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| -rw-r--r-- | basegfx/source/polygon/b2dlinegeometry.cxx | 1056 |
1 files changed, 1056 insertions, 0 deletions
diff --git a/basegfx/source/polygon/b2dlinegeometry.cxx b/basegfx/source/polygon/b2dlinegeometry.cxx new file mode 100644 index 000000000..6dda8f9e7 --- /dev/null +++ b/basegfx/source/polygon/b2dlinegeometry.cxx @@ -0,0 +1,1056 @@ +/* -*- 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 <osl/diagnose.h> +#include <sal/log.hxx> +#include <basegfx/polygon/b2dlinegeometry.hxx> +#include <basegfx/point/b2dpoint.hxx> +#include <basegfx/vector/b2dvector.hxx> +#include <basegfx/polygon/b2dpolygontools.hxx> +#include <basegfx/polygon/b2dpolypolygontools.hxx> +#include <basegfx/range/b2drange.hxx> +#include <basegfx/matrix/b2dhommatrix.hxx> +#include <basegfx/curve/b2dcubicbezier.hxx> +#include <basegfx/matrix/b2dhommatrixtools.hxx> +#include <com/sun/star/drawing/LineCap.hpp> +#include <basegfx/polygon/b2dpolypolygoncutter.hxx> +#include <basegfx/polygon/b2dpolygontriangulator.hxx> + +namespace basegfx::utils +{ + B2DPolyPolygon createAreaGeometryForLineStartEnd( + const B2DPolygon& rCandidate, + const B2DPolyPolygon& rArrow, + bool bStart, + double fWidth, + double fCandidateLength, + double fDockingPosition, // 0->top, 1->bottom + double* pConsumedLength, + double fShift) + { + B2DPolyPolygon aRetval; + assert((rCandidate.count() > 1) && "createAreaGeometryForLineStartEnd: Line polygon has too few points"); + assert((rArrow.count() > 0) && "createAreaGeometryForLineStartEnd: Empty arrow utils::PolyPolygon"); + assert((fWidth > 0.0) && "createAreaGeometryForLineStartEnd: Width too small"); + assert((fDockingPosition >= 0.0 && fDockingPosition <= 1.0) && + "createAreaGeometryForLineStartEnd: fDockingPosition out of range [0.0 .. 1.0]"); + + if(fWidth < 0.0) + { + fWidth = -fWidth; + } + + if(rCandidate.count() > 1 && rArrow.count() && !fTools::equalZero(fWidth)) + { + if(fDockingPosition < 0.0) + { + fDockingPosition = 0.0; + } + else if(fDockingPosition > 1.0) + { + fDockingPosition = 1.0; + } + + // init return value from arrow + aRetval.append(rArrow); + + // get size of the arrow + const B2DRange aArrowSize(getRange(rArrow)); + + // build ArrowTransform; center in X, align with axis in Y + B2DHomMatrix aArrowTransform(basegfx::utils::createTranslateB2DHomMatrix( + -aArrowSize.getCenter().getX(), -aArrowSize.getMinimum().getY())); + + // scale to target size + const double fArrowScale(fWidth / (aArrowSize.getWidth())); + aArrowTransform.scale(fArrowScale, fArrowScale); + + // get arrow size in Y + B2DPoint aUpperCenter(aArrowSize.getCenter().getX(), aArrowSize.getMaximum().getY()); + aUpperCenter *= aArrowTransform; + const double fArrowYLength(B2DVector(aUpperCenter).getLength()); + + // move arrow to have docking position centered + aArrowTransform.translate(0.0, -fArrowYLength * fDockingPosition + fShift); + + // prepare polygon length + if(fTools::equalZero(fCandidateLength)) + { + fCandidateLength = getLength(rCandidate); + } + + // get the polygon vector we want to plant this arrow on + const double fConsumedLength(fArrowYLength * (1.0 - fDockingPosition) - fShift); + const B2DVector aHead(rCandidate.getB2DPoint(bStart ? 