📄 mgcdistlin3tri3.cpp
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// Magic Software, Inc.
// http://www.magic-software.com
// Copyright (c) 2000, All Rights Reserved
//
// Source code from Magic Software is supplied under the terms of a license
// agreement and may not be copied or disclosed except in accordance with the
// terms of that agreement. The various license agreements may be found at
// the Magic Software web site. This file is subject to the license
//
// FREE SOURCE CODE
// http://www.magic-software.com/License/free.pdf
#include "MgcDistLin3Lin3.h"
#include "MgcDistVec3Tri3.h"#include "MgcDistLin3Tri3.h"
#include "MgcRTLib.h"
static const MgcReal gs_fTolerance = 1e-05;
//----------------------------------------------------------------------------MgcReal MgcSqrDistance (const MgcLine3& rkLine, const MgcTriangle3& rkTri,
MgcReal* pfLinP, MgcReal* pfTriP0, MgcReal* pfTriP1)
{
MgcVector3 kDiff = rkTri.Origin() - rkLine.Origin();
MgcReal fA00 = rkLine.Direction().SquaredLength();
MgcReal fA01 = -rkLine.Direction().Dot(rkTri.Edge0());
MgcReal fA02 = -rkLine.Direction().Dot(rkTri.Edge1());
MgcReal fA11 = rkTri.Edge0().SquaredLength();
MgcReal fA12 = rkTri.Edge0().Dot(rkTri.Edge1());
MgcReal fA22 = rkTri.Edge1().Dot(rkTri.Edge1());
MgcReal fB0 = -kDiff.Dot(rkLine.Direction());
MgcReal fB1 = kDiff.Dot(rkTri.Edge0());
MgcReal fB2 = kDiff.Dot(rkTri.Edge1());
MgcReal fCof00 = fA11*fA22-fA12*fA12;
MgcReal fCof01 = fA02*fA12-fA01*fA22;
MgcReal fCof02 = fA01*fA12-fA02*fA11;
MgcReal fDet = fA00*fCof00+fA01*fCof01+fA02*fCof02;
MgcSegment3 kTriSeg;
MgcVector3 kPt;
MgcReal fSqrDist, fSqrDist0, fR, fS, fT, fR0, fS0, fT0;
if ( MgcMath::Abs(fDet) >= gs_fTolerance )
{
MgcReal fCof11 = fA00*fA22-fA02*fA02;
MgcReal fCof12 = fA02*fA01-fA00*fA12;
MgcReal fCof22 = fA00*fA11-fA01*fA01;
MgcReal fInvDet = 1.0/fDet;
MgcReal fRhs0 = -fB0*fInvDet;
MgcReal fRhs1 = -fB1*fInvDet;
MgcReal fRhs2 = -fB2*fInvDet;
fR = fCof00*fRhs0+fCof01*fRhs1+fCof02*fRhs2;
fS = fCof01*fRhs0+fCof11*fRhs1+fCof12*fRhs2;
fT = fCof02*fRhs0+fCof12*fRhs1+fCof22*fRhs2;
if ( fS+fT <= 1.0 )
{
if ( fS < 0.0 )
{
if ( fT < 0.0 ) // region 4
{
// min on face s=0 or t=0
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge1();
fSqrDist = MgcSqrDistance(rkLine,kTriSeg,0,&fT);
fS = 0.0;
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge0();
fSqrDist0 = MgcSqrDistance(rkLine,kTriSeg,0,&fS0);
fT0 = 0.0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fS = fS0;
fT = fT0;
}
}
else // region 3
{
// min on face s=0
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge1();
fSqrDist = MgcSqrDistance(rkLine,kTriSeg,0,&fT);
fS = 0.0;
}
}
else if ( fT < 0.0 ) // region 5
{
// min on face t=0
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge0();
fSqrDist = MgcSqrDistance(rkLine,kTriSeg,0,&fS);
fT = 0.0;
}
else // region 0
{
// line intersects triangle
fSqrDist = 0.0;
}
}
else
{
if ( fS < 0.0 ) // region 2
{
// min on face s=0 or s+t=1
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge1();
fSqrDist = MgcSqrDistance(rkLine,kTriSeg,0,&fT);
fS = 0.0;
kTriSeg.Origin() = rkTri.Origin()+rkTri.Edge0();
kTriSeg.Direction() = rkTri.Edge1()-rkTri.Edge0();
fSqrDist0 = MgcSqrDistance(rkLine,kTriSeg,0,&fT0);
fS0 = 1.0-fT0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fS = fS0;
fT = fT0;
}
}
else if ( fT < 0.0 ) // region 6
{
// min on face t=0 or s+t=1
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge0();
fSqrDist = MgcSqrDistance(rkLine,kTriSeg,0,&fS);
fT = 0.0;
kTriSeg.Origin() = rkTri.Origin()+rkTri.Edge0();
kTriSeg.Direction() = rkTri.Edge1()-rkTri.Edge0();
fSqrDist0 = MgcSqrDistance(rkLine,kTriSeg,0,&fT0);
fS0 = 1.0-fT0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fS = fS0;
fT = fT0;
}
}
else // region 1
{
// min on face s+t=1
kTriSeg.Origin() = rkTri.Origin()+rkTri.Edge0();
kTriSeg.Direction() = rkTri.Edge1()-rkTri.Edge0();
fSqrDist = MgcSqrDistance(rkLine,kTriSeg,0,&fT);
fS = 1.0-fT;
}
}
}
else
{
// line and triangle are parallel
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge0();
fSqrDist = MgcSqrDistance(rkLine,kTriSeg,&fR,&fS);
fT = 0.0;
kTriSeg.Direction() = rkTri.Edge1();
fSqrDist0 = MgcSqrDistance(rkLine,kTriSeg,&fR0,&fT0);
fS0 = 0.0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fR = fR0;
fS = fS0;
fT = fT0;
}
kTriSeg.Origin() = rkTri.Origin() + rkTri.Edge0();
kTriSeg.Direction() = rkTri.Edge1() - rkTri.Edge0();
fSqrDist0 = MgcSqrDistance(rkLine,kTriSeg,&fR0,&fT0);
fS0 = 1.0-fT0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fR = fR0;
fS = fS0;
fT = fT0;
}
}
if ( pfLinP )
*pfLinP = fR;
if ( pfTriP0 )
*pfTriP0 = fS;
if ( pfTriP1 )
*pfTriP1 = fT;
return MgcMath::Abs(fSqrDist);
}
//----------------------------------------------------------------------------
MgcReal MgcSqrDistance (const MgcRay3& rkRay, const MgcTriangle3& rkTri,
MgcReal* pfRayP, MgcReal* pfTriP0, MgcReal* pfTriP1)
{
MgcVector3 kDiff = rkTri.Origin() - rkRay.Origin();
MgcReal fA00 = rkRay.Direction().SquaredLength();
MgcReal fA01 = -rkRay.Direction().Dot(rkTri.Edge0());
MgcReal fA02 = -rkRay.Direction().Dot(rkTri.Edge1());
MgcReal fA11 = rkTri.Edge0().SquaredLength();
MgcReal fA12 = rkTri.Edge0().Dot(rkTri.Edge1());
MgcReal fA22 = rkTri.Edge1().Dot(rkTri.Edge1());
MgcReal fB0 = -kDiff.Dot(rkRay.Direction());
MgcReal fB1 = kDiff.Dot(rkTri.Edge0());
MgcReal fB2 = kDiff.Dot(rkTri.Edge1());
MgcReal fCof00 = fA11*fA22-fA12*fA12;
MgcReal fCof01 = fA02*fA12-fA01*fA22;
MgcReal fCof02 = fA01*fA12-fA02*fA11;
MgcReal fDet = fA00*fCof00+fA01*fCof01+fA02*fCof02;
MgcSegment3 kTriSeg;
MgcVector3 kPt;
MgcReal fSqrDist, fSqrDist0, fR, fS, fT, fR0, fS0, fT0;
if ( MgcMath::Abs(fDet) >= gs_fTolerance )
{
MgcReal fCof11 = fA00*fA22-fA02*fA02;
MgcReal fCof12 = fA02*fA01-fA00*fA12;
MgcReal fCof22 = fA00*fA11-fA01*fA01;
MgcReal fInvDet = 1.0/fDet;
MgcReal fRhs0 = -fB0*fInvDet;
MgcReal fRhs1 = -fB1*fInvDet;
MgcReal fRhs2 = -fB2*fInvDet;
fR = fCof00*fRhs0+fCof01*fRhs1+fCof02*fRhs2;
fS = fCof01*fRhs0+fCof11*fRhs1+fCof12*fRhs2;
fT = fCof02*fRhs0+fCof12*fRhs1+fCof22*fRhs2;
if ( fR <= 0.0 )
{
if ( fS+fT <= 1.0 )
{
if ( fS < 0.0 )
{
if ( fT < 0.0 ) // region 4m
{
// min on face s=0 or t=0 or r=0
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge1();
fSqrDist = MgcSqrDistance(rkRay,kTriSeg,&fR,&fT);
fS = 0.0;
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge0();
fSqrDist0 = MgcSqrDistance(rkRay,kTriSeg,&fR0,&fS0);
fT0 = 0.0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fR = fR0;
fS = fS0;
fT = fT0;
}
fSqrDist0 = MgcSqrDistance(rkRay.Origin(),rkTri,
&fS0,&fT0);
fR0 = 0.0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fR = fR0;
fS = fS0;
fT = fT0;
}
}
else // region 3m
{
// min on face s=0 or r=0
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge1();
fSqrDist = MgcSqrDistance(rkRay,kTriSeg,&fR,&fT);
fS = 0.0;
fSqrDist0 = MgcSqrDistance(rkRay.Origin(),rkTri,
&fS0,&fT0);
fR0 = 0.0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fR = fR0;
fS = fS0;
fT = fT0;
}
}
}
else if ( fT < 0.0 ) // region 5m
{
// min on face t=0 or r=0
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge0();
fSqrDist = MgcSqrDistance(rkRay,kTriSeg,&fR,&fS);
fT = 0.0;
fSqrDist0 = MgcSqrDistance(rkRay.Origin(),rkTri,&fS0,
&fT0);
fR0 = 0.0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fR = fR0;
fS = fS0;
fT = fT0;
}
}
else // region 0m
{
// min on face r=0
fSqrDist = MgcSqrDistance(rkRay.Origin(),rkTri,&fS,&fT);
fR = 0.0;
}
}
else
{
if ( fS < 0.0 ) // region 2m
{
// min on face s=0 or s+t=1 or r=0
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge1();
fSqrDist = MgcSqrDistance(rkRay,kTriSeg,&fR,&fT);
fS = 0.0;
kTriSeg.Origin() = rkTri.Origin()+rkTri.Edge0();
kTriSeg.Direction() = rkTri.Edge1()-rkTri.Edge0();
fSqrDist0 = MgcSqrDistance(rkRay,kTriSeg,&fR0,&fT0);
fS0 = 1.0-fT0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fR = fR0;
fS = fS0;
fT = fT0;
}
fSqrDist0 = MgcSqrDistance(rkRay.Origin(),rkTri,&fS0,
&fT0);
fR0 = 0.0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fR = fR0;
fS = fS0;
fT = fT0;
}
}
else if ( fT < 0.0 ) // region 6m
{
// min on face t=0 or s+t=1 or r=0
kTriSeg.Origin() = rkTri.Origin();
kTriSeg.Direction() = rkTri.Edge0();
fSqrDist = MgcSqrDistance(rkRay,kTriSeg,&fR,&fS);
fT = 0.0;
kTriSeg.Origin() = rkTri.Origin()+rkTri.Edge0();
kTriSeg.Direction() = rkTri.Edge1()-rkTri.Edge0();
fSqrDist0 = MgcSqrDistance(rkRay,kTriSeg,&fR0,&fT0);
fS0 = 1.0-fT0;
if ( fSqrDist0 < fSqrDist )
{
fSqrDist = fSqrDist0;
fR = fR0;
fS = fS0;
fT = fT0;
}
fSqrDist0 = MgcSqrDistance(rkRay.Origin(),rkTri,&fS0,
&fT0);
fR0 = 0.0;
if ( fSqrDist0 < fSqrDist )
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