lottie: Newly added support for the text feature.

This enhancement enables embedded glyphs rendering.
The 'fonts' and 'chars' properties are now supported.

README.md

@@ -256,8 +256,7 @@ ThorVG aims to fully support Lottie Animation features. Lottie is a JSON-based v
 Currently, ThorVG provides experimental support for Lottie Animation, and while most features are supported, a few advanced properties of Lottie may not be available yet:
 <br />
 
- - Texts 
- - Shape Modifiers (Pucker/Bloat, Twist, Merge, ZigZag)
+ - Shape Modifiers
  - Layer Effects
  - Expressions
 

src/loaders/lottie/tvgLottieBuilder.cpp

@@ -418,7 +418,7 @@ static void _updateEllipse(LottieGroup* parent, LottieObject** child, float fram
 
 static void _updatePath(LottieGroup* parent, LottieObject** child, float frameNo, TVG_UNUSED Inlist<RenderContext>& contexts, RenderContext* ctx)
 {
-    auto path= static_cast<LottiePath*>(*child);
+    auto path = static_cast<LottiePath*>(*child);
 
     if (ctx->repeater) {
         auto p = Shape::gen();
@@ -439,6 +439,77 @@ static void _updatePath(LottieGroup* parent, LottieObject** child, float frameNo
 }
 
 
+static void _updateText(LottieGroup* parent, LottieObject** child, float frameNo, TVG_UNUSED Inlist<RenderContext>& contexts, TVG_UNUSED RenderContext* ctx)
+{
+    auto text = static_cast<LottieText*>(*child);
+    auto& doc = text->doc(frameNo);
+    auto p = doc.text;
+
+    if (!p || !text->font) return;
+
+    auto scale = doc.size * 0.01f;
+    float spacing = text->spacing(frameNo) / scale;
+    Point cursor = {0.0f, 0.0f};
+    auto scene = Scene::gen();
+
+    //text string
+    while (*p != '\0') {
+        //find the glyph
+        for (auto g = text->font->chars.data; g < text->font->chars.end(); ++g) {
+            auto glyph = *g;
+            //draw matched glyphs
+            if (!strncmp(glyph->code, p, glyph->len)) {
+                //TODO: caching?
+                auto shape = Shape::gen();
+                for (auto g = glyph->children.data; g < glyph->children.end(); ++g) {
+                    auto group = static_cast<LottieGroup*>(*g);
+                    for (auto p = group->children.data; p < group->children.end(); ++p) {
+                        if (static_cast<LottiePath*>(*p)->pathset(frameNo, P(shape)->rs.path.cmds, P(shape)->rs.path.pts)) {
+                            P(shape)->update(RenderUpdateFlag::Path);
+                        }
+                    }
+                }
+                shape->fill(doc.color.rgb[0], doc.color.rgb[1], doc.color.rgb[2]);
+                shape->translate(cursor.x, cursor.y);
+
+                if (doc.stroke.render) {
+                    shape->stroke(StrokeJoin::Round);
+                    shape->stroke(doc.stroke.width / scale);
+                    shape->stroke(doc.stroke.color.rgb[0], doc.stroke.color.rgb[1], doc.stroke.color.rgb[2]);
+                }
+
+                scene->push(std::move(shape));
+
+                p += glyph->len; 
+
+                //end of text, new line of the cursor position
+                if (*p == 13 || *p == 3) {
+                    cursor.x = 0.0f;
+                    cursor.y += (doc.height / scale);
+                    ++p;
+                //advance the cursor position horizontally
+                } else {
+                    cursor.x += glyph->width + spacing;
+                }
+                break;
+            }
+        }
+    }
+
+    //text layout position
+    Point layout = {doc.bbox.pos.x, (doc.bbox.pos.y * 0.5f) - doc.shift};
+
+    //adjust the layout
+    if (doc.justify == 1) layout.x -= (cursor.x * scale);              //right aligned
+    else if (doc.justify == 2) layout.x -= (cursor.x * 0.5f * scale);  //center aligned
+
+    scene->translate(layout.x, layout.y);
+    scene->scale(scale);
+
+    parent->scene->push(std::move(scene));
+}
+
+
 static void _updateStar(LottieGroup* parent, LottiePolyStar* star, Matrix* transform, float frameNo, Shape* merging)
 {
     static constexpr auto POLYSTAR_MAGIC_NUMBER = 0.47829f / 0.28f;
@@ -790,6 +861,10 @@ static void _updateChildren(LottieGroup* parent, float frameNo, Inlist<RenderCon
                     _updateTrimpath(parent, child, frameNo, contexts, ctx);
                     break;
                 }
+                case LottieObject::Text: {
+                    _updateText(parent, child, frameNo, contexts, ctx);
+                    break;
+                }
                 case LottieObject::Repeater: {
                     _updateRepeater(parent, child, frameNo, contexts, ctx);
                     break;
@@ -1028,6 +1103,26 @@ static void _checkFragment(LottieGroup* parent)
 }
 
 
+static void _attachFont(LottieComposition* comp, LottieLayer* parent)
+{
+    //TODO: Consider to migrate this attachment to the frame update time.
+    for (auto c = parent->children.data; c < parent->children.end(); ++c) {
+        auto text = static_cast<LottieText*>(*c);
+        auto& doc = text->doc(0);
+        if (!doc.name) continue;
+        auto len = strlen(doc.name);
+        for (uint32_t i = 0; i < comp->fonts.count; ++i) {
+            auto font = comp->fonts[i];
+            auto len2 = strlen(font->name);
+            if (!strncmp(font->name, doc.name, len < len2 ? len : len2)) {
+                text->font = font;
+                break;
+            }
+        }
+    }
+}
+
+
 static bool _buildComposition(LottieComposition* comp, LottieGroup* parent)
 {
     if (parent->children.count == 0) return false;
@@ -1049,6 +1144,9 @@ static bool _buildComposition(LottieComposition* comp, LottieGroup* parent)
 
         _checkFragment(static_cast<LottieGroup*>(*c));
 
+        //attach the necessary font data
+        if (child->type == LottieLayer::Text) _attachFont(comp, child);
+
         child->statical &= parent->statical;
         parent->statical &= child->statical;
     }

src/loaders/lottie/tvgLottieModel.cpp

@@ -203,4 +203,9 @@ LottieComposition::~LottieComposition()
     for (auto a = assets.data; a < assets.end(); ++a) {
         delete(*a);
     }
+
+    //delete fonts
+    for (auto f = fonts.data; f < fonts.end(); ++f) {
+        delete(*f);
+    }
 }

src/loaders/lottie/tvgLottieModel.h

@@ -219,6 +219,7 @@ struct LottieObject
         Polystar,
         Image,
         Trimpath,
+        Text,
         Repeater,
         RoundedCorner
     };
@@ -235,6 +236,61 @@ struct LottieObject
 };
 
 
+struct LottieGlyph
+{
+    Array<LottieObject*> children;   //glyph shapes.
+    float width;
+    char* code;
+    uint16_t size;
+    uint8_t len;
+
+    void prepare()
+    {
+        len = strlen(code);
+    }
+
+    ~LottieGlyph()
+    {
+        for (auto p = children.data; p < children.end(); ++p) delete(*p);
+        free(code);
+    }
+};
+
+
+struct LottieFont
+{
+    enum Origin : uint8_t { Local = 0, CssURL, ScriptURL, FontURL, Embedded };
+
+    ~LottieFont()
+    {
+        for (auto c = chars.data; c < chars.end(); ++c) delete(*c);
+        free(style);
+        free(family);
+        free(name);
+    }
+
+    Array<LottieGlyph*> chars;
+    char* name = nullptr;
+    char* family = nullptr;
+    char* style = nullptr;
+    float ascent = 0.0f;
+    Origin origin = Embedded;
+};
+
+
+struct LottieText : LottieObject
+{
+    void prepare()
+    {
+        LottieObject::type = LottieObject::Text;
+    }
+
+    LottieTextDoc doc;
+    LottieFont* font;
+    LottieFloat spacing = 0.0f;  //letter spacing
+};
+
+
 struct LottieTrimpath : LottieObject
 {
     enum Type : uint8_t { Individual = 1, Simultaneous = 2 };
@@ -561,6 +617,7 @@ struct LottieComposition
     float frameRate;
     Array<LottieObject*> assets;
     Array<LottieInterpolator*> interpolators;
+    Array<LottieFont*> fonts;
     bool initiated = false;
 };
 

src/loaders/lottie/tvgLottieParser.cpp

@@ -153,6 +153,28 @@ StrokeJoin LottieParser::getStrokeJoin()
 }
 
 
+void LottieParser::getValue(TextDocument& doc)
+{
+    enterObject();
+    while (auto key = nextObjectKey()) {
+        if (!strcmp(key, "s")) doc.size = getFloat();
+        else if (!strcmp(key, "f")) doc.name = getStringCopy();
+        else if (!strcmp(key, "t")) doc.text = getStringCopy();
+        else if (!strcmp(key, "j")) doc.justify = getInt();
+        else if (!strcmp(key, "tr")) doc.tracking = getInt();
+        else if (!strcmp(key, "lh")) doc.height = getFloat();
+        else if (!strcmp(key, "ls")) doc.shift = getFloat();
+        else if (!strcmp(key, "fc")) getValue(doc.color);
+        else if (!strcmp(key, "ps")) getValue(doc.bbox.pos);
+        else if (!strcmp(key, "sz")) getValue(doc.bbox.size);
+        else if (!strcmp(key, "sc")) getValue(doc.stroke.color);
+        else if (!strcmp(key, "sw")) doc.stroke.width = getFloat();
+        else if (!strcmp(key, "of")) doc.stroke.render = getBool();
+        else skip(key);
+    }
+}
+
+
 void LottieParser::getValue(PathSet& path)
 {
     Array<Point> outs, ins, pts;
@@ -427,6 +449,8 @@ void LottieParser::parsePropertyInternal(T& prop)
         getValue(prop.value);
     //multi value property
     } else {
+        //TODO: Here might be a single frame.
+        //Can we figure out the frame number in advance?
         enterArray();
         while (nextArrayValue()) {
             //keyframes value
@@ -816,14 +840,14 @@ LottieObject* LottieParser::parseObject()
 }
 
 
-void LottieParser::parseObject(LottieGroup* parent)
+void LottieParser::parseObject(Array<LottieObject*>& parent)
 {
     enterObject();
     while (auto key = nextObjectKey()) {
         if (!strcmp(key, "ty")) {
             if (auto child = parseObject()) {
                 if (child->hidden) delete(child);
-                else parent->children.push(child);
+                else parent.push(child);
             }
         } else skip(key);
     }
@@ -907,6 +931,24 @@ LottieObject* LottieParser::parseAsset()
 }
 
 
+LottieFont* LottieParser::parseFont()
+{
+    enterObject();
+
+    auto font = new LottieFont;
+
+    while (auto key = nextObjectKey()) {
+        if (!strcmp(key, "fName")) font->name = getStringCopy();
+        else if (!strcmp(key, "fFamily")) font->family = getStringCopy();
+        else if (!strcmp(key, "fStyle")) font->style = getStringCopy();
+        else if (!strcmp(key, "ascent")) font->ascent = getFloat();
+        else if (!strcmp(key, "origin")) font->origin = (LottieFont::Origin) getInt();
+        else skip(key);
+    }
+    return font;
+}
+
+
 void LottieParser::parseAssets()
 {
     enterArray();
@@ -918,6 +960,58 @@ void LottieParser::parseAssets()
 }
 
 
+void LottieParser::parseChars()
+{
+    if (comp->fonts.count == 0) {
+        TVGERR("LOTTIE", "No font data?");
+        return;
+    }
+
+    enterArray();
+    while (nextArrayValue()) {
+        enterObject();
+        //a new glyph
+        auto glyph = new LottieGlyph;
+        char* style = nullptr;
+        char* family = nullptr;
+        while (auto key = nextObjectKey()) {
+            if (!strcmp("ch", key)) glyph->code = getStringCopy();
+            else if (!strcmp("size", key)) glyph->size = static_cast<uint16_t>(getFloat());
+            else if (!strcmp("style", key)) style = const_cast<char*>(getString());
+            else if (!strcmp("w", key)) glyph->width = getFloat();
+            else if (!strcmp("fFamily", key)) family = const_cast<char*>(getString());
+            else if (!strcmp("data", key))
+            {   //glyph shapes
+                enterObject();
+                while (auto key = nextObjectKey()) {
+                    if (!strcmp(key, "shapes")) parseShapes(glyph->children);
+                }
+            } else skip(key);
+        }
+        //aggregate the font characters
+        for (uint32_t i = 0; i < comp->fonts.count; ++i) {
+            auto& font = comp->fonts[i];
+            if (!strcmp(font->family, family) && !strcmp(font->style, style)) font->chars.push(glyph);
+            else TVGERR("LOTTIE", "No font data?");
+        }
+        glyph->prepare();
+    }
+}
+
+void LottieParser::parseFonts()
+{
+    enterObject();
+    while (auto key = nextObjectKey()) {
+        if (!strcmp("list", key)) {
+            enterArray();
+            while (nextArrayValue()) {
+                comp->fonts.push(parseFont());
+            }
+        } else skip(key);
+    }
+}
+
+
 LottieObject* LottieParser::parseGroup()
 {
     auto group = new LottieGroup;
@@ -928,7 +1022,7 @@ LottieObject* LottieParser::parseGroup()
             group->name = getStringCopy();
         } else if (!strcmp(key, "it")) {
             enterArray();
-            while (nextArrayValue()) parseObject(group);
+            while (nextArrayValue()) parseObject(group->children);
         } else skip(key);
     }
     if (group->children.empty()) {
@@ -947,7 +1041,7 @@ void LottieParser::parseTimeRemap(LottieLayer* layer)
 }
 
 
-void LottieParser::parseShapes(LottieLayer* layer)
+void LottieParser::parseShapes(Array<LottieObject*>& parent)
 {
     enterArray();
     while (nextArrayValue()) {
@@ -955,11 +1049,11 @@ void LottieParser::parseShapes(LottieLayer* layer)
         while (auto key = nextObjectKey()) {
             if (!strcmp(key, "it")) {
                 enterArray();
-                while (nextArrayValue()) parseObject(layer);
+                while (nextArrayValue()) parseObject(parent);
             } else if (!strcmp(key, "ty")) {
                 if (auto child = parseObject()) {
                     if (child->hidden) delete(child);
-                    else layer->children.push(child);
+                    else parent.push(child);
                 }
             } else skip(key);
         }
@@ -967,6 +1061,43 @@ void LottieParser::parseShapes(LottieLayer* layer)
 }
 
 
+void LottieParser::parseTextRange(LottieText* text)
+{
+    enterArray();
+    while (nextArrayValue()) {
+        enterObject();
+        while (auto key2 = nextObjectKey()) {
+            if (!strcmp(key2, "a")) {  //text style
+                enterObject();
+                while (auto key3 = nextObjectKey()) {
+                    if (!strcmp(key3, "t")) parseProperty(text->spacing);
+                    else skip(key3);
+                }
+            } else skip(key2);
+        }
+    }
+}
+
+
+void LottieParser::parseText(Array<LottieObject*>& parent)
+{
+    enterObject();
+
+    auto text = new LottieText;
+
+    while (auto key = nextObjectKey()) {
+        if (!strcmp(key, "d")) parseProperty(text->doc);
+        else if (!strcmp(key, "a")) parseTextRange(text);
+        //else if (!strcmp(key, "p")) TVGLOG("LOTTIE", "Text Follow Path (p) is not supported"); 
+        //else if (!strcmp(key, "m")) TVGLOG("LOTTIE", "Text Alignment Option (m) is not supported");
+        else skip(key);
+    }
+
+    text->prepare();
+    parent.push(text);
+}
+
+
 void LottieParser::getLayerSize(uint32_t& val)
 {
     if (val == 0) {
@@ -1032,7 +1163,7 @@ LottieLayer* LottieParser::parseLayer()
             layer->transform = parseTransform(ddd);
         }
         else if (!strcmp(key, "ao")) layer->autoOrient = getInt();
-        else if (!strcmp(key, "shapes")) parseShapes(layer);
+        else if (!strcmp(key, "shapes")) parseShapes(layer->children);
         else if (!strcmp(key, "ip")) layer->inFrame = getFloat();
         else if (!strcmp(key, "op")) layer->outFrame = getFloat();
         else if (!strcmp(key, "st")) layer->startFrame = getFloat();
@@ -1047,6 +1178,7 @@ LottieLayer* LottieParser::parseLayer()
         else if (!strcmp(key, "hd")) layer->hidden = getBool();
         else if (!strcmp(key, "refId")) layer->refId = getStringCopy();
         else if (!strcmp(key, "td")) layer->matteSrc = getInt();      //used for matte layer
+        else if (!strcmp(key, "t")) parseText(layer->children);
         else if (!strcmp(key, "ef"))
         {
             TVGERR("LOTTIE", "layer effect(ef) is not supported!");
@@ -1126,6 +1258,8 @@ bool LottieParser::parse()
         else if (!strcmp(key, "nm")) comp->name = getStringCopy();
         else if (!strcmp(key, "assets")) parseAssets();
         else if (!strcmp(key, "layers")) comp->root = parseLayers();
+        else if (!strcmp(key, "fonts")) parseFonts();
+        else if (!strcmp(key, "chars")) parseChars();
         else skip(key);
     }
 

src/loaders/lottie/tvgLottieParser.h

@@ -51,6 +51,8 @@ private:
 
     void getInperpolatorPoint(Point& pt);
     void getPathSet(LottiePathSet& path);
+    void getLayerSize(uint32_t& val);
+    void getValue(TextDocument& doc);
     void getValue(PathSet& path);
     void getValue(Array<Point>& pts);
     void getValue(ColorStop& color);
@@ -58,7 +60,6 @@ private:
     void getValue(uint8_t& val);
     void getValue(Point& pt);
     void getValue(RGB24& color);
-    void getLayerSize(uint32_t& val);
 
     template<typename T> bool parseTangent(const char *key, LottieVectorFrame<T>& value);
     template<typename T> bool parseTangent(const char *key, LottieScalarFrame<T>& value);
@@ -85,14 +86,19 @@ private:
     LottieMask* parseMask();
     LottieTrimpath* parseTrimpath();
     LottieRepeater* parseRepeater();
+    LottieFont* parseFont();
 
-    void parseObject(LottieGroup* parent);
-    void parseShapes(LottieLayer* layer);
+    void parseObject(Array<LottieObject*>& parent);
+    void parseShapes(Array<LottieObject*>& parent);
+    void parseText(Array<LottieObject*>& parent);
     void parseMasks(LottieLayer* layer);
     void parseTimeRemap(LottieLayer* layer);
     void parseStrokeDash(LottieStroke* stroke);
     void parseGradient(LottieGradient* gradient, const char* key);
+    void parseTextRange(LottieText* text);
     void parseAssets();
+    void parseFonts();
+    void parseChars();
 
     //Current parsing context
     struct Context {

src/loaders/lottie/tvgLottieProperty.h

@@ -51,6 +51,30 @@ struct ColorStop
 };
 
 
+struct LottieFont;
+
+struct TextDocument
+{
+    char* text = nullptr;
+    float height;
+    float shift;
+    RGB24 color;
+    struct {
+        Point pos;
+        Point size;
+    } bbox;
+    struct {
+        RGB24 color;
+        float width;
+        bool render = false;
+    } stroke;
+    char* name = nullptr;
+    uint16_t size;
+    uint8_t justify;
+    uint8_t tracking;
+};
+
+
 static inline RGB24 operator-(const RGB24& lhs, const RGB24& rhs)
 {
     return {lhs.rgb[0] - rhs.rgb[0], lhs.rgb[1] - rhs.rgb[1], lhs.rgb[2] - rhs.rgb[2]};
@@ -505,6 +529,66 @@ struct LottiePosition
 };
 
 
+struct LottieTextDoc
+{
+    Array<LottieScalarFrame<TextDocument>>* frames = nullptr;
+    TextDocument value;
+
+    ~LottieTextDoc()
+    {
+        free(value.text);
+        free(value.name);
+
+        if (!frames) return;
+        for (auto p = frames->data; p < frames->end(); ++p) {
+            free((*p).value.text);
+            free((*p).value.name);
+        }
+        delete(frames);
+    }
+
+    LottieScalarFrame<TextDocument>& newFrame()
+    {
+        if (!frames) frames = new Array<LottieScalarFrame<TextDocument>>;
+        if (frames->count + 1 >= frames->reserved) {
+            auto old = frames->reserved;
+            frames->grow(frames->count + 2);
+            memset((void*)(frames->data + old), 0x00, sizeof(LottieScalarFrame<TextDocument>) * (frames->reserved - old));
+        }
+        ++frames->count;
+        return frames->last();
+    }
+
+    LottieScalarFrame<TextDocument>& nextFrame()
+    {
+        return (*frames)[frames->count];
+    }
+
+    TextDocument& operator()(float frameNo)
+    {
+        if (!frames) return value;
+        if (frames->count == 1 || frameNo <= frames->first().no) return frames->first().value;
+        if (frameNo >= frames->last().no) return frames->last().value;
+
+        uint32_t low = 0;
+        uint32_t high = frames->count - 1;
+
+        while (low <= high) {
+            auto mid = low + (high - low) / 2;
+            auto frame = frames->data + mid;
+            if (mathEqual(frameNo, frame->no)) return frame->value;
+            else if (frameNo < frame->no) high = mid - 1;
+            else low = mid + 1;
+        }
+        if (high < low) low = high;
+
+        return (*frames)[low].value;
+    }
+
+    void prepare() {}
+};
+
+
 using LottiePoint = LottieProperty<Point>;
 using LottieFloat = LottieProperty<float>;
 using LottieOpacity = LottieProperty<uint8_t>;

src/renderer/sw_engine/tvgSwRasterTexmap.h

@@ -1108,8 +1108,7 @@ static bool _rasterTexmapPolygon(SwSurface* surface, const SwImage* image, const
 
     float ys = FLT_MAX, ye = -1.0f;
     for (int i = 0; i < 4; i++) {
-        mathMultiply(&vertices[i].pt, transform);
-
+        if (transform) mathMultiply(&vertices[i].pt, transform);
         if (vertices[i].pt.y < ys) ys = vertices[i].pt.y;
         if (vertices[i].pt.y > ye) ye = vertices[i].pt.y;
     }