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-rw-r--r--basegfx/source/polygon/b2dpolypolygoncutter.cxx1145
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diff --git a/basegfx/source/polygon/b2dpolypolygoncutter.cxx b/basegfx/source/polygon/b2dpolypolygoncutter.cxx
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+/* -*- 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 <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(const B2DPolyPolygon& rOriginal)
+ : maOriginal(rOriginal),
+ mbIsCurve(false),
+ mbChanged(false)
+ {
+ sal_uInt32 nOriginalCount(maOriginal.count());
+
+ if(!nOriginalCount)
+ return;
+
+ B2DPolyPolygon aGeometry(utils::addPointsAtCutsAndTouches(maOriginal));
+ 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)
+ {
+ if(rCandidate.count() > 0)
+ {
+ solver aSolver(rCandidate);
+ 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)
+ {
+ 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)
+ {
+ B2DPolyPolygonVector aInput(rInput);
+
+ // first step: prepareForPolygonOperation and simple merge of non-overlapping
+ // PolyPolygons for speedup; this is possible for the wanted OR-operation
+ if(!aInput.empty())
+ {
+ B2DPolyPolygonVector aResult;
+ aResult.reserve(aInput.size());
+
+ for(const basegfx::B2DPolyPolygon & a : aInput)
+ {
+ 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);
+ }
+ }
+
+ aInput = aResult;
+ }
+
+ // second step: melt pairwise to a single PolyPolygon
+ while(aInput.size() > 1)
+ {
+ B2DPolyPolygonVector aResult;
+ aResult.reserve((aInput.size() / 2) + 1);
+
+ for(size_t a(0); a < aInput.size(); a += 2)
+ {
+ if(a + 1 < aInput.size())
+ {
+ // a pair for processing
+ aResult.push_back(solvePolygonOperationOr(aInput[a], aInput[a + 1]));
+ }
+ else
+ {
+ // last single PolyPolygon; copy to target to not lose it
+ aResult.push_back(aInput[a]);
+ }
+ }
+
+ aInput = aResult;
+ }
+
+ // third step: get result
+ if(aInput.size() == 1)
+ {
+ return aInput[0];
+ }
+
+ return B2DPolyPolygon();
+ }
+
+} // end of namespace
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */