/*]  Copyright (c) 2009-2011, Charles McGarvey  [*****************************
**]  All rights reserved.
*
* Distributable under the terms and conditions of the 2-clause BSD license;
* see the file COPYING for a complete text of the license.
*
*****************************************************************************/

#ifndef _MOOF_RAY_HH_
#define _MOOF_RAY_HH_

#include <moof/drawable.hh>
#include <moof/image.hh>
#include <moof/math.hh>
#include <moof/opengl.hh>


/**
 * \file ray.hh
 * A class for lines that start at one point and go to infinity in some
 * direction.
 */

namespace moof {


/**
 * A line that goes to infinity.
 */
template <int D>
struct ray : public drawable
{
	typedef moof::vector< scalar, fixed<D> > vector;

	// solution = point + t*direction
	vector	point;
	vector	direction;

	struct contact
	{
		scalar	distance;	// distance from the origin to the nearest point
		vector	normal;		// surface normal at contact point

		bool operator < (const contact& rhs)
		{
			return distance < rhs.distance;
		}
	};

	void solve(vector& p, scalar t) const
	{
		p = point + t*direction;
	}

	void draw(scalar alpha = 0.0) const
	{
		vector end = point + 1000.0 * direction;
		// FIXME: this is kinda cheesy

		image::reset_binding();
		glBegin(GL_LINES);
			glVertex(point);
			glVertex(end);
		glEnd();
	}

	void normalize()
	{
		direction.normalize();
	}
};

typedef ray<2> ray2;
typedef ray<3> ray3;


} // namespace moof

#endif // _MOOF_RAY_HH_