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Diffstat (limited to 'chart2/source/view/main/Clipping.cxx')
| -rw-r--r-- | chart2/source/view/main/Clipping.cxx | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/chart2/source/view/main/Clipping.cxx b/chart2/source/view/main/Clipping.cxx new file mode 100644 index 000000000..463b74975 --- /dev/null +++ b/chart2/source/view/main/Clipping.cxx @@ -0,0 +1,300 @@ +/* -*- 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 <Clipping.hxx> +#include <CommonConverters.hxx> +#include <BaseGFXHelper.hxx> + +#include <osl/diagnose.h> + +#include <com/sun/star/drawing/Position3D.hpp> +#include <com/sun/star/drawing/DoubleSequence.hpp> + +namespace chart +{ +using namespace ::com::sun::star; +using ::basegfx::B2DRectangle; +using ::basegfx::B2DTuple; + +namespace{ +/** @descr This is a supporting function for lcl_clip2d. It computes a new parametric + value for an entering (dTE) or leaving (dTL) intersection point with one + of the edges bounding the clipping area. + For explanation of the parameters please refer to : + + Liang-Biarsky parametric line-clipping algorithm as described in: + Computer Graphics: principles and practice, 2nd ed., + James D. Foley et al., + Section 3.12.4 on page 117. +*/ +bool lcl_CLIPt(double fDenom,double fNum, double & fTE, double & fTL) +{ + double fT; + + if (fDenom > 0) // Intersection enters: PE + { + fT = fNum / fDenom; // Parametric value at the intersection. + if (fT > fTL) // fTE and fTL crossover + return false; // therefore reject the line. + else if (fT > fTE) // A new fTE has been found. + fTE = fT; + } + else if (fDenom < 0) // Intersection leaves: PL + { + fT = fNum / fDenom; // Parametric Value at the intersection. + if (fT < fTE) // fTE and fTL crossover + return false; // therefore reject the line. + else if (fT < fTL) // A new fTL has been found. + fTL = fT; + } + else if (fNum > 0) + return false; // Line lies on the outside of the edge. + + return true; +} + +/** @descr The line given by its two endpoints rP0 and rP1 is clipped at the rectangle + rRectangle. If there is at least a part of it visible then sal_True is returned and + the endpoints of that part are stored in rP0 and rP1. The points rP0 and rP1 + may have the same coordinates. + @param rP0 Start point of the line to clip. Modified to contain a start point inside + the clipping area if possible. + @param rP1 End point of the line to clip. Modified to contain an end point inside + the clipping area if possible. + @param rRectangle Clipping area. + @return If the line lies completely or partly inside the clipping area then TRUE + is returned. If the line lies completely outside then sal_False is returned and rP0 and + rP1 are left unmodified. +*/ +bool lcl_clip2d(B2DTuple& rPoint0, B2DTuple& rPoint1, const B2DRectangle& rRectangle) +{ + //Direction vector of the line. + B2DTuple aDirection = rPoint1 - rPoint0; + + if( aDirection.getX()==0 && aDirection.getY()==0 && rRectangle.isInside(rPoint0) ) + { + // Degenerate case of a zero length line. + return true; + } + else + { + // Values of the line parameter where the line enters resp. leaves the rectangle. + double fTE = 0, + fTL = 1; + + // Test