#ifndef _DeferredShader_H__
#define _DeferredShader_H__

#include "common.h"
#include "glInterface.h"
#include <Cg/cg.h>
#include <Cg/cgGL.h>


namespace CHCDemoEngine 
{ 

class FrameBufferObject;


/** This class implements a deferred shading algorithm that takes
	a frame buffer object as input and outputs an image in the given size
*/
class DeferredShader
{
public:
	/** constructor for a deferred shader taking the requested output image size
	*/
	DeferredShader(int w, int h);

	~DeferredShader();
	/** The algorithm renders the scene given an fbo.
		The fbo must have color buffer, position buffer, normal buffer.
	*/
	void Render(FrameBufferObject *fbo);

	/** Initialises the deferred shader and loads the required shaders:
		This function has to be called only once.
	*/
	static void Init(CGcontext context);


protected:

	void FirstPass(FrameBufferObject *fbo);
	void AntiAliasing(FrameBufferObject *fbo);

	int mWidth;
	int mHeight;

	//FrameBufferObject *mFbo;
};

} // namespace 
#endif // _DeferredShader_H__