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// Geometric Tools, LLC
// Copyright (c) 1998-2014
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
// http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
//
// File Version: 5.0.1 (2010/10/01)
#include "Wm5MathematicsPCH.h"
#include "Wm5IntrLine3Triangle3.h"
namespace Wm5
{
//----------------------------------------------------------------------------
template <typename Real>
IntrLine3Triangle3<Real>::IntrLine3Triangle3 (const Line3<Real>& rkLine,
const Triangle3<Real>& rkTriangle)
:
mLine(&rkLine),
mTriangle(&rkTriangle)
{
}
//----------------------------------------------------------------------------
template <typename Real>
const Line3<Real>& IntrLine3Triangle3<Real>::GetLine () const
{
return *mLine;
}
//----------------------------------------------------------------------------
template <typename Real>
const Triangle3<Real>& IntrLine3Triangle3<Real>::GetTriangle () const
{
return *mTriangle;
}
//----------------------------------------------------------------------------
template <typename Real>
bool IntrLine3Triangle3<Real>::Test ()
{
// Compute the offset origin, edges, and normal.
Vector3<Real> diff = mLine->Origin - mTriangle->V[0];
Vector3<Real> edge1 = mTriangle->V[1] - mTriangle->V[0];
Vector3<Real> edge2 = mTriangle->V[2] - mTriangle->V[0];
Vector3<Real> normal = edge1.Cross(edge2);
// Solve Q + t*D = b1*E1 + b2*E2 (Q = diff, D = line direction,
// E1 = edge1, E2 = edge2, N = Cross(E1,E2)) by
// |Dot(D,N)|*b1 = sign(Dot(D,N))*Dot(D,Cross(Q,E2))
// |Dot(D,N)|*b2 = sign(Dot(D,N))*Dot(D,Cross(E1,Q))
// |Dot(D,N)|*t = -sign(Dot(D,N))*Dot(Q,N)
Real DdN = mLine->Direction.Dot(normal);
Real sign;
if (DdN > Math<Real>::ZERO_TOLERANCE)
{
sign = (Real)1;
}
else if (DdN < -Math<Real>::ZERO_TOLERANCE)
{
sign = (Real)-1;
DdN = -DdN;
}
else
{
// Line and triangle are parallel, call it a "no intersection"
// even if the line does intersect.
mIntersectionType = IT_EMPTY;
return false;
}
Real DdQxE2 = sign*mLine->Direction.Dot(diff.Cross(edge2));
if (DdQxE2 >= (Real)0)
{
Real DdE1xQ = sign*mLine->Direction.Dot(edge1.Cross(diff));
if (DdE1xQ >= (Real)0)
{
if (DdQxE2 + DdE1xQ <= DdN)
{
// Line intersects triangle.
mIntersectionType = IT_POINT;
return true;
}
// else: b1+b2 > 1, no intersection
}
// else: b2 < 0, no intersection
}
// else: b1 < 0, no intersection
mIntersectionType = IT_EMPTY;
return false;
}
//----------------------------------------------------------------------------
template <typename Real>
bool IntrLine3Triangle3<Real>::Find ()
{
// Compute the offset origin, edges, and normal.
Vector3<Real> diff = mLine->Origin - mTriangle->V[0];
Vector3<Real> edge1 = mTriangle->V[1] - mTriangle->V[0];
Vector3<Real> edge2 = mTriangle->V[2] - mTriangle->V[0];
Vector3<Real> normal = edge1.Cross(edge2);
// Solve Q + t*D = b1*E1 + b2*E2 (Q = diff, D = line direction,
// E1 = edge1, E2 = edge2, N = Cross(E1,E2)) by
// |Dot(D,N)|*b1 = sign(Dot(D,N))*Dot(D,Cross(Q,E2))
// |Dot(D,N)|*b2 = sign(Dot(D,N))*Dot(D,Cross(E1,Q))
// |Dot(D,N)|*t = -sign(Dot(D,N))*Dot(Q,N)
Real DdN = mLine->Direction.Dot(normal);
Real sign;
if (DdN > Math<Real>::ZERO_TOLERANCE)
{
sign = (Real)1;
}
else if (DdN < -Math<Real>::ZERO_TOLERANCE)
{
sign = (Real)-1;
DdN = -DdN;
}
else
{
// Line and triangle are parallel, call it a "no intersection"
// even if the line does intersect.
mIntersectionType = IT_EMPTY;
return false;
}
Real DdQxE2 = sign*mLine->Direction.Dot(diff.Cross(edge2));
if (DdQxE2 >= (Real)0)
{
Real DdE1xQ = sign*mLine->Direction.Dot(edge1.Cross(diff));
if (DdE1xQ >= (Real)0)
{
if (DdQxE2 + DdE1xQ <= DdN)
{
// Line intersects triangle.
Real QdN = -sign*diff.Dot(normal);
Real inv = ((Real)1)/DdN;
mLineParameter = QdN*inv;
mTriBary1 = DdQxE2*inv;
mTriBary2 = DdE1xQ*inv;
mTriBary0 = (Real)1 - mTriBary1 - mTriBary2;
mIntersectionType = IT_POINT;
return true;
}
// else: b1+b2 > 1, no intersection
}
// else: b2 < 0, no intersection
}
// else: b1 < 0, no intersection
return false;
}
//----------------------------------------------------------------------------
template <typename Real>
Real IntrLine3Triangle3<Real>::GetLineParameter () const
{
return mLineParameter;
}
//----------------------------------------------------------------------------
template <typename Real>
Real IntrLine3Triangle3<Real>::GetTriBary0 () const
{
return mTriBary0;
}
//----------------------------------------------------------------------------
template <typename Real>
Real IntrLine3Triangle3<Real>::GetTriBary1 () const
{
return mTriBary1;
}
//----------------------------------------------------------------------------
template <typename Real>
Real IntrLine3Triangle3<Real>::GetTriBary2 () const
{
return mTriBary2;
}
//----------------------------------------------------------------------------
//----------------------------------------------------------------------------
// Explicit instantiation.
//----------------------------------------------------------------------------
template WM5_MATHEMATICS_ITEM
class IntrLine3Triangle3<float>;
template WM5_MATHEMATICS_ITEM
class IntrLine3Triangle3<double>;
//----------------------------------------------------------------------------
}
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