0 : rCandidate.count() - 1)); + const B2DVector aTail(getPositionAbsolute(rCandidate, + bStart ? fConsumedLength : fCandidateLength - fConsumedLength, fCandidateLength)); + + // from that vector, take the needed rotation and add rotate for arrow to transformation + const B2DVector aTargetDirection(aHead - aTail); + const double fRotation(atan2(aTargetDirection.getY(), aTargetDirection.getX()) + M_PI_2); + + // rotate around docking position + aArrowTransform.rotate(fRotation); + + // move arrow docking position to polygon head + aArrowTransform.translate(aHead.getX(), aHead.getY()); + + // transform retval and close + aRetval.transform(aArrowTransform); + aRetval.setClosed(true); + + // if pConsumedLength is asked for, fill it + if(pConsumedLength) + { + *pConsumedLength = fConsumedLength; + } + } + + return aRetval; + } +} // end of namespace + +namespace basegfx +{ + // anonymous namespace for local helpers + namespace + { + bool impIsSimpleEdge(const B2DCubicBezier& rCandidate, double fMaxCosQuad, double fMaxPartOfEdgeQuad) + { + // isBezier() is true, already tested by caller + const B2DVector aEdge(rCandidate.getEndPoint() - rCandidate.getStartPoint()); + + if(aEdge.equalZero()) + { + // start and end point the same, but control vectors used -> balloon curve loop + // is not a simple edge + return false; + } + + // get tangentA and scalar with edge + const B2DVector aTangentA(rCandidate.getTangent(0.0)); + const double fScalarAE(aEdge.scalar(aTangentA)); + + if(fTools::lessOrEqual(fScalarAE, 0.0)) + { + // angle between TangentA and Edge is bigger or equal 90 degrees + return false; + } + + // get self-scalars for E and A + const double fScalarE(aEdge.scalar(aEdge)); + const double fScalarA(aTangentA.scalar(aTangentA)); + const double fLengthCompareE(fScalarE * fMaxPartOfEdgeQuad); + + if(fTools::moreOrEqual(fScalarA, fLengthCompareE)) + { + // length of TangentA is more than fMaxPartOfEdge of length of edge + return false; + } + + if(fTools::lessOrEqual(fScalarAE * fScalarAE, fScalarA * fScalarE * fMaxCosQuad)) + { + // angle between TangentA and Edge is bigger or equal angle defined by fMaxCos + return false; + } + + // get tangentB and scalar with edge + const B2DVector aTangentB(rCandidate.getTangent(1.0)); + const double fScalarBE(aEdge.scalar(aTangentB)); + + if(fTools::lessOrEqual(fScalarBE, 0.0)) + { + // angle between TangentB and Edge is bigger or equal 90 degrees + return false; + } + + // get self-scalar for B + const double fScalarB(aTangentB.scalar(aTangentB)); + + if(fTools::moreOrEqual(fScalarB, fLengthCompareE)) + { + // length of TangentB is more than fMaxPartOfEdge of length of edge + return false; + } + + if(fTools::lessOrEqual(fScalarBE * fScalarBE, fScalarB * fScalarE * fMaxCosQuad)) + { + // angle between TangentB and Edge is bigger or equal defined by fMaxCos + return false; + } + + return true; + } + + void impSubdivideToSimple(const B2DCubicBezier& rCandidate, B2DPolygon& rTarget, double fMaxCosQuad, double fMaxPartOfEdgeQuad, sal_uInt32 nMaxRecursionDepth) + { + if(!nMaxRecursionDepth || impIsSimpleEdge(rCandidate, fMaxCosQuad, fMaxPartOfEdgeQuad)) + { + rTarget.appendBezierSegment(rCandidate.getControlPointA(), rCandidate.getControlPointB(), rCandidate.getEndPoint()); + } + else + { + B2DCubicBezier aLeft, aRight; + rCandidate.split(0.5, &aLeft, &aRight); + + impSubdivideToSimple(aLeft, rTarget, fMaxCosQuad, fMaxPartOfEdgeQuad, nMaxRecursionDepth - 1); + impSubdivideToSimple(aRight, rTarget, fMaxCosQuad, fMaxPartOfEdgeQuad, nMaxRecursionDepth - 1); + } + } + + B2DPolygon subdivideToSimple(const B2DPolygon& rCandidate, double fMaxCosQuad, double fMaxPartOfEdgeQuad) + { + const sal_uInt32 nPointCount(rCandidate.count()); + + if(rCandidate.areControlPointsUsed() && nPointCount) + { + const sal_uInt32 nEdgeCount(rCandidate.isClosed() ? nPointCount : nPointCount - 1); + B2DPolygon aRetval; + B2DCubicBezier aEdge; + + // prepare edge for loop + aEdge.setStartPoint(rCandidate.getB2DPoint(0)); + aRetval.append(aEdge.getStartPoint()); + + for(sal_uInt32 a(0); a < nEdgeCount; a++) + { + // fill B2DCubicBezier + const sal_uInt32 nNextIndex((a + 1) % nPointCount); + aEdge.setControlPointA(rCandidate.getNextControlPoint(a)); + aEdge.setControlPointB(rCandidate.getPrevControlPoint(nNextIndex)); + aEdge.setEndPoint(rCandidate.getB2DPoint(nNextIndex)); + + // get rid of unnecessary bezier segments + aEdge.testAndSolveTrivialBezier(); + + if(aEdge.isBezier()) + { + // before splitting recursively with internal simple criteria, use + // ExtremumPosFinder to remove those + std::vector< double > aExtremumPositions; + + aExtremumPositions.reserve(4); + aEdge.getAllExtremumPositions(aExtremumPositions); + + const sal_uInt32 nCount(aExtremumPositions.size()); + + if(nCount) + { + if(nCount > 1) + { + // create order from left to right + std::sort(aExtremumPositions.begin(), aExtremumPositions.end()); + } + + for(sal_uInt32 b(0); b < nCount;) + { + // split aEdge at next split pos + B2DCubicBezier aLeft; + const double fSplitPos(aExtremumPositions[b++]); + + aEdge.split(fSplitPos, &aLeft, &aEdge); + aLeft.testAndSolveTrivialBezier(); + + // consume left part + if(aLeft.isBezier()) + { + impSubdivideToSimple(aLeft, aRetval, fMaxCosQuad, fMaxPartOfEdgeQuad, 6); + } + else + { + aRetval.append(aLeft.getEndPoint()); + } + + if(b < nCount) + { + // correct the remaining split positions to fit to shortened aEdge + const double fScaleFactor(1.0 / (1.0 - fSplitPos)); + + for(sal_uInt32 c(b); c < nCount; c++) + { + aExtremumPositions[c] = (aExtremumPositions[c] - fSplitPos) * fScaleFactor; + } + } + } + + // test the shortened rest of aEdge + aEdge.testAndSolveTrivialBezier(); + + // consume right part + if(aEdge.isBezier()) + { + impSubdivideToSimple(aEdge, aRetval, fMaxCosQuad, fMaxPartOfEdgeQuad, 6); + } + else + { + aRetval.append(aEdge.getEndPoint()); + } + } + else + { + impSubdivideToSimple(aEdge, aRetval, fMaxCosQuad, fMaxPartOfEdgeQuad, 6); + } + } + else + { + // straight edge, add point + aRetval.append(aEdge.getEndPoint()); + } + + // prepare edge for next step + aEdge.setStartPoint(aEdge.getEndPoint()); + } + + // copy closed flag and check for double points + aRetval.setClosed(rCandidate.isClosed()); + aRetval.removeDoublePoints(); + + return aRetval; + } + else + { + return rCandidate; + } + } + + B2DPolygon createAreaGeometryForEdge( + const B2DCubicBezier& rEdge, + double fHalfLineWidth, + bool bStartRound, + bool bEndRound, + bool bStartSquare, + bool bEndSquare, + basegfx::triangulator::B2DTriangleVector* pTriangles) + { + // create polygon for edge + // Unfortunately, while it would be geometrically correct to not add + // the in-between points EdgeEnd and EdgeStart, it leads to rounding + // errors when converting to integer polygon coordinates for painting + if(rEdge.isBezier()) + { + // prepare target and data common for upper and lower + B2DPolygon aBezierPolygon; + const B2DVector aPureEdgeVector(rEdge.getEndPoint() - rEdge.getStartPoint()); + const double fEdgeLength(aPureEdgeVector.getLength()); + const bool bIsEdgeLengthZero(fTools::equalZero(fEdgeLength)); + B2DVector aTangentA(rEdge.getTangent(0.0)); aTangentA.normalize(); + B2DVector aTangentB(rEdge.getTangent(1.0)); aTangentB.normalize(); + const B2DVector aNormalizedPerpendicularA(getPerpendicular(aTangentA)); + const B2DVector aNormalizedPerpendicularB(getPerpendicular(aTangentB)); + + // create upper displacement vectors and check if they cut + const B2DVector aPerpendStartA(aNormalizedPerpendicularA * -fHalfLineWidth); + const B2DVector aPerpendEndA(aNormalizedPerpendicularB * -fHalfLineWidth); + double fCutA(0.0); + const CutFlagValue aCutA(utils::findCut( + rEdge.getStartPoint(), aPerpendStartA, + rEdge.getEndPoint(), aPerpendEndA, + CutFlagValue::ALL, &fCutA)); + const bool bCutA(aCutA != CutFlagValue::NONE); + + // create lower displacement vectors and check if they cut + const B2DVector aPerpendStartB(aNormalizedPerpendicularA * fHalfLineWidth); + const B2DVector aPerpendEndB(aNormalizedPerpendicularB * fHalfLineWidth); + double fCutB(0.0); + const CutFlagValue aCutB(utils::findCut( + rEdge.getEndPoint(), aPerpendEndB, + rEdge.getStartPoint(), aPerpendStartB, + CutFlagValue::ALL, &fCutB)); + const bool bCutB(aCutB != CutFlagValue::NONE); + + // check if cut happens + const bool bCut(bCutA || bCutB); + B2DPoint aCutPoint; + + // create left edge + if(bStartRound || bStartSquare) + { + if(bStartRound) + { + basegfx::B2DPolygon aStartPolygon(utils::createHalfUnitCircle()); + + aStartPolygon.transform( + utils::createScaleShearXRotateTranslateB2DHomMatrix( + fHalfLineWidth, fHalfLineWidth, + 0.0, + atan2(aTangentA.getY(), aTangentA.getX()) + M_PI_2, + rEdge.getStartPoint().getX(), rEdge.getStartPoint().getY())); + aBezierPolygon.append(aStartPolygon); + } + else // bStartSquare + { + const basegfx::B2DPoint aStart(rEdge.getStartPoint() - (aTangentA * fHalfLineWidth)); + + if(bCutB) + { + aBezierPolygon.append(rEdge.getStartPoint() + aPerpendStartB); + } + + aBezierPolygon.append(aStart + aPerpendStartB); + aBezierPolygon.append(aStart + aPerpendStartA); + + if(bCutA) + { + aBezierPolygon.append(rEdge.getStartPoint() + aPerpendStartA); + } + } + } + else + { + // append original in-between point + aBezierPolygon.append(rEdge.getStartPoint()); + } + + // create upper edge. + { + if(bCutA) + { + // calculate cut point and add + aCutPoint = rEdge.getStartPoint() + (aPerpendStartA * fCutA); + aBezierPolygon.append(aCutPoint); + } + else + { + // create scaled bezier segment + const B2DPoint aStart(rEdge.getStartPoint() + aPerpendStartA); + const B2DPoint aEnd(rEdge.getEndPoint() + aPerpendEndA); + const B2DVector aEdge(aEnd - aStart); + const double fLength(aEdge.getLength()); + const double fScale(bIsEdgeLengthZero ? 1.0 : fLength / fEdgeLength); + const B2DVector fRelNext(rEdge.getControlPointA() - rEdge.getStartPoint()); + const B2DVector fRelPrev(rEdge.getControlPointB() - rEdge.getEndPoint()); + + aBezierPolygon.append(aStart); + aBezierPolygon.appendBezierSegment(aStart + (fRelNext * fScale), aEnd + (fRelPrev * fScale), aEnd); + } + } + + // create right edge + if(bEndRound || bEndSquare) + { + if(bEndRound) + { + basegfx::B2DPolygon aEndPolygon(utils::createHalfUnitCircle()); + + aEndPolygon.transform( + utils::createScaleShearXRotateTranslateB2DHomMatrix( + fHalfLineWidth, fHalfLineWidth, + 0.0, + atan2(aTangentB.getY(), aTangentB.getX()) - M_PI_2, + rEdge.getEndPoint().getX(), rEdge.getEndPoint().getY())); + aBezierPolygon.append(aEndPolygon); + } + else // bEndSquare + { + const basegfx::B2DPoint aEnd(rEdge.getEndPoint() + (aTangentB * fHalfLineWidth)); + + if(bCutA) + { + aBezierPolygon.append(rEdge.getEndPoint() + aPerpendEndA); + } + + aBezierPolygon.append(aEnd + aPerpendEndA); + aBezierPolygon.append(aEnd + aPerpendEndB); + + if(bCutB) + { + aBezierPolygon.append(rEdge.getEndPoint() + aPerpendEndB); + } + } + } + else + { + // append original in-between point + aBezierPolygon.append(rEdge.getEndPoint()); + } + + // create lower edge. + { + if(bCutB) + { + // calculate cut point and add + aCutPoint = rEdge.getEndPoint() + (aPerpendEndB * fCutB); + aBezierPolygon.append(aCutPoint); + } + else + { + // create scaled bezier segment + const B2DPoint aStart(rEdge.getEndPoint() + aPerpendEndB); + const B2DPoint aEnd(rEdge.getStartPoint() + aPerpendStartB); + const B2DVector aEdge(aEnd - aStart); + const double fLength(aEdge.getLength()); + const double fScale(bIsEdgeLengthZero ? 1.0 : fLength / fEdgeLength); + const B2DVector fRelNext(rEdge.getControlPointB() - rEdge.getEndPoint()); + const B2DVector fRelPrev(rEdge.getControlPointA() - rEdge.getStartPoint()); + + aBezierPolygon.append(aStart); + aBezierPolygon.appendBezierSegment(aStart + (fRelNext * fScale), aEnd + (fRelPrev * fScale), aEnd); + } + } + + // close + aBezierPolygon.setClosed(true); + + if(bStartRound || bEndRound) + { + // double points possible when round caps are used at start or end + aBezierPolygon.removeDoublePoints(); + } + + if(bCut && ((bStartRound || bStartSquare) && (bEndRound || bEndSquare))) + { + // When cut exists and both ends are extended with caps, a self-intersecting polygon + // is created; one cut point is known, but there is a 2nd one in the caps geometry. + // Solve by using tooling. + // Remark: This nearly never happens due to curve preparations to extreme points + // and maximum angle turning, but I constructed a test case and checked that it is + // working properly. + const B2DPolyPolygon aTemp(utils::solveCrossovers(aBezierPolygon)); + const sal_uInt32 nTempCount(aTemp.count()); + + if(nTempCount) + { + if(nTempCount > 1) + { + // as expected, multiple polygons (with same orientation). Remove + // the one which contains aCutPoint, or better take the one without + for (sal_uInt32 a(0); a < nTempCount; a++) + { + aBezierPolygon = aTemp.getB2DPolygon(a); + + const sal_uInt32 nCandCount(aBezierPolygon.count()); + + for(sal_uInt32 b(0); b < nCandCount; b++) + { + if(aCutPoint.equal(aBezierPolygon.getB2DPoint(b))) + { + aBezierPolygon.clear(); + break; + } + } + + if(aBezierPolygon.count()) + { + break; + } + } + + OSL_ENSURE(aBezierPolygon.count(), "Error in line geometry creation, could not solve self-intersection (!)"); + } + else + { + // none found, use result + aBezierPolygon = aTemp.getB2DPolygon(0); + } + } + else + { + OSL_ENSURE(false, "Error in line geometry creation, could not solve self-intersection (!)"); + } + } + + if(nullptr != pTriangles) + { + const basegfx::triangulator::B2DTriangleVector aResult( + basegfx::triangulator::triangulate( + aBezierPolygon)); + pTriangles->insert(pTriangles->end(), aResult.begin(), aResult.end()); + aBezierPolygon.clear(); + } + + // return + return aBezierPolygon; + } + else + { + // Get start and end point, create tangent and set to needed length + B2DVector aTangent(rEdge.getEndPoint() - rEdge.getStartPoint()); + aTangent.setLength(fHalfLineWidth); + + // prepare return value + B2DPolygon aEdgePolygon; + + // buffered angle + double fAngle(0.0); + bool bAngle(false); + + // buffered perpendicular + B2DVector aPerpend; + bool bPerpend(false); + + // create left vertical + if(bStartRound) + { + aEdgePolygon = utils::createHalfUnitCircle(); + fAngle = atan2(aTangent.getY(), aTangent.getX()); + bAngle = true; + aEdgePolygon.transform( + utils::createScaleShearXRotateTranslateB2DHomMatrix( + fHalfLineWidth, fHalfLineWidth, + 0.0, + fAngle + M_PI_2, + rEdge.getStartPoint().getX(), rEdge.getStartPoint().getY())); + } + else + { + aPerpend.setX(-aTangent.getY()); + aPerpend.setY(aTangent.getX()); + bPerpend = true; + + if(bStartSquare) + { + const basegfx::B2DPoint aStart(rEdge.getStartPoint() - aTangent); + + aEdgePolygon.append(aStart + aPerpend); + aEdgePolygon.append(aStart - aPerpend); + } + else + { + aEdgePolygon.append(rEdge.getStartPoint() + aPerpend); + aEdgePolygon.append(rEdge.getStartPoint()); // keep the in-between point for numerical reasons + aEdgePolygon.append(rEdge.getStartPoint() - aPerpend); + } + } + + // create right vertical + if(bEndRound) + { + basegfx::B2DPolygon aEndPolygon(utils::createHalfUnitCircle()); + + if(!bAngle) + { + fAngle = atan2(aTangent.getY(), aTangent.getX()); + } + + aEndPolygon.transform( + utils::createScaleShearXRotateTranslateB2DHomMatrix( + fHalfLineWidth, fHalfLineWidth, + 0.0, + fAngle - M_PI_2, + rEdge.getEndPoint().getX(), rEdge.getEndPoint().getY())); + aEdgePolygon.append(aEndPolygon); + } + else + { + if(!bPerpend) + { + aPerpend.setX(-aTangent.getY()); + aPerpend.setY(aTangent.getX()); + } + + if(bEndSquare) + { + const basegfx::B2DPoint aEnd(rEdge.getEndPoint() + aTangent); + + aEdgePolygon.append(aEnd - aPerpend); + aEdgePolygon.append(aEnd + aPerpend); + } + else + { + aEdgePolygon.append(rEdge.getEndPoint() - aPerpend); + aEdgePolygon.append(rEdge.getEndPoint()); // keep the in-between point for numerical reasons + aEdgePolygon.append(rEdge.getEndPoint() + aPerpend); + } + } + + // close and return + aEdgePolygon.setClosed(true); + + if(nullptr != pTriangles) + { + const basegfx::triangulator::B2DTriangleVector aResult( + basegfx::triangulator::triangulate( + aEdgePolygon)); + pTriangles->insert(pTriangles->end(), aResult.begin(), aResult.end()); + aEdgePolygon.clear(); + } + + return aEdgePolygon; + } + } + + B2DPolygon createAreaGeometryForJoin( + const B2DVector& rTangentPrev, + const B2DVector& rTangentEdge, + const B2DVector& rPerpendPrev, + const B2DVector& rPerpendEdge, + const B2DPoint& rPoint, + double fHalfLineWidth, + B2DLineJoin eJoin, + double fMiterMinimumAngle, + basegfx::triangulator::B2DTriangleVector* pTriangles) + { + SAL_WARN_IF(fHalfLineWidth <= 0.0,"basegfx","createAreaGeometryForJoin: LineWidth too small (!)"); + assert((eJoin != B2DLineJoin::NONE) && "createAreaGeometryForJoin: B2DLineJoin::NONE not allowed (!)"); + + // LineJoin from tangent rPerpendPrev to tangent rPerpendEdge in rPoint + B2DPolygon aEdgePolygon; + const B2DPoint aStartPoint(rPoint + rPerpendPrev); + const B2DPoint aEndPoint(rPoint + rPerpendEdge); + + // test if for Miter, the angle is too small and the fallback + // to bevel needs to be used + if(eJoin == B2DLineJoin::Miter) + { + const double fAngle(fabs(rPerpendPrev.angle(rPerpendEdge))); + + if((M_PI - fAngle) < fMiterMinimumAngle) + { + // fallback to bevel + eJoin = B2DLineJoin::Bevel; + } + } + + switch(eJoin) + { + case B2DLineJoin::Miter : + { + if(nullptr != pTriangles) + { + pTriangles->emplace_back( + aEndPoint, + rPoint, + aStartPoint); + } + else + { + aEdgePolygon.append(aEndPoint); + aEdgePolygon.append(rPoint); + aEdgePolygon.append(aStartPoint); + } + + // Look for the cut point between start point along rTangentPrev and + // end point along rTangentEdge. -rTangentEdge should be used, but since + // the cut value is used for interpolating along the first edge, the negation + // is not needed since the same fCut will be found on the first edge. + // If it exists, insert it to complete the mitered fill polygon. + double fCutPos(0.0); + utils::findCut(aStartPoint, rTangentPrev, aEndPoint, rTangentEdge, CutFlagValue::ALL, &fCutPos); + + if(fCutPos != 0.0) + { + const B2DPoint aCutPoint(aStartPoint + (rTangentPrev * fCutPos)); + + if(nullptr != pTriangles) + { + pTriangles->emplace_back( + aStartPoint, + aCutPoint, + aEndPoint); + } + else + { + aEdgePolygon.append(aCutPoint); + } + } + + break; + } + case B2DLineJoin::Round : + { + // use tooling to add needed EllipseSegment + double fAngleStart(atan2(rPerpendPrev.getY(), rPerpendPrev.getX())); + double fAngleEnd(atan2(rPerpendEdge.getY(), rPerpendEdge.getX())); + + // atan2 results are [-PI .. PI], consolidate to [0.0 .. 2PI] + if(fAngleStart < 0.0) + { + fAngleStart += 2 * M_PI; + } + + if(fAngleEnd < 0.0) + { + fAngleEnd += 2 * M_PI; + } + + const B2DPolygon aBow(utils::createPolygonFromEllipseSegment(rPoint, fHalfLineWidth, fHalfLineWidth, fAngleStart, fAngleEnd)); + + if(aBow.count() > 1) + { + if(nullptr != pTriangles) + { + for(sal_uInt32 a(0); a < aBow.count() - 1; a++) + { + pTriangles->emplace_back( + 0 == a ? aStartPoint : aBow.getB2DPoint(a), + rPoint, + aBow.count() - 1 == a + 1 ? aEndPoint : aBow.getB2DPoint(a + 1)); + } + } + else + { + // #i101491# + // use the original start/end positions; the ones from bow creation may be numerically + // different due to their different creation. To guarantee good merging quality with edges + // and edge roundings (and to reduce point count) + aEdgePolygon = aBow; + aEdgePolygon.setB2DPoint(0, aStartPoint); + aEdgePolygon.setB2DPoint(aEdgePolygon.count() - 1, aEndPoint); + aEdgePolygon.append(rPoint); + } + + break; + } + else + { + [[fallthrough]]; // wanted fall-through to default + } + } + default: // B2DLineJoin::Bevel + { + if(nullptr != pTriangles) + { + pTriangles->emplace_back( + aEndPoint, + rPoint, + aStartPoint); + } + else + { + aEdgePolygon.append(aEndPoint); + aEdgePolygon.append(rPoint); + aEdgePolygon.append(aStartPoint); + } + + break; + } + } + + // create last polygon part for edge + aEdgePolygon.setClosed(true); + + return aEdgePolygon; + } + } // end of anonymous namespace + + namespace utils + { + B2DPolyPolygon createAreaGeometry( + const B2DPolygon& rCandidate, + double fHalfLineWidth, + B2DLineJoin eJoin, + css::drawing::LineCap eCap, + double fMaxAllowedAngle, + double fMaxPartOfEdge, + double fMiterMinimumAngle, + basegfx::triangulator::B2DTriangleVector* pTriangles) + { + if(fMaxAllowedAngle > M_PI_2) + { + fMaxAllowedAngle = M_PI_2; + } + else if(fMaxAllowedAngle < 0.01 * M_PI_2) + { + fMaxAllowedAngle = 0.01 * M_PI_2; + } + + if(fMaxPartOfEdge > 1.0) + { + fMaxPartOfEdge = 1.0; + } + else if(fMaxPartOfEdge < 0.01) + { + fMaxPartOfEdge = 0.01; + } + + if(fMiterMinimumAngle > M_PI) + { + fMiterMinimumAngle = M_PI; + } + else if(fMiterMinimumAngle < 0.01 * M_PI) + { + fMiterMinimumAngle = 0.01 * M_PI; + } + + B2DPolygon aCandidate(rCandidate); + const double fMaxCos(cos(fMaxAllowedAngle)); + + aCandidate.removeDoublePoints(); + aCandidate = subdivideToSimple(aCandidate, fMaxCos * fMaxCos, fMaxPartOfEdge * fMaxPartOfEdge); + + const sal_uInt32 nPointCount(aCandidate.count()); + + if(nPointCount) + { + B2DPolyPolygon aRetval; + const bool bIsClosed(aCandidate.isClosed()); + const sal_uInt32 nEdgeCount(bIsClosed ? nPointCount : nPointCount - 1); + const bool bLineCap(!bIsClosed && eCap != css::drawing::LineCap_BUTT); + + if(nEdgeCount) + { + B2DCubicBezier aEdge; + B2DCubicBezier aPrev; + + const bool bEventuallyCreateLineJoin(eJoin != B2DLineJoin::NONE); + // prepare edge + aEdge.setStartPoint(aCandidate.getB2DPoint(0)); + + if(bIsClosed && bEventuallyCreateLineJoin) + { + // prepare previous edge + const sal_uInt32 nPrevIndex(nPointCount - 