#include "DeferredRenderer.h"
#include "FrameBufferObject.h"
#include "RenderState.h"
#include "SampleGenerator.h"
#include "Vector3.h"
#include "Camera.h"
#include "shaderenv.h"
#include "Halton.h"
#include "ShadowMapping.h"
#include "Light.h"

#include <IL/il.h>
#include <assert.h>


#ifdef _CRT_SET
	#define _CRTDBG_MAP_ALLOC
	#include <stdlib.h>
	#include <crtdbg.h>

	// redefine new operator
	#define DEBUG_NEW new(_NORMAL_BLOCK, __FILE__, __LINE__)
	#define new DEBUG_NEW
#endif


using namespace std;


static void startil()
{
	ilInit();
	assert(ilGetError() == IL_NO_ERROR);
}


static void stopil()
{
	ilShutDown();
	assert(ilGetError() == IL_NO_ERROR);
}

namespace CHCDemoEngine
{

static CGprogram sCgSsaoProgram = NULL;
static CGprogram sCgGiProgram = NULL;

static CGprogram sCgDeferredProgram = NULL;
static CGprogram sCgAntiAliasingProgram = NULL;
static CGprogram sCgDeferredShadowProgram = NULL;

static CGparameter sColorsTexCombineParam;
static CGparameter sSsaoTexCombineParam;

static CGparameter sColorsTexDeferredParam;
static CGparameter sPositionsTexDeferredParam;
static CGparameter sNormalsTexDeferredParam;

static CGprogram sCgCombinedSsaoProgram = NULL;
static CGprogram sCgCombinedIllumProgram = NULL;

static CGparameter sColorsTexLogLumParam;

static CGparameter sDownSampleOffsetParam;
static CGparameter sFilterOffsetsParam;
static CGparameter sFilterWeightsParam;

static CGprogram sCgDownSampleProgram;
static CGprogram sCgToneProgram;
static CGprogram sCgLogLumProgram;


ShaderContainer DeferredRenderer::sShaders;


///////////////////////////////////////


static CGparameter sColorsTexParam;
static CGparameter sNormalsTexParam;

static CGparameter sOldModelViewProjMatrixParam;
static CGparameter sModelViewProjMatrixParam;
static CGparameter sEyePosParam;
static CGparameter sEyePosShadowParam;
static CGparameter sSamplesParam; 
static CGparameter sOldTexParam;
static CGparameter sNoiseTexParam;
static CGparameter sTemporalCoherenceParam;


///////////////////////////////////////


static CGparameter sColorsTexGiParam;
static CGparameter sNormalsTexGiParam;


static CGparameter sOldModelViewProjMatrixGiParam;
static CGparameter sModelViewProjMatrixGiParam;
static CGparameter sSamplesGiParam; 
static CGparameter sOldSsaoTexGiParam;
static CGparameter sOldIllumTexGiParam;
static CGparameter sNoiseTexGiParam;
static CGparameter sTemporalCoherenceGiParam;


static CGparameter sColorsTexCombinedIllumParam;
static CGparameter sSsaoTexCombinedIllumParam;
static CGparameter sIllumTexCombinedIllumParam;

static CGparameter sColorsTexCombinedSsaoParam;
static CGparameter sSsaoTexCombinedSsaoParam;

static CGparameter sTLParam;
static CGparameter sTRParam;
static CGparameter sBRParam;
static CGparameter sBLParam;


static CGparameter sTLGiParam;
static CGparameter sTRGiParam;
static CGparameter sBRGiParam;
static CGparameter sBLGiParam;

static CGparameter sEyePosGiParam;



////////////

static CGparameter sColorsTexAntiAliasingParam;
static CGparameter sNormalsTexAntiAliasingParam;


static CGparameter sShadowMapParam;
static CGparameter sPositionsTexShadowParam;  
static CGparameter sColorsTexShadowParam;  
static CGparameter sNormalsTexShadowParam;

static CGparameter sShadowMatrixParam;
static CGparameter sSampleWidthParam;

static CGparameter sNoiseTexShadowParam;
static CGparameter sSamplesShadowParam; 

static CGparameter sLightDirParam;
static CGparameter sLightDirShadowParam;
static CGparameter sImageKeyParam;
static CGparameter sMiddleGreyParam;
static CGparameter sWhiteLumParam;


static CGparameter sColorsTexInitialParam;
static CGparameter sColorsTexToneParam;

static CGparameter sColorsTexDownSampleParam;

//#define USE_3D_SSAO


static GLuint noiseTex = 0;

// ssao random spherical samples
#ifdef USE_3D_SSAO
static Sample2 samples3[NUM_SAMPLES];
#else
static Sample2 samples2[NUM_SAMPLES];
#endif

// number of pcf tabs
Sample2 pcfSamples[NUM_PCF_TABS];

int DeferredRenderer::colorBufferIdx = 0;


static void PrintGLerror(char *msg)
{
	GLenum errCode;
	const GLubyte *errStr;
	
	if ((errCode = glGetError()) != GL_NO_ERROR) 
	{
		errStr = gluErrorString(errCode);
		fprintf(stderr,"OpenGL ERROR: %s: %s\n", errStr, msg);
	}
}

static void ComputeSampleOffsets(float *sampleOffsets, int w, int h)
{
	/*
	const float xoffs = 0.5f / w;
	const float yoffs = 0.5f / h;

	sampleOffsets[0] =  xoffs; sampleOffsets[1] =  yoffs;
	sampleOffsets[2] =  xoffs; sampleOffsets[3] = -yoffs;
	sampleOffsets[4] = -xoffs; sampleOffsets[5] = -yoffs;
	sampleOffsets[6] = -xoffs; sampleOffsets[7] =  yoffs;
	*/
	//const float xoffs = .5f / w;
	//const float yoffs = .5f / h;
	
	const float xoffs = 1.0f / w;
	const float yoffs = 1.0f / h;

	int idx  = 0;

	for (int x = -1; x <= 1; ++ x)
	{
		for (int y = -1; y <= 1; ++ y)
		{
			sampleOffsets[idx + 0] = x * xoffs;
			sampleOffsets[idx + 1] = y * yoffs;

			idx += 2;
		}
	}
}

/** Generate poisson disc distributed sample points on the unit disc
*/
static void GenerateSamples(int sampling)
{
#ifdef USE_3D_SSAO

	SphericalSampleGenerator sph(NUM_SAMPLES, 1.0f);
	sph.Generate((float *)samples3);

