[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, 17 insertions, 5 deletions

diff --git a/experimental/svg/model/SkSVGEllipse.cpp b/experimental/svg/model/SkSVGEllipse.cpp
index 481af5c3ab..3f38b222d5 100644
--- a/experimental/svg/model/SkSVGEllipse.cpp
+++ b/experimental/svg/model/SkSVGEllipse.cpp
@@ -55,14 +55,26 @@ void SkSVGEllipse::onSetAttribute(SkSVGAttribute attr, const SkSVGValue& v) {
     }
 }
 
-void SkSVGEllipse::onDraw(SkCanvas* canvas, const SkSVGLengthContext& lctx,
-                          const SkPaint& paint, SkPath::FillType) const {
+SkRect SkSVGEllipse::resolve(const SkSVGLengthContext& lctx) const {
     const auto cx = lctx.resolve(fCx, SkSVGLengthContext::LengthType::kHorizontal);
     const auto cy = lctx.resolve(fCy, SkSVGLengthContext::LengthType::kVertical);
     const auto rx = lctx.resolve(fRx, SkSVGLengthContext::LengthType::kHorizontal);
     const auto ry = lctx.resolve(fRy, SkSVGLengthContext::LengthType::kVertical);
 
-    if (rx > 0 && ry > 0) {
-        canvas->drawOval(SkRect::MakeXYWH(cx - rx, cy - ry, rx * 2, ry * 2), paint);
-    }
+    return (rx > 0 && ry > 0)
+        ? SkRect::MakeXYWH(cx - rx, cy - ry, rx * 2, ry * 2)
+        : SkRect::MakeEmpty();
+}
+
+void SkSVGEllipse::onDraw(SkCanvas* canvas, const SkSVGLengthContext& lctx,
+                          const SkPaint& paint, SkPath::FillType) const {
+    canvas->drawOval(this->resolve(lctx), paint);
+}
+
+SkPath SkSVGEllipse::onAsPath(const SkSVGRenderContext& ctx) const {
+    SkPath path;
+    path.addOval(this->resolve(ctx.lengthContext()));
+    this->mapToParent(&path);
+
+    return path;
 }