Revert "Death to C++"

This reverts commit 066ac22605.

vendor/lunasvg/source/svgrenderstate.cpp

@@ -0,0 +1,61 @@
+#include "svgrenderstate.h"
+
+namespace lunasvg {
+
+SVGBlendInfo::SVGBlendInfo(const SVGElement* element)
+    : m_clipper(element->clipper())
+    , m_masker(element->masker())
+    , m_opacity(element->opacity())
+{
+}
+
+bool SVGBlendInfo::requiresCompositing(SVGRenderMode mode) const
+{
+    return (m_clipper && m_clipper->requiresMasking()) || (mode == SVGRenderMode::Painting && (m_masker || m_opacity < 1.f));
+}
+
+bool SVGRenderState::hasCycleReference(const SVGElement* element) const
+{
+    auto current = this;
+    do {
+        if(element == current->element())
+            return true;
+        current = current->parent();
+    } while(current);
+    return false;
+}
+
+void SVGRenderState::beginGroup(const SVGBlendInfo& blendInfo)
+{
+    auto requiresCompositing = blendInfo.requiresCompositing(m_mode);
+    if(requiresCompositing) {
+        auto boundingBox = m_currentTransform.mapRect(m_element->paintBoundingBox());
+        boundingBox.intersect(m_canvas->extents());
+        m_canvas = Canvas::create(boundingBox);
+    } else {
+        m_canvas->save();
+    }
+
+    if(!requiresCompositing && blendInfo.clipper()) {
+        blendInfo.clipper()->applyClipPath(*this);
+    }
+}
+
+void SVGRenderState::endGroup(const SVGBlendInfo& blendInfo)
+{
+    if(m_canvas == m_parent->canvas()) {
+        m_canvas->restore();
+        return;
+    }
+
+    auto opacity = m_mode == SVGRenderMode::Clipping ? 1.f : blendInfo.opacity();
+    if(blendInfo.clipper())
+        blendInfo.clipper()->applyClipMask(*this);
+    if(m_mode == SVGRenderMode::Painting && blendInfo.masker()) {
+        blendInfo.masker()->applyMask(*this);
+    }
+
+    m_parent->m_canvas->blendCanvas(*m_canvas, BlendMode::Src_Over, opacity);
+}
+
+} // namespace lunasvg