#else
	switch (sampling)
	{
	case DeferredRenderer::SAMPLING_POISSON:
		{
			PoissonDiscSampleGenerator2 poisson(NUM_SAMPLES, 1.0f);
			poisson.Generate((float *)samples2);
		}
		break;
	case DeferredRenderer::SAMPLING_QUADRATIC:
		{
			QuadraticDiscSampleGenerator2 g(NUM_SAMPLES, 1.0f);
			g.Generate((float *)samples2);
		}
		break;
	default: // SAMPLING_DEFAULT

		RandomSampleGenerator2 g(NUM_SAMPLES, 1.0f);
		g.Generate((float *)samples2);
	}
#endif
}


static void CreateNoiseTex2D(int w, int h)
{
	//GLubyte *randomNormals = new GLubyte[mWidth * mHeight * 3];
	float *randomNormals = new float[w * h * 3];

	static HaltonSequence halton;
	float r[2];

	for (int i = 0; i < w * h * 3; i += 3)
	{
		
#ifdef USE_3D_SSAO
		//halton.GetNext(2, r);
		r[0] = RandomValue(0, 1);
		r[1] = RandomValue(0, 1);

		const float theta = 2.0f * acos(sqrt(1.0f - r[0]));
		const float phi = 2.0f * M_PI * r[1];

		randomNormals[i + 0] = sin(theta) * cos(phi);
		randomNormals[i + 1] = sin(theta) * sin(phi);
		randomNormals[i + 2] = cos(theta);
#else
		// create random samples on a circle
		r[0] = RandomValue(0, 1);
		//halton.GetNext(1, r);

		const float theta = 2.0f * acos(sqrt(1.0f - r[0]));
		
		randomNormals[i + 0] = cos(theta);
		randomNormals[i + 1] = sin(theta);
		randomNormals[i + 2] = 0;
#endif
	}

	glEnable(GL_TEXTURE_2D);
	glGenTextures(1, &noiseTex);
	glBindTexture(GL_TEXTURE_2D, noiseTex);
		
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F_ARB, w, h, 0, GL_RGB, GL_FLOAT, randomNormals);

	glBindTexture(GL_TEXTURE_2D, 0);
	glDisable(GL_TEXTURE_2D);

	delete [] randomNormals;

	cout << "created noise texture" << endl;

	PrintGLerror("noisetexture");
}


static void InitBuffer(FrameBufferObject *fbo, int index)
{
	// read the second buffer, write to the first buffer
	fbo->Bind();
	glDrawBuffers(1, mrt + index);

	//glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glEnd();

	FrameBufferObject::Release();
}


DeferredRenderer::DeferredRenderer(int w, int h, Camera *cam, float scaleFactor):
mWidth(w), mHeight(h), 
mCamera(cam),
mUseTemporalCoherence(true),
mRegenerateSamples(true),
mSamplingMethod(SAMPLING_POISSON),
mShadingMethod(DEFAULT),
mIllumFboIndex(0)
{
	// create noise texture for ssao
	CreateNoiseTex2D(w, h);


	///////////
	//-- the flip-flop fbos

	mIllumFbo = new FrameBufferObject(w / 2, h / 2, FrameBufferObject::DEPTH_NONE);
	mFBOs.push_back(mIllumFbo);

	for (int i = 0; i < 4; ++ i)
	{
		mIllumFbo->AddColorBuffer(ColorBufferObject::RGB_FLOAT_32, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_LINEAR);
		InitBuffer(mIllumFbo, i);
	}

	mDownSampleFbo = new FrameBufferObject(w / 2, h / 2, FrameBufferObject::DEPTH_NONE);
	mDownSampleFbo->AddColorBuffer(ColorBufferObject::RGBA_FLOAT_32, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_LINEAR);
	mDownSampleFbo->AddColorBuffer(ColorBufferObject::RGB_FLOAT_16, ColorBufferObject::WRAP_CLAMP_TO_EDGE, ColorBufferObject::FILTER_LINEAR);

	mFBOs.push_back(mDownSampleFbo);
}


DeferredRenderer::~DeferredRenderer() 
{
	CLEAR_CONTAINER(mFBOs);
	glDeleteTextures(1, &noiseTex);
}


void DeferredRenderer::SetUseTemporalCoherence(bool temporal)
{
	mUseTemporalCoherence = temporal;
}


void DeferredRenderer::ReleaseCG()
{
	CLEAR_CONTAINER(sShaders);
}


void DeferredRenderer::InitCG(CGcontext context)
{	
	ShaderProgram *pr;


	sCgDeferredProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
								"src/shaders/deferred.cg", 
								RenderState::sCgFragmentProfile,
								"main",
								NULL);

	if (sCgDeferredProgram != NULL)
	{
		cgGLLoadProgram(sCgDeferredProgram);

		// we need size of texture for scaling
		sPositionsTexDeferredParam = cgGetNamedParameter(sCgDeferredProgram, "positions");  
		sColorsTexDeferredParam = cgGetNamedParameter(sCgDeferredProgram, "colors");  
		sNormalsTexDeferredParam = cgGetNamedParameter(sCgDeferredProgram, "normals");
		
		sLightDirParam = cgGetNamedParameter(sCgDeferredProgram, "lightDir");

		pr = new ShaderProgram(sCgDeferredProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "deferred program failed to load" << endl;


	///////////////

	sCgSsaoProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
#ifdef USE_3D_SSAO
								"src/shaders/ssao3d.cg",
#else
								"src/shaders/ssao.cg", 
#endif
								RenderState::sCgFragmentProfile,
								"main",
								NULL);

	if (sCgSsaoProgram != NULL)
	{
		cgGLLoadProgram(sCgSsaoProgram);

		sColorsTexParam = cgGetNamedParameter(sCgSsaoProgram, "colors");  
		sEyePosParam = cgGetNamedParameter(sCgSsaoProgram, "eyePos");
		sNormalsTexParam = cgGetNamedParameter(sCgSsaoProgram, "normals");  
		sNoiseTexParam = cgGetNamedParameter(sCgSsaoProgram, "noiseTexture");
		
		sOldModelViewProjMatrixParam = cgGetNamedParameter(sCgSsaoProgram, "oldModelViewProj");
		sModelViewProjMatrixParam = cgGetNamedParameter(sCgSsaoProgram, "modelViewProj");
		sTemporalCoherenceParam = cgGetNamedParameter(sCgSsaoProgram, "temporalCoherence");

		sOldTexParam = cgGetNamedParameter(sCgSsaoProgram, "oldTex");  
		sSamplesParam = cgGetNamedParameter(sCgSsaoProgram, "samples");

		sTLParam = cgGetNamedParameter(sCgSsaoProgram, "tl"); 
		sTRParam = cgGetNamedParameter(sCgSsaoProgram, "tr"); 
		sBRParam = cgGetNamedParameter(sCgSsaoProgram, "br"); 
		sBLParam = cgGetNamedParameter(sCgSsaoProgram, "bl"); 

		pr = new ShaderProgram(sCgSsaoProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "ssao program failed to load" << endl;

	sCgGiProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
								"src/shaders/globillum.cg", 
								RenderState::sCgFragmentProfile,
								"main",
								NULL);

	if (sCgGiProgram != NULL)
	{
		cgGLLoadProgram(sCgGiProgram);

		// we need size of texture for scaling
		sColorsTexGiParam = cgGetNamedParameter(sCgGiProgram, "colors");  
		sNormalsTexGiParam = cgGetNamedParameter(sCgGiProgram, "normals");  
		
		sOldModelViewProjMatrixGiParam = cgGetNamedParameter(sCgGiProgram, "oldModelViewProj");
		sModelViewProjMatrixGiParam = cgGetNamedParameter(sCgGiProgram, "modelViewProj");
		sTemporalCoherenceGiParam = cgGetNamedParameter(sCgGiProgram, "temporalCoherence");

		sNoiseTexGiParam = cgGetNamedParameter(sCgGiProgram, "noiseTexture");
		sSamplesGiParam = cgGetNamedParameter(sCgGiProgram, "samples");
		
		sOldSsaoTexGiParam = cgGetNamedParameter(sCgGiProgram, "oldSsaoTex");  
		sOldIllumTexGiParam = cgGetNamedParameter(sCgGiProgram, "oldIllumTex"); 

		sTLGiParam = cgGetNamedParameter(sCgGiProgram, "tl"); 
		sTRGiParam = cgGetNamedParameter(sCgGiProgram, "tr"); 
		sBRGiParam = cgGetNamedParameter(sCgGiProgram, "br"); 
		sBLGiParam = cgGetNamedParameter(sCgGiProgram, "bl"); 

		sEyePosGiParam = cgGetNamedParameter(sCgGiProgram, "eyePos");

		pr = new ShaderProgram(sCgGiProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "globillum program failed to load" << endl;

	sCgCombinedIllumProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
								"src/shaders/globillum.cg", 
								RenderState::sCgFragmentProfile,
								"combine",
								NULL);

	if (sCgCombinedIllumProgram != NULL)
	{
		cgGLLoadProgram(sCgCombinedIllumProgram);

		sColorsTexCombinedIllumParam = cgGetNamedParameter(sCgCombinedIllumProgram, "colors");  
		sSsaoTexCombinedIllumParam = cgGetNamedParameter(sCgCombinedIllumProgram, "ssaoTex");
		sIllumTexCombinedIllumParam = cgGetNamedParameter(sCgCombinedIllumProgram, "illumTex");

		pr = new ShaderProgram(sCgCombinedIllumProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "combined illum program failed to load" << endl;


	sCgCombinedSsaoProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
								"src/shaders/ssao.cg", 
								RenderState::sCgFragmentProfile,
								"combine",
								NULL);

	if (sCgCombinedSsaoProgram != NULL)
	{
		cgGLLoadProgram(sCgCombinedSsaoProgram);

		sColorsTexCombinedSsaoParam = cgGetNamedParameter(sCgCombinedSsaoProgram, "colors");  
		sSsaoTexCombinedSsaoParam = cgGetNamedParameter(sCgCombinedSsaoProgram, "ssaoTex");

		sFilterOffsetsParam = cgGetNamedParameter(sCgCombinedSsaoProgram, "filterOffs");
		sFilterWeightsParam = cgGetNamedParameter(sCgCombinedSsaoProgram, "filterWeights");

		pr = new ShaderProgram(sCgCombinedSsaoProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "combied illum program failed to load" << endl;

	
	sCgAntiAliasingProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
								"src/shaders/antialiasing.cg", 
								RenderState::sCgFragmentProfile,
								"main",
								NULL);

	if (sCgAntiAliasingProgram != NULL)
	{
		cgGLLoadProgram(sCgAntiAliasingProgram);

		sColorsTexAntiAliasingParam = cgGetNamedParameter(sCgAntiAliasingProgram, "colors");  
		sNormalsTexAntiAliasingParam = cgGetNamedParameter(sCgAntiAliasingProgram, "normals");

		pr = new ShaderProgram(sCgAntiAliasingProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "antialiasing program failed to load" << endl;

	sCgDeferredShadowProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
								"src/shaders/deferred.cg", 
								RenderState::sCgFragmentProfile,
								"main_shadow",
								NULL);

	if (sCgDeferredShadowProgram != NULL)
	{
		cgGLLoadProgram(sCgDeferredShadowProgram);

		// we need size of texture for scaling
		sPositionsTexShadowParam = cgGetNamedParameter(sCgDeferredShadowProgram, "positions");  
		sColorsTexShadowParam = cgGetNamedParameter(sCgDeferredShadowProgram, "colors");  
		sNormalsTexShadowParam = cgGetNamedParameter(sCgDeferredShadowProgram, "normals");

		sShadowMapParam = cgGetNamedParameter(sCgDeferredShadowProgram, "shadowMap");  
		sSampleWidthParam = cgGetNamedParameter(sCgDeferredShadowProgram, "sampleWidth");
		sShadowMatrixParam = cgGetNamedParameter(sCgDeferredShadowProgram, "shadowMatrix");

		sNoiseTexShadowParam = cgGetNamedParameter(sCgDeferredShadowProgram, "noiseTexture");
		sSamplesShadowParam = cgGetNamedParameter(sCgDeferredShadowProgram, "samples");
		sLightDirShadowParam = cgGetNamedParameter(sCgDeferredShadowProgram, "lightDir");

		sEyePosShadowParam = cgGetNamedParameter(sCgDeferredShadowProgram, "eyePos");