1); + aPrev.setStartPoint(aCandidate.getB2DPoint(nPrevIndex)); + aPrev.setControlPointA(aCandidate.getNextControlPoint(nPrevIndex)); + aPrev.setControlPointB(aCandidate.getPrevControlPoint(0)); + aPrev.setEndPoint(aEdge.getStartPoint()); + } + + for(sal_uInt32 a(0); a < nEdgeCount; a++) + { + // fill current Edge + const sal_uInt32 nNextIndex((a + 1) % nPointCount); + aEdge.setControlPointA(aCandidate.getNextControlPoint(a)); + aEdge.setControlPointB(aCandidate.getPrevControlPoint(nNextIndex)); + aEdge.setEndPoint(aCandidate.getB2DPoint(nNextIndex)); + + // check and create linejoin + if(bEventuallyCreateLineJoin && (bIsClosed || a != 0)) + { + B2DVector aTangentPrev(aPrev.getTangent(1.0)); aTangentPrev.normalize(); + B2DVector aTangentEdge(aEdge.getTangent(0.0)); aTangentEdge.normalize(); + B2VectorOrientation aOrientation(getOrientation(aTangentPrev, aTangentEdge)); + + if(aOrientation == B2VectorOrientation::Neutral) + { + // they are parallel or empty; if they are both not zero and point + // in opposite direction, a half-circle is needed + if(!aTangentPrev.equalZero() && !aTangentEdge.equalZero()) + { + const double fAngle(fabs(aTangentPrev.angle(aTangentEdge))); + + if(fTools::equal(fAngle, M_PI)) + { + // for half-circle production, fallback to positive + // orientation + aOrientation = B2VectorOrientation::Positive; + } + } + } + + if(aOrientation == B2VectorOrientation::Positive) + { + const B2DVector aPerpendPrev(getPerpendicular(aTangentPrev) * -fHalfLineWidth); + const B2DVector aPerpendEdge(getPerpendicular(aTangentEdge) * -fHalfLineWidth); + + aRetval.append( + createAreaGeometryForJoin( + aTangentPrev, + aTangentEdge, + aPerpendPrev, + aPerpendEdge, + aEdge.getStartPoint(), + fHalfLineWidth, + eJoin, + fMiterMinimumAngle, + pTriangles)); + } + else if(aOrientation == B2VectorOrientation::Negative) + { + const B2DVector aPerpendPrev(getPerpendicular(aTangentPrev) * fHalfLineWidth); + const B2DVector aPerpendEdge(getPerpendicular(aTangentEdge) * fHalfLineWidth); + + aRetval.append( + createAreaGeometryForJoin( + aTangentEdge, + aTangentPrev, + aPerpendEdge, + aPerpendPrev, + aEdge.getStartPoint(), + fHalfLineWidth, + eJoin, + fMiterMinimumAngle, + pTriangles)); + } + } + + // create geometry for edge + const bool bLast(a + 1 == nEdgeCount); + + if(bLineCap) + { + const bool bFirst(!a); + + aRetval.append( + createAreaGeometryForEdge( + aEdge, + fHalfLineWidth, + bFirst && eCap == css::drawing::LineCap_ROUND, + bLast && eCap == css::drawing::LineCap_ROUND, + bFirst && eCap == css::drawing::LineCap_SQUARE, + bLast && eCap == css::drawing::LineCap_SQUARE, + pTriangles)); + } + else + { + aRetval.append( + createAreaGeometryForEdge( + aEdge, + fHalfLineWidth, + false, + false, + false, + false, + pTriangles)); + } + + // prepare next step + if(!bLast) + { + if(bEventuallyCreateLineJoin) + { + aPrev = aEdge; + } + + aEdge.setStartPoint(aEdge.getEndPoint()); + } + } + } + else + { + // point count, but no edge count -> single point + const basegfx::B2DPolygon aCircle( + createPolygonFromCircle( + aCandidate.getB2DPoint(0), + fHalfLineWidth)); + + if(nullptr != pTriangles) + { + const basegfx::triangulator::B2DTriangleVector aResult( + basegfx::triangulator::triangulate( + aCircle)); + pTriangles->insert(pTriangles->end(), aResult.begin(), aResult.end()); + } + else + { + aRetval.append(aCircle); + } + } + + return aRetval; + } + else + { + return B2DPolyPolygon(rCandidate); + } + } + } // end of namespace utils +} // end of namespace basegfx + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |