//////////////////////////////////////////////////////////////////////
//
//                             Pixie
//
// Copyright © 1999 - 2003, Okan Arikan
//
// Contact: okan@cs.berkeley.edu
//
// This library 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 2 of the License, or (at your option) any later version.
// 
// This library 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 library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
///////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////
//
//  File				:	photon.h
//  Classes				:	CPhotonHider
//  Description			:
//
////////////////////////////////////////////////////////////////////////
#ifndef PHOTON_H
#define PHOTON_H

#include "common/global.h"		// The global header file
#include "shading.h"
#include "ray.h"
#include "random.h"

///////////////////////////////////////////////////////////////////////
// Class				:	CPhotonHider
// Description			:	This class implements the photon hider
// Comments				:
// Date last edited		:	3/8/2003
class	CPhotonHider : public CShadingContext {
	typedef enum {
		PHOTON_ESTIMATE,		// Estimate the energy per unit area
		PHOTON_TRACE			// Create/trace photons from the light source
	} EPhotonStage;

public:
									CPhotonHider(COptions *,CXform *,SOCKET,CAttributes *);
			virtual					~CPhotonHider();

			// The main hider interface
			// The following functions are commented out for we want the CShadingContext to handle those
			void					renderFrame();									// Right after world end to force rendering of the entire frame

			// Since we're not doing any rasterization, the following functions are simple stubs

			// Delayed rendering functions
			void					drawObject(CObject *,const float *,const float *) { }

			// Primitive creation functions
			void					drawGrid(CSurface *,int,int,float,float,float,float) { }
			void					drawRibbon(CSurface *,int,float,float) { }
			void					drawPoints(CSurface *,int) { }
protected:
			void					solarBegin(const float *,const float *);
			void					solarEnd();
			void					illuminateBegin(const float *,const float *,const float *);
			void					illuminateEnd();
private:
			void					tracePhoton(float *,float *,float *);

			EPhotonStage			stage;					// The current stage
			float					bias;					// The initial intersection bias

			float					powerScale;				// The scaling factor for individual photon powers
			float					minPower;				// The variables to find the range of the illumination
			float					maxPower;				//     for the current light
			float					avgPower;
			float					numPower;

			float					photonPower;			// The scale factor for the current batch

			CSobol<4>				gen4;					// 4D random number generator
			CSobol<3>				gen3;					// 3D random number generator
			CSobol<2>				gen2;					// 3D random number generator

			float					worldRadius;			// The radius of the world
			vector					worldCenter;			// The center of the world

			CArray<CPhotonMap *>	balanceList;			// The list of photon maps that need re-balancing

			CSurface				*phony;					// Phony object we used on the light sources
};

#endif