		PoissonDiscSampleGenerator2 poisson(NUM_PCF_TABS, 1.0f);
		poisson.Generate((float *)pcfSamples);

		cgGLSetParameterArray2f(sSamplesShadowParam, 0, NUM_PCF_TABS, (const float *)pcfSamples);

		pr = new ShaderProgram(sCgDeferredShadowProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "deferred program failed to load" << endl;

	sCgLogLumProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
								"src/shaders/tonemap.cg", 
								RenderState::sCgFragmentProfile,
								"CalcAvgLogLum",
								NULL);

	if (sCgLogLumProgram != NULL)
	{
		cgGLLoadProgram(sCgLogLumProgram);
		sColorsTexLogLumParam = cgGetNamedParameter(sCgLogLumProgram, "colors"); 

		pr = new ShaderProgram(sCgLogLumProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "avg loglum program failed to load" << endl;


	sCgToneProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
								"src/shaders/tonemap.cg", 
								RenderState::sCgFragmentProfile,
								"ToneMap",
								NULL);

	if (sCgToneProgram != NULL)
	{
		cgGLLoadProgram(sCgToneProgram);

		sImageKeyParam = cgGetNamedParameter(sCgToneProgram, "imageKey");
		sMiddleGreyParam = cgGetNamedParameter(sCgToneProgram, "middleGrey");
		sWhiteLumParam = cgGetNamedParameter(sCgToneProgram, "whiteLum");

		sColorsTexToneParam = cgGetNamedParameter(sCgToneProgram, "colors");  

		pr = new ShaderProgram(sCgToneProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "tone program failed to load" << endl;


	sCgDownSampleProgram = 
		cgCreateProgramFromFile(context, 
								CG_SOURCE,
								"src/shaders/tonemap.cg", 
								RenderState::sCgFragmentProfile,
								"DownSample",
								NULL);

	if (sCgDownSampleProgram != NULL)
	{
		cgGLLoadProgram(sCgDownSampleProgram);

		// we need size of texture for scaling
		sColorsTexDownSampleParam = cgGetNamedParameter(sCgDownSampleProgram, "colors"); 
		sDownSampleOffsetParam = cgGetNamedParameter(sCgDownSampleProgram, "downSampleOffs");

		pr = new ShaderProgram(sCgDownSampleProgram);
		sShaders.push_back(pr);
	}
	else
		cerr << "downsample program failed to load" << endl;

	PrintGLerror("init");
}


void DeferredRenderer::Render(FrameBufferObject *fbo, 
							  const Matrix4x4 &oldProjViewMatrix,
							  const Matrix4x4 &projViewMatrix,
							  float tempCohFactor,
							  DirectionalLight *light,
							  bool useToneMapping,
							  ShadowMap *shadowMap
							  )
{
	// switch roles of old and new fbo
	// the algorihm uses two input fbos, where the one
	// contais the color buffer from the last frame, 
	// the other one will be written

	mIllumFboIndex = 2 - mIllumFboIndex;
	

	cgGLEnableProfile(RenderState::sCgFragmentProfile);

	glDisable(GL_ALPHA_TEST);
	glDisable(GL_TEXTURE_2D);
	glDisable(GL_LIGHTING);
	glDisable(GL_BLEND);
	glDisable(GL_DEPTH_TEST);

	glPushAttrib(GL_VIEWPORT_BIT);
	glViewport(0, 0, mWidth, mHeight);

	glMatrixMode(GL_PROJECTION);
	glPushMatrix();
	glLoadIdentity();

	const float offs = 0.5f;
	glOrtho(-offs, offs, -offs, offs, 0, 1);

	glMatrixMode(GL_MODELVIEW);
	glPushMatrix();
	glLoadIdentity();

	if (shadowMap)
		FirstPassShadow(fbo, light, shadowMap);
	else
		FirstPass(fbo, light);

	switch (mShadingMethod)
	{
	case SSAO:
		// downsample fbo buffers for colors, normals
		DownSample(fbo, colorBufferIdx, mDownSampleFbo, 0);
		DownSample(fbo, 1, mDownSampleFbo, 1);

		ComputeSsao(fbo, tempCohFactor, oldProjViewMatrix, projViewMatrix);
		CombineSsao(fbo);
		break;
	case GI:
		// downsample fbo buffers for colors, normals
		DownSample(fbo, colorBufferIdx, mDownSampleFbo, 0);
		DownSample(fbo, 1, mDownSampleFbo, 1);

		ComputeGlobIllum(fbo, tempCohFactor, projViewMatrix, oldProjViewMatrix);
		CombineIllum(fbo);
		break;
	default: // DEFAULT
		// do nothing: standard deferred shading
		break;
	}

	if (useToneMapping)
	{
		float imageKey, whiteLum, middleGrey;

		ComputeToneParameters(fbo, light, imageKey, whiteLum, middleGrey);
		ToneMap(fbo, imageKey, whiteLum, middleGrey);
	}

	AntiAliasing(fbo, light);

	glEnable(GL_LIGHTING);
	glDisable(GL_TEXTURE_2D);

	glMatrixMode(GL_PROJECTION);
	glPopMatrix();

	glMatrixMode(GL_MODELVIEW);
	glPopMatrix();

	glPopAttrib();

	FrameBufferObject::Release();
	cgGLDisableProfile(RenderState::sCgFragmentProfile);
}


void DeferredRenderer::ComputeSsao(FrameBufferObject *fbo, 
								   float tempCohFactor,
								   const Matrix4x4 &oldProjViewMatrix,
								   const Matrix4x4 &projViewMatrix
								   )
{
#ifdef USE_3D_SSAO
	// bias from [-1, 1] to [0, 1]
	static Matrix4x4 biasMatrix(0.5f, 0.0f, 0.0f, 0.5f,
								0.0f, 0.5f, 0.0f, 0.5f,
								0.0f, 0.0f, 0.5f, 0.5f,
								0.0f, 0.0f, 0.0f, 1.0f); 

	Matrix4x4 m = projViewMatrix * biasMatrix; 
	cgGLSetMatrixParameterfc(sModelViewProjMatrixParam, (const float *)m.x);
#else
	cgGLSetMatrixParameterfc(sModelViewProjMatrixParam, (const float *)projViewMatrix.x);
#endif


	cgGLSetMatrixParameterfc(sOldModelViewProjMatrixParam, (const float *)oldProjViewMatrix.x);
#if 0
	GLuint colorsTex = fbo->GetColorBuffer(colorBufferIdx)->GetTexture();
	GLuint normalsTex = fbo->GetColorBuffer(1)->GetTexture();
#else
	GLuint colorsTex = mDownSampleFbo->GetColorBuffer(0)->GetTexture();
	GLuint normalsTex = mDownSampleFbo->GetColorBuffer(1)->GetTexture();
#endif

