Ray.cc

/**********************************************************************
 * blaRAY -- photon mapper/raytracer
 * (C) 2008 by Tomasz bla Fortuna <bla@thera.be>, <bla@af.gliwice.pl>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 *
 * See Docs/LICENSE
 *********************/

#include <cmath>

#include "General/Types.hh"
#include "Math/Vector.hh"
#include "Render/Ray.hh"

namespace Render {
        Ray Ray::RayFromPoints(const Math::Vector &Source,
                               const Math::Vector &Destination)
        {
                return Ray(Source, (Destination - Source).Normalize());
        }


        Ray Ray::Reflect(const Math::Vector &Normal,
                         const Math::Vector &Point) const
        {
                const Math::Vector tmp = Normal * (2 * Normal.Dot(this->D));
                return Ray(Point, this->D - tmp);
        }

        Ray Ray::Refract(const Math::Vector &Normal,
                         const Math::Vector &Point,
                         Double FromN, Double IntoN) const
        {
                const Double n = FromN / IntoN;
                const Double c1 = - Normal.Dot(this->D);
                const Double c2 = std::sqrt(1.0 - n*n * (1.0 - c1*c1) );
                const Double c3 = n * c1 - c2;
                const Math::Vector Dir = (this->D * n) + (Normal * c3);
                return Ray(Point, Dir);
        }

        std::ostream &operator<<(std::ostream &os, const Ray &R)
        {
                os << "[Ray Start="
                   << R.Start()
                   << " Dir="
                   << R.Direction()
                   << "]";
                return os;
        }

}

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