| /* |
| * Copyright 2012 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| #include "SkGeometry.h" |
| #include "SkOpEdgeBuilder.h" |
| #include "SkReduceOrder.h" |
| |
| void SkOpEdgeBuilder::init() { |
| fCurrentContour = fContoursHead; |
| fOperand = false; |
| fXorMask[0] = fXorMask[1] = (fPath->getFillType() & 1) ? kEvenOdd_PathOpsMask |
| : kWinding_PathOpsMask; |
| fUnparseable = false; |
| fSecondHalf = preFetch(); |
| } |
| |
| void SkOpEdgeBuilder::addOperand(const SkPath& path) { |
| SkASSERT(fPathVerbs.count() > 0 && fPathVerbs.end()[-1] == SkPath::kDone_Verb); |
| fPathVerbs.pop(); |
| fPath = &path; |
| fXorMask[1] = (fPath->getFillType() & 1) ? kEvenOdd_PathOpsMask |
| : kWinding_PathOpsMask; |
| preFetch(); |
| } |
| |
| int SkOpEdgeBuilder::count() const { |
| SkOpContour* contour = fContoursHead; |
| int count = 0; |
| while (contour) { |
| count += contour->count() > 0; |
| contour = contour->next(); |
| } |
| return count; |
| } |
| |
| bool SkOpEdgeBuilder::finish(SkChunkAlloc* allocator) { |
| fOperand = false; |
| if (fUnparseable || !walk(allocator)) { |
| return false; |
| } |
| complete(); |
| if (fCurrentContour && !fCurrentContour->count()) { |
| fContoursHead->remove(fCurrentContour); |
| } |
| return true; |
| } |
| |
| void SkOpEdgeBuilder::closeContour(const SkPoint& curveEnd, const SkPoint& curveStart) { |
| if (!SkDPoint::ApproximatelyEqual(curveEnd, curveStart)) { |
| *fPathVerbs.append() = SkPath::kLine_Verb; |
| *fPathPts.append() = curveStart; |
| } else { |
| fPathPts[fPathPts.count() - 1] = curveStart; |
| } |
| *fPathVerbs.append() = SkPath::kClose_Verb; |
| } |
| |
| // very tiny points cause numerical instability : don't allow them |
| static void force_small_to_zero(SkPoint* pt) { |
| if (SkScalarAbs(pt->fX) < FLT_EPSILON_ORDERABLE_ERR) { |
| pt->fX = 0; |
| } |
| if (SkScalarAbs(pt->fY) < FLT_EPSILON_ORDERABLE_ERR) { |
| pt->fY = 0; |
| } |
| } |
| |
| int SkOpEdgeBuilder::preFetch() { |
| if (!fPath->isFinite()) { |
| fUnparseable = true; |
| return 0; |
| } |
| SkPath::RawIter iter(*fPath); |
| SkPoint curveStart; |
| SkPoint curve[4]; |
| SkPoint pts[4]; |
| SkPath::Verb verb; |
| bool lastCurve = false; |
| do { |
| verb = iter.next(pts); |
| switch (verb) { |
| case SkPath::kMove_Verb: |
| if (!fAllowOpenContours && lastCurve) { |
| closeContour(curve[0], curveStart); |
| } |
| *fPathVerbs.append() = verb; |
| force_small_to_zero(&pts[0]); |
| *fPathPts.append() = pts[0]; |
| curveStart = curve[0] = pts[0]; |
| lastCurve = false; |
| continue; |
| case SkPath::kLine_Verb: |
| force_small_to_zero(&pts[1]); |
| if (SkDPoint::ApproximatelyEqual(curve[0], pts[1])) { |
| uint8_t lastVerb = fPathVerbs.top(); |
| if (lastVerb != SkPath::kLine_Verb && lastVerb != SkPath::kMove_Verb) { |
| fPathPts.top() = pts[1]; |
| } |
| continue; // skip degenerate points |
| } |
| break; |
| case SkPath::kQuad_Verb: |
| force_small_to_zero(&pts[1]); |
| force_small_to_zero(&pts[2]); |
| curve[1] = pts[1]; |
| curve[2] = pts[2]; |
| verb = SkReduceOrder::Quad(curve, pts); |
| if (verb == SkPath::kMove_Verb) { |
| continue; // skip degenerate points |
| } |
| break; |
| case SkPath::kConic_Verb: |
| force_small_to_zero(&pts[1]); |
| force_small_to_zero(&pts[2]); |
| curve[1] = pts[1]; |
| curve[2] = pts[2]; |
| verb = SkReduceOrder::Conic(curve, iter.conicWeight(), pts); |
| if (verb == SkPath::kMove_Verb) { |
| continue; // skip degenerate points |
| } |
| break; |
| case SkPath::kCubic_Verb: |
| force_small_to_zero(&pts[1]); |
| force_small_to_zero(&pts[2]); |
| force_small_to_zero(&pts[3]); |
| curve[1] = pts[1]; |
| curve[2] = pts[2]; |
| curve[3] = pts[3]; |
| verb = SkReduceOrder::Cubic(curve, pts); |
| if (verb == SkPath::kMove_Verb) { |