	GLuint oldTex = mIllumFbo->GetColorBuffer(2 - mIllumFboIndex)->GetTexture();

	glPushAttrib(GL_VIEWPORT_BIT);
	glViewport(0, 0, mIllumFbo->GetWidth(), mIllumFbo->GetHeight());

	// read the second buffer, write to the first buffer
	mIllumFbo->Bind();
	glDrawBuffers(1, mrt + mIllumFboIndex);

	
	cgGLBindProgram(sCgSsaoProgram);

	cgGLSetTextureParameter(sColorsTexParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexParam);

	cgGLSetTextureParameter(sNormalsTexParam, normalsTex);
	cgGLEnableTextureParameter(sNormalsTexParam);

	cgGLSetTextureParameter(sNoiseTexParam, noiseTex);
	cgGLEnableTextureParameter(sNoiseTexParam);

	cgGLSetTextureParameter(sOldTexParam, oldTex);
	cgGLEnableTextureParameter(sOldTexParam);
	
	Vector3 pos = mCamera->GetPosition();
	cgGLSetParameter3f(sEyePosParam, pos.x, pos.y, pos.z);
	
	cgGLSetParameter1f(sTemporalCoherenceParam, (mUseTemporalCoherence && !mRegenerateSamples) ? tempCohFactor : 0);

	if (mUseTemporalCoherence || mRegenerateSamples)
	{
		mRegenerateSamples = false;

		// q: should we generate new samples or only rotate the old ones?
		// in the first case, the sample patterns look nicer, but the kernel
		// needs longer to converge
		GenerateSamples(mSamplingMethod); 

#ifdef USE_3D_SSAO
		cgGLSetParameterArray3f(sSamplesParam, 0, NUM_SAMPLES, (const float *)samples3);
#else
		cgGLSetParameterArray2f(sSamplesParam, 0, NUM_SAMPLES, (const float *)samples2);
#endif
	}

	Vector3 tl, tr, bl, br;
	ComputeViewVectors(tl, tr, bl, br);

	cgGLSetParameter3f(sBLParam, bl.x, bl.y, bl.z);
	cgGLSetParameter3f(sBRParam, br.x, br.y, br.z);
	cgGLSetParameter3f(sTLParam, tl.x, tl.y, tl.z);
	cgGLSetParameter3f(sTRParam, tr.x, tr.y, tr.z);


	glBegin(GL_QUADS);

	// note: slightly larger texture could hide ambient occlusion error on border but costs resolution
	const float offs = 0.5f;
	
	glTexCoord2f(0, 0); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, bl.x, bl.y, bl.z); glVertex3f(-offs, -offs, -0.5f);
	glTexCoord2f(1, 0); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, br.x, br.y, br.z); glVertex3f( offs, -offs, -0.5f);
	glTexCoord2f(1, 1); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, tr.x, tr.y, tr.z); glVertex3f( offs,  offs, -0.5f);
	glTexCoord2f(0, 1); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, tl.x, tl.y, tl.z); glVertex3f(-offs,  offs, -0.5f);

	//cout<<bl << " " << br << endl;

	glEnd();

	cgGLDisableTextureParameter(sColorsTexParam);
	cgGLDisableTextureParameter(sNormalsTexParam);
	cgGLDisableTextureParameter(sNoiseTexParam);
	cgGLDisableTextureParameter(sOldTexParam);

	glPopAttrib();

	PrintGLerror("ssao first pass");
}


void DeferredRenderer::ComputeViewVectors(Vector3 &tl, Vector3 &tr, Vector3 &bl, Vector3 &br)
{
	Vector3 ftl, ftr, fbl, fbr, ntl, ntr, nbl, nbr;

	mCamera->ComputePoints(ftl, ftr, fbl, fbr, ntl, ntr, nbl, nbr);

	bl = Normalize(nbl - fbl);
	br = Normalize(nbr - fbr);
	tl = Normalize(ntl - ftl);
	tr = Normalize(ntr - ftr);
}


static void SetVertex(float x, float y, float x_offs, float y_offs)
{
	glMultiTexCoord2fARB(GL_TEXTURE0_ARB, x, y); // center
	glMultiTexCoord2fARB(GL_TEXTURE1_ARB, x - x_offs, y + y_offs); // left top
	glMultiTexCoord2fARB(GL_TEXTURE2_ARB, x + x_offs, y - y_offs); // right bottom
	glMultiTexCoord2fARB(GL_TEXTURE3_ARB, x + x_offs, y + y_offs); // right top
	glMultiTexCoord2fARB(GL_TEXTURE4_ARB, x - x_offs, y - y_offs); // left bottom

	glMultiTexCoord4fARB(GL_TEXTURE5_ARB, x - x_offs, y, x + x_offs, y); // left right
	glMultiTexCoord4fARB(GL_TEXTURE6_ARB, x, y + y_offs, x, y - y_offs); // top bottom

	glVertex3f(x - 0.5f, y - 0.5f, -0.5f);
}


void DeferredRenderer::AntiAliasing(FrameBufferObject *fbo, DirectionalLight *light)
{
	FrameBufferObject::Release();

	ColorBufferObject *colorBuffer = fbo->GetColorBuffer(colorBufferIdx);

	GLuint colorsTex = colorBuffer->GetTexture();
	GLuint normalsTex = fbo->GetColorBuffer(2)->GetTexture();

	cgGLBindProgram(sCgAntiAliasingProgram);
	
	cgGLSetTextureParameter(sColorsTexAntiAliasingParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexAntiAliasingParam);

	cgGLSetTextureParameter(sNormalsTexAntiAliasingParam, normalsTex);
	cgGLEnableTextureParameter(sNormalsTexAntiAliasingParam);

	// glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glColor3f(1.0f, 1.0f, 1.0f);

	glBegin(GL_QUADS);

	// the neighbouring texels
	float x_offs = 1.0f / mWidth;
	float y_offs = 1.0f / mHeight;

	SetVertex(0, 0, x_offs, y_offs);
	SetVertex(1, 0, x_offs, y_offs);
	SetVertex(1, 1, x_offs, y_offs);
	SetVertex(0, 1, x_offs, y_offs);

	glEnd();

	cgGLDisableTextureParameter(sColorsTexAntiAliasingParam);
	cgGLDisableTextureParameter(sNormalsTexAntiAliasingParam);

	PrintGLerror("antialiasing");
}


void DeferredRenderer::FirstPass(FrameBufferObject *fbo, DirectionalLight *light)
{
	GLuint colorsTex = fbo->GetColorBuffer(colorBufferIdx)->GetTexture();
	GLuint normalsTex = fbo->GetColorBuffer(1)->GetTexture();
	GLuint positionsTex = fbo->GetColorBuffer(2)->GetTexture();

	fbo->Bind();

	colorBufferIdx = 3 - colorBufferIdx;
	glDrawBuffers(1, mrt + colorBufferIdx);
	
	cgGLBindProgram(sCgDeferredProgram);

	cgGLSetTextureParameter(sColorsTexDeferredParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexDeferredParam);

	cgGLSetTextureParameter(sPositionsTexDeferredParam, positionsTex);
	cgGLEnableTextureParameter(sPositionsTexDeferredParam);

	cgGLSetTextureParameter(sNormalsTexDeferredParam, normalsTex);
	cgGLEnableTextureParameter(sNormalsTexDeferredParam);
	
	Vector3 lightDir = -light->GetDirection();
	cgGLSetParameter3f(sLightDirParam, lightDir.x, lightDir.y, lightDir.z);

	Vector3 tl, tr, bl, br;
	ComputeViewVectors(tl, tr, bl, br);
	
	// note: slightly larger texture could hide ambient occlusion error on border but costs resolution
	const float offs = 0.5f;
	
	glBegin(GL_QUADS);

	glTexCoord2f(0, 0); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, bl.x, bl.y, bl.z); glVertex3f(-offs, -offs, -0.5f);
	glTexCoord2f(1, 0); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, br.x, br.y, br.z); glVertex3f( offs, -offs, -0.5f);
	glTexCoord2f(1, 1); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, tr.x, tr.y, tr.z); glVertex3f( offs,  offs, -0.5f);
	glTexCoord2f(0, 1); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, tl.x, tl.y, tl.z); glVertex3f(-offs,  offs, -0.5f);

	glEnd();

	cgGLDisableTextureParameter(sColorsTexDeferredParam);
	cgGLDisableTextureParameter(sPositionsTexDeferredParam);
	cgGLDisableTextureParameter(sNormalsTexDeferredParam);

	PrintGLerror("deferred shading");
}



void DeferredRenderer::ComputeGlobIllum(FrameBufferObject *fbo, 
										float tempCohFactor,
										const Matrix4x4 &projViewMatrix,
										const Matrix4x4 &oldProjViewMatrix)
{
	cgGLSetMatrixParameterfc(sOldModelViewProjMatrixGiParam, (const float *)oldProjViewMatrix.x);
	cgGLSetMatrixParameterfc(sModelViewProjMatrixGiParam, (const float *)projViewMatrix.x);

#if 0
	GLuint colorsTex = fbo->GetColorBuffer(colorBufferIdx)->GetTexture();
	GLuint normalsTex = fbo->GetColorBuffer(1)->GetTexture();
#else
	GLuint colorsTex = mDownSampleFbo->GetColorBuffer(0)->GetTexture();
	GLuint normalsTex = mDownSampleFbo->GetColorBuffer(1)->GetTexture();
#endif

	glPushAttrib(GL_VIEWPORT_BIT);
	glViewport(0, 0, mIllumFbo->GetWidth(), mIllumFbo->GetHeight());

	// read the second buffer, write to the first buffer
	mIllumFbo->Bind();

	glDrawBuffers(2, mrt + mIllumFboIndex);

	GLuint oldSsaoTex = mIllumFbo->GetColorBuffer(2 - mIllumFboIndex)->GetTexture();
	GLuint oldIllumTex = mIllumFbo->GetColorBuffer(2 - mIllumFboIndex + 1)->GetTexture();
	
	cgGLBindProgram(sCgGiProgram);


	cgGLSetTextureParameter(sColorsTexGiParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexGiParam);

	cgGLSetTextureParameter(sNormalsTexGiParam, normalsTex);
	cgGLEnableTextureParameter(sNormalsTexGiParam);

	cgGLSetTextureParameter(sNoiseTexGiParam, noiseTex);
	cgGLEnableTextureParameter(sNoiseTexGiParam);

	cgGLSetTextureParameter(sOldSsaoTexGiParam, oldSsaoTex);
	cgGLEnableTextureParameter(sOldSsaoTexGiParam);

	cgGLSetTextureParameter(sOldIllumTexGiParam, oldIllumTex);
	cgGLEnableTextureParameter(sOldIllumTexGiParam);


	cgGLSetParameter1f(sTemporalCoherenceGiParam, (mUseTemporalCoherence && !mRegenerateSamples) ? tempCohFactor : 0);


	if (mUseTemporalCoherence || mRegenerateSamples)
	{
		mRegenerateSamples = false;

		// q: should we generate new samples or only rotate the old ones?
		// in the first case, the sample patterns look nicer, but the kernel
		// needs longer to converge
		GenerateSamples(mSamplingMethod); 

		cgGLSetParameterArray2f(sSamplesGiParam, 0, NUM_SAMPLES, (const float *)samples2);
	}


	Vector3 tl, tr, bl, br;
	ComputeViewVectors(tl, tr, bl, br);
	
	const Vector3 pos = mCamera->GetPosition();
	cgGLSetParameter3f(sEyePosGiParam, pos.x, pos.y, pos.z);

	cgGLSetParameter3f(sBLGiParam, bl.x, bl.y, bl.z);
	cgGLSetParameter3f(sBRGiParam, br.x, br.y, br.z);
	cgGLSetParameter3f(sTLGiParam, tl.x, tl.y, tl.z);
	cgGLSetParameter3f(sTRGiParam, tr.x, tr.y, tr.z);


	// note: slightly larger texture could hide ambient occlusion error on border but costs resolution
	const float offs = 0.5f;
	
	glBegin(GL_QUADS);

	glTexCoord2f(0, 0); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, bl.x, bl.y, bl.z); glVertex3f(-offs, -offs, -0.5f);
	glTexCoord2f(1, 0); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, br.x, br.y, br.z); glVertex3f( offs, -offs, -0.5f);
	glTexCoord2f(1, 1); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, tr.x, tr.y, tr.z); glVertex3f( offs,  offs, -0.5f);
	glTexCoord2f(0, 1); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, tl.x, tl.y, tl.z); glVertex3f(-offs,  offs, -0.5f);

	glEnd();

	cgGLDisableTextureParameter(sColorsTexGiParam);
	cgGLDisableTextureParameter(sNormalsTexGiParam);
	cgGLDisableTextureParameter(sNoiseTexGiParam);
	cgGLDisableTextureParameter(sOldSsaoTexGiParam);
	cgGLDisableTextureParameter(sOldIllumTexGiParam);

	glPopAttrib();

