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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 "Clipping.hxx"
#include "CommonConverters.hxx"
#include "BaseGFXHelper.hxx"
#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 it's 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;
}
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;
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.getLength())
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 an 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: */
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