diff options
Diffstat (limited to 'gfx/skia/skia/src/pathops/SkPathWriter.cpp')
| -rw-r--r-- | gfx/skia/skia/src/pathops/SkPathWriter.cpp | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/pathops/SkPathWriter.cpp b/gfx/skia/skia/src/pathops/SkPathWriter.cpp new file mode 100644 index 0000000000..9ded489834 --- /dev/null +++ b/gfx/skia/skia/src/pathops/SkPathWriter.cpp @@ -0,0 +1,434 @@ +/* + * 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 "src/pathops/SkPathWriter.h" + +#include "include/core/SkTypes.h" +#include "include/private/base/SkMath.h" +#include "src/base/SkTSort.h" +#include "src/pathops/SkOpSegment.h" +#include "src/pathops/SkOpSpan.h" +#include "src/pathops/SkPathOpsDebug.h" +#include "src/pathops/SkPathOpsTypes.h" + +// wrap path to keep track of whether the contour is initialized and non-empty +SkPathWriter::SkPathWriter(SkPath& path) + : fPathPtr(&path) +{ + init(); +} + +void SkPathWriter::close() { + if (fCurrent.isEmpty()) { + return; + } + SkASSERT(this->isClosed()); +#if DEBUG_PATH_CONSTRUCTION + SkDebugf("path.close();\n"); +#endif + fCurrent.close(); + fPathPtr->addPath(fCurrent); + fCurrent.reset(); + init(); +} + +void SkPathWriter::conicTo(const SkPoint& pt1, const SkOpPtT* pt2, SkScalar weight) { + SkPoint pt2pt = this->update(pt2); +#if DEBUG_PATH_CONSTRUCTION + SkDebugf("path.conicTo(%1.9g,%1.9g, %1.9g,%1.9g, %1.9g);\n", + pt1.fX, pt1.fY, pt2pt.fX, pt2pt.fY, weight); +#endif + fCurrent.conicTo(pt1, pt2pt, weight); +} + +void SkPathWriter::cubicTo(const SkPoint& pt1, const SkPoint& pt2, const SkOpPtT* pt3) { + SkPoint pt3pt = this->update(pt3); +#if DEBUG_PATH_CONSTRUCTION + SkDebugf("path.cubicTo(%1.9g,%1.9g, %1.9g,%1.9g, %1.9g,%1.9g);\n", + pt1.fX, pt1.fY, pt2.fX, pt2.fY, pt3pt.fX, pt3pt.fY); +#endif + fCurrent.cubicTo(pt1, pt2, pt3pt); +} + +bool SkPathWriter::deferredLine(const SkOpPtT* pt) { + SkASSERT(fFirstPtT); + SkASSERT(fDefer[0]); + if (fDefer[0] == pt) { + // FIXME: why we're adding a degenerate line? Caller should have preflighted this. + return true; + } + if (pt->contains(fDefer[0])) { + // FIXME: why we're adding a degenerate line? + return true; + } + if (this->matchedLast(pt)) { + return false; + } + if (fDefer[1] && this->changedSlopes(pt)) { + this->lineTo(); + fDefer[0] = fDefer[1]; + } + fDefer[1] = pt; + return true; +} + +void SkPathWriter::deferredMove(const SkOpPtT* pt) { + if (!fDefer[1]) { + fFirstPtT = fDefer[0] = pt; + return; + } + SkASSERT(fDefer[0]); + if (!this->matchedLast(pt)) { + this->finishContour(); + fFirstPtT = fDefer[0] = pt; + } +} + +void SkPathWriter::finishContour() { + if (!this->matchedLast(fDefer[0])) { + if (!fDefer[1]) { + return; + } + this->lineTo(); + } + if (fCurrent.isEmpty()) { + return; + } + if (this->isClosed()) { + this->close(); + } else { + SkASSERT(fDefer[1]); + fEndPtTs.push_back(fFirstPtT); + fEndPtTs.push_back(fDefer[1]); + fPartials.push_back(fCurrent); + this->init(); + } +} + +void SkPathWriter::init() { + fCurrent.reset(); + fFirstPtT = fDefer[0] = fDefer[1] = nullptr; +} + +bool SkPathWriter::isClosed() const { + return this->matchedLast(fFirstPtT); +} + +void SkPathWriter::lineTo() { + if (fCurrent.isEmpty()) { + this->moveTo(); + } +#if DEBUG_PATH_CONSTRUCTION + SkDebugf("path.lineTo(%1.9g,%1.9g);\n", fDefer[1]->fPt.fX, fDefer[1]->fPt.fY); +#endif + fCurrent.lineTo(fDefer[1]->fPt); +} + +bool SkPathWriter::matchedLast(const