[SkSVGDevice] Initial clipping support

Implement SVG clips based on clip stack flattening -
which is now exposed in SkClipStack::asPath() and shared
with SkCanvas's simplify-clip code.

R=reed@google.com,mtklein@google.com

Review URL: https://codereview.chromium.org/876923003

1 files changed, 4 insertions, 23 deletions

diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 5b37e08b30..56cfb8d652 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -1446,30 +1446,11 @@ void SkCanvas::onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edg
     fClipStack.clipDevPath(devPath, op, kSoft_ClipEdgeStyle == edgeStyle);
 
     if (fAllowSimplifyClip) {
-        devPath.reset();
-        devPath.setFillType(SkPath::kInverseEvenOdd_FillType);
-        const SkClipStack* clipStack = getClipStack();
-        SkClipStack::Iter iter(*clipStack, SkClipStack::Iter::kBottom_IterStart);
-        const SkClipStack::Element* element;
-        while ((element = iter.next())) {
-            SkClipStack::Element::Type type = element->getType();
-            SkPath operand;
-            if (type != SkClipStack::Element::kEmpty_Type) {
-                element->asPath(&operand);
-            }
-            SkRegion::Op elementOp = element->getOp();
-            if (elementOp == SkRegion::kReplace_Op) {
-                devPath = operand;
-            } else {
-                Op(devPath, operand, (SkPathOp) elementOp, &devPath);
-            }
-            // if the prev and curr clips disagree about aa -vs- not, favor the aa request.
-            // perhaps we need an API change to avoid this sort of mixed-signals about
-            // clipping.
-            if (element->isAA()) {
-                edgeStyle = kSoft_ClipEdgeStyle;
-            }
+        bool clipIsAA = getClipStack()->asPath(&devPath);
+        if (clipIsAA) {
+            edgeStyle = kSoft_ClipEdgeStyle;
         }
+
         op = SkRegion::kReplace_Op;
     }