loader SvgSceneBuilder: Add root node to clipping viewBox.

If the boundary of scene created through the scenebuilder is larger than the viewbox,
scene(SVG's root) should be clipped to the size of the viewbox.
So, if scene need a clip, add a parent root and add clippath composition to that root.

diff --git a/src/loaders/svg/tvgSvgSceneBuilder.cpp b/src/loaders/svg/tvgSvgSceneBuilder.cpp
index 38b3b6e..0bbc023 100644 (file)
--- a/src/loaders/svg/tvgSvgSceneBuilder.cpp
+++ b/src/loaders/svg/tvgSvgSceneBuilder.cpp
@@ -386,6 +386,32 @@ unique_ptr<Scene> _sceneBuildHelper(const SvgNode* node, float vx, float vy, flo
     return nullptr;
 }
 
+unique_ptr<Scene> _buildRoot(const SvgNode* node, float vx, float vy, float vw, float vh)
+{
+    unique_ptr<Scene> root;
+    auto docNode = move(_sceneBuildHelper(node, vx, vy, vw, vh));
+    float x, y, w, h;
+
+    if (docNode->bounds(&x, &y, &w, &h) != Result::Success) return nullptr;
+
+    if (x < vx || y < vy || w > vh || h > vh) {
+        auto viewBoxClip = Shape::gen();
+        viewBoxClip->appendRect(vx, vy ,vw, vh, 0, 0);
+        viewBoxClip->fill(0, 0, 0, 255);
+
+        auto compositeLayer = Scene::gen();
+        compositeLayer->composite(move(viewBoxClip), tvg::CompositeMethod::ClipPath);
+        compositeLayer->push(move(docNode));
+
+        root = Scene::gen();
+        root->push(move(compositeLayer));
+    }
+    else
+    {
+        root = move(docNode);
+    }
+    return root;
+}
 
 SvgSceneBuilder::SvgSceneBuilder()
 {
@@ -401,5 +427,5 @@ unique_ptr<Scene> SvgSceneBuilder::build(SvgNode* node)
 {
     if (!node || (node->type != SvgNodeType::Doc)) return nullptr;
 
-    return _sceneBuildHelper(node, node->node.doc.vx, node->node.doc.vy, node->node.doc.vw, node->node.doc.vh);
+    return _buildRoot(node, node->node.doc.vx, node->node.doc.vy, node->node.doc.vw, node->node.doc.vh);
 }