib/spine_flutter.dart

@@ -1,6 +1,8 @@
 
 import 'dart:ffi';
 import 'dart:io';
+import 'dart:typed_data';
+import 'dart:ui';
 import 'package:ffi/ffi.dart';
 
 import 'package:flutter/services.dart';
@@ -60,6 +62,46 @@ Pointer<spine_skeleton_data> loadSkeletonDataBinary(Pointer<spine_atlas> atlas,
   return skeletonData;
 }
 
+Pointer<spine_skeleton_drawable> createSkeletonDrawable(Pointer<spine_skeleton_data> skeletonData) {
+  return _bindings.spine_skeleton_drawable_create(skeletonData);
+}
+
+void updateSkeletonDrawable(Pointer<spine_skeleton_drawable> drawable, double deltaTime) {
+  _bindings.spine_skeleton_drawable_update(drawable, deltaTime);
+}
+
+class RenderCommand {
+  late Vertices vertices;
+  late int atlasPageIndex;
+  RenderCommand? next;
+
+  RenderCommand(Pointer<spine_render_command> nativeCmd) {
+    atlasPageIndex = nativeCmd.ref.atlasPage;
+    int numVertices = nativeCmd.ref.numVertices;
+    int numIndices = nativeCmd.ref.numIndices;
+    // We pass the native data as views directly to Vertices.raw. According to the sources, the data
+    // is copied, so it doesn't matter that we free up the underlying memory on the next
+    // render call. See the implementation of Vertices.raw() here:
+    // https://github.com/flutter/engine/blob/5c60785b802ad2c8b8899608d949342d5c624952/lib/ui/painting/vertices.cc#L21
+    vertices = Vertices.raw(VertexMode.triangles,
+        nativeCmd.ref.positions.asTypedList(numVertices * 2),
+        textureCoordinates: nativeCmd.ref.uvs.asTypedList(numVertices * 2),
+        colors: nativeCmd.ref.colors.asTypedList(numVertices),
+        indices: nativeCmd.ref.indices.asTypedList(numIndices));
+  }
+}
+
+List<RenderCommand> renderSkeletonDrawable(Pointer<spine_skeleton_drawable> drawable) {
+  Pointer<spine_render_command> nativeCmd = _bindings.spine_skeleton_drawable_render(drawable);
+  List<RenderCommand> commands = [];
+  while(nativeCmd.address != nullptr.address) {
+    commands.add(RenderCommand(nativeCmd));
+    nativeCmd = nativeCmd.ref.next;
+  }
+  return commands;
+
+}
+
 const String _libName = 'spine_flutter';
 
 final DynamicLibrary _dylib = () {

spine-flutter/lib/spine_flutter_bindings_generated.dart

@@ -129,6 +129,76 @@ class SpineFlutterBindings {
       'spine_skeleton_data_dispose');
   late final _spine_skeleton_data_dispose = _spine_skeleton_data_disposePtr
       .asFunction<void Function(ffi.Pointer<spine_skeleton_data>)>();
+
+  ffi.Pointer<spine_skeleton_drawable> spine_skeleton_drawable_create(
+    ffi.Pointer<spine_skeleton_data> skeletonData,
+  ) {
+    return _spine_skeleton_drawable_create(
+      skeletonData,
+    );
+  }
+
+  late final _spine_skeleton_drawable_createPtr = _lookup<
+          ffi.NativeFunction<
+              ffi.Pointer<spine_skeleton_drawable> Function(
+                  ffi.Pointer<spine_skeleton_data>)>>(
+      'spine_skeleton_drawable_create');
+  late final _spine_skeleton_drawable_create =
+      _spine_skeleton_drawable_createPtr.asFunction<
+          ffi.Pointer<spine_skeleton_drawable> Function(
+              ffi.Pointer<spine_skeleton_data>)>();
+
+  void spine_skeleton_drawable_update(
+    ffi.Pointer<spine_skeleton_drawable> drawable,
+    double deltaTime,
+  ) {
+    return _spine_skeleton_drawable_update(
+      drawable,
+      deltaTime,
+    );
+  }
+
+  late final _spine_skeleton_drawable_updatePtr = _lookup<
+      ffi.NativeFunction<
+          ffi.Void Function(ffi.Pointer<spine_skeleton_drawable>,
+              ffi.Float)>>('spine_skeleton_drawable_update');
+  late final _spine_skeleton_drawable_update =
+      _spine_skeleton_drawable_updatePtr.asFunction<
+          void Function(ffi.Pointer<spine_skeleton_drawable>, double)>();
+
+  ffi.Pointer<spine_render_command> spine_skeleton_drawable_render(
+    ffi.Pointer<spine_skeleton_drawable> drawable,
+  ) {
+    return _spine_skeleton_drawable_render(
+      drawable,
+    );
+  }
+
+  late final _spine_skeleton_drawable_renderPtr = _lookup<
+          ffi.NativeFunction<
+              ffi.Pointer<spine_render_command> Function(
+                  ffi.Pointer<spine_skeleton_drawable>)>>(
+      'spine_skeleton_drawable_render');
+  late final _spine_skeleton_drawable_render =
+      _spine_skeleton_drawable_renderPtr.asFunction<
+          ffi.Pointer<spine_render_command> Function(
+              ffi.Pointer<spine_skeleton_drawable>)>();
+
+  void spine_skeleton_drawable_dispose(
+    ffi.Pointer<spine_skeleton_drawable> drawable,
+  ) {
+    return _spine_skeleton_drawable_dispose(
+      drawable,
+    );
+  }
+
+  late final _spine_skeleton_drawable_disposePtr = _lookup<
+          ffi.NativeFunction<
+              ffi.Void Function(ffi.Pointer<spine_skeleton_drawable>)>>(
+      'spine_skeleton_drawable_dispose');
+  late final _spine_skeleton_drawable_dispose =
+      _spine_skeleton_drawable_disposePtr
+          .asFunction<void Function(ffi.Pointer<spine_skeleton_drawable>)>();
 }
 
 class spine_atlas extends ffi.Struct {
@@ -147,3 +217,42 @@ class spine_skeleton_data extends ffi.Struct {
 
   external ffi.Pointer<ffi.Int8> error;
 }
+
+abstract class spine_blend_mode {
+  static const int SPINE_BLEND_MODE_NORMAL = 0;
+  static const int SPINE_BLEND_MODE_ADDITIVE = 1;
+  static const int SPINE_BLEND_MODE_MULTIPLY = 2;
+  static const int SPINE_BLEND_MODE_SCREEN = 3;
+}
+
+class spine_render_command extends ffi.Struct {
+  external ffi.Pointer<ffi.Float> positions;
+
+  external ffi.Pointer<ffi.Float> uvs;
+
+  external ffi.Pointer<ffi.Int32> colors;
+
+  @ffi.Int32()
+  external int numVertices;
+
+  external ffi.Pointer<ffi.Uint16> indices;
+
+  @ffi.Int32()
+  external int numIndices;
+
+  @ffi.Int32()
+  external int atlasPage;
+
+  @ffi.Int32()
+  external int blendMode;
+
+  external ffi.Pointer<spine_render_command> next;
+}
+
+class spine_skeleton_drawable extends ffi.Struct {
+  external ffi.Pointer<ffi.Void> skeleton;
+
+  external ffi.Pointer<ffi.Void> animationState;
+
+  external ffi.Pointer<spine_render_command> renderCommand;
+}

spine-flutter/src/spine_flutter.cpp

@@ -13,6 +13,7 @@ FFI_PLUGIN_EXPORT int32_t spine_minor_version() {
 }
 
 FFI_PLUGIN_EXPORT spine_atlas* spine_atlas_load(const char *atlasData) {
+    if (!atlasData) return nullptr;
     int length = strlen(atlasData);
     auto atlas = new Atlas(atlasData, length, "", (TextureLoader*)nullptr, false);
     spine_atlas *result = SpineExtension::calloc<spine_atlas>(1, __FILE__, __LINE__);
@@ -36,6 +37,9 @@ FFI_PLUGIN_EXPORT void spine_atlas_dispose(spine_atlas *atlas) {
 }
 
 FFI_PLUGIN_EXPORT spine_skeleton_data *spine_skeleton_data_load_json(spine_atlas *atlas, const char *skeletonData) {
+    if (!atlas) return nullptr;
+    if (!atlas->atlas) return nullptr;
+    if (!skeletonData) return nullptr;
     SkeletonJson json((Atlas*)atlas->atlas);
     SkeletonData *data = json.readSkeletonData(skeletonData);
     spine_skeleton_data *result = SpineExtension::calloc<spine_skeleton_data>(1, __FILE__, __LINE__);
@@ -47,6 +51,10 @@ FFI_PLUGIN_EXPORT spine_skeleton_data *spine_skeleton_data_load_json(spine_atlas
 }
 
 FFI_PLUGIN_EXPORT spine_skeleton_data* spine_skeleton_data_load_binary(spine_atlas *atlas, const unsigned char *skeletonData, int32_t length) {
+    if (!atlas) return nullptr;
+    if (!atlas->atlas) return nullptr;
+    if (!skeletonData) return nullptr;
+    if (length <= 0) return nullptr;
     SkeletonBinary binary((Atlas*)atlas->atlas);
     SkeletonData *data = binary.readSkeletonData(skeletonData, length);
     spine_skeleton_data *result = SpineExtension::calloc<spine_skeleton_data>(1, __FILE__, __LINE__);
@@ -64,6 +72,180 @@ FFI_PLUGIN_EXPORT void spine_skeleton_data_dispose(spine_skeleton_data *skeleton
     SpineExtension::free(skeletonData, __FILE__, __LINE__);
 }
 
+FFI_PLUGIN_EXPORT spine_skeleton_drawable *spine_skeleton_drawable_create(spine_skeleton_data *skeletonData) {
+    spine_skeleton_drawable *drawable = SpineExtension::calloc<spine_skeleton_drawable>(1, __FILE__, __LINE__);
+    drawable->skeleton = new Skeleton((SkeletonData*)skeletonData->skeletonData);
+    drawable->animationState = new AnimationState(new AnimationStateData((SkeletonData*)skeletonData->skeletonData));
+    return drawable;
+}
+
+FFI_PLUGIN_EXPORT void spine_skeleton_drawable_update(spine_skeleton_drawable *drawable, float deltaTime) {
+    if (!drawable) return;
+    if (!drawable->skeleton) return;
+    if (!drawable->animationState) return;
+
+    Skeleton *skeleton = (Skeleton*)drawable->skeleton;
+    AnimationState *animationState = (AnimationState*)drawable->animationState;
+    animationState->update(deltaTime);
+    animationState->apply(*skeleton);
+    skeleton->updateWorldTransform();
+}
+
+spine_render_command *spine_render_command_create(int32_t numVertices, int32_t numIndices, spine_blend_mode blendMode, int pageIndex) {
+    spine_render_command *cmd = SpineExtension::alloc<spine_render_command>(1, __FILE__, __LINE__);
+    cmd->positions = SpineExtension::alloc<float>(numVertices * 2, __FILE__, __LINE__);
+    cmd->uvs = SpineExtension::alloc<float>(numVertices * 2, __FILE__, __LINE__);
+    cmd->colors = SpineExtension::alloc<int32_t>(numVertices, __FILE__, __LINE__);
+    cmd->numVertices = numVertices;
+    cmd->indices = SpineExtension::alloc<uint16_t>(numIndices, __FILE__, __LINE__);
+    cmd->numIndices = numIndices;
+    cmd->blendMode = blendMode;
+    cmd->atlasPage = pageIndex;
+    cmd->next = nullptr;
+    return cmd;
+}
+
+void spine_render_command_dispose(spine_render_command *cmd) {
+    if (!cmd) return;
+    if (cmd->positions) SpineExtension::free(cmd->positions, __FILE__, __LINE__);
+    if (cmd->uvs) SpineExtension::free(cmd->uvs, __FILE__, __LINE__);
+    if (cmd->colors) SpineExtension::free(cmd->colors, __FILE__, __LINE__);
+    if (cmd->indices) SpineExtension::free(cmd->indices, __FILE__, __LINE__);
+    SpineExtension::free(cmd, __FILE__, __LINE__);
+}
+
+FFI_PLUGIN_EXPORT spine_render_command *spine_skeleton_drawable_render(spine_skeleton_drawable *drawable) {
+    if (!drawable) return nullptr;
+    if (!drawable->skeleton) return nullptr;
+
+    while (drawable->renderCommand) {
+        spine_render_command *cmd = drawable->renderCommand;
+        drawable->renderCommand = cmd->next;
+        spine_render_command_dispose(cmd);
+    }
+
+    Vector<unsigned short> quadIndices;
+    quadIndices.add(0);
+    quadIndices.add(1);
+    quadIndices.add(2);
+    quadIndices.add(2);
+    quadIndices.add(3);
+    quadIndices.add(0);
+    Vector<float> worldVertices;
+    SkeletonClipping clipper;
+    Skeleton *skeleton = (Skeleton*)drawable->skeleton;
+    spine_render_command *lastCommand = nullptr;
+
+    for (unsigned i = 0; i < skeleton->getSlots().size(); ++i) {
+        Slot &slot = *skeleton->getDrawOrder()[i];
+        Attachment *attachment = slot.getAttachment();
+        if (!attachment) continue;
+
+        // Early out if the slot color is 0 or the bone is not active
+        if (slot.getColor().a == 0 || !slot.getBone().isActive()) {
+            clipper.clipEnd(slot);
+            continue;
+        }
+
+        Vector<float> *vertices = &worldVertices;
+        int verticesCount = 0;
+        Vector<float> *uvs = NULL;
+        Vector<unsigned short> *indices;
+        int indicesCount = 0;
+        Color *attachmentColor;
+        int pageIndex = -1;
+
+        if (attachment->getRTTI().isExactly(RegionAttachment::rtti)) {
+            RegionAttachment *regionAttachment = (RegionAttachment *) attachment;
+            attachmentColor = &regionAttachment->getColor();
+
+            // Early out if the slot color is 0
+            if (attachmentColor->a == 0) {
+                clipper.clipEnd(slot);
+                continue;
+            }
+
+            worldVertices.setSize(8, 0);
+            regionAttachment->computeWorldVertices(slot, worldVertices, 0, 2);
+            verticesCount = 4;
+            uvs = &regionAttachment->getUVs();
+            indices = &quadIndices;
+            indicesCount = 6;
+            pageIndex = ((AtlasRegion *) regionAttachment->getRendererObject())->page->index;
+
+        } else if (attachment->getRTTI().isExactly(MeshAttachment::rtti)) {
+            MeshAttachment *mesh = (MeshAttachment *) attachment;
+            attachmentColor = &mesh->getColor();
+
+            // Early out if the slot color is 0
+            if (attachmentColor->a == 0) {
+                clipper.clipEnd(slot);
+                continue;
+            }
+
+            worldVertices.setSize(mesh->getWorldVerticesLength(), 0);
+            pageIndex = ((AtlasRegion *) mesh->getRendererObject())->page->index;
+            mesh->computeWorldVertices(slot, 0, mesh->getWorldVerticesLength(), worldVertices.buffer(), 0, 2);
+            verticesCount = mesh->getWorldVerticesLength() >> 1;
+            uvs = &mesh->getUVs();
+            indices = &mesh->getTriangles();
+            indicesCount = indices->size();
+
+        } else if (attachment->getRTTI().isExactly(ClippingAttachment::rtti)) {
+            ClippingAttachment *clip = (ClippingAttachment *) slot.getAttachment();
+            clipper.clipStart(slot, clip);
+            continue;
+        } else
+            continue;
+
+        uint8_t r = static_cast<uint8_t>(skeleton->getColor().r * slot.getColor().r * attachmentColor->r * 255);
+        uint8_t g = static_cast<uint8_t>(skeleton->getColor().g * slot.getColor().g * attachmentColor->g * 255);
+        uint8_t b = static_cast<uint8_t>(skeleton->getColor().b * slot.getColor().b * attachmentColor->b * 255);
+        uint8_t a = static_cast<uint8_t>(skeleton->getColor().a * slot.getColor().a * attachmentColor->a * 255);
+        uint32_t color = (a << 24) | (r << 16) | (g << 8) | b;
+
+        if (clipper.isClipping()) {
+            clipper.clipTriangles(worldVertices, *indices, *uvs, 2);
+            vertices = &clipper.getClippedVertices();
+            verticesCount = clipper.getClippedVertices().size() >> 1;
+            uvs = &clipper.getClippedUVs();
+            indices = &clipper.getClippedTriangles();
+            indicesCount = clipper.getClippedTriangles().size();
+        }
+
+        spine_render_command *cmd = spine_render_command_create(verticesCount, indicesCount, (spine_blend_mode)slot.getData().getBlendMode(), pageIndex);
+
+        memcpy(cmd->positions, vertices->buffer(), (verticesCount << 2) * sizeof(float));
+        memcpy(cmd->uvs, uvs->buffer(), (verticesCount << 2) * sizeof(float));
+        for (int ii = 0; ii < verticesCount; ii++) cmd->colors[ii] = color;
+        memcpy(cmd->indices, indices->buffer(), indices->size() * sizeof(uint16_t));
+
+        if (!lastCommand) {
+            drawable->renderCommand = lastCommand = cmd;
+        } else {
+            lastCommand->next = cmd;
+            lastCommand = cmd;
+        }
+
+        clipper.clipEnd(slot);
+    }
+    clipper.clipEnd();
+
+    return drawable->renderCommand;
+}
+
+FFI_PLUGIN_EXPORT void spine_skeleton_drawable_dispose(spine_skeleton_drawable *drawable) {
+    if (!drawable) return;
+    if (drawable->skeleton) delete (Skeleton*)drawable->skeleton;
+    if (drawable->animationState) delete (AnimationState*)drawable->animationState;
+    while (drawable->renderCommand) {
+        spine_render_command *cmd = drawable->renderCommand;
+        drawable->renderCommand = cmd->next;
+        spine_render_command_dispose(cmd);
+    }
+    SpineExtension::free(drawable, __FILE__, __LINE__);
+}
+
 spine::SpineExtension *spine::getDefaultExtension() {
    return new spine::DefaultSpineExtension();
 }

spine-flutter/src/spine_flutter.h

@@ -45,3 +45,33 @@ FFI_PLUGIN_EXPORT spine_skeleton_data* spine_skeleton_data_load_json(spine_atlas
 FFI_PLUGIN_EXPORT spine_skeleton_data* spine_skeleton_data_load_binary(spine_atlas *atlas, const unsigned char *skeletonData, int32_t length);
 FFI_PLUGIN_EXPORT void spine_skeleton_data_dispose(spine_skeleton_data *skeletonData);
 
+typedef enum spine_blend_mode {
+    SPINE_BLEND_MODE_NORMAL = 0,
+    SPINE_BLEND_MODE_ADDITIVE,
+    SPINE_BLEND_MODE_MULTIPLY,
+    SPINE_BLEND_MODE_SCREEN
+} spine_blend_mode;
+
+typedef struct spine_render_command {
+    float *positions;
+    float *uvs;
+    int32_t *colors;
+    int32_t numVertices;
+    uint16_t *indices;
+    int32_t numIndices;
+    int32_t atlasPage;
+    spine_blend_mode blendMode;
+    struct spine_render_command *next;
+} spine_render_command;
+
+typedef struct spine_skeleton_drawable {
+    void *skeleton;
+    void *animationState;
+    spine_render_command *renderCommand;
+} spine_skeleton_drawable;
+
+FFI_PLUGIN_EXPORT spine_skeleton_drawable *spine_skeleton_drawable_create(spine_skeleton_data *skeletonData);
+FFI_PLUGIN_EXPORT void spine_skeleton_drawable_update(spine_skeleton_drawable *drawable, float deltaTime);
+FFI_PLUGIN_EXPORT spine_render_command *spine_skeleton_drawable_render(spine_skeleton_drawable *drawable);
+FFI_PLUGIN_EXPORT void spine_skeleton_drawable_dispose(spine_skeleton_drawable *drawable);
+