[SVGDom] ClipPath support

  * clip-path attribute handling
  * clipPath container element
  * asPath() SkSVGNode virtual for capturing subtree geometry

R=robertphillips@google.com,stephana@google.com

Change-Id: I9597534fe3047b631da6309eafac055dff5696e9
Reviewed-on: https://skia-review.googlesource.com/5650
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/experimental/svg/model/SkSVGRenderContext.cpp b/experimental/svg/model/SkSVGRenderContext.cpp
index fd0262319a..d8307a05c0 100644
--- a/experimental/svg/model/SkSVGRenderContext.cpp
+++ b/experimental/svg/model/SkSVGRenderContext.cpp
@@ -280,6 +280,10 @@ void SkSVGRenderContext::applyPresentationAttributes(const SkSVGPresentationAttr
     if (auto* opacity = attrs.fOpacity.getMaybeNull()) {
         this->applyOpacity(opacity->value(), flags);
     }
+
+    if (auto* clip = attrs.fClipPath.getMaybeNull()) {
+        this->applyClip(*clip);
+    }
 }
 
 void SkSVGRenderContext::applyOpacity(SkScalar opacity, uint32_t flags) {
@@ -312,6 +316,26 @@ void SkSVGRenderContext::applyOpacity(SkScalar opacity, uint32_t flags) {
     }
 }
 
+void SkSVGRenderContext::applyClip(const SkSVGClip& clip) {
+    if (clip.type() != SkSVGClip::Type::kIRI) {
+        return;
+    }
+
+    const SkSVGNode* clipNode = this->findNodeById(clip.iri());
+    if (!clipNode || clipNode->tag() != SkSVGTag::kClipPath) {
+        return;
+    }
+
+    const SkPath clipPath = clipNode->asPath(*this);
+
+    // Only save if needed
+    if (fCanvas->getSaveCount() == fCanvasSaveCount) {
+        fCanvas->save();
+    }
+
+    fCanvas->clipPath(clipPath, true);
+}
+
 const SkPaint* SkSVGRenderContext::fillPaint() const {
     const SkSVGPaint::Type paintType = fPresentationContext->fInherited.fFill.get()->type();
     return paintType != SkSVGPaint::Type::kNone ? &fPresentationContext->fFillPaint : nullptr;