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Diffstat (limited to 'basegfx/source/polygon/b2dpolypolygoncutter.cxx')
| -rw-r--r-- | basegfx/source/polygon/b2dpolypolygoncutter.cxx | 1149 |
1 files changed, 1149 insertions, 0 deletions
diff --git a/basegfx/source/polygon/b2dpolypolygoncutter.cxx b/basegfx/source/polygon/b2dpolypolygoncutter.cxx new file mode 100644 index 000000000..b548939f3 --- /dev/null +++ b/basegfx/source/polygon/b2dpolypolygoncutter.cxx @@ -0,0 +1,1149 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#include <basegfx/numeric/ftools.hxx> +#include <basegfx/polygon/b2dpolypolygoncutter.hxx> +#include <basegfx/point/b2dpoint.hxx> +#include <basegfx/vector/b2dvector.hxx> +#include <basegfx/polygon/b2dpolygon.hxx> +#include <basegfx/polygon/b2dpolygontools.hxx> +#include <basegfx/polygon/b2dpolygoncutandtouch.hxx> +#include <basegfx/range/b2drange.hxx> +#include <basegfx/polygon/b2dpolypolygontools.hxx> +#include <basegfx/curve/b2dcubicbezier.hxx> +#include <sal/log.hxx> +#include <utility> +#include <vector> +#include <algorithm> + +namespace basegfx +{ + namespace + { + + struct StripHelper + { + B2DRange maRange; + sal_Int32 mnDepth; + B2VectorOrientation meOrinetation; + }; + + struct PN + { + public: + B2DPoint maPoint; + sal_uInt32 mnI; + sal_uInt32 mnIP; + sal_uInt32 mnIN; + }; + + struct VN + { + public: + B2DVector maPrev; + B2DVector maNext; + + // to have the correct curve segments in the crossover checks, + // it is necessary to keep the original next vectors, too. Else, + // it may happen to use an already switched next vector which + // would interpolate the wrong comparison point + B2DVector maOriginalNext; + }; + + struct SN + { + public: + PN* mpPN; + + bool operator<(const SN& rComp) const + { + if(fTools::equal(mpPN->maPoint.getX(), rComp.mpPN->maPoint.getX())) + { + if(fTools::equal(mpPN->maPoint.getY(), rComp.mpPN->maPoint.getY())) + { + return (mpPN->mnI < rComp.mpPN->mnI); + } + else + { + return fTools::less(mpPN->maPoint.getY(), rComp.mpPN->maPoint.getY()); + } + } + else + { + return fTools::less(mpPN->maPoint.getX(), rComp.mpPN->maPoint.getX()); + } + } + }; + + typedef std::vector< PN > PNV; + typedef std::vector< VN > VNV; + typedef std::vector< SN > SNV; + typedef std::pair< basegfx::B2DPoint /*orig*/, basegfx::B2DPoint /*repl*/ > CorrectionPair; + + class solver + { + private: + const B2DPolyPolygon maOriginal; + PNV maPNV; + VNV maVNV; + SNV maSNV; + std::vector< CorrectionPair > + maCorrectionTable; + + bool mbIsCurve : 1; + bool mbChanged : 1; + + void impAddPolygon(const sal_uInt32 aPos, const B2DPolygon& rGeometry) + { + const sal_uInt32 nCount(rGeometry.count()); + PN aNewPN; + VN aNewVN; + SN aNewSN; + + for(sal_uInt32 a(0); a < nCount; a++) + { + const B2DPoint aPoint(rGeometry.getB2DPoint(a)); + aNewPN.maPoint = aPoint; + aNewPN.mnI = aPos + a; + aNewPN.mnIP = aPos + ((a != 0) ? a - 1 : nCount - 1); + aNewPN.mnIN = aPos + ((a + 1 == nCount) ? 0 : a + 1); + maPNV.push_back(aNewPN); + + if(mbIsCurve) + { + aNewVN.maPrev = rGeometry.getPrevControlPoint(a) - aPoint; + aNewVN.maNext = rGeometry.getNextControlPoint(a) - aPoint; + aNewVN.maOriginalNext = aNewVN.maNext; + maVNV.push_back(aNewVN); + } + + aNewSN.mpPN = &maPNV[maPNV.size() - 1]; + maSNV.push_back(aNewSN); + } + } + + static bool impLeftOfEdges(const B2DVector& rVecA, const B2DVector& rVecB, const B2DVector& rTest) + { + // tests if rTest is left of both directed line segments along the line -rVecA, rVecB. Test is + // with border. + if(rVecA.cross(rVecB) > 0.0) + { + // b is left turn seen from a, test if Test is left of both and so inside (left is seen as inside) + const bool bBoolA(fTools::moreOrEqual(rVecA.cross(rTest), 0.0)); + const bool bBoolB(fTools::lessOrEqual(rVecB.cross(rTest), 0.0)); + + return (bBoolA && bBoolB); + } + else + { + // b is right turn seen from a, test if Test is right of both and so outside (left is seen as inside) + const bool bBoolA(fTools::lessOrEqual(rVecA.cross(rTest), 0.0)); + const bool bBoolB(fTools::moreOrEqual(rVecB.cross(rTest), 0.0)); + + return (!(bBoolA && bBoolB)); + } + } + + void impSwitchNext(PN& rPNa, PN& rPNb) + { + std::swap(rPNa.mnIN, rPNb.mnIN); + + if(mbIsCurve) + { + VN& rVNa = maVNV[rPNa.mnI]; + VN& rVNb = maVNV[rPNb.mnI]; + + std::swap(rVNa.maNext, rVNb.maNext); + } + + if(!mbChanged) + { + mbChanged = true; + } + } + + B2DCubicBezier createSegment(const PN& rPN, bool bPrev) const + { + const B2DPoint& rStart(rPN.maPoint); + const B2DPoint& rEnd(maPNV[bPrev ? rPN.mnIP : rPN.mnIN].maPoint); + const B2DVector& rCPA(bPrev ? maVNV[rPN.mnI].maPrev : maVNV[rPN.mnI].maNext); + // Use maOriginalNext, not maNext to create the original (yet unchanged) + // curve segment. Otherwise, this segment would NOT ne correct. + const B2DVector& rCPB(bPrev ? maVNV[maPNV[rPN.mnIP].mnI].maOriginalNext : maVNV[maPNV[rPN.mnIN].mnI].maPrev); + + return B2DCubicBezier(rStart, rStart + rCPA, rEnd + rCPB, rEnd); + } + + void impHandleCommon(PN& rPNa, PN& rPNb) + { + if(mbIsCurve) + { + const B2DCubicBezier aNextA(createSegment(rPNa, false)); + const B2DCubicBezier aPrevA(createSegment(rPNa, true)); + + if(aNextA.equal(aPrevA)) + { + // deadend on A (identical edge) + return; + } + + const B2DCubicBezier aNextB(createSegment(rPNb, false)); + const B2DCubicBezier aPrevB(createSegment(rPNb, true)); + + if(aNextB.equal(aPrevB)) + { + // deadend on B (identical edge) + return; + } + + if(aPrevA.equal(aPrevB)) + { + // common edge in same direction + return; + } + else if(aPrevA.equal(aNextB)) + { + // common edge in opposite direction + if(aNextA.equal(aPrevB)) + { + // common edge in opposite direction continues + return; + } + else + { + // common edge in opposite direction leave + impSwitchNext(rPNa, rPNb); + } + } + else if(aNextA.equal(aNextB)) + { + // common edge in same direction enter + // search leave edge + PN* pPNa2 = &maPNV[rPNa.mnIN]; + PN* pPNb2 = &maPNV[rPNb.mnIN]; + bool bOnEdge(true); + + do + { + const B2DCubicBezier aNextA2(createSegment(*pPNa2, false)); + const B2DCubicBezier aNextB2(createSegment(*pPNb2, false)); + + if(aNextA2.equal(aNextB2)) + { + pPNa2 = &maPNV[pPNa2->mnIN]; + pPNb2 = &maPNV[pPNb2->mnIN]; + } + else + { + bOnEdge = false; + } + } + while(bOnEdge && pPNa2 != &rPNa && pPNb2 != &rPNb); + + if(bOnEdge) + { + // loop over two identical polygon paths + return; + } + else + { + // enter at rPNa, rPNb; leave at pPNa2, pPNb2. No common edges + // at enter/leave. Check for crossover. + const B2DVector aPrevCA(aPrevA.interpolatePoint(0.5) - aPrevA.getStartPoint()); + const B2DVector aNextCA(aNextA.interpolatePoint(0.5) - aNextA.getStartPoint()); + const B2DVector aPrevCB(aPrevB.interpolatePoint(0.5) - aPrevB.getStartPoint()); + const bool bEnter(impLeftOfEdges(aPrevCA, aNextCA, aPrevCB)); + + const B2DCubicBezier aNextA2(createSegment(*pPNa2, false)); + const B2DCubicBezier aPrevA2(createSegment(*pPNa2, true)); + const B2DCubicBezier aNextB2(createSegment(*pPNb2, false)); + const B2DVector aPrevCA2(aPrevA2.interpolatePoint(0.5) - aPrevA2.getStartPoint()); + const B2DVector aNextCA2(aNextA2.interpolatePoint(0.5) - aNextA2.getStartPoint()); + const