/***************************************************************************
 *   Copyright (C) 1998-2009 by authors (see AUTHORS.txt )                 *
 *                                                                         *
 *   This file is part of LuxRender.                                       *
 *                                                                         *
 *   Lux Renderer 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     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   Lux Renderer 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/>. *
 *                                                                         *
 *   This project is based on PBRT ; see http://www.pbrt.org               *
 *   Lux Renderer website : http://www.luxrender.net                       *
 ***************************************************************************/

// cone.cpp*
#include "shape.h"
// Cone Declarations

namespace lux
{

class Cone: public Shape {
public:
	// Cone Public Methods
	Cone(const Transform &o2w, bool ro, const string &name, 
	     float height, float rad,  float rad2, float tm );
	virtual ~Cone() { }

	virtual BBox ObjectBound() const;
	virtual bool Intersect(const Ray &ray, float *tHit,
	               DifferentialGeometry *dg) const;
	virtual bool IntersectP(const Ray &ray) const;
	virtual float Area() const;
	virtual Point Sample(float u1, float u2, float u3, 
			Normal *Ns) const {
		float z = u1 * ((radius2 > 0.f) ? height2 : height);
		float t = u2 * phiMax;
		Point p = Point(cosf(t), sinf(t), z);
		float nz = radius / sqrtf(radius*radius + height*height);
		*Ns = Normalize(ObjectToWorld * Normal(p.x, p.y, -nz));
		p.x *= radius * (1 - u1);
		p.y *= radius * (1 - u1);
		if (reverseOrientation) *Ns *= -1.f;

		return ObjectToWorld * p;
	}

	static Shape* CreateShape(const Transform &o2w, bool reverseOrientation, const ParamSet &params);

protected:
	// Cone Data
	float radius, radius2, height, height2, phiMax;
};

}//namespace lux

