svg_loader: move the display property to the style

The display property, like any other node's style property,
should be part of a node style. This ensures its correct
copying and inheritance.
For the 'symbol' node, which is not rendered unless it is
used within a 'use' node, the display property can also be
applied. Because of that it cannot be utilized during scene
construction to determine whether the symbol is being defined
or used within a 'use' context.

src/loaders/svg/tvgSvgCssStyle.cpp

@@ -57,6 +57,14 @@ static void _copyStyle(SvgStyleProperty* to, const SvgStyleProperty* from)
             to->flagsImportance = (to->flagsImportance | SvgStyleFlags::PaintOrder);
         }
     }
+    if (((from->flags & SvgStyleFlags::Display) && !(to->flags & SvgStyleFlags::Display)) ||
+        _isImportanceApplicable(to->flagsImportance, from->flagsImportance, SvgStyleFlags::Display)) {
+        to->display = from->display;
+        to->flags = (to->flags | SvgStyleFlags::Display);
+        if (from->flagsImportance & SvgStyleFlags::Display) {
+            to->flagsImportance = (to->flagsImportance | SvgStyleFlags::Display);
+        }
+    }
     //Fill
     if (((from->fill.flags & SvgFillFlags::Paint) && !(to->flags & SvgStyleFlags::Fill)) ||
         _isImportanceApplicable(to->flagsImportance, from->flagsImportance, SvgStyleFlags::Fill)) {

src/loaders/svg/tvgSvgLoader.cpp

@@ -1156,8 +1156,9 @@ static void _handleDisplayAttr(TVG_UNUSED SvgLoaderData* loader, SvgNode* node,
     //       The default is "inline" which means visible and "none" means invisible.
     //       Depending on the type of node, additional functionality may be required.
     //       refer to https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/display
-    if (!strcmp(value, "none")) node->display = false;
+    node->style->flags = (node->style->flags | SvgStyleFlags::Display);
-    else node->display = true;
+    if (!strcmp(value, "none")) node->style->display = false;
+    else node->style->display = true;
 }
 
 
@@ -1442,7 +1443,7 @@ static SvgNode* _createNode(SvgNode* parent, SvgNodeType type)
     node->style->paintOrder = _toPaintOrder("fill stroke");
 
     //Default display is true("inline").
-    node->display = true;
+    node->style->display = true;
 
     node->parent = parent;
     node->type = type;
@@ -1518,7 +1519,7 @@ static SvgNode* _createClipPathNode(SvgLoaderData* loader, SvgNode* parent, cons
     loader->svgParse->node = _createNode(parent, SvgNodeType::ClipPath);
     if (!loader->svgParse->node) return nullptr;
 
-    loader->svgParse->node->display = false;
+    loader->svgParse->node->style->display = false;
     loader->svgParse->node->node.clip.userSpace = true;
 
     func(buf, bufLength, _attrParseClipPathNode, loader);
@@ -1543,7 +1544,6 @@ static SvgNode* _createSymbolNode(SvgLoaderData* loader, SvgNode* parent, const
     loader->svgParse->node = _createNode(parent, SvgNodeType::Symbol);
     if (!loader->svgParse->node) return nullptr;
 
-    loader->svgParse->node->display = false;
     loader->svgParse->node->node.symbol.align = AspectRatioAlign::XMidYMid;
     loader->svgParse->node->node.symbol.meetOrSlice = AspectRatioMeetOrSlice::Meet;
     loader->svgParse->node->node.symbol.overflowVisible = false;
@@ -2969,6 +2969,9 @@ static void _styleCopy(SvgStyleProperty* to, const SvgStyleProperty* from)
     if (from->flags & SvgStyleFlags::PaintOrder) {
         to->paintOrder = from->paintOrder;
     }
+    if (from->flags & SvgStyleFlags::Display) {
+        to->display = from->display;
+    }
     //Fill
     to->fill.flags = (to->fill.flags | from->fill.flags);
     if (from->fill.flags & SvgFillFlags::Paint) {
@@ -3029,7 +3032,6 @@ static void _styleCopy(SvgStyleProperty* to, const SvgStyleProperty* from)
 
 static void _copyAttr(SvgNode* to, const SvgNode* from)
 {
-    to->display = from->display;
     //Copy matrix attribute
     if (from->transform) {
         to->transform = (Matrix*)malloc(sizeof(Matrix));
@@ -3373,7 +3375,7 @@ static void _inefficientNodeCheck(TVG_UNUSED SvgNode* node)
 #ifdef THORVG_LOG_ENABLED
     auto type = simpleXmlNodeTypeToString(node->type);
 
-    if (!node->display && node->type != SvgNodeType::ClipPath && node->type != SvgNodeType::Symbol) TVGLOG("SVG", "Inefficient elements used [Display is none][Node Type : %s]", type);
+    if (!node->style->display && node->type != SvgNodeType::ClipPath) TVGLOG("SVG", "Inefficient elements used [Display is none][Node Type : %s]", type);
     if (node->style->opacity == 0) TVGLOG("SVG", "Inefficient elements used [Opacity is zero][Node Type : %s]", type);
     if (node->style->fill.opacity == 0 && node->style->stroke.opacity == 0) TVGLOG("SVG", "Inefficient elements used [Fill opacity and stroke opacity are zero][Node Type : %s]", type);
 

src/loaders/svg/tvgSvgLoaderCommon.h

@@ -485,11 +485,12 @@ struct SvgStyleProperty
     SvgComposite mask;
     int opacity;
     SvgColor color;
-    bool curColorSet;
     char* cssClass;
-    bool paintOrder; //true if default (fill, stroke), false otherwise
     SvgStyleFlags flags;
     SvgStyleFlags flagsImportance; //indicates the importance of the flag - if set, higher priority is applied (https://drafts.csswg.org/css-cascade-4/#importance)
+    bool curColorSet;
+    bool paintOrder; //true if default (fill, stroke), false otherwise
+    bool display;
 };
 
 struct SvgNode
@@ -518,7 +519,6 @@ struct SvgNode
         SvgCssStyleNode cssStyle;
         SvgSymbolNode symbol;
     } node;
-    bool display;
     ~SvgNode();
 };
 

src/loaders/svg/tvgSvgSceneBuilder.cpp

@@ -310,7 +310,7 @@ static void _applyProperty(SvgLoaderData& loaderData, SvgNode* node, Shape* vg,
 
     //Clip transformation is applied directly to the path in the _appendClipShape function
     if (node->transform && !clip) vg->transform(*node->transform);
-    if (node->type == SvgNodeType::Doc || !node->display) return;
+    if (node->type == SvgNodeType::Doc || !node->style->display) return;
 
     //If fill property is nullptr then do nothing
     if (style->fill.paint.none) {
@@ -782,13 +782,13 @@ static unique_ptr<Scene> _sceneBuildHelper(SvgLoaderData& loaderData, const SvgN
         // For a Symbol node, the viewBox transformation has to be applied first - see _useBuildHelper()
         if (!mask && node->transform && node->type != SvgNodeType::Symbol) scene->transform(*node->transform);
 
-        if (node->display && node->style->opacity != 0) {
+        if (node->style->display && node->style->opacity != 0) {
             auto child = node->child.data;
             for (uint32_t i = 0; i < node->child.count; ++i, ++child) {
                 if (_isGroupType((*child)->type)) {
                     if ((*child)->type == SvgNodeType::Use)
                         scene->push(_useBuildHelper(loaderData, *child, vBox, svgPath, depth + 1, isMaskWhite));
-                    else
+                    else if (!((*child)->type == SvgNodeType::Symbol && node->type != SvgNodeType::Use))
                         scene->push(_sceneBuildHelper(loaderData, *child, vBox, svgPath, false, depth + 1, isMaskWhite));
                 } else if ((*child)->type == SvgNodeType::Image) {
                     auto image = _imageBuildHelper(loaderData, *child, vBox, svgPath);