office-gobmx/tools/source/generic/line.cxx
2011-11-27 13:25:56 -06:00

364 lines
10 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License version 3 for more details
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#define _LINE_CXX
#include <tools/link.hxx>
#include <tools/line.hxx>
#include <tools/debug.hxx>
#include <cstdlib>
#include <math.h>
// --------
// - Line -
// --------
double Line::GetLength() const
{
return hypot( maStart.X() - maEnd.X(), maStart.Y() - maEnd.Y() );
}
// ------------------------------------------------------------------------
sal_Bool Line::Intersection( const Line& rLine, Point& rIntersection ) const
{
double fX, fY;
sal_Bool bRet;
if( Intersection( rLine, fX, fY ) )
{
rIntersection.X() = FRound( fX );
rIntersection.Y() = FRound( fY );
bRet = sal_True;
}
else
bRet = sal_False;
return bRet;
}
// ------------------------------------------------------------------------
sal_Bool Line::Intersection( const Line& rLine, double& rIntersectionX, double& rIntersectionY ) const
{
const double fAx = maEnd.X() - maStart.X();
const double fAy = maEnd.Y() - maStart.Y();
const double fBx = rLine.maStart.X() - rLine.maEnd.X();
const double fBy = rLine.maStart.Y() - rLine.maEnd.Y();
const double fDen = fAy * fBx - fAx * fBy;
sal_Bool bOk = sal_False;
if( fDen != 0. )
{
const double fCx = maStart.X() - rLine.maStart.X();
const double fCy = maStart.Y() - rLine.maStart.Y();
const double fA = fBy * fCx - fBx * fCy;
const sal_Bool bGreater = ( fDen > 0. );
bOk = sal_True;
if ( bGreater )
{
if ( ( fA < 0. ) || ( fA > fDen ) )
bOk = sal_False;
}
else if ( ( fA > 0. ) || ( fA < fDen ) )
bOk = sal_False;
if ( bOk )
{
const double fB = fAx * fCy - fAy * fCx;
if ( bGreater )
{
if ( ( fB < 0. ) || ( fB > fDen ) )
bOk = sal_False;
}
else if ( ( fB > 0. ) || ( fB < fDen ) )
bOk = sal_False;
if( bOk )
{
const double fAlpha = fA / fDen;
rIntersectionX = ( maStart.X() + fAlpha * fAx );
rIntersectionY = ( maStart.Y() + fAlpha * fAy );
}
}
}
return bOk;
}
// ------------------------------------------------------------------------
sal_Bool Line::Intersection( const Rectangle& rRect, Line& rIntersection ) const
{
const sal_Bool bStartInside = rRect.IsInside( maStart );
const sal_Bool bEndInside = rRect.IsInside( maEnd );
sal_Bool bRet = sal_True;
if( bStartInside && bEndInside )
{
// line completely inside rect
rIntersection.maStart = maStart;
rIntersection.maEnd = maEnd;
}
else
{
// calculate intersections
const Point aTL( rRect.TopLeft() ), aTR( rRect.TopRight() );
const Point aBR( rRect.BottomRight() ), aBL( rRect.BottomLeft() );
Point aIntersect1, aIntersect2;
Point* pCurIntersection = &aIntersect1;
if( Intersection( Line( aTL, aTR ), *pCurIntersection ) )
pCurIntersection = &aIntersect2;
if( Intersection( Line( aTR, aBR ), *pCurIntersection ) )
pCurIntersection = ( pCurIntersection == &aIntersect1 ) ? &aIntersect2 : NULL;
if( pCurIntersection && Intersection( Line( aBR, aBL ), *pCurIntersection ) )
pCurIntersection = ( pCurIntersection == &aIntersect1 ) ? &aIntersect2 : NULL;
if( pCurIntersection && Intersection( Line( aBL, aTL ), *pCurIntersection ) )
pCurIntersection = ( pCurIntersection == &aIntersect1 ) ? &aIntersect2 : NULL;
if( !pCurIntersection )
{
// two intersections
rIntersection.maStart = aIntersect1;
rIntersection.maEnd = aIntersect2;
}
else if( pCurIntersection == &aIntersect2 )
{
// one intersection
rIntersection.maStart = aIntersect1;
if( ( maStart != aIntersect1 ) && bStartInside )
rIntersection.maEnd = maStart;
else if( ( maEnd != aIntersect1 ) && bEndInside )
rIntersection.maEnd = maEnd;
else
rIntersection.maEnd = rIntersection.maStart;
}
else
bRet = sal_False;
}
return bRet;
}
// ------------------------------------------------------------------------
Point Line::NearestPoint( const Point& rPoint ) const
{
Point aRetPt;
if ( maStart != maEnd )
{
const double fDistX = maEnd.X() - maStart.X();
const double fDistY = maStart.Y() - maEnd.Y();
const double fTau = ( ( maStart.Y() - rPoint.Y() ) * fDistY -
( maStart.X() - rPoint.X() ) * fDistX ) /
( fDistX * fDistX + fDistY * fDistY );
if( fTau < 0.0 )
aRetPt = maStart;
else if( fTau <= 1.0 )
{
aRetPt.X() = FRound( maStart.X() + fTau * fDistX );
aRetPt.Y() = FRound( maStart.Y() - fTau * fDistY );
}
else
aRetPt = maEnd;
}
else
aRetPt = maStart;
return aRetPt;
}
// ------------------------------------------------------------------------
double Line::GetDistance( const double& rPtX, const double& rPtY ) const
{
double fDist;
if( maStart != maEnd )
{
const double fDistX = maEnd.X() - maStart.X();
const double fDistY = maEnd.Y() - maStart.Y();
const double fACX = maStart.X() - rPtX;
const double fACY = maStart.Y() - rPtY;
const double fL2 = fDistX * fDistX + fDistY * fDistY;
const double fR = ( fACY * -fDistY - fACX * fDistX ) / fL2;
const double fS = ( fACY * fDistX - fACX * fDistY ) / fL2;
if( fR < 0.0 )
{
fDist = hypot( maStart.X() - rPtX, maStart.Y() - rPtY );
if( fS < 0.0 )
fDist *= -1.0;
}
else if( fR <= 1.0 )
fDist = fS * sqrt( fL2 );
else
{
fDist = hypot( maEnd.X() - rPtX, maEnd.Y() - rPtY );
if( fS < 0.0 )
fDist *= -1.0;
}
}
else
fDist = hypot( maStart.X() - rPtX, maStart.Y() - rPtY );
return fDist;
}
// ------------------------------------------------------------------------
void Line::Enum( const Link& rEnumLink )
{
DBG_ASSERT( rEnumLink.IsSet(), "This call doesn't make any sense with !rEnumLink.IsSet()" );
Point aEnum;
long nX;
long nY;
if( maStart.X() == maEnd.X() )
{
const long nEndY = maEnd.Y();
nX = maStart.X();
nY = maStart.Y();
if( nEndY > nY )
{
while( nY <= nEndY )
{
aEnum.X() = nX;
aEnum.Y() = nY++;
rEnumLink.Call( &aEnum );
}
}
else
{
while( nY >= nEndY )
{
aEnum.X() = nX;
aEnum.Y() = nY--;
rEnumLink.Call( &aEnum );
}
}
}
else if( maStart.Y() == maEnd.Y() )
{
const long nEndX = maEnd.X();
nX = maStart.X();
nY = maStart.Y();
if( nEndX > nX )
{
while( nX <= nEndX )
{
aEnum.X() = nX++;
aEnum.Y() = nY;
rEnumLink.Call( &aEnum );
}
}
else
{
while( nX >= nEndX )
{
aEnum.X() = nX--;
aEnum.Y() = nY;
rEnumLink.Call( &aEnum );
}
}
}
else
{
const long nDX = labs( maEnd.X() - maStart.X() );
const long nDY = labs( maEnd.Y() - maStart.Y() );
const long nStartX = maStart.X();
const long nStartY = maStart.Y();
const long nEndX = maEnd.X();
const long nEndY = maEnd.Y();
const long nXInc = ( nStartX < nEndX ) ? 1L : -1L;
const long nYInc = ( nStartY < nEndY ) ? 1L : -1L;
if( nDX >= nDY )
{
const long nDYX = ( nDY - nDX ) << 1;
const long nDY2 = nDY << 1;
long nD = nDY2 - nDX;
for( nX = nStartX, nY = nStartY; nX != nEndX; nX += nXInc )
{
aEnum.X() = nX;
aEnum.Y() = nY;
rEnumLink.Call( &aEnum );
if( nD < 0L )
nD += nDY2;
else
nD += nDYX, nY += nYInc;
}
}
else
{
const long nDYX = ( nDX - nDY ) << 1;
const long nDY2 = nDX << 1;
long nD = nDY2 - nDY;
for( nX = nStartX, nY = nStartY; nY != nEndY; nY += nYInc )
{
aEnum.X() = nX;
aEnum.Y() = nY;
rEnumLink.Call( &aEnum );
if( nD < 0L )
nD += nDY2;
else
nD += nDYX, nX += nXInc;
}
}
// last point
aEnum.X() = nEndX;
aEnum.Y() = nEndY;
rEnumLink.Call( &aEnum );
}
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */