| /* |
| * 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 "SkOpCoincidence.h" |
| #include "SkOpEdgeBuilder.h" |
| #include "SkPathOpsCommon.h" |
| #include "SkPathWriter.h" |
| #include "SkTSort.h" |
| |
| const SkOpAngle* AngleWinding(SkOpSpanBase* start, SkOpSpanBase* end, int* windingPtr, |
| bool* sortablePtr) { |
| // find first angle, initialize winding to computed fWindSum |
| SkOpSegment* segment = start->segment(); |
| const SkOpAngle* angle = segment->spanToAngle(start, end); |
| if (!angle) { |
| *windingPtr = SK_MinS32; |
| return nullptr; |
| } |
| bool computeWinding = false; |
| const SkOpAngle* firstAngle = angle; |
| bool loop = false; |
| bool unorderable = false; |
| int winding = SK_MinS32; |
| do { |
| angle = angle->next(); |
| if (!angle) { |
| return nullptr; |
| } |
| unorderable |= angle->unorderable(); |
| if ((computeWinding = unorderable || (angle == firstAngle && loop))) { |
| break; // if we get here, there's no winding, loop is unorderable |
| } |
| loop |= angle == firstAngle; |
| segment = angle->segment(); |
| winding = segment->windSum(angle); |
| } while (winding == SK_MinS32); |
| // if the angle loop contains an unorderable span, the angle order may be useless |
| // directly compute the winding in this case for each span |
| if (computeWinding) { |
| firstAngle = angle; |
| winding = SK_MinS32; |
| do { |
| SkOpSpanBase* startSpan = angle->start(); |
| SkOpSpanBase* endSpan = angle->end(); |
| SkOpSpan* lesser = startSpan->starter(endSpan); |
| int testWinding = lesser->windSum(); |
| if (testWinding == SK_MinS32) { |
| testWinding = lesser->computeWindSum(); |
| } |
| if (testWinding != SK_MinS32) { |
| segment = angle->segment(); |
| winding = testWinding; |
| } |
| angle = angle->next(); |
| } while (angle != firstAngle); |
| } |
| *sortablePtr = !unorderable; |
| *windingPtr = winding; |
| return angle; |
| } |
| |
| SkOpSegment* FindUndone(SkOpContourHead* contourList, SkOpSpanBase** startPtr, |
| SkOpSpanBase** endPtr) { |
| SkOpSegment* result; |
| SkOpContour* contour = contourList; |
| do { |
| result = contour->undoneSegment(startPtr, endPtr); |
| if (result) { |
| return result; |
| } |
| } while ((contour = contour->next())); |
| return nullptr; |
| } |
| |
| SkOpSegment* FindChase(SkTDArray<SkOpSpanBase*>* chase, SkOpSpanBase** startPtr, |
| SkOpSpanBase** endPtr) { |
| while (chase->count()) { |
| SkOpSpanBase* span; |
| chase->pop(&span); |
| SkOpSegment* segment = span->segment(); |
| *startPtr = span->ptT()->next()->span(); |
| bool done = true; |
| *endPtr = nullptr; |
| if (SkOpAngle* last = segment->activeAngle(*startPtr, startPtr, endPtr, &done)) { |
| *startPtr = last->start(); |
| *endPtr = last->end(); |
| #if TRY_ROTATE |
| *chase->insert(0) = span; |
| #else |
| *chase->append() = span; |
| #endif |
| return last->segment(); |
| } |
| if (done) { |
| continue; |
| } |
| // find first angle, initialize winding to computed wind sum |
| int winding; |
| bool sortable; |
| const SkOpAngle* angle = AngleWinding(*startPtr, *endPtr, &winding, &sortable); |
| if (winding == SK_MinS32) { |
| continue; |
| } |
| int sumWinding SK_INIT_TO_AVOID_WARNING; |
| if (sortable) { |
| segment = angle->segment(); |
| sumWinding = segment->updateWindingReverse(angle); |
| } |
| SkOpSegment* first = nullptr; |
| const SkOpAngle* firstAngle = angle; |
| while ((angle = angle->next()) != firstAngle) { |
| segment = angle->segment(); |
| SkOpSpanBase* start = angle->start(); |
| SkOpSpanBase* end = angle->end(); |
