///////////////////////////////////////////////////////////////////////////

//

// Copyright (c) 2002-2012, 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

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

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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"

#include "ImathNamespace.h"

IMATH_INTERNAL_NAMESPACE_HEADER_ENTER

//-----------------------------------------------------------------

// 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;

}

IMATH_INTERNAL_NAMESPACE_HEADER_EXIT

#endif // INCLUDED_IMATHVECALGO_H