#include <stdlib.h>                 /* rand() */

#include <iostream>

#include "Ray.h"

Ray::Ray()
{
}

Ray::Ray(const Vector & origin, const Vector & direction)
{
    m_origin = origin;
    m_direction = direction;
    m_direction.normalize();
}

Ray Ray::randomRay()
{
    return Ray(Vector(0, 0, 0), Vector::randomVector());
}

/*
 * return a vector for the point at distance dist
 * from the ray's origin point, along its direction.
 */
Vector Ray::getPositionAt(double dist) const
{
    Vector v;
    v[0] = m_origin[0] + dist * m_direction[0];
    v[1] = m_origin[1] + dist * m_direction[1];
    v[2] = m_origin[2] + dist * m_direction[2];
    return v;
}

std::ostream & operator<<(std::ostream & out, const Ray & r)
{
    out << "(" << r.getOrigin() << " -> " << r.getDirection() << ")";
    return out;
}

Ray Ray::shift(double amt)
{
    return Ray(getPositionAt(amt), m_direction);
}