| int maxWinding SK_INIT_TO_AVOID_WARNING; |
| if (sortable) { |
| segment->setUpWinding(start, end, &maxWinding, &sumWinding); |
| } |
| if (!segment->done(angle)) { |
| if (!first && (sortable || start->starter(end)->windSum() != SK_MinS32)) { |
| first = segment; |
| *startPtr = start; |
| *endPtr = end; |
| } |
| // OPTIMIZATION: should this also add to the chase? |
| if (sortable) { |
| (void) segment->markAngle(maxWinding, sumWinding, angle); |
| } |
| } |
| } |
| if (first) { |
| #if TRY_ROTATE |
| *chase->insert(0) = span; |
| #else |
| *chase->append() = span; |
| #endif |
| return first; |
| } |
| } |
| return nullptr; |
| } |
| |
| #if DEBUG_ACTIVE_SPANS |
| void DebugShowActiveSpans(SkOpContourHead* contourList) { |
| SkOpContour* contour = contourList; |
| do { |
| contour->debugShowActiveSpans(); |
| } while ((contour = contour->next())); |
| } |
| #endif |
| |
| bool SortContourList(SkOpContourHead** contourList, bool evenOdd, bool oppEvenOdd) { |
| SkTDArray<SkOpContour* > list; |
| SkOpContour* contour = *contourList; |
| do { |
| if (contour->count()) { |
| contour->setOppXor(contour->operand() ? evenOdd : oppEvenOdd); |
| *list.append() = contour; |
| } |
| } while ((contour = contour->next())); |
| int count = list.count(); |
| if (!count) { |
| return false; |
| } |
| if (count > 1) { |
| SkTQSort<SkOpContour>(list.begin(), list.end() - 1); |
| } |
| contour = list[0]; |
| SkOpContourHead* contourHead = static_cast<SkOpContourHead*>(contour); |
| contour->globalState()->setContourHead(contourHead); |
| *contourList = contourHead; |
| for (int index = 1; index < count; ++index) { |
| SkOpContour* next = list[index]; |
| contour->setNext(next); |
| contour = next; |
| } |
| contour->setNext(nullptr); |
| return true; |
| } |
| |
| class DistanceLessThan { |
| public: |
| DistanceLessThan(double* distances) : fDistances(distances) { } |
| double* fDistances; |
| bool operator()(const int one, const int two) { |
| return fDistances[one] < fDistances[two]; |
| } |
| }; |
| |
| /* |
| check start and end of each contour |
| if not the same, record them |
| match them up |
| connect closest |
| reassemble contour pieces into new path |
| */ |
| void Assemble(const SkPathWriter& path, SkPathWriter* simple) { |
| SkChunkAlloc allocator(4096); // FIXME: constant-ize, tune |
| SkOpContourHead contour; |
| SkOpGlobalState globalState(nullptr, &contour SkDEBUGPARAMS(false) |
| SkDEBUGPARAMS(nullptr)); |
| #if DEBUG_SHOW_TEST_NAME |
| SkDebugf("</div>\n"); |
| #endif |
| #if DEBUG_PATH_CONSTRUCTION |
| SkDebugf("%s\n", __FUNCTION__); |
| #endif |
| SkOpEdgeBuilder builder(path, &contour, &allocator, &globalState); |
| builder.finish(&allocator); |
| SkTDArray<const SkOpContour* > runs; // indices of partial contours |
| const SkOpContour* eContour = builder.head(); |
| do { |
| if (!eContour->count()) { |
| continue; |
| } |
| const SkPoint& eStart = eContour->start(); |
| const SkPoint& eEnd = eContour->end(); |
| #if DEBUG_ASSEMBLE |
| SkDebugf("%s contour", __FUNCTION__); |
| if (!SkDPoint::ApproximatelyEqual(eStart, eEnd)) { |
| SkDebugf("[%d]", runs.count()); |
| } else { |
| SkDebugf(" "); |
| } |
| SkDebugf(" start=(%1.9g,%1.9g) end=(%1.9g,%1.9g)\n", |
| eStart.fX, eStart.fY, eEnd.fX, eEnd.fY); |
| #endif |
| if (SkDPoint::ApproximatelyEqual(eStart, eEnd)) { |
| eContour->toPath(simple); |
| continue; |
| } |
| *runs.append() = eContour; |
| } while ((eContour = eContour->next())); |
| int count = runs.count(); |
| if (count == 0) { |
| return; |