B2DVector aNextCB2(aNextB2.interpolatePoint(0.5) - aNextB2.getStartPoint()); + const bool bLeave(impLeftOfEdges(aPrevCA2, aNextCA2, aNextCB2)); + + if(bEnter != bLeave) + { + // crossover + impSwitchNext(rPNa, rPNb); + } + } + } + else if(aNextA.equal(aPrevB)) + { + // common edge in opposite direction enter + impSwitchNext(rPNa, rPNb); + } + else + { + // no common edges, check for crossover + const B2DVector aPrevCA(aPrevA.interpolatePoint(0.5) - aPrevA.getStartPoint()); + const B2DVector aNextCA(aNextA.interpolatePoint(0.5) - aNextA.getStartPoint()); + const B2DVector aPrevCB(aPrevB.interpolatePoint(0.5) - aPrevB.getStartPoint()); + const B2DVector aNextCB(aNextB.interpolatePoint(0.5) - aNextB.getStartPoint()); + + const bool bEnter(impLeftOfEdges(aPrevCA, aNextCA, aPrevCB)); + const bool bLeave(impLeftOfEdges(aPrevCA, aNextCA, aNextCB)); + + if(bEnter != bLeave) + { + // crossover + impSwitchNext(rPNa, rPNb); + } + } + } + else + { + const B2DPoint& rNextA(maPNV[rPNa.mnIN].maPoint); + const B2DPoint& rPrevA(maPNV[rPNa.mnIP].maPoint); + + if(rNextA.equal(rPrevA)) + { + // deadend on A + return; + } + + const B2DPoint& rNextB(maPNV[rPNb.mnIN].maPoint); + const B2DPoint& rPrevB(maPNV[rPNb.mnIP].maPoint); + + if(rNextB.equal(rPrevB)) + { + // deadend on B + return; + } + + if(rPrevA.equal(rPrevB)) + { + // common edge in same direction + return; + } + else if(rPrevA.equal(rNextB)) + { + // common edge in opposite direction + if(rNextA.equal(rPrevB)) + { + // common edge in opposite direction continues + return; + } + else + { + // common edge in opposite direction leave + impSwitchNext(rPNa, rPNb); + } + } + else if(rNextA.equal(rNextB)) + { + // common edge in same direction enter + // search leave edge + PN* pPNa2 = &maPNV[rPNa.mnIN]; + PN* pPNb2 = &maPNV[rPNb.mnIN]; + bool bOnEdge(true); + + do + { + const B2DPoint& rNextA2(maPNV[pPNa2->mnIN].maPoint); + const B2DPoint& rNextB2(maPNV[pPNb2->mnIN].maPoint); + + if(rNextA2.equal(rNextB2)) + { + pPNa2 = &maPNV[pPNa2->mnIN]; + pPNb2 = &maPNV[pPNb2->mnIN]; + } + else + { + bOnEdge = false; + } + } + while(bOnEdge && pPNa2 != &rPNa && pPNb2 != &rPNb); + + if(bOnEdge) + { + // loop over two identical polygon paths + return; + } + else + { + // enter at rPNa, rPNb; leave at pPNa2, pPNb2. No common edges + // at enter/leave. Check for crossover. + const B2DPoint& aPointE(rPNa.maPoint); + const B2DVector aPrevAE(rPrevA - aPointE); + const B2DVector aNextAE(rNextA - aPointE); + const B2DVector aPrevBE(rPrevB - aPointE); + + const B2DPoint& aPointL(pPNa2->maPoint); + const B2DVector aPrevAL(maPNV[pPNa2->mnIP].maPoint - aPointL); + const B2DVector aNextAL(maPNV[pPNa2->mnIN].maPoint - aPointL); + const B2DVector aNextBL(maPNV[pPNb2->mnIN].maPoint - aPointL); + + const bool bEnter(impLeftOfEdges(aPrevAE, aNextAE, aPrevBE)); + const bool bLeave(impLeftOfEdges(aPrevAL, aNextAL, aNextBL)); + + if(bEnter != bLeave) + { + // crossover; switch start or end + impSwitchNext(rPNa, rPNb); + } + } + } + else if(rNextA.equal(rPrevB)) + { + // common edge in opposite direction enter + impSwitchNext(rPNa, rPNb); + } + else + { + // no common edges, check for crossover + const B2DPoint& aPoint(rPNa.maPoint); + const B2DVector aPrevA(rPrevA - aPoint); + const B2DVector aNextA(rNextA - aPoint); + const B2DVector aPrevB(rPrevB - aPoint); + const B2DVector aNextB(rNextB - aPoint); + + const bool bEnter(impLeftOfEdges(aPrevA, aNextA, aPrevB)); + const bool bLeave(impLeftOfEdges(aPrevA, aNextA, aNextB)); + + if(bEnter != bLeave) + { + // crossover + impSwitchNext(rPNa, rPNb); + } + } + } + } + + void impSolve() + { + // sort by point to identify common nodes easier + std::sort(maSNV.begin(), maSNV.end()); + + // handle common nodes + const sal_uInt32 nNodeCount(maSNV.size()); + sal_uInt32 a(0); + + // snap unsharp-equal points + if(nNodeCount) + { + basegfx::B2DPoint* pLast(&maSNV[0].mpPN->maPoint); + + for(a = 1; a < nNodeCount; a++) + { + basegfx::B2DPoint* pCurrent(&maSNV[a].mpPN->maPoint); + + if(pLast->equal(*pCurrent) && (pLast->getX() != pCurrent->getX() || pLast->getY() != pCurrent->getY())) + { + const basegfx::B2DPoint aMiddle((*pLast + *pCurrent) * 0.5); + + if(pLast->getX() != aMiddle.getX() || pLast->getY() != aMiddle.getY()) + { + maCorrectionTable.emplace_back(*pLast, aMiddle); + *pLast = aMiddle; + } + + if(pCurrent->getX() != aMiddle.getX() || pCurrent->getY() != aMiddle.getY()) + { + maCorrectionTable.emplace_back(*pCurrent, aMiddle); + *pCurrent = aMiddle; + } + } + + pLast = pCurrent; + } + } + + for(a = 0; a < nNodeCount - 1; a++) + { + // test a before using it, not after. Also use nPointCount instead of aSortNodes.size() + PN& rPNb = *(maSNV[a].mpPN); + + for(sal_uInt32 b(a + 1); b < nNodeCount && rPNb.maPoint.equal(maSNV[b].mpPN->maPoint); b++) + { + impHandleCommon(rPNb, *maSNV[b].mpPN); + } + } + } + + public: + explicit solver(const B2DPolygon& rOriginal) + : maOriginal(B2DPolyPolygon(rOriginal)), + mbIsCurve(false), + mbChanged(false) + { + const sal_uInt32 nOriginalCount(rOriginal.count()); + + if(!nOriginalCount) + return; + + B2DPolygon aGeometry(utils::addPointsAtCutsAndTouches(rOriginal)); + aGeometry.removeDoublePoints(); + aGeometry = utils::simplifyCurveSegments(aGeometry); + mbIsCurve = aGeometry.areControlPointsUsed(); + + const sal_uInt32 nPointCount(aGeometry.count()); + + // If it's not a bezier polygon, at least four points are needed to create + // a self-intersection. If it's a bezier polygon, the minimum point number + // is two, since with a single point You get a curve, but no self-intersection + if(!(nPointCount > 3 || (nPointCount > 1 && mbIsCurve))) + return; + + // reserve space in point, control and sort vector. + maSNV.reserve(nPointCount); + maPNV.reserve(nPointCount); + maVNV.reserve(mbIsCurve ? nPointCount : 0); + + // fill data + impAddPolygon(0, aGeometry); + + // solve common nodes + impSolve(); + } + + explicit solver(B2DPolyPolygon aOriginal, size_t* pPointLimit = nullptr) + : maOriginal(std::move(aOriginal)), + mbIsCurve(false), + mbChanged(false) + { + sal_uInt32 nOriginalCount(maOriginal.count()); + + if(!nOriginalCount) + return; + + B2DPolyPolygon aGeometry(utils::addPointsAtCutsAndTouches(maOriginal, pPointLimit)); + aGeometry.removeDoublePoints(); + aGeometry = utils::simplifyCurveSegments(aGeometry); + mbIsCurve = aGeometry.areControlPointsUsed(); + nOriginalCount = aGeometry.count(); + + if(!nOriginalCount) + return; + + sal_uInt32 nPointCount(0); + sal_uInt32 a(0); + + // count points + for(a = 0; a < nOriginalCount; a++) + { + const B2DPolygon& aCandidate(aGeometry.getB2DPolygon(a)); + const sal_uInt32 nCandCount(aCandidate.count()); + + // If it's not a bezier curve, at least three points would be needed to have a + // topological relevant (not empty) polygon. Since it's not known here if trivial + // edges (dead ends) will be kept or sorted out, add non-bezier polygons with + // more than one point. + // For bezier curves, the minimum for defining an area is also one. + if(nCandCount) + { + nPointCount += nCandCount; + } + } + + if(!nPointCount) + return; + + // reserve