lottie: support Layer Effect Fill type

During the fill properties, only color/opacity is available.
Not support other properties since they are unclear spec now.

issue: https://github.com/thorvg/thorvg/issues/2718

src/loaders/lottie/tvgLottieBuilder.cpp

@@ -1314,14 +1314,20 @@ void LottieBuilder::updateEffect(LottieLayer* layer, float frameNo)
     for (auto ef = layer->effects.begin(); ef < layer->effects.end(); ++ef) {
         if (!(*ef)->enable) continue;
         switch ((*ef)->type) {
+            case LottieEffect::Fill: {
+                auto effect = static_cast<LottieFxFill*>(*ef);
+                auto color = effect->color(frameNo);
+                layer->scene->push(SceneEffect::Fill, color.rgb[0], color.rgb[1], color.rgb[2], (int)(255.0f *effect->opacity(frameNo)));
+                break;
+            }
             case LottieEffect::DropShadow: {
-                auto effect = static_cast<LottieDropShadow*>(*ef);
+                auto effect = static_cast<LottieFxDropShadow*>(*ef);
                 auto color = effect->color(frameNo);
                 layer->scene->push(SceneEffect::DropShadow, color.rgb[0], color.rgb[1], color.rgb[2], (int)effect->opacity(frameNo), effect->angle(frameNo), effect->distance(frameNo), effect->blurness(frameNo) * BLUR_TO_SIGMA, QUALITY);
                 break;
             }
             case LottieEffect::GaussianBlur: {
-                auto effect = static_cast<LottieGaussianBlur*>(*ef);
+                auto effect = static_cast<LottieFxGaussianBlur*>(*ef);
                 layer->scene->push(SceneEffect::GaussianBlur, effect->blurness(frameNo) * BLUR_TO_SIGMA, effect->direction(frameNo) - 1, effect->wrap(frameNo), QUALITY);
                 break;
             }

src/loaders/lottie/tvgLottieModel.h

@@ -83,6 +83,7 @@ struct LottieEffect
     {
         DropShadow = 0,
         GaussianBlur = 1,
+        Fill = 2,
     };
 
     virtual ~LottieEffect() {}
@@ -92,28 +93,45 @@ struct LottieEffect
 };
 
 
-struct LottieDropShadow : LottieEffect
+struct LottieFxFill : LottieEffect
+{
+    //LottieFloat fillMask?
+    //LottieDropDown allMask?
+    LottieColor color;
+    //LottieDropDown inverted
+    //LottieSlider horizontalFeather
+    //LottieSlider verticalFeather
+    LottieSlider opacity = 0;
+
+    LottieFxFill()
+    {
+        type = Fill;
+    }
+};
+
+
+struct LottieFxDropShadow : LottieEffect
 {
     LottieColor color;
-    LottieFloat opacity = 0;
+    LottieSlider opacity = 0;
     LottieAngle angle = 0.0f;
     LottieSlider distance = 0.0f;
     LottieSlider blurness = 0.0f;
 
-    LottieDropShadow()
+    LottieFxDropShadow()
     {
         type = DropShadow;
     }
 };
 
 
-struct LottieGaussianBlur : LottieEffect
+struct LottieFxGaussianBlur : LottieEffect
 {
     LottieSlider blurness = 0.0f;
     LottieCheckbox direction = 0;
     LottieCheckbox wrap = 0;
 
-    LottieGaussianBlur()
+    LottieFxGaussianBlur()
     {
         type = GaussianBlur;
     }

src/loaders/lottie/tvgLottieParser.cpp

@@ -60,8 +60,9 @@ static unsigned long _int2str(int num)
 LottieEffect* LottieParser::getEffect(int type)
 {
     switch (type) {
-        case 25: return new LottieDropShadow;
+        case 21: return new LottieFxFill;
-        case 29: return new LottieGaussianBlur;
+        case 25: return new LottieFxDropShadow;
+        case 29: return new LottieFxGaussianBlur;
         default: return nullptr;
     }
 }
@@ -1268,7 +1269,30 @@ void LottieParser::parseMasks(LottieLayer* layer)
 }
 
 
-void LottieParser::parseGaussianBlur(LottieGaussianBlur* effect)
+void LottieParser::parseFill(LottieFxFill* effect)
+{
+    int idx = 0;  //fill mask -> all mask -> color -> invert -> h feather -> v feather -> opacity
+    enterArray();
+    while (nextArrayValue()) {
+        enterObject();
+        while (auto key = nextObjectKey()) {
+            if (KEY_AS("v")) {
+                enterObject();
+                while (auto key = nextObjectKey()) {
+                    if (KEY_AS("k")) {
+                        if (idx == 2) parsePropertyInternal(effect->color);
+                        else if (idx == 6) parsePropertyInternal(effect->opacity);
+                        else skip();
+                    } else skip();
+                }
+                ++idx;
+            } else skip();
+        }
+    }
+}
+
+
+void LottieParser::parseGaussianBlur(LottieFxGaussianBlur* effect)
 {
     int idx = 0;  //blurness -> direction -> wrap
     enterArray();
@@ -1292,7 +1316,7 @@ void LottieParser::parseGaussianBlur(LottieGaussianBlur* effect)
 }
 
 
-void LottieParser::parseDropShadow(LottieDropShadow* effect)
+void LottieParser::parseDropShadow(LottieFxDropShadow* effect)
 {
     int idx = 0;  //color -> opacity -> angle -> distance -> blur
     enterArray();
@@ -1321,12 +1345,16 @@ void LottieParser::parseDropShadow(LottieDropShadow* effect)
 void LottieParser::parseEffect(LottieEffect* effect)
 {
     switch (effect->type) {
+        case LottieEffect::Fill: {
+            parseFill(static_cast<LottieFxFill*>(effect));
+            break;
+        }
         case LottieEffect::GaussianBlur: {
-            parseGaussianBlur(static_cast<LottieGaussianBlur*>(effect));
+            parseGaussianBlur(static_cast<LottieFxGaussianBlur*>(effect));
             break;
         }
         case LottieEffect::DropShadow: {
-            parseDropShadow(static_cast<LottieDropShadow*>(effect));
+            parseDropShadow(static_cast<LottieFxDropShadow*>(effect));
             break;
         }
         default: break;
@@ -1336,11 +1364,10 @@ void LottieParser::parseEffect(LottieEffect* effect)
 
 void LottieParser::parseEffects(LottieLayer* layer)
 {
-    auto invalid = true;
-
     enterArray();
     while (nextArrayValue()) {
         LottieEffect* effect = nullptr;
+        auto invalid = true;
         enterObject();
         while (auto key = nextObjectKey()) {
             //type must be priortized.

src/loaders/lottie/tvgLottieParser.h

@@ -98,8 +98,9 @@ private:
     LottieFont* parseFont();
     LottieMarker* parseMarker();
 
-    void parseGaussianBlur(LottieGaussianBlur* effect);
+    void parseFill(LottieFxFill* effect);
-    void parseDropShadow(LottieDropShadow* effect);
+    void parseGaussianBlur(LottieFxGaussianBlur* effect);
+    void parseDropShadow(LottieFxDropShadow* effect);
 
     bool parseDirection(LottieShape* shape, const char* key);
     bool parseCommon(LottieObject* obj, const char* key);