ray.h

/*
    This file is part of Nori, a simple educational ray tracer
 
    Copyright (c) 2015 by Wenzel Jakob
 
    Nori is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License Version 3
    as published by the Free Software Foundation.
 
    Nori is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
 
#if !defined(__NORI_RAY_H)
#define __NORI_RAY_H
 
#include <nori/vector.h>
 
NORI_NAMESPACE_BEGIN
 
template <typename _PointType, typename _VectorType> struct TRay {
    typedef _PointType                  PointType;
    typedef _VectorType                 VectorType;
    typedef typename PointType::Scalar  Scalar;
 
    PointType o;     
    VectorType d;    
    VectorType dRcp; 
    Scalar mint;     
    Scalar maxt;     
 
    TRay() : mint(Epsilon), 
        maxt(std::numeric_limits<Scalar>::infinity()) { }
    
    TRay(const PointType &o, const VectorType &d) : o(o), d(d), 
            mint(Epsilon), maxt(std::numeric_limits<Scalar>::infinity()) {
        update();
    }
 
    TRay(const PointType &o, const VectorType &d, 
        Scalar mint, Scalar maxt) : o(o), d(d), mint(mint), maxt(maxt) {
        update();
    }
 
    TRay(const TRay &ray) 
     : o(ray.o), d(ray.d), dRcp(ray.dRcp),
       mint(ray.mint), maxt(ray.maxt) { }
 
    TRay(const TRay &ray, Scalar mint, Scalar maxt) 
     : o(ray.o), d(ray.d), dRcp(ray.dRcp), mint(mint), maxt(maxt) { }
 
    void update() {
        dRcp = d.cwiseInverse();
    }
 
    PointType operator() (Scalar t) const { return o + t * d; }
 
    TRay reverse() const {
        TRay result;
        result.o = o; result.d = -d; result.dRcp = -dRcp;
        result.mint = mint; result.maxt = maxt;
        return result;
    }
 
    std::string toString() const {
        return tfm::format(
                "Ray[\n"
                "  o = %s,\n"
                "  d = %s,\n"
                "  mint = %f,\n"
                "  maxt = %f\n"
                "]", o.toString(), d.toString(), mint, maxt);
    }
};
 
NORI_NAMESPACE_END
 
#endif /* __NORI_RAY_H */