| continue; // skip degenerate points |
| } |
| break; |
| case SkPath::kClose_Verb: |
| closeContour(curve[0], curveStart); |
| lastCurve = false; |
| continue; |
| case SkPath::kDone_Verb: |
| continue; |
| } |
| *fPathVerbs.append() = verb; |
| int ptCount = SkPathOpsVerbToPoints(verb); |
| fPathPts.append(ptCount, &pts[1]); |
| if (verb == SkPath::kConic_Verb) { |
| *fWeights.append() = iter.conicWeight(); |
| } |
| curve[0] = pts[ptCount]; |
| lastCurve = true; |
| } while (verb != SkPath::kDone_Verb); |
| if (!fAllowOpenContours && lastCurve) { |
| closeContour(curve[0], curveStart); |
| } |
| *fPathVerbs.append() = SkPath::kDone_Verb; |
| return fPathVerbs.count() - 1; |
| } |
| |
| bool SkOpEdgeBuilder::close() { |
| complete(); |
| return true; |
| } |
| |
| bool SkOpEdgeBuilder::walk(SkChunkAlloc* allocator) { |
| uint8_t* verbPtr = fPathVerbs.begin(); |
| uint8_t* endOfFirstHalf = &verbPtr[fSecondHalf]; |
| SkPoint* pointsPtr = fPathPts.begin() - 1; |
| SkScalar* weightPtr = fWeights.begin(); |
| SkPath::Verb verb; |
| while ((verb = (SkPath::Verb) *verbPtr) != SkPath::kDone_Verb) { |
| if (verbPtr == endOfFirstHalf) { |
| fOperand = true; |
| } |
| verbPtr++; |
| switch (verb) { |
| case SkPath::kMove_Verb: |
| if (fCurrentContour && fCurrentContour->count()) { |
| if (fAllowOpenContours) { |
| complete(); |
| } else if (!close()) { |
| return false; |
| } |
| } |
| if (!fCurrentContour) { |
| fCurrentContour = fContoursHead->appendContour(allocator); |
| } |
| fCurrentContour->init(fGlobalState, fOperand, |
| fXorMask[fOperand] == kEvenOdd_PathOpsMask); |
| pointsPtr += 1; |
| continue; |
| case SkPath::kLine_Verb: |
| fCurrentContour->addLine(pointsPtr, fAllocator); |
| break; |
| case SkPath::kQuad_Verb: |
| fCurrentContour->addQuad(pointsPtr, fAllocator); |
| break; |
| case SkPath::kConic_Verb: |
| fCurrentContour->addConic(pointsPtr, *weightPtr++, fAllocator); |
| break; |
| case SkPath::kCubic_Verb: { |
| // split self-intersecting cubics in two before proceeding |
| // if the cubic is convex, it doesn't self intersect. |
| SkScalar loopT; |
| SkDCubic::CubicType cubicType; |
| if (SkDCubic::ComplexBreak(pointsPtr, &loopT, &cubicType)) { |
| SkPoint cubicPair[7]; |
| SkChopCubicAt(pointsPtr, cubicPair, loopT); |
| if (!SkScalarsAreFinite(&cubicPair[0].fX, SK_ARRAY_COUNT(cubicPair) * 2)) { |
| return false; |
| } |
| SkPoint cStorage[2][4]; |
| SkPath::Verb v1 = SkReduceOrder::Cubic(&cubicPair[0], cStorage[0]); |
| SkPath::Verb v2 = SkReduceOrder::Cubic(&cubicPair[3], cStorage[1]); |
| if (v1 != SkPath::kMove_Verb && v2 != SkPath::kMove_Verb) { |
| SkPoint* curve1 = v1 == SkPath::kCubic_Verb ? &cubicPair[0] : cStorage[0]; |
| SkPoint* curve2 = v2 == SkPath::kCubic_Verb ? &cubicPair[3] : cStorage[1]; |
| for (int index = 0; index < SkPathOpsVerbToPoints(v1); ++index) { |
| force_small_to_zero(&curve1[index]); |
| } |
| for (int index = 0; index < SkPathOpsVerbToPoints(v2); ++index) { |
| force_small_to_zero(&curve2[index]); |
| } |
| fCurrentContour->addCurve(v1, curve1, fAllocator)->setCubicType(cubicType); |
| fCurrentContour->addCurve(v2, curve2, fAllocator)->setCubicType(cubicType); |
| } else { |
| fCurrentContour->addCubic(pointsPtr, fAllocator); |
| } |
| } else { |
| fCurrentContour->addCubic(pointsPtr, fAllocator); |
| } |
| } break; |
| case SkPath::kClose_Verb: |
| SkASSERT(fCurrentContour); |
| if (!close()) { |
| return false; |
| } |
| continue; |
| default: |
| SkDEBUGFAIL("bad verb"); |
| return false; |
| } |
| SkASSERT(fCurrentContour); |
| fCurrentContour->debugValidate(); |
| pointsPtr += SkPathOpsVerbToPoints(verb); |
| } |
| if (fCurrentContour && fCurrentContour->count() &&!fAllowOpenContours && !close()) { |
| return false; |
| } |
| return true; |
| } |