	PrintGLerror("globillum first pass");
}


void DeferredRenderer::CombineIllum(FrameBufferObject *fbo)
{
	GLuint colorsTex = fbo->GetColorBuffer(colorBufferIdx)->GetTexture();

	GLuint ssaoTex = mIllumFbo->GetColorBuffer(mIllumFboIndex)->GetTexture();
	GLuint illumTex = mIllumFbo->GetColorBuffer(mIllumFboIndex + 1)->GetTexture();


	fbo->Bind();

	// overwrite old color texture
	colorBufferIdx = 3 - colorBufferIdx;

	glDrawBuffers(1, mrt + colorBufferIdx);

	cgGLBindProgram(sCgCombinedIllumProgram);


	cgGLSetTextureParameter(sColorsTexCombinedIllumParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexCombinedIllumParam);

	cgGLSetTextureParameter(sSsaoTexCombinedIllumParam, ssaoTex);
	cgGLEnableTextureParameter(sSsaoTexCombinedIllumParam);

	cgGLSetTextureParameter(sIllumTexCombinedIllumParam, illumTex);
	cgGLEnableTextureParameter(sIllumTexCombinedIllumParam);
	
	glColor3f(1.0f, 1.0f, 1.0f);

	const float offs = 0.5f;

	glBegin(GL_QUADS);

	glTexCoord2f(0, 0); glVertex3f(-offs, -offs, -0.5f);
	glTexCoord2f(1, 0); glVertex3f( offs, -offs, -0.5f);
	glTexCoord2f(1, 1); glVertex3f( offs,  offs, -0.5f);
	glTexCoord2f(0, 1); glVertex3f(-offs,  offs, -0.5f);

	glEnd();

	cgGLDisableTextureParameter(sColorsTexCombinedIllumParam);
	cgGLDisableTextureParameter(sSsaoTexCombinedIllumParam);
	cgGLDisableTextureParameter(sIllumTexCombinedIllumParam);

	PrintGLerror("combine");
}


static float GaussianDistribution(float x, float y, float rho)
{
    float g = 1.0f / sqrtf(2.0f * M_PI * rho * rho);
    g *= expf( -(x*x + y*y) / (2.0f * rho * rho));

    return g;
}


void DeferredRenderer::CombineSsao(FrameBufferObject *fbo)
{
	fbo->Bind();

	GLuint colorsTex = fbo->GetColorBuffer(colorBufferIdx)->GetTexture();
	GLuint positionsTex = fbo->GetColorBuffer(2)->GetTexture();
	
	GLuint ssaoTex = mIllumFbo->GetColorBuffer(mIllumFboIndex)->GetTexture();

	// overwrite old color texture
	colorBufferIdx = 3 - colorBufferIdx;
	glDrawBuffers(1, mrt + colorBufferIdx);

	cgGLBindProgram(sCgCombinedSsaoProgram);

	float filterOffsets[NUM_DOWNSAMPLES * 2];
	float filterWeights[NUM_DOWNSAMPLES];

	PoissonDiscSampleGenerator2 poisson(NUM_DOWNSAMPLES, 1.0f);
	poisson.Generate((float *)filterOffsets);

	const float xoffs = 2.0f / fbo->GetWidth();
	const float yoffs = 2.0f / fbo->GetHeight();

	for (int i = 0; i < NUM_DOWNSAMPLES; ++ i)
	{
		float x = filterOffsets[2 * i + 0];
		float y = filterOffsets[2 * i + 1];

		filterOffsets[2 * i + 0] *= xoffs;
		filterOffsets[2 * i + 1] *= yoffs;

		filterWeights[i] = GaussianDistribution(x, y, 1.0f);
	}

	//ComputeSampleOffsets(filterOffsets, fbo->GetWidth(), fbo->GetHeight());
	cgGLSetParameterArray2f(sFilterOffsetsParam, 0, NUM_DOWNSAMPLES, (const float *)filterOffsets);
	cgGLSetParameterArray1f(sFilterWeightsParam, 0, NUM_DOWNSAMPLES, (const float *)filterWeights);

	cgGLSetTextureParameter(sColorsTexCombinedSsaoParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexCombinedSsaoParam);

	cgGLSetTextureParameter(sSsaoTexCombinedSsaoParam, ssaoTex);
	cgGLEnableTextureParameter(sSsaoTexCombinedSsaoParam);

	
	glColor3f(1.0f, 1.0f, 1.0f);

	const float offs = 0.5f;

	glBegin(GL_QUADS);

	glTexCoord2f(0, 0); glVertex3f(-offs, -offs, -0.5f);
	glTexCoord2f(1, 0); glVertex3f( offs, -offs, -0.5f);
	glTexCoord2f(1, 1); glVertex3f( offs,  offs, -0.5f);
	glTexCoord2f(0, 1); glVertex3f(-offs,  offs, -0.5f);

	glEnd();

	cgGLDisableTextureParameter(sColorsTexCombinedSsaoParam);
	cgGLDisableTextureParameter(sSsaoTexCombinedSsaoParam);
	
	PrintGLerror("combine ssao");
}


void DeferredRenderer::FirstPassShadow(FrameBufferObject *fbo, 
									   DirectionalLight *light, 
									   ShadowMap *shadowMap)
{
	fbo->Bind();

	GLuint colorsTex = fbo->GetColorBuffer(colorBufferIdx)->GetTexture();
	GLuint normalsTex = fbo->GetColorBuffer(1)->GetTexture();
	GLuint positionsTex = fbo->GetColorBuffer(2)->GetTexture();

	GLuint shadowTex = shadowMap->GetDepthTexture();

	Matrix4x4 shadowMatrix;
	shadowMap->GetTextureMatrix(shadowMatrix);

	colorBufferIdx = 3 - colorBufferIdx;
	glDrawBuffers(1, mrt + colorBufferIdx);

	
	cgGLBindProgram(sCgDeferredShadowProgram);

	cgGLSetTextureParameter(sColorsTexShadowParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexShadowParam);

	cgGLSetTextureParameter(sPositionsTexShadowParam, positionsTex);
	cgGLEnableTextureParameter(sPositionsTexShadowParam);

	cgGLSetTextureParameter(sNormalsTexShadowParam, normalsTex);
	cgGLEnableTextureParameter(sNormalsTexShadowParam);
	
	cgGLSetTextureParameter(sShadowMapParam, shadowTex);
	cgGLEnableTextureParameter(sShadowMapParam);

	cgGLSetParameter1f(sSampleWidthParam, 2.0f / shadowMap->GetSize());
	
	 
	cgGLSetMatrixParameterfc(sShadowMatrixParam, (const float *)shadowMatrix.x);

	cgGLSetTextureParameter(sNoiseTexShadowParam, noiseTex);
	cgGLEnableTextureParameter(sNoiseTexShadowParam);

	Vector3 lightDir = -light->GetDirection();
	cgGLSetParameter3f(sLightDirShadowParam, lightDir.x, lightDir.y, lightDir.z);

	Vector3 tl, tr, bl, br;
	ComputeViewVectors(tl, tr, bl, br);
	
	const Vector3 pos = mCamera->GetPosition();
	cgGLSetParameter3f(sEyePosShadowParam, pos.x, pos.y, pos.z);

	// note: slightly larger texture could hide ambient occlusion error on border but costs resolution
	const float offs = 0.5f;
	
	glBegin(GL_QUADS);

	glTexCoord2f(0, 0); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, bl.x, bl.y, bl.z); glVertex3f(-offs, -offs, -0.5f);
	glTexCoord2f(1, 0); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, br.x, br.y, br.z); glVertex3f( offs, -offs, -0.5f);
	glTexCoord2f(1, 1); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, tr.x, tr.y, tr.z); glVertex3f( offs,  offs, -0.5f);
	glTexCoord2f(0, 1); glMultiTexCoord3fARB(GL_TEXTURE1_ARB, tl.x, tl.y, tl.z); glVertex3f(-offs,  offs, -0.5f);

	glEnd();

	cgGLDisableTextureParameter(sColorsTexShadowParam);
	cgGLDisableTextureParameter(sPositionsTexShadowParam);
	cgGLDisableTextureParameter(sNormalsTexShadowParam);
	cgGLDisableTextureParameter(sShadowMapParam);
	cgGLDisableTextureParameter(sNoiseTexShadowParam);

	PrintGLerror("deferred shading + shadows");
}


void DeferredRenderer::SetSamplingMethod(SAMPLING_METHOD s) 
{ 
	if (s != mSamplingMethod)
	{
		mSamplingMethod = s; 
		mRegenerateSamples = true;
	}
}


void DeferredRenderer::SetShadingMethod(SHADING_METHOD s)
{
	if (s != mShadingMethod)
	{
		mShadingMethod = s; 
		mRegenerateSamples = true;
	}
}


void DeferredRenderer::ComputeToneParameters(FrameBufferObject *fbo, 
											 DirectionalLight *light,
											 float &imageKey, 
											 float &whiteLum,
											 float &middleGrey)
{
	// hack: estimate value where sky burns out
	whiteLum = log(WHITE_LUMINANCE);
	
	////////////////////
	//-- linear interpolate brightness key depending on the current sun position

	const float minKey = 0.09f;
	const float maxKey = 0.36f;

	const float lightIntensity = DotProd(-light->GetDirection(), Vector3::UNIT_Z());
	middleGrey = lightIntensity * maxKey + (1.0f - lightIntensity) * minKey;


	//////////
	//-- compute avg loglum

	ColorBufferObject *colorBuffer = fbo->GetColorBuffer(colorBufferIdx);
	GLuint colorsTex = colorBuffer->GetTexture();

	fbo->Bind();

	colorBufferIdx = 3 - colorBufferIdx;
	glDrawBuffers(1, mrt + colorBufferIdx);
	
	cgGLBindProgram(sCgLogLumProgram);
	
	cgGLSetTextureParameter(sColorsTexLogLumParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexLogLumParam);
	
	const float offs = 0.5f;

	glBegin(GL_QUADS);

	glTexCoord2f(0, 0); glVertex3f(-offs, -offs, -0.5f);
	glTexCoord2f(1, 0); glVertex3f( offs, -offs, -0.5f);
	glTexCoord2f(1, 1); glVertex3f( offs,  offs, -0.5f);
	glTexCoord2f(0, 1); glVertex3f(-offs,  offs, -0.5f);

	glEnd();

	cgGLDisableTextureParameter(sColorsTexLogLumParam);

	PrintGLerror("ToneMapParams");


	///////////////////
	//-- compute avg loglum in scene using mipmapping

	glBindTexture(GL_TEXTURE_2D, fbo->GetColorBuffer(colorBufferIdx)->GetTexture());
	glGenerateMipmapEXT(GL_TEXTURE_2D);
}


static void ExportData(float *data, int w, int h)
{
	startil();

	cout << "w: " << w << " h: " << h << endl;
	ILstring filename = ILstring("downsample2.jpg");
	ilRegisterType(IL_FLOAT);

	const int depth = 1;
	const int bpp = 4;

	if (!ilTexImage(w, h, depth, bpp, IL_RGBA, IL_FLOAT, data))
	{
		cerr << "IL error " << ilGetError() << endl;
		stopil();
		return;
	}

	if (!ilSaveImage(filename))
	{
		cerr << "TGA write error " << ilGetError() << endl;
	}

	stopil();

	// cout << "exported buffer" << endl;
}


void DeferredRenderer::DownSample(FrameBufferObject *fbo, int bufferIdx,
								  FrameBufferObject *downSampleFbo, 
								  int downSampleBufferIdx)
{
	ColorBufferObject *colorBuffer = fbo->GetColorBuffer(bufferIdx);
	GLuint colorsTex = colorBuffer->GetTexture();

	glPushAttrib(GL_VIEWPORT_BIT);
	glViewport(0, 0, downSampleFbo->GetWidth(), downSampleFbo->GetHeight());

	cgGLBindProgram(sCgDownSampleProgram);
	
	cgGLSetTextureParameter(sColorsTexDownSampleParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexDownSampleParam);

	float downSampleOffsets[NUM_DOWNSAMPLES * 2];
	ComputeSampleOffsets(downSampleOffsets, fbo->GetWidth(), fbo->GetHeight());