space in point, control and sort vector. + maSNV.reserve(nPointCount); + maPNV.reserve(nPointCount); + maVNV.reserve(mbIsCurve ? nPointCount : 0); + + // fill data + sal_uInt32 nInsertIndex(0); + + for(a = 0; a < nOriginalCount; a++) + { + const B2DPolygon& aCandidate(aGeometry.getB2DPolygon(a)); + const sal_uInt32 nCandCount(aCandidate.count()); + + // use same condition as above, the data vector is + // pre-allocated + if(nCandCount) + { + impAddPolygon(nInsertIndex, aCandidate); + nInsertIndex += nCandCount; + } + } + + // solve common nodes + impSolve(); + } + + B2DPolyPolygon getB2DPolyPolygon() + { + if(mbChanged) + { + B2DPolyPolygon aRetval; + const sal_uInt32 nCount(maPNV.size()); + sal_uInt32 nCountdown(nCount); + + for(sal_uInt32 a(0); nCountdown && a < nCount; a++) + { + PN& rPN = maPNV[a]; + + if(rPN.mnI != SAL_MAX_UINT32) + { + // unused node, start new part polygon + B2DPolygon aNewPart; + PN* pPNCurr = &rPN; + + do + { + const B2DPoint& rPoint = pPNCurr->maPoint; + aNewPart.append(rPoint); + + if(mbIsCurve) + { + const VN& rVNCurr = maVNV[pPNCurr->mnI]; + + if(!rVNCurr.maPrev.equalZero()) + { + aNewPart.setPrevControlPoint(aNewPart.count() - 1, rPoint + rVNCurr.maPrev); + } + + if(!rVNCurr.maNext.equalZero()) + { + aNewPart.setNextControlPoint(aNewPart.count() - 1, rPoint + rVNCurr.maNext); + } + } + + pPNCurr->mnI = SAL_MAX_UINT32; + nCountdown--; + pPNCurr = &(maPNV[pPNCurr->mnIN]); + } + while(pPNCurr != &rPN && pPNCurr->mnI != SAL_MAX_UINT32); + + // close and add + aNewPart.setClosed(true); + aRetval.append(aNewPart); + } + } + + return aRetval; + } + else + { + const sal_uInt32 nCorrectionSize(maCorrectionTable.size()); + + // no change, return original + if(!nCorrectionSize) + { + return maOriginal; + } + + // apply coordinate corrections to ensure inside/outside correctness after solving + const sal_uInt32 nPolygonCount(maOriginal.count()); + basegfx::B2DPolyPolygon aRetval(maOriginal); + + for(sal_uInt32 a(0); a < nPolygonCount; a++) + { + basegfx::B2DPolygon aTemp(aRetval.getB2DPolygon(a)); + const sal_uInt32 nPointCount(aTemp.count()); + bool bChanged(false); + + for(sal_uInt32 b(0); b < nPointCount; b++) + { + const basegfx::B2DPoint aCandidate(aTemp.getB2DPoint(b)); + + for(sal_uInt32 c(0); c < nCorrectionSize; c++) + { + if(maCorrectionTable[c].first.getX() == aCandidate.getX() && maCorrectionTable[c].first.getY() == aCandidate.getY()) + { + aTemp.setB2DPoint(b, maCorrectionTable[c].second); + bChanged = true; + } + } + } + + if(bChanged) + { + aRetval.setB2DPolygon(a, aTemp); + } + } + + return aRetval; + } + } + }; + + } // end of anonymous namespace +} // end of namespace basegfx + +namespace basegfx::utils +{ + + B2DPolyPolygon solveCrossovers(const B2DPolyPolygon& rCandidate, size_t* pPointLimit) + { + if(rCandidate.count() > 0) + { + solver aSolver(rCandidate, pPointLimit); + return aSolver.getB2DPolyPolygon(); + } + else + { + return rCandidate; + } + } + + B2DPolyPolygon solveCrossovers(const B2DPolygon& rCandidate) + { + solver aSolver(rCandidate); + return aSolver.getB2DPolyPolygon(); + } + + B2DPolyPolygon stripNeutralPolygons(const B2DPolyPolygon& rCandidate) + { + B2DPolyPolygon aRetval; + + for(sal_uInt32 a(0); a < rCandidate.count(); a++) + { + const B2DPolygon& aCandidate(rCandidate.getB2DPolygon(a)); + + if(utils::getOrientation(aCandidate) != B2VectorOrientation::Neutral) + { + aRetval.append(aCandidate); + } + } + + return aRetval; + } + + B2DPolyPolygon createNonzeroConform(const B2DPolyPolygon& rCandidate) + { + if (rCandidate.count() > 1000) + { + SAL_WARN("basegfx", "this poly is too large, " << rCandidate.count() << " elements, to be able to process timeously, falling back to ignoring the winding rule, which is likely to cause rendering artifacts"); + return rCandidate; + } + + B2DPolyPolygon aCandidate; + + // remove all self-intersections and intersections + if(rCandidate.count() == 1) + { + aCandidate = basegfx::utils::solveCrossovers(rCandidate.getB2DPolygon(0)); + } + else + { + aCandidate = basegfx::utils::solveCrossovers(rCandidate); + } + + // cleanup evtl. neutral polygons + aCandidate = basegfx::utils::stripNeutralPolygons(aCandidate); + + // remove all polygons which have the same orientation as the polygon they are directly contained in + const sal_uInt32 nCount(aCandidate.count()); + + if(nCount > 1) + { + sal_uInt32 a, b; + std::vector< StripHelper > aHelpers; + aHelpers.resize(nCount); + + for(a = 0; a < nCount; a++) + { + const B2DPolygon& aCand(aCandidate.getB2DPolygon(a)); + StripHelper* pNewHelper = &(aHelpers[a]); + pNewHelper->maRange = utils::getRange(aCand); + pNewHelper->meOrinetation = utils::getOrientation(aCand); + + // initialize with own orientation + pNewHelper->mnDepth = (pNewHelper->meOrinetation == B2VectorOrientation::Negative ? -1 : 1); + } + + for(a = 0; a < nCount - 1; a++) + { + const B2DPolygon& aCandA(aCandidate.getB2DPolygon(a)); + StripHelper& rHelperA = aHelpers[a]; + + for(b = a + 1; b < nCount; b++) + { + const B2DPolygon& aCandB(aCandidate.getB2DPolygon(b)); + StripHelper& rHelperB = aHelpers[b]; + const bool bAInB(rHelperB.maRange.isInside(rHelperA.maRange) && utils::isInside(aCandB, aCandA, true)); + + if(bAInB) + { + // A is inside B, add orientation of B to A + rHelperA.mnDepth += (rHelperB.meOrinetation == B2VectorOrientation::Negative ? -1 : 1); + } + + const bool bBInA(rHelperA.maRange.isInside(rHelperB.maRange) && utils::isInside(aCandA, aCandB, true)); + + if(bBInA) + { + // B is inside A, add orientation of A to B + rHelperB.mnDepth += (rHelperA.meOrinetation == B2VectorOrientation::Negative ? -1 : 1); + } + } + } + + const B2DPolyPolygon aSource(aCandidate); + aCandidate.clear(); + + for(a = 0; a < nCount; a++) + { + const StripHelper& rHelper = aHelpers[a]; + // for contained unequal oriented polygons sum will be 0 + // for contained equal it will be >=2 or <=-2 + // for free polygons (not contained) it will be 1 or -1 + // -> accept all which are >=-1 && <= 1 + bool bAcceptEntry(rHelper.mnDepth >= -1 && rHelper.mnDepth <= 1); + + if(bAcceptEntry) + { + aCandidate.append(aSource.getB2DPolygon(a)); + } + } + } + + return aCandidate; + } + + B2DPolyPolygon stripDispensablePolygons(const B2DPolyPolygon& rCandidate, bool bKeepAboveZero) + { + const sal_uInt32 nCount(rCandidate.count()); + B2DPolyPolygon aRetval; + + if(nCount) + { + if(nCount == 1) + { + if(!bKeepAboveZero && utils::getOrientation(rCandidate.getB2DPolygon(0)) == B2VectorOrientation::Positive) + { + aRetval = rCandidate; + } + } + else + { + sal_uInt32 a, b; + std::vector< StripHelper > aHelpers; + aHelpers.resize(nCount); + + for(a = 0; a < nCount; a++) + { + const B2DPolygon& aCandidate(rCandidate.getB2DPolygon(a)); + StripHelper* pNewHelper = &(aHelpers[a]); + pNewHelper->maRange = utils::getRange(aCandidate); + pNewHelper->meOrinetation = utils::getOrientation(aCandidate); + pNewHelper->mnDepth = (pNewHelper->meOrinetation == B2VectorOrientation::Negative ? -1 : 0); + } + + for(a = 0; a < nCount - 1; a++) + { + const B2DPolygon& aCandA(rCandidate.getB2DPolygon(a)); + StripHelper& rHelperA = aHelpers[a]; + + for(b = a + 1; b < nCount; b++) + { + const B2DPolygon& aCandB(rCandidate.getB2DPolygon(b)); + StripHelper& rHelperB = aHelpers[b]; + const bool bAInB(rHelperB.maRange.isInside(rHelperA.maRange) && utils::isInside(aCandB, aCandA, true)); + const bool bBInA(rHelperA.maRange.isInside(rHelperB.maRange) && utils::isInside(aCandA, aCandB, true)); + + if(bAInB && bBInA) + { + // congruent + if(rHelperA.meOrinetation == rHelperB.meOrinetation) + { + // two polys or two holes. Lower one of them to get one of them out of the way. + // Since each will be contained in the other one, both will be increased, too. + // So, for lowering, increase only one of them + rHelperA.mnDepth++; + } + else + { + // poly and hole. They neutralize, so get rid of both. Move securely below zero. + rHelperA.mnDepth = - static_cast<sal_Int32>(nCount); + rHelperB.mnDepth = - static_cast<sal_Int32>(nCount); + } + } + else + { + if(bAInB) + { + if(rHelperB.meOrinetation == B2VectorOrientation::Negative) + { + rHelperA.mnDepth--; + } + else + { + rHelperA.mnDepth++; + } + } + else if(bBInA) + { + if(rHelperA.meOrinetation == B2VectorOrientation::Negative) + { + rHelperB.mnDepth--; + } + else + { + rHelperB.mnDepth++; + } + } + } + } + } + + for(a = 0; a < nCount; a++) + { + const StripHelper& rHelper = aHelpers[a]; + bool bAcceptEntry(bKeepAboveZero ? 1 <= rHelper.mnDepth : rHelper.mnDepth == 0); + + if(bAcceptEntry) + { + aRetval.append(rCandidate.getB2DPolygon(a)); + } + } + } + } + + return aRetval; + } + + B2DPolyPolygon prepareForPolygonOperation(const B2DPolygon& rCandidate) + { + solver aSolver(rCandidate); + B2DPolyPolygon aRetval(stripNeutralPolygons(aSolver.getB2DPolyPolygon())); + + return correctOrientations(aRetval); + } + + B2DPolyPolygon prepareForPolygonOperation(const B2DPolyPolygon& rCandidate) + { + solver aSolver(rCandidate); + B2DPolyPolygon aRetval(stripNeutralPolygons(aSolver.getB2DPolyPolygon())); + + return correctOrientations(aRetval); + } + + B2DPolyPolygon solvePolygonOperationOr(const B2DPolyPolygon& rCandidateA, const B2DPolyPolygon& rCandidateB) + { + if(!rCandidateA.count()) + { + return rCandidateB; + } + else if(!rCandidateB.count()) + { + return rCandidateA; + } + else + { + // concatenate polygons, solve crossovers and throw away all sub-polygons + // which have a depth other than 0. + B2DPolyPolygon aRetval(rCandidateA); + + aRetval.append(rCandidateB); + aRetval = solveCrossovers(aRetval); + aRetval = stripNeutralPolygons(aRetval); + + return stripDispensablePolygons(aRetval); + } + } + + B2DPolyPolygon solvePolygonOperationXor(const B2DPolyPolygon& rCandidateA, const B2DPolyPolygon& rCandidateB) + { + if(!rCandidateA.count()) + { + return rCandidateB; + } + else if(!rCandidateB.count()) + { + return rCandidateA; + } + else + { + // XOR is pretty simple: By definition it is the simple concatenation of + // the single polygons since we imply XOR fill rule. Make it intersection-free + // and correct orientations + B2DPolyPolygon aRetval(rCandidateA); + + aRetval.append(rCandidateB); + aRetval = solveCrossovers(aRetval); + aRetval = stripNeutralPolygons(aRetval); + + return correctOrientations(aRetval); + } + } + + B2DPolyPolygon solvePolygonOperationAnd(const B2DPolyPolygon& rCandidateA, const B2DPolyPolygon& rCandidateB) + { + if(!rCandidateA.count()) + { + return B2DPolyPolygon(); + } + else if(!rCandidateB.count()) + { + return B2DPolyPolygon(); + } + else + { + // tdf#130150 shortcut & precision: If both are simple ranges, + // solve based on ranges + if(basegfx::utils::isRectangle(rCandidateA) && basegfx::utils::isRectangle(rCandidateB)) + { + // *if* both are ranges, AND always can be solved + const basegfx::B2DRange aRangeA(rCandidateA.getB2DRange()); + const basegfx::B2DRange aRangeB(rCandidateB.getB2DRange()); + + if(aRangeA.isInside(aRangeB)) + { + // 2nd completely inside 1st -> 2nd is result of AND + return rCandidateB; + } + + if(aRangeB.isInside(aRangeA)) + { + // 2nd completely inside 1st -> 2nd is result of AND + return rCandidateA; + } + + // solve by intersection + basegfx::B2DRange aIntersect(aRangeA); + aIntersect.intersect(aRangeB); + + if(aIntersect.isEmpty()) + { + // no overlap -> empty polygon as result of AND + return B2DPolyPolygon(); + } + + // create polygon result + return B2DPolyPolygon( + basegfx::utils::createPolygonFromRect( + aIntersect)); + } + + // concatenate polygons, solve crossovers and throw away all sub-polygons + // with a depth of < 1. This means to keep all polygons where at least two + // polygons do overlap. + B2DPolyPolygon aRetval(rCandidateA); + + aRetval.append(rCandidateB); + aRetval = solveCrossovers(aRetval); + aRetval = stripNeutralPolygons(aRetval); + + return stripDispensablePolygons(aRetval, true); + } + } + + B2DPolyPolygon solvePolygonOperationDiff(const B2DPolyPolygon& rCandidateA, const B2DPolyPolygon& rCandidateB) + { + if(!rCandidateA.count()) + { + return B2DPolyPolygon(); + } + else if(!rCandidateB.count()) + { + return rCandidateA; + } + else + { + // Make B topologically to holes and append to A + B2DPolyPolygon aRetval(rCandidateB); + + aRetval.flip(); + aRetval.append(rCandidateA); + + // solve crossovers and throw away all sub-polygons which have a + // depth other than 0. + aRetval = basegfx::utils::solveCrossovers(aRetval); + aRetval = basegfx::utils::stripNeutralPolygons(aRetval); + + return basegfx::utils::stripDispensablePolygons(aRetval); + } + } + + B2DPolyPolygon mergeToSinglePolyPolygon(const B2DPolyPolygonVector& rInput) + { + if(rInput.empty()) + return B2DPolyPolygon(); + + // first step: prepareForPolygonOperation and simple merge of non-overlapping + // PolyPolygons for speedup; this is possible for the wanted OR-operation + B2DPolyPolygonVector aResult; + aResult.reserve(rInput.size()); + + for(const basegfx::B2DPolyPolygon & a : rInput) + { + const basegfx::B2DPolyPolygon aCandidate(prepareForPolygonOperation(a)); + + if(!aResult.empty()) + { + const B2DRange aCandidateRange(aCandidate.getB2DRange()); + bool bCouldMergeSimple(false); + + for(auto & b: aResult) + { + basegfx::B2DPolyPolygon aTarget(b); + const B2DRange aTargetRange(aTarget.getB2DRange()); + + if(!aCandidateRange.overlaps(aTargetRange)) + { + aTarget.append(aCandidate); + b = aTarget; + bCouldMergeSimple = true; + break; + } + } + + if(!bCouldMergeSimple) + { + aResult.push_back(aCandidate); + } + } + else + { + aResult.push_back(aCandidate); + } + } + + // second step: melt pairwise to a single PolyPolygon + while(aResult.size() > 1) + { + B2DPolyPolygonVector aResult2; + aResult2.reserve((aResult.size() / 2) + 1); + + for(size_t a(0); a < aResult.size(); a += 2) + { + if(a + 1 < aResult.size()) + { + // a pair for processing + aResult2.push_back(solvePolygonOperationOr(aResult[a], aResult[a + 1])); + } + else + { + // last single PolyPolygon; copy to target to not lose it + aResult2.push_back(aResult[a]); + } + } + + aResult = aResult2; + } + + // third step: get result + if(aResult.size() == 1) + { + return aResult[0]; + } + + return B2DPolyPolygon(); + } + +} // end of namespace + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |