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/*
* SOLID - Software Library for Interference Detection
*
* Copyright (C) 2001-2003 Dtecta. All rights reserved.
*
* This library may be distributed under the terms of the Q Public License
* (QPL) as defined by Trolltech AS of Norway and appearing in the file
* LICENSE.QPL included in the packaging of this file.
*
* This library may be distributed and/or modified under the terms of the
* GNU General Public License (GPL) version 2 as published by the Free Software
* Foundation and appearing in the file LICENSE.GPL included in the
* packaging of this file.
*
* This library is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
* WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* Commercial use or any other use of this library not covered by either
* the QPL or the GPL requires an additional license from Dtecta.
* Please contact info@dtecta.com for enquiries about the terms of commercial
* use of this library.
*/
//#define BACKFACE_CULLING
#include "DT_Triangle.h"
MT_BBox DT_Triangle::bbox() const
{
return MT_BBox((*this)[0]).hull((*this)[1]).hull((*this)[2]);
}
MT_Scalar DT_Triangle::supportH(const MT_Vector3& v) const
{
return GEN_max(GEN_max(v.dot((*this)[0]), v.dot((*this)[1])), v.dot((*this)[2]));
}
MT_Point3 DT_Triangle::support(const MT_Vector3& v) const
{
MT_Vector3 dots(v.dot((*this)[0]), v.dot((*this)[1]), v.dot((*this)[2]));
return (*this)[dots.maxAxis()];
}
bool DT_Triangle::ray_cast(const MT_Point3& source, const MT_Point3& target,
MT_Scalar& param, MT_Vector3& normal) const
{
MT_Vector3 d1 = (*this)[1] - (*this)[0];
MT_Vector3 d2 = (*this)[2] - (*this)[0];
MT_Vector3 n = d1.cross(d2);
MT_Vector3 r = target - source;
MT_Scalar delta = -r.dot(n);
MT_Scalar rounding_error = GEN_max(GEN_max(MT_abs(n[0]), MT_abs(n[1])), MT_abs(n[2])) * MT_EPSILON;
#ifdef BACKFACE_CULLING
if (delta > rounding_error)
#else
if (MT_abs(delta) > rounding_error)
#endif
// The ray is not parallel to the triangle's plane.
// (Coplanar rays are ignored.)
{
MT_Vector3 b = source - (*this)[0];
MT_Scalar lambda = b.dot(n) / delta;
if (MT_Scalar(0.0) <= lambda && lambda <= param)
// The ray intersects the triangle's plane.
{
MT_Vector3 u = b.cross(r);
MT_Scalar mu1 = d2.dot(u) / delta;
if (MT_Scalar(0.0) <= mu1 && mu1 <= MT_Scalar(1.0))
{
MT_Scalar mu2 = -d1.dot(u) / delta;
if (MT_Scalar(0.0) <= mu2 && mu1 + mu2 <= MT_Scalar(1.0))
// The ray intersects the triangle.
{
param = lambda;
// Return a normal that points at the source.
#ifdef BACKFACE_CULLING
normal = n;
#else
normal = delta > MT_Scalar(0.0) ? n : -n;
#endif
return true;
}
}
}
}
return false;
}
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