| } |
| SkTDArray<int> sLink, eLink; |
| sLink.append(count); |
| eLink.append(count); |
| int rIndex, iIndex; |
| for (rIndex = 0; rIndex < count; ++rIndex) { |
| sLink[rIndex] = eLink[rIndex] = SK_MaxS32; |
| } |
| const int ends = count * 2; // all starts and ends |
| const int entries = (ends - 1) * count; // folded triangle : n * (n - 1) / 2 |
| SkTDArray<double> distances; |
| distances.append(entries); |
| for (rIndex = 0; rIndex < ends - 1; ++rIndex) { |
| const SkOpContour* oContour = runs[rIndex >> 1]; |
| const SkPoint& oPt = rIndex & 1 ? oContour->end() : oContour->start(); |
| const int row = rIndex < count - 1 ? rIndex * ends : (ends - rIndex - 2) |
| * ends - rIndex - 1; |
| for (iIndex = rIndex + 1; iIndex < ends; ++iIndex) { |
| const SkOpContour* iContour = runs[iIndex >> 1]; |
| const SkPoint& iPt = iIndex & 1 ? iContour->end() : iContour->start(); |
| double dx = iPt.fX - oPt.fX; |
| double dy = iPt.fY - oPt.fY; |
| double dist = dx * dx + dy * dy; |
| distances[row + iIndex] = dist; // oStart distance from iStart |
| } |
| } |
| SkTDArray<int> sortedDist; |
| sortedDist.append(entries); |
| for (rIndex = 0; rIndex < entries; ++rIndex) { |
| sortedDist[rIndex] = rIndex; |
| } |
| SkTQSort<int>(sortedDist.begin(), sortedDist.end() - 1, DistanceLessThan(distances.begin())); |
| int remaining = count; // number of start/end pairs |
| for (rIndex = 0; rIndex < entries; ++rIndex) { |
| int pair = sortedDist[rIndex]; |
| int row = pair / ends; |
| int col = pair - row * ends; |
| int thingOne = row < col ? row : ends - row - 2; |
| int ndxOne = thingOne >> 1; |
| bool endOne = thingOne & 1; |
| int* linkOne = endOne ? eLink.begin() : sLink.begin(); |
| if (linkOne[ndxOne] != SK_MaxS32) { |
| continue; |
| } |
| int thingTwo = row < col ? col : ends - row + col - 1; |
| int ndxTwo = thingTwo >> 1; |
| bool endTwo = thingTwo & 1; |
| int* linkTwo = endTwo ? eLink.begin() : sLink.begin(); |
| if (linkTwo[ndxTwo] != SK_MaxS32) { |
| continue; |
| } |
| SkASSERT(&linkOne[ndxOne] != &linkTwo[ndxTwo]); |
| bool flip = endOne == endTwo; |
| linkOne[ndxOne] = flip ? ~ndxTwo : ndxTwo; |
| linkTwo[ndxTwo] = flip ? ~ndxOne : ndxOne; |
| if (!--remaining) { |
| break; |
| } |
| } |
| SkASSERT(!remaining); |
| #if DEBUG_ASSEMBLE |
| for (rIndex = 0; rIndex < count; ++rIndex) { |
| int s = sLink[rIndex]; |
| int e = eLink[rIndex]; |
| SkDebugf("%s %c%d <- s%d - e%d -> %c%d\n", __FUNCTION__, s < 0 ? 's' : 'e', |
| s < 0 ? ~s : s, rIndex, rIndex, e < 0 ? 'e' : 's', e < 0 ? ~e : e); |
| } |
| #endif |
| rIndex = 0; |
| do { |
| bool forward = true; |
| bool first = true; |
| int sIndex = sLink[rIndex]; |
| SkASSERT(sIndex != SK_MaxS32); |
| sLink[rIndex] = SK_MaxS32; |
| int eIndex; |
| if (sIndex < 0) { |
| eIndex = sLink[~sIndex]; |
| sLink[~sIndex] = SK_MaxS32; |
| } else { |
| eIndex = eLink[sIndex]; |
| eLink[sIndex] = SK_MaxS32; |
| } |
| SkASSERT(eIndex != SK_MaxS32); |
| #if DEBUG_ASSEMBLE |
| SkDebugf("%s sIndex=%c%d eIndex=%c%d\n", __FUNCTION__, sIndex < 0 ? 's' : 'e', |
| sIndex < 0 ? ~sIndex : sIndex, eIndex < 0 ? 's' : 'e', |
| eIndex < 0 ? ~eIndex : eIndex); |
| #endif |
| do { |
| const SkOpContour* contour = runs[rIndex]; |
| if (first) { |
| first = false; |
| const SkPoint* startPtr = &contour->start(); |
| simple->deferredMove(startPtr[0]); |
| } |
| if (forward) { |
| contour->toPartialForward(simple); |
| } else { |
| contour->toPartialBackward(simple); |
| } |
| #if DEBUG_ASSEMBLE |
| SkDebugf("%s rIndex=%d eIndex=%s%d close=%d\n", __FUNCTION__, rIndex, |
| eIndex < 0 ? "~" : "", eIndex < 0 ? ~eIndex : eIndex, |
| sIndex == ((rIndex != eIndex) ^ forward ? eIndex : ~eIndex)); |
| #endif |
| if (sIndex == ((rIndex != eIndex) ^ forward ? eIndex : ~eIndex)) { |
| simple->close(); |
| break; |
| } |
| if (forward) { |
| eIndex = eLink[rIndex]; |
| SkASSERT(eIndex != SK_MaxS32); |
| eLink[rIndex] = SK_MaxS32; |
| if (eIndex >= 0) { |
| SkASSERT(sLink[eIndex] == rIndex); |
| sLink[eIndex] = SK_MaxS32; |
| } else { |
| SkASSERT(eLink[~eIndex] == ~rIndex); |
| eLink[~eIndex] = SK_MaxS32; |
| } |
| } else { |
| eIndex = sLink[rIndex]; |
| SkASSERT(eIndex != SK_MaxS32); |
| sLink[rIndex] = SK_MaxS32; |
| if (eIndex >= 0) { |
| SkASSERT(eLink[eIndex] == rIndex); |
| eLink[eIndex] = SK_MaxS32; |
| } else { |
| SkASSERT(sLink[~eIndex] == ~rIndex); |
| sLink[~eIndex] = SK_MaxS32; |
| } |
| } |
| rIndex = eIndex; |
| if (rIndex < 0) { |
| forward ^= 1; |
| rIndex = ~rIndex; |
| } |
| } while (true); |
| for (rIndex = 0; rIndex < count; ++rIndex) { |
| if (sLink[rIndex] != SK_MaxS32) { |
| break; |
| } |
| } |
| } while (rIndex < count); |
| #if DEBUG_ASSEMBLE |
| for (rIndex = 0; rIndex < count; ++rIndex) { |
| SkASSERT(sLink[rIndex] == SK_MaxS32); |
| SkASSERT(eLink[rIndex] == SK_MaxS32); |
| } |
| #endif |
| } |
| |
| static void align(SkOpContourHead* contourList) { |
| SkOpContour* contour = contourList; |
| do { |
| contour->align(); |
| } while ((contour = contour->next())); |
| } |
| |
| static void addAlignIntersections(SkOpContourHead* contourList, SkChunkAlloc* allocator) { |
| SkOpContour* contour = contourList; |
| do { |
| contour->addAlignIntersections(contourList, allocator); |
| } while ((contour = contour->next())); |
| } |
| |
| static void calcAngles(SkOpContourHead* contourList, SkChunkAlloc* allocator) { |
| SkOpContour* contour = contourList; |
| do { |
| contour->calcAngles(allocator); |
| } while ((contour = contour->next())); |
| } |
| |
| static void findCollapsed(SkOpContourHead* contourList) { |
| SkOpContour* contour = contourList; |
| do { |
| contour->findCollapsed(); |
| } while ((contour = contour->next())); |
| } |
| |
| static bool missingCoincidence(SkOpContourHead* contourList, |
| SkOpCoincidence* coincidence, SkChunkAlloc* allocator) { |
| SkOpContour* contour = contourList; |
| bool result = false; |
| do { |
| result |= contour->missingCoincidence(coincidence, allocator); |
| } while ((contour = contour->next())); |
| return result; |
| } |
| |
| static bool moveMultiples(SkOpContourHead* contourList) { |
| SkOpContour* contour = contourList; |
| do { |
| if (!contour->moveMultiples()) { |
| return false; |
| } |
| } while ((contour = contour->next())); |
| return true; |
| } |
| |
| static void moveNearby(SkOpContourHead* contourList) { |
| SkOpContour* contour = contourList; |
| do { |
| contour->moveNearby(); |
| } while ((contour = contour->next())); |
| } |
| |
| static void sortAngles(SkOpContourHead* contourList) { |
| SkOpContour* contour = contourList; |
| do { |
| contour->sortAngles(); |
| } while ((contour = contour->next())); |
| } |
| |
| bool HandleCoincidence(SkOpContourHead* contourList, SkOpCoincidence* coincidence, |
| SkChunkAlloc* allocator) { |
| SkOpGlobalState* globalState = contourList->globalState(); |
| // combine t values when multiple intersections occur on some segments but not others |
| DEBUG_COINCIDENCE_HEALTH(contourList, "start"); |
| if (!moveMultiples(contourList)) { |
| return false; |
| } |
| DEBUG_COINCIDENCE_HEALTH(contourList, "moveMultiples"); |
| findCollapsed(contourList); |
| DEBUG_COINCIDENCE_HEALTH(contourList, "findCollapsed"); |
| // move t values and points together to eliminate small/tiny gaps |
| moveNearby(contourList); |
| DEBUG_COINCIDENCE_HEALTH(contourList, "moveNearby"); |
| align(contourList); // give all span members common values |
| DEBUG_COINCIDENCE_HEALTH(contourList, "align"); |
| if (!coincidence->fixAligned()) { // aligning may have marked a coincidence pt-t deleted |
| return false; |
| } |
| DEBUG_COINCIDENCE_HEALTH(contourList, "fixAligned"); |
| #if DEBUG_VALIDATE |
| globalState->setPhase(SkOpGlobalState::kIntersecting); |
| #endif |
| // look for intersections on line segments formed by moving end points |
| addAlignIntersections(contourList, allocator); |
| DEBUG_COINCIDENCE_HEALTH(contourList, "addAlignIntersections"); |
| if (coincidence->addMissing(allocator)) { |
| DEBUG_COINCIDENCE_HEALTH(contourList, "addMissing"); |
| moveNearby(contourList); |
| DEBUG_COINCIDENCE_HEALTH(contourList, "moveNearby2"); |
| align(contourList); // give all span members common values |
| DEBUG_COINCIDENCE_HEALTH(contourList, "align2"); |
| if (!coincidence->fixAligned()) { // aligning may have marked a coincidence pt-t deleted |
| return false; |
| } |
| DEBUG_COINCIDENCE_HEALTH(contourList, "fixAligned2"); |
| } |
| #if DEBUG_VALIDATE |
| globalState->setPhase(SkOpGlobalState::kWalking); |
| #endif |
| // check to see if, loosely, coincident ranges may be expanded |
| if (coincidence->expand()) { |
| DEBUG_COINCIDENCE_HEALTH(contourList, "expand1"); |
| if (!coincidence->addExpanded(allocator PATH_OPS_DEBUG_VALIDATE_PARAMS(globalState))) { |
| return false; |
| } |
| } |
| DEBUG_COINCIDENCE_HEALTH(contourList, "expand2"); |
| // the expanded ranges may not align -- add the missing spans |
| if (!coincidence->mark()) { // mark spans of coincident segments as coincident |
| return false; |
| } |
| DEBUG_COINCIDENCE_HEALTH(contourList, "mark1"); |
| // look for coincidence missed earlier |
| if (missingCoincidence(contourList, coincidence, allocator)) { |
| DEBUG_COINCIDENCE_HEALTH(contourList, "missingCoincidence1"); |
| (void) coincidence->expand(); |
| DEBUG_COINCIDENCE_HEALTH(contourList, "expand3"); |
| if (!coincidence->addExpanded(allocator PATH_OPS_DEBUG_VALIDATE_PARAMS(globalState))) { |
| return false; |
| } |
| DEBUG_COINCIDENCE_HEALTH(contourList, "addExpanded2"); |
| coincidence->mark(); |
| } |
| DEBUG_COINCIDENCE_HEALTH(contourList, "missingCoincidence2"); |
| SkOpCoincidence overlaps; |
| do { |
| SkOpCoincidence* pairs = overlaps.isEmpty() ? coincidence : &overlaps; |
| if (!pairs->apply()) { // adjust the winding value to account for coincident edges |
| return false; |
| } |
| DEBUG_COINCIDENCE_HEALTH(contourList, "pairs->apply"); |
| // For each coincident pair that overlaps another, when the receivers (the 1st of the pair) |
| // are different, construct a new pair to resolve their mutual span |
| if (!pairs->findOverlaps(&overlaps, allocator)) { |
| return false; |
| } |
| DEBUG_COINCIDENCE_HEALTH(contourList, "pairs->findOverlaps"); |
| } while (!overlaps.isEmpty()); |
| calcAngles(contourList, allocator); |
| sortAngles(contourList); |
| if (globalState->angleCoincidence()) { |
| (void) missingCoincidence(contourList, coincidence, allocator); |
| if (!coincidence->apply()) { |
| return false; |
| } |
| } |
| #if DEBUG_ACTIVE_SPANS |
| coincidence->debugShowCoincidence(); |
| DebugShowActiveSpans(contourList); |
| #endif |
| return true; |
| } |
