bool RenderSVGResourceClipper::pathOnlyClipping(GraphicsContext& context, const AffineTransform& animatedLocalTransform, const FloatRect& objectBoundingBox)
{
// If the current clip-path gets clipped itself, we have to fallback to masking.
if (!style().svgStyle().clipperResource().isEmpty())
return false;
WindRule clipRule = RULE_NONZERO;
Path clipPath = Path();
// If clip-path only contains one visible shape or path, we can use path-based clipping. Invisible
// shapes don't affect the clipping and can be ignored. If clip-path contains more than one
// visible shape, the additive clipping may not work, caused by the clipRule. EvenOdd
// as well as NonZero can cause self-clipping of the elements.
// See also http://www.w3.org/TR/SVG/painting.html#FillRuleProperty
for (Node* childNode = clipPathElement().firstChild(); childNode; childNode = childNode->nextSibling()) {
RenderObject* renderer = childNode->renderer();
if (!renderer)
continue;
// Only shapes or paths are supported for direct clipping. We need to fallback to masking for texts.
if (renderer->isSVGText())
return false;
if (!childNode->isSVGElement() || !downcast<SVGElement>(*childNode).isSVGGraphicsElement())
continue;
SVGGraphicsElement& styled = downcast<SVGGraphicsElement>(*childNode);
const RenderStyle& style = renderer->style();
if (style.display() == NONE || style.visibility() != VISIBLE)
continue;
const SVGRenderStyle& svgStyle = style.svgStyle();
// Current shape in clip-path gets clipped too. Fallback to masking.
if (!svgStyle.clipperResource().isEmpty())
return false;
// Fallback to masking, if there is more than one clipping path.
if (clipPath.isEmpty()) {
styled.toClipPath(clipPath);
clipRule = svgStyle.clipRule();
} else
return false;
}
// Only one visible shape/path was found. Directly continue clipping and transform the content to userspace if necessary.
if (clipPathElement().clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
AffineTransform transform;
transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
clipPath.transform(transform);
}
// Transform path by animatedLocalTransform.
clipPath.transform(animatedLocalTransform);
// The SVG specification wants us to clip everything, if clip-path doesn't have a child.
if (clipPath.isEmpty())
clipPath.addRect(FloatRect());
context.clipPath(clipPath, clipRule);
return true;
}
void BeginClipPathDisplayItem::replay(GraphicsContext& context) const
{
context.save();
context.clipPath(m_clipPath, AntiAliased);
}
void ClipPath::apply(GraphicsContext& context) const
{
context.clipPath(m_path, m_windRule);
}
