| /* |
| * 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 "SkAddIntersections.h" |
| #include "SkOpEdgeBuilder.h" |
| #include "SkPathOpsCommon.h" |
| #include "SkPathWriter.h" |
| |
| static SkOpSegment* findChaseOp(SkTDArray<SkOpSpan*>& chase, int* tIndex, int* endIndex) { |
| while (chase.count()) { |
| SkOpSpan* span; |
| chase.pop(&span); |
| const SkOpSpan& backPtr = span->fOther->span(span->fOtherIndex); |
| SkOpSegment* segment = backPtr.fOther; |
| *tIndex = backPtr.fOtherIndex; |
| bool sortable = true; |
| bool done = true; |
| *endIndex = -1; |
| if (const SkOpAngle* last = segment->activeAngle(*tIndex, tIndex, endIndex, &done, |
| &sortable)) { |
| if (last->unorderable()) { |
| continue; |
| } |
| *tIndex = last->start(); |
| *endIndex = last->end(); |
| #if TRY_ROTATE |
| *chase.insert(0) = span; |
| #else |
| *chase.append() = span; |
| #endif |
| return last->segment(); |
| } |
| if (done) { |
| continue; |
| } |
| if (!sortable) { |
| continue; |
| } |
| // find first angle, initialize winding to computed fWindSum |
| const SkOpAngle* angle = segment->spanToAngle(*tIndex, *endIndex); |
| if (!angle) { |
| continue; |
| } |
| const SkOpAngle* firstAngle = angle; |
| SkDEBUGCODE(bool loop = false); |
| int winding; |
| do { |
| angle = angle->next(); |
| SkASSERT(angle != firstAngle || !loop); |
| SkDEBUGCODE(loop |= angle == firstAngle); |
| segment = angle->segment(); |
| winding = segment->windSum(angle); |
| } while (winding == SK_MinS32); |
| int sumMiWinding = segment->updateWindingReverse(angle); |
| int sumSuWinding = segment->updateOppWindingReverse(angle); |
| if (segment->operand()) { |
| SkTSwap<int>(sumMiWinding, sumSuWinding); |
| } |
| SkOpSegment* first = NULL; |
| while ((angle = angle->next()) != firstAngle) { |
| segment = angle->segment(); |
| int start = angle->start(); |
| int end = angle->end(); |
| int maxWinding, sumWinding, oppMaxWinding, oppSumWinding; |
| segment->setUpWindings(start, end, &sumMiWinding, &sumSuWinding, |
| &maxWinding, &sumWinding, &oppMaxWinding, &oppSumWinding); |
| if (!segment->done(angle)) { |
| if (!first) { |
| first = segment; |
| *tIndex = start; |
| *endIndex = end; |
| } |
| // OPTIMIZATION: should this also add to the chase? |
| (void) segment->markAngle(maxWinding, sumWinding, oppMaxWinding, |
| oppSumWinding, angle); |
| } |
| } |
| if (first) { |
| #if TRY_ROTATE |
| *chase.insert(0) = span; |
| #else |
| *chase.append() = span; |
| #endif |
| return first; |
| } |
| } |
| return NULL; |
| } |
| |
| /* |
| static bool windingIsActive(int winding, int oppWinding, int spanWinding, int oppSpanWinding, |
| bool windingIsOp, PathOp op) { |
| bool active = windingIsActive(winding, spanWinding); |
| if (!active) { |
| return false; |
| } |
| if (oppSpanWinding && windingIsActive(oppWinding, oppSpanWinding)) { |
| switch (op) { |
| case kIntersect_Op: |
| case kUnion_Op: |
| return true; |
| case kDifference_Op: { |
| int absSpan = abs(spanWinding); |
| int absOpp = abs(oppSpanWinding); |
| return windingIsOp ? absSpan < absOpp : absSpan > absOpp; |
| } |
| case kXor_Op: |
| return spanWinding != oppSpanWinding; |
| default: |
| SkASSERT(0); |
| } |
| } |
| bool opActive = oppWinding != 0; |
| return gOpLookup[op][opActive][windingIsOp]; |
| } |
| */ |
| |
| static bool bridgeOp(SkTArray<SkOpContour*, true>& contourList, const SkPathOp op, |
| const int xorMask, const int xorOpMask, SkPathWriter* simple) { |
| bool firstContour = true; |
| bool unsortable = false; |
| bool topUnsortable = false; |
| bool firstPass = true; |
| SkPoint lastTopLeft; |
| SkPoint topLeft = {SK_ScalarMin, SK_ScalarMin}; |
| do { |
| int index, endIndex; |
| bool topDone; |
| bool onlyVertical = false; |
| lastTopLeft = topLeft; |
| SkOpSegment* current = FindSortableTop(contourList, SkOpAngle::kBinarySingle, &firstContour, |
| &index, &endIndex, &topLeft, &topUnsortable, &topDone, &onlyVertical, firstPass); |
| if (!current) { |
| if ((!topUnsortable || firstPass) && !topDone) { |
| SkASSERT(topLeft.fX != SK_ScalarMin && topLeft.fY != SK_ScalarMin); |
| if (lastTopLeft.fX == SK_ScalarMin && lastTopLeft.fY == SK_ScalarMin) { |
| if (firstPass) { |
| firstPass = false; |
| } else { |
| break; |
| } |
| } |
| topLeft.fX = topLeft.fY = SK_ScalarMin; |
| continue; |
| } |
| break; |
| } else if (onlyVertical) { |
| break; |
| } |
| firstPass = !topUnsortable || lastTopLeft != topLeft; |
| SkTDArray<SkOpSpan*> chase; |
| do { |
| if (current->activeOp(index, endIndex, xorMask, xorOpMask, op)) { |
| do { |
| if (!unsortable && current->done()) { |
| break; |
| } |
| SkASSERT(unsortable || !current->done()); |
| int nextStart = index; |
| int nextEnd = endIndex; |
| SkOpSegment* next = current->findNextOp(&chase, &nextStart, &nextEnd, |
| &unsortable, op, xorMask, xorOpMask); |
| if (!next) { |
| if (!unsortable && simple->hasMove() |
| && current->verb() != SkPath::kLine_Verb |
| && !simple->isClosed()) { |
| current->addCurveTo(index, endIndex, simple, true); |
| #if DEBUG_ACTIVE_SPANS |
| if (!simple->isClosed()) { |
| DebugShowActiveSpans(contourList); |
| } |
| #endif |
| // SkASSERT(simple->isClosed()); |
| } |
| break; |
| } |
| #if DEBUG_FLOW |
| SkDebugf("%s current id=%d from=(%1.9g,%1.9g) to=(%1.9g,%1.9g)\n", __FUNCTION__, |
| current->debugID(), current->xyAtT(index).fX, current->xyAtT(index).fY, |
| current->xyAtT(endIndex).fX, current->xyAtT(endIndex).fY); |
| #endif |
| current->addCurveTo(index, endIndex, simple, true); |
| current = next; |
| index = nextStart; |
| endIndex = nextEnd; |
| } while (!simple->isClosed() && (!unsortable |
| || !current->done(SkMin32(index, endIndex)))); |
| if (current->activeWinding(index, endIndex) && !simple->isClosed()) { |
| // FIXME : add to simplify, xor cpaths |
| int min = SkMin32(index, endIndex); |
| if (!unsortable && !simple->isEmpty()) { |
| unsortable = current->checkSmall(min); |
| } |
| if (!current->done(min)) { |
| current->addCurveTo(index, endIndex, simple, true); |
| current->markDoneBinary(min); |
| } |
| } |
| simple->close(); |
| } else { |
| SkOpSpan* last = current->markAndChaseDoneBinary(index, endIndex); |
| if (last && !last->fChased && !last->fLoop) { |
| last->fChased = true; |
| SkASSERT(!SkPathOpsDebug::ChaseContains(chase, last)); |
| *chase.append() = last; |
| #if DEBUG_WINDING |
| SkDebugf("%s chase.append id=%d windSum=%d small=%d\n", __FUNCTION__, |
| last->fOther->span(last->fOtherIndex).fOther->debugID(), last->fWindSum, |
| last->fSmall); |
| #endif |
| } |
| } |
| current = findChaseOp(chase, &index, &endIndex); |
| #if DEBUG_ACTIVE_SPANS |
| DebugShowActiveSpans(contourList); |
| #endif |
| if (!current) { |
| break; |
| } |
| } while (true); |
| } while (true); |
| 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 |
| }; |
| |
| bool Op(const SkPath& one, const SkPath& two, SkPathOp op, SkPath* result) { |
| #if DEBUG_SHOW_TEST_NAME |
| char* debugName = DEBUG_FILENAME_STRING; |
| if (debugName && debugName[0]) { |
| SkPathOpsDebug::BumpTestName(debugName); |
| SkPathOpsDebug::ShowPath(one, two, op, debugName); |
| } |
| #endif |
| op = gOpInverse[op][one.isInverseFillType()][two.isInverseFillType()]; |
| SkPath::FillType fillType = gOutInverse[op][one.isInverseFillType()][two.isInverseFillType()] |
| ? SkPath::kInverseEvenOdd_FillType : SkPath::kEvenOdd_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 |
| SkPathOpsDebug::gSortCount = SkPathOpsDebug::gSortCountDefault; |
| #endif |
| // turn path into list of segments |
| SkTArray<SkOpContour> contours; |
| // FIXME: add self-intersecting cubics' T values to segment |
| SkOpEdgeBuilder builder(*minuend, contours); |
| const int xorMask = builder.xorMask(); |
| builder.addOperand(*subtrahend); |
| if (!builder.finish()) { |
| return false; |
| } |
| result->reset(); |
| result->setFillType(fillType); |
| const int xorOpMask = builder.xorMask(); |
| SkTArray<SkOpContour*, true> contourList; |
| MakeContourList(contours, contourList, xorMask == kEvenOdd_PathOpsMask, |
| xorOpMask == kEvenOdd_PathOpsMask); |
| SkOpContour** currentPtr = contourList.begin(); |
| if (!currentPtr) { |
| return true; |
| } |
| SkOpContour** listEnd = contourList.end(); |
| // find all intersections between segments |
| do { |
| SkOpContour** nextPtr = currentPtr; |
| SkOpContour* current = *currentPtr++; |
| if (current->containsCubics()) { |
| AddSelfIntersectTs(current); |
| } |
| SkOpContour* next; |
| do { |
| next = *nextPtr++; |
| } while (AddIntersectTs(current, next) && nextPtr != listEnd); |
| } while (currentPtr != listEnd); |
| // eat through coincident edges |
| |
| int total = 0; |
| int index; |
| for (index = 0; index < contourList.count(); ++index) { |
| total += contourList[index]->segments().count(); |
| } |
| if (!HandleCoincidence(&contourList, total)) { |
| return false; |
| } |
| // construct closed contours |
| SkPathWriter wrapper(*result); |
| bridgeOp(contourList, op, xorMask, xorOpMask, &wrapper); |
| { // if some edges could not be resolved, assemble remaining fragments |
| SkPath temp; |
| temp.setFillType(fillType); |
| SkPathWriter assembled(temp); |
| Assemble(wrapper, &assembled); |
| *result = *assembled.nativePath(); |
| result->setFillType(fillType); |
| } |
| return true; |
| } |
