///////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
// Digital Ltd. LLC
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Industrial Light & Magic nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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///////////////////////////////////////////////////////////////////////////
#ifndef INCLUDED_IMATHVECALGO_H
#define INCLUDED_IMATHVECALGO_H
//-------------------------------------------------------------------------
//
// This file contains algorithms applied to or in conjunction
// with points (Imath::Vec2 and Imath::Vec3).
// The assumption made is that these functions are called much
// less often than the basic point functions or these functions
// require more support classes.
//
//-------------------------------------------------------------------------
#include "ImathVec.h"
#include "ImathLimits.h"
namespace Imath {
//-----------------------------------------------------------------
// Find the projection of vector t onto vector s (Vec2, Vec3, Vec4)
//-----------------------------------------------------------------
template <class Vec> Vec project (const Vec &s, const Vec &t);
//------------------------------------------------
// Find a vector that is perpendicular to s and
// in the same plane as s and t (Vec2, Vec3, Vec4)
//------------------------------------------------
template <class Vec> Vec orthogonal (const Vec &s, const Vec &t);
//-----------------------------------------------
// Find the direction of a ray s after reflection
// off a plane with normal t (Vec2, Vec3, Vec4)
//-----------------------------------------------
template <class Vec> Vec reflect (const Vec &s, const Vec &t);
//--------------------------------------------------------------------
// Find the vertex of triangle (v0, v1, v2) that is closest to point p
// (Vec2, Vec3, Vec4)
//--------------------------------------------------------------------
template <class Vec> Vec closestVertex (const Vec &v0,
const Vec &v1,
const Vec &v2,
const Vec &p);
//---------------
// Implementation
//---------------
template <class Vec>
Vec
project (const Vec &s, const Vec &t)
{
Vec sNormalized = s.normalized();
return sNormalized * (sNormalized ^ t);
}
template <class Vec>
Vec
orthogonal (const Vec &s, const Vec &t)
{
return t - project (s, t);
}
template <class Vec>
Vec
reflect (const Vec &s, const Vec &t)
{
return s - typename Vec::BaseType(2) * (s - project(t, s));
}
template <class Vec>
Vec
closestVertex(const Vec &v0,
const Vec &v1,
const Vec &v2,
const Vec &p)
{
Vec nearest = v0;
typename Vec::BaseType neardot = (v0 - p).length2();
typename Vec::BaseType tmp = (v1 - p).length2();
if (tmp < neardot)
{
neardot = tmp;
nearest = v1;
}
tmp = (v2 - p).length2();
if (tmp < neardot)
{
neardot = tmp;
nearest = v2;
}
return nearest;
}
} // namespace Imath
#endif