Add render child element

sammycage · Apr 8, 2024 · e03f683 · e03f683
1 parent d1eec96
commit e03f683
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Showing 2 changed files with 23 additions and 0 deletions.
diff --git a/include/lunasvg.h b/include/lunasvg.h
@@ -198,6 +198,8 @@ class LUNASVG_API DomElement {
      */
     Element* get() { return m_element; }
 
+	Bitmap renderToBitmap(std::uint32_t width, std::uint32_t height, std::uint32_t backgroundColor = 0x00000000) const;
+
 private:
     Element* m_element = nullptr;
 };

diff --git a/source/lunasvg.cpp b/source/lunasvg.cpp
@@ -335,6 +335,27 @@ Matrix DomElement::getAbsoluteTransform() const
     return getLocalTransform();
 }
 
+Bitmap DomElement::renderToBitmap(std::uint32_t width, std::uint32_t height, std::uint32_t backgroundColor) const {
+    auto elementBounds = m_element->box()->map(m_element->box()->strokeBoundingBox());
+    if(width == 0 && height == 0) {
+        width = static_cast<std::uint32_t>(std::ceil(elementBounds.w));
+        height = static_cast<std::uint32_t>(std::ceil(elementBounds.h));
+    } else if(width != 0 && height == 0) {
+        height = static_cast<std::uint32_t>(std::ceil(width * elementBounds.h / elementBounds.w));
+    } else if(height != 0 && width == 0) {
+        width = static_cast<std::uint32_t>(std::ceil(height * elementBounds.w / elementBounds.h));
+    }
+
+    Matrix matrix(width / elementBounds.w, 0, 0, height / elementBounds.h, -elementBounds.x * (width / elementBounds.w), -elementBounds.y * (height / elementBounds.h));
+    Bitmap bitmap(width, height);
+    bitmap.clear(backgroundColor);
+    RenderState state(nullptr, RenderMode::Display);
+    state.canvas = Canvas::create(bitmap.data(), bitmap.width(), bitmap.height(), bitmap.stride());
+    state.transform = Transform(matrix);
+    m_element->box()->render(state);
+    return bitmap;
+}
+
 std::unique_ptr<Document> Document::loadFromFile(const std::string& filename)
 {
     std::ifstream fs;