SkOpPtT* test) const { + if (test == fDefer[1]) { + return true; + } + if (!test) { + return false; + } + if (!fDefer[1]) { + return false; + } + return test->contains(fDefer[1]); +} + +void SkPathWriter::moveTo() { +#if DEBUG_PATH_CONSTRUCTION + SkDebugf("path.moveTo(%1.9g,%1.9g);\n", fFirstPtT->fPt.fX, fFirstPtT->fPt.fY); +#endif + fCurrent.moveTo(fFirstPtT->fPt); +} + +void SkPathWriter::quadTo(const SkPoint& pt1, const SkOpPtT* pt2) { + SkPoint pt2pt = this->update(pt2); +#if DEBUG_PATH_CONSTRUCTION + SkDebugf("path.quadTo(%1.9g,%1.9g, %1.9g,%1.9g);\n", + pt1.fX, pt1.fY, pt2pt.fX, pt2pt.fY); +#endif + fCurrent.quadTo(pt1, pt2pt); +} + +// if last point to be written matches the current path's first point, alter the +// last to avoid writing a degenerate lineTo when the path is closed +SkPoint SkPathWriter::update(const SkOpPtT* pt) { + if (!fDefer[1]) { + this->moveTo(); + } else if (!this->matchedLast(fDefer[0])) { + this->lineTo(); + } + SkPoint result = pt->fPt; + if (fFirstPtT && result != fFirstPtT->fPt && fFirstPtT->contains(pt)) { + result = fFirstPtT->fPt; + } + fDefer[0] = fDefer[1] = pt; // set both to know that there is not a pending deferred line + return result; +} + +bool SkPathWriter::someAssemblyRequired() { + this->finishContour(); + return !fEndPtTs.empty(); +} + +bool SkPathWriter::changedSlopes(const SkOpPtT* ptT) const { + if (matchedLast(fDefer[0])) { + return false; + } + SkVector deferDxdy = fDefer[1]->fPt - fDefer[0]->fPt; + SkVector lineDxdy = ptT->fPt - fDefer[1]->fPt; + return deferDxdy.fX * lineDxdy.fY != deferDxdy.fY * lineDxdy.fX; +} + +class DistanceLessThan { +public: + DistanceLessThan(double* distances) : fDistances(distances) { } + double* fDistances; + bool operator()(const int one, const int two) const { + 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 SkPathWriter::assemble() { + if (!this->someAssemblyRequired()) { + return; + } +#if DEBUG_PATH_CONSTRUCTION + SkDebugf("%s\n", __FUNCTION__); +#endif + SkOpPtT const* const* runs = fEndPtTs.begin(); // starts, ends of partial contours + int endCount = fEndPtTs.size(); // all starts and ends + SkASSERT(endCount > 0); + SkASSERT(endCount == fPartials.size() * 2); +#if DEBUG_ASSEMBLE + for (int index = 0; index < endCount; index += 2) { + const SkOpPtT* eStart = runs[index]; + const SkOpPtT* eEnd = runs[index + 1]; + SkASSERT(eStart != eEnd); + SkASSERT(!eStart->contains(eEnd)); + SkDebugf("%s contour start=(%1.9g,%1.9g) end=(%1.9g,%1.9g)\n", __FUNCTION__, + eStart->fPt.fX, eStart->fPt.fY, eEnd->fPt.fX, eEnd->fPt.fY); + } +#endif + // lengthen any partial contour adjacent to a simple segment + for (int pIndex = 0; pIndex < endCount; pIndex++) { + SkOpPtT* opPtT = const_cast<SkOpPtT*>(runs[pIndex]); + SkPath p; + SkPathWriter partWriter(p); + do { + if (!zero_or_one(opPtT->fT)) { + break; + } + SkOpSpanBase* opSpanBase = opPtT->span(); + SkOpSpanBase* start = opPtT->fT ? opSpanBase->prev() : opSpanBase->upCast()->next(); + int step = opPtT->fT ? 