path ops : add support for inverse fill
add inverse fill, reverse diff, and gm tests
cleaned up some interfaces
Review URL: https://codereview.chromium.org/14371011
git-svn-id: http://skia.googlecode.com/svn/trunk@8798 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/pathops/SkPathOpsOp.cpp b/src/pathops/SkPathOpsOp.cpp
index 5a3576ff..07a8bab 100644
--- a/src/pathops/SkPathOpsOp.cpp
+++ b/src/pathops/SkPathOpsOp.cpp
@@ -206,18 +206,48 @@
return simple->someAssemblyRequired();
}
+// pretty picture:
+// https://docs.google.com/a/google.com/drawings/d/1sPV8rPfpEFXymBp3iSbDRWAycp1b-7vD9JP2V-kn9Ss/edit?usp=sharing
+static const SkPathOp gOpInverse[kReverseDifference_PathOp + 1][2][2] = {
+// inside minuend outside minuend
+// inside subtrahend outside subtrahend inside subtrahend outside subtrahend
+ {{ kDifference_PathOp, kIntersect_PathOp }, { kUnion_PathOp, kReverseDifference_PathOp }},
+ {{ kIntersect_PathOp, kDifference_PathOp }, { kReverseDifference_PathOp, kUnion_PathOp }},
+ {{ kUnion_PathOp, kReverseDifference_PathOp }, { kDifference_PathOp, kIntersect_PathOp }},
+ {{ kXOR_PathOp, kXOR_PathOp }, { kXOR_PathOp, kXOR_PathOp }},
+ {{ kReverseDifference_PathOp, kUnion_PathOp }, { kIntersect_PathOp, kDifference_PathOp }},
+};
+
+static const bool gOutInverse[kReverseDifference_PathOp + 1][2][2] = {
+ {{ false, false }, { true, false }}, // diff
+ {{ false, false }, { false, true }}, // sect
+ {{ false, true }, { true, true }}, // union
+ {{ false, true }, { true, false }}, // xor
+ {{ false, true }, { false, false }}, // rev diff
+};
+
void Op(const SkPath& one, const SkPath& two, SkPathOp op, SkPath* result) {
+ op = gOpInverse[op][one.isInverseFillType()][two.isInverseFillType()];
+ result->reset();
+ SkPath::FillType fillType = gOutInverse[op][one.isInverseFillType()][two.isInverseFillType()]
+ ? SkPath::kInverseEvenOdd_FillType : SkPath::kEvenOdd_FillType;
+ result->setFillType(fillType);
+ const SkPath* minuend = &one;
+ const SkPath* subtrahend = &two;
+ if (op == kReverseDifference_PathOp) {
+ minuend = &two;
+ subtrahend = &one;
+ op = kDifference_PathOp;
+ }
#if DEBUG_SORT || DEBUG_SWAP_TOP
gDebugSortCount = gDebugSortCountDefault;
#endif
- result->reset();
- result->setFillType(SkPath::kEvenOdd_FillType);
// turn path into list of segments
SkTArray<SkOpContour> contours;
// FIXME: add self-intersecting cubics' T values to segment
- SkOpEdgeBuilder builder(one, contours);
+ SkOpEdgeBuilder builder(*minuend, contours);
const int xorMask = builder.xorMask();
- builder.addOperand(two);
+ builder.addOperand(*subtrahend);
builder.finish();
const int xorOpMask = builder.xorMask();
SkTDArray<SkOpContour*> contourList;
@@ -264,7 +294,7 @@
bridgeOp(contourList, op, xorMask, xorOpMask, &wrapper);
{ // if some edges could not be resolved, assemble remaining fragments
SkPath temp;
- temp.setFillType(SkPath::kEvenOdd_FillType);
+ temp.setFillType(fillType);
SkPathWriter assembled(temp);
Assemble(wrapper, &assembled);
*result = *assembled.nativePath();