| /* |
| * Copyright 2014 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkMatrix.h" |
| #include "SkOpEdgeBuilder.h" |
| #include "SkPathPriv.h" |
| #include "SkPathOps.h" |
| #include "SkPathOpsCommon.h" |
| |
| static bool one_contour(const SkPath& path) { |
| SkChunkAlloc allocator(256); |
| int verbCount = path.countVerbs(); |
| uint8_t* verbs = (uint8_t*) allocator.alloc(sizeof(uint8_t) * verbCount, |
| SkChunkAlloc::kThrow_AllocFailType); |
| (void) path.getVerbs(verbs, verbCount); |
| for (int index = 1; index < verbCount; ++index) { |
| if (verbs[index] == SkPath::kMove_Verb) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| void FixWinding(SkPath* path) { |
| SkPath::FillType fillType = path->getFillType(); |
| if (fillType == SkPath::kInverseEvenOdd_FillType) { |
| fillType = SkPath::kInverseWinding_FillType; |
| } else if (fillType == SkPath::kEvenOdd_FillType) { |
| fillType = SkPath::kWinding_FillType; |
| } |
| SkPathPriv::FirstDirection dir; |
| if (one_contour(*path) && SkPathPriv::CheapComputeFirstDirection(*path, &dir)) { |
| if (dir != SkPathPriv::kCCW_FirstDirection) { |
| SkPath temp; |
| temp.reverseAddPath(*path); |
| *path = temp; |
| } |
| path->setFillType(fillType); |
| return; |
| } |
| SkChunkAlloc allocator(4096); |
| SkOpContourHead contourHead; |
| SkOpGlobalState globalState(NULL, &contourHead); |
| SkOpEdgeBuilder builder(*path, &contourHead, &allocator, &globalState); |
| builder.finish(&allocator); |
| SkASSERT(contourHead.next()); |
| contourHead.resetReverse(); |
| bool writePath = false; |
| SkOpSpan* topSpan; |
| globalState.setPhase(SkOpGlobalState::kFixWinding); |
| while ((topSpan = FindSortableTop(&contourHead))) { |
| SkOpSegment* topSegment = topSpan->segment(); |
| SkOpContour* topContour = topSegment->contour(); |
| SkASSERT(topContour->isCcw() >= 0); |
| #if DEBUG_WINDING |
| SkDebugf("%s id=%d nested=%d ccw=%d\n", __FUNCTION__, |
| topSegment->debugID(), globalState.nested(), topContour->isCcw()); |
| #endif |
| if ((globalState.nested() & 1) != SkToBool(topContour->isCcw())) { |
| topContour->setReverse(); |
| writePath = true; |
| } |
| topContour->markDone(); |
| globalState.clearNested(); |
| } |
| if (!writePath) { |
| path->setFillType(fillType); |
| return; |
| } |
| SkPath empty; |
| SkPathWriter woundPath(empty); |
| SkOpContour* test = &contourHead; |
| do { |
| if (test->reversed()) { |
| test->toReversePath(&woundPath); |
| } else { |
| test->toPath(&woundPath); |
| } |
| } while ((test = test->next())); |
| *path = *woundPath.nativePath(); |
| path->setFillType(fillType); |
| } |
| |
| void SkOpBuilder::add(const SkPath& path, SkPathOp op) { |
| if (0 == fOps.count() && op != kUnion_SkPathOp) { |
| fPathRefs.push_back() = SkPath(); |
| *fOps.append() = kUnion_SkPathOp; |
| } |
| fPathRefs.push_back() = path; |
| *fOps.append() = op; |
| } |
| |
| void SkOpBuilder::reset() { |
| fPathRefs.reset(); |
| fOps.reset(); |
| } |
| |
| /* OPTIMIZATION: Union doesn't need to be all-or-nothing. A run of three or more convex |
| paths with union ops could be locally resolved and still improve over doing the |
| ops one at a time. */ |
| bool SkOpBuilder::resolve(SkPath* result) { |
| SkPath original = *result; |
| int count = fOps.count(); |
| bool allUnion = true; |
| SkPathPriv::FirstDirection firstDir = SkPathPriv::kUnknown_FirstDirection; |
| for (int index = 0; index < count; ++index) { |
| SkPath* test = &fPathRefs[index]; |
| if (kUnion_SkPathOp != fOps[index] || test->isInverseFillType()) { |
| allUnion = false; |
| break; |
| } |
| // If all paths are convex, track direction, reversing as needed. |
| if (test->isConvex()) { |
| SkPathPriv::FirstDirection dir; |
| if (!SkPathPriv::CheapComputeFirstDirection(*test, &dir)) { |
| allUnion = false; |
| break; |
| } |
| if (firstDir == SkPathPriv::kUnknown_FirstDirection) { |
| firstDir = dir; |
| } else if (firstDir != dir) { |
| SkPath temp; |
| temp.reverseAddPath(*test); |
| *test = temp; |
| } |
| continue; |
| } |
| // If the path is not convex but its bounds do not intersect the others, simplify is enough. |
| const SkRect& testBounds = test->getBounds(); |
| for (int inner = 0; inner < index; ++inner) { |
| // OPTIMIZE: check to see if the contour bounds do not intersect other contour bounds? |
| if (SkRect::Intersects(fPathRefs[inner].getBounds(), testBounds)) { |
| allUnion = false; |
| break; |
| } |
| } |
| } |
| if (!allUnion) { |
| *result = fPathRefs[0]; |
| for (int index = 1; index < count; ++index) { |
| if (!Op(*result, fPathRefs[index], fOps[index], result)) { |
| reset(); |
| *result = original; |
| return false; |
| } |
| } |
| reset(); |
| return true; |
| } |
| SkPath sum; |
| for (int index = 0; index < count; ++index) { |
| if (!Simplify(fPathRefs[index], &fPathRefs[index])) { |
| reset(); |
| *result = original; |
| return false; |
| } |
| if (!fPathRefs[index].isEmpty()) { |
| // convert the even odd result back to winding form before accumulating it |
| FixWinding(&fPathRefs[index]); |
| sum.addPath(fPathRefs[index]); |
| } |
| } |
| reset(); |
| bool success = Simplify(sum, result); |
| if (!success) { |
| *result = original; |
| } |
| return success; |
| } |