1 : -1; + const SkOpSegment* opSegment = opSpanBase->segment(); + const SkOpSegment* nextSegment = opSegment->isSimple(&start, &step); + if (!nextSegment) { + break; + } + SkOpSpanBase* opSpanEnd = start->t() ? start->prev() : start->upCast()->next(); + if (start->starter(opSpanEnd)->alreadyAdded()) { + break; + } + nextSegment->addCurveTo(start, opSpanEnd, &partWriter); + opPtT = opSpanEnd->ptT(); + SkOpPtT** runsPtr = const_cast<SkOpPtT**>(&runs[pIndex]); + *runsPtr = opPtT; + } while (true); + partWriter.finishContour(); + const SkTArray<SkPath>& partPartials = partWriter.partials(); + if (partPartials.empty()) { + continue; + } + // if pIndex is even, reverse and prepend to fPartials; otherwise, append + SkPath& partial = const_cast<SkPath&>(fPartials[pIndex >> 1]); + const SkPath& part = partPartials[0]; + if (pIndex & 1) { + partial.addPath(part, SkPath::kExtend_AddPathMode); + } else { + SkPath reverse; + reverse.reverseAddPath(part); + reverse.addPath(partial, SkPath::kExtend_AddPathMode); + partial = reverse; + } + } + SkTDArray<int> sLink, eLink; + int linkCount = endCount / 2; // number of partial contours + sLink.append(linkCount); + eLink.append(linkCount); + int rIndex, iIndex; + for (rIndex = 0; rIndex < linkCount; ++rIndex) { + sLink[rIndex] = eLink[rIndex] = SK_MaxS32; + } + const int entries = endCount * (endCount - 1) / 2; // folded triangle + SkSTArray<8, double, true> distances(entries); + SkSTArray<8, int, true> sortedDist(entries); + SkSTArray<8, int, true> distLookup(entries); + int rRow = 0; + int dIndex = 0; + for (rIndex = 0; rIndex < endCount - 1; ++rIndex) { + const SkOpPtT* oPtT = runs[rIndex]; + for (iIndex = rIndex + 1; iIndex < endCount; ++iIndex) { + const SkOpPtT* iPtT = runs[iIndex]; + double dx = iPtT->fPt.fX - oPtT->fPt.fX; + double dy = iPtT->fPt.fY - oPtT->fPt.fY; + double dist = dx * dx + dy * dy; + distLookup.push_back(rRow + iIndex); + distances.push_back(dist); // oStart distance from iStart + sortedDist.push_back(dIndex++); + } + rRow += endCount; + } + SkASSERT(dIndex == entries); + SkTQSort<int>(sortedDist.begin(), sortedDist.end(), DistanceLessThan(distances.begin())); + int remaining = linkCount; // number of start/end pairs + for (rIndex = 0; rIndex < entries; ++rIndex) { + int pair = sortedDist[rIndex]; + pair = distLookup[pair]; + int row = pair / endCount; + int col = pair - row * endCount; + int ndxOne = row >> 1; + bool endOne = row & 1; + int* linkOne = endOne ? eLink.begin() : sLink.begin(); + if (linkOne[ndxOne] != SK_MaxS32) { + continue; + } + int ndxTwo = col >> 1; + bool endTwo = col & 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 < linkCount; ++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 SkPath& contour = fPartials[rIndex]; + if (!first) { + SkPoint prior, next; + if (!fPathPtr->getLastPt(&prior)) { + return; + } + if (forward) { + next = contour.getPoint(0); + } else { + SkAssertResult(contour.getLastPt(&next)); + } + if (prior != next) { + /* TODO: if there is a gap between open path written so far and path to come, + connect by following segments from one to the other, rather than introducing + a diagonal to connect the two. + */ + } + } + if (forward) { + fPathPtr->addPath(contour, + first ? SkPath::kAppend_AddPathMode : SkPath::kExtend_AddPathMode); + } else { + SkASSERT(!first); + fPathPtr->reversePathTo(contour); + } + if (first) { + first = false; + } +#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)) { + fPathPtr->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 < linkCount; ++rIndex) { + if (sLink[rIndex] != SK_MaxS32) { + break; + } + } + } while (rIndex < linkCount); +#if DEBUG_ASSEMBLE + for (rIndex = 0; rIndex < linkCount; ++rIndex) { + SkASSERT(sLink[rIndex] == SK_MaxS32); + SkASSERT(eLink[rIndex] == SK_MaxS32); + } +#endif + return; +} |