whether at least a part lies in the four half-planes with respect to + // the rectangles four edges. + if( lcl_CLIPt(aDirection.getX(), rRectangle.getMinX() - rPoint0.getX(), fTE, fTL) ) + if( lcl_CLIPt(-aDirection.getX(), rPoint0.getX() - rRectangle.getMaxX(), fTE, fTL) ) + if( lcl_CLIPt(aDirection.getY(), rRectangle.getMinY() - rPoint0.getY(), fTE, fTL) ) + if( lcl_CLIPt(-aDirection.getY(), rPoint0.getY() - rRectangle.getMaxY(), fTE, fTL) ) + { + // At least a part is visible. + if (fTL < 1) + { + // Compute the new end point. + rPoint1.setX( rPoint0.getX() + fTL * aDirection.getX() ); + rPoint1.setY( rPoint0.getY() + fTL * aDirection.getY() ); + } + if (fTE > 0) + { + // Compute the new starting point. + rPoint0.setX( rPoint0.getX() + fTE * aDirection.getX() ); + rPoint0.setY( rPoint0.getY() + fTE * aDirection.getY() ); + } + return true; + } + + // Line is not visible. + return false; + } +} + +bool lcl_clip2d_(drawing::Position3D& rPoint0, drawing::Position3D& rPoint1, const B2DRectangle& rRectangle) +{ + B2DTuple aP0(rPoint0.PositionX,rPoint0.PositionY); + B2DTuple aP1(rPoint1.PositionX,rPoint1.PositionY); + bool bRet = lcl_clip2d( aP0, aP1, rRectangle ); + + rPoint0.PositionX = aP0.getX(); + rPoint0.PositionY = aP0.getY(); + rPoint1.PositionX = aP1.getX(); + rPoint1.PositionY = aP1.getY(); + + return bRet; +} + +unsigned int round_up_nearest_pow2(unsigned int v) +{ + // compute the next highest power of 2 of 32-bit v + --v; + v |= v >> 1; + v |= v >> 2; + v |= v >> 4; + v |= v >> 8; + v |= v >> 16; + ++v; + return v; +} + +void lcl_addPointToPoly( drawing::PolyPolygonShape3D& rPoly + , const drawing::Position3D& rPos + , sal_Int32 nPolygonIndex + , std::vector< sal_Int32 >& rResultPointCount + , sal_Int32 nReservePointCount ) +{ + if(nPolygonIndex<0) + { + OSL_FAIL( "The polygon index needs to be > 0"); + nPolygonIndex=0; + } + + //make sure that we have enough polygons + if(nPolygonIndex >= rPoly.SequenceX.getLength() ) + { + rPoly.SequenceX.realloc(nPolygonIndex+1); + rPoly.SequenceY.realloc(nPolygonIndex+1); + rPoly.SequenceZ.realloc(nPolygonIndex+1); + rResultPointCount.resize(nPolygonIndex+1,0); + } + + drawing::DoubleSequence* pOuterSequenceX = &rPoly.SequenceX.getArray()[nPolygonIndex]; + drawing::DoubleSequence* pOuterSequenceY = &rPoly.SequenceY.getArray()[nPolygonIndex]; + drawing::DoubleSequence* pOuterSequenceZ = &rPoly.SequenceZ.getArray()[nPolygonIndex]; + + sal_Int32 nNewResultPointCount = rResultPointCount[nPolygonIndex]+1; + sal_Int32 nSeqLength = pOuterSequenceX->getLength(); + + if( nSeqLength <= nNewResultPointCount ) + { + sal_Int32 nReallocLength = nReservePointCount > SAL_MAX_INT16 ? round_up_nearest_pow2(nNewResultPointCount) * 2 : nReservePointCount; + if( nNewResultPointCount > nReallocLength ) + { + nReallocLength = nNewResultPointCount; + OSL_FAIL("this should not be the case to avoid performance problems"); + } + pOuterSequenceX->realloc(nReallocLength); + pOuterSequenceY->realloc(nReallocLength); + pOuterSequenceZ->realloc(nReallocLength); + } + + double* pInnerSequenceX = pOuterSequenceX->getArray(); + double* pInnerSequenceY = pOuterSequenceY->getArray(); + double* pInnerSequenceZ = pOuterSequenceZ->getArray(); + + pInnerSequenceX[nNewResultPointCount-1] = rPos.PositionX; + pInnerSequenceY[nNewResultPointCount-1] = rPos.PositionY; + pInnerSequenceZ[nNewResultPointCount-1] = rPos.PositionZ; + rResultPointCount[nPolygonIndex]=nNewResultPointCount; +} + +}//end anonymous namespace + +void Clipping::clipPolygonAtRectangle( const drawing::PolyPolygonShape3D& rPolygon + , const B2DRectangle& rRectangle + , drawing::PolyPolygonShape3D& aResult + , bool bSplitPiecesToDifferentPolygons ) +{ + aResult.SequenceX.realloc(0); + aResult.SequenceY.realloc(0); + aResult.SequenceZ.realloc(0); + + if(!rPolygon.SequenceX.hasElements()) + return; + + //need clipping?: + { + ::basegfx::B3DRange a3DRange( BaseGFXHelper::getBoundVolume( rPolygon ) ); + ::basegfx::B2DRange a2DRange( a3DRange.getMinX(), a3DRange.getMinY(), a3DRange.getMaxX(), a3DRange.getMaxY() ); + if( rRectangle.isInside( a2DRange ) ) + { + aResult = rPolygon; + return; + } + else + { + a2DRange.intersect( rRectangle ); + if( a2DRange.isEmpty() ) + return; + } + } + + std::vector< sal_Int32 > aResultPointCount;//per polygon index + + //apply clipping: + drawing::Position3D aFrom; + drawing::Position3D aTo; + + sal_Int32 nNewPolyIndex = 0; + sal_Int32 nOldPolyCount = rPolygon.SequenceX.getLength(); + for(sal_Int32 nOldPolyIndex=0; nOldPolyIndex<nOldPolyCount; nOldPolyIndex++, nNewPolyIndex++ ) + { + sal_Int32 nOldPointCount = rPolygon.SequenceX[nOldPolyIndex].getLength(); + + // set last point to a position outside the rectangle, such that the first + // time lcl_clip2d returns true, the comparison to last will always yield false + drawing::Position3D aLast(rRectangle.getMinX()-1.0,rRectangle.getMinY()-1.0, 0.0 ); + + for(sal_Int32 nOldPoint=1; nOldPoint<nOldPointCount; nOldPoint++) + { + aFrom = getPointFromPoly(rPolygon,nOldPoint-1,nOldPolyIndex); + aTo = getPointFromPoly(rPolygon,nOldPoint,nOldPolyIndex); + if( lcl_clip2d_(aFrom, aTo, rRectangle) ) + { + // compose a Polygon of as many consecutive points as possible + if(aFrom == aLast) + { + if( aTo != aFrom ) + { + lcl_addPointToPoly( aResult, aTo, nNewPolyIndex, aResultPointCount, nOldPointCount ); + } + } + else + { + if( bSplitPiecesToDifferentPolygons && nOldPoint!=1 ) + { + if( nNewPolyIndex < aResult.SequenceX.getLength() + && aResultPointCount[nNewPolyIndex]>0 ) + nNewPolyIndex++; + } + lcl_addPointToPoly( aResult, aFrom, nNewPolyIndex, aResultPointCount, nOldPointCount ); + if( aTo != aFrom ) + lcl_addPointToPoly( aResult, aTo, nNewPolyIndex, aResultPointCount, nOldPointCount ); + } + aLast = aTo; + } + } + } + //free unused space + for( sal_Int32 nPolygonIndex = aResultPointCount.size(); nPolygonIndex--; ) + { + drawing::DoubleSequence* pOuterSequenceX = &aResult.SequenceX.getArray()[nPolygonIndex]; + drawing::DoubleSequence* pOuterSequenceY = &aResult.SequenceY.getArray()[nPolygonIndex]; + drawing::DoubleSequence* pOuterSequenceZ = &aResult.SequenceZ.getArray()[nPolygonIndex]; + + sal_Int32 nUsedPointCount = aResultPointCount[nPolygonIndex]; + pOuterSequenceX->realloc(nUsedPointCount); + pOuterSequenceY->realloc(nUsedPointCount); + pOuterSequenceZ->realloc(nUsedPointCount); + } +} + +} //namespace chart + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |