lottie: minor optimization.

remove an unnecessary scene in the lottie render tree.

src/loaders/lottie/tvgLottieBuilder.cpp

@@ -1136,19 +1136,10 @@ bool LottieBuilder::update(LottieComposition* comp, float frameNo)
     if (frameNo < comp->startFrame) frameNo = comp->startFrame;
     if (frameNo >= comp->endFrame) frameNo = (comp->endFrame - 1);
 
-    //Update root layer
-    auto root = comp->root;
-
-    //Prepare render data
-    if (!root->scene) {
-        auto scene = Scene::gen();
-        root->scene = scene.get();
-        comp->scene->push(std::move(scene));
-    } else {
-        root->scene->clear();
-    }
-
     //update children layers
+    auto root = comp->root;
+    root->scene->clear();
+
     for (auto child = root->children.end() - 1; child >= root->children.data; --child) {
         _updateLayer(root, static_cast<LottieLayer*>(*child), frameNo);
     }
@@ -1158,10 +1149,10 @@ bool LottieBuilder::update(LottieComposition* comp, float frameNo)
 
 void LottieBuilder::build(LottieComposition* comp)
 {
-    if (!comp || !comp->root || comp->scene) return;
+    if (!comp) return;
 
-    comp->scene = Scene::gen().release();
-    if (!comp->scene) return;
+    comp->root->scene = Scene::gen().release();
+    if (!comp->root->scene) return;
 
     _buildComposition(comp, comp->root);
 
@@ -1170,5 +1161,5 @@ void LottieBuilder::build(LottieComposition* comp)
     //viewport clip
     auto clip = Shape::gen();
     clip->appendRect(0, 0, static_cast<float>(comp->w), static_cast<float>(comp->h));
-    comp->scene->composite(std::move(clip), CompositeMethod::ClipPath);
+    comp->root->scene->composite(std::move(clip), CompositeMethod::ClipPath);
 }

src/loaders/lottie/tvgLottieLoader.cpp

@@ -50,15 +50,13 @@ static float _str2float(const char* str, int len)
 void LottieLoader::run(unsigned tid)
 {
     //update frame
-    if (comp && comp->scene) {
+    if (comp) {
         builder->update(comp, frameNo);
     //initial loading
     } else {
-        if (!comp) {
-            LottieParser parser(content, dirName);
-            if (!parser.parse()) return;
-            comp = parser.comp;
-        }
+        LottieParser parser(content, dirName);
+        if (!parser.parse()) return;
+        comp = parser.comp;
         builder->build(comp);
     }
 }
@@ -294,7 +292,7 @@ Paint* LottieLoader::paint()
     this->done();
     if (!comp) return nullptr;
     comp->initiated = true;
-    return comp->scene;
+    return comp->root->scene;
 }
 
 

src/loaders/lottie/tvgLottieModel.cpp

@@ -207,7 +207,7 @@ float LottieLayer::remap(float frameNo)
 
 LottieComposition::~LottieComposition()
 {
-    if (!initiated) delete(scene);
+    if (!initiated) delete(root->scene);
 
     delete(root);
     free(version);

src/loaders/lottie/tvgLottieModel.h

@@ -609,8 +609,6 @@ struct LottieComposition
         return endFrame - startFrame;
     }
 
-    Scene* scene = nullptr;       //tvg render data
-
     LottieLayer* root = nullptr;
     char* version = nullptr;
     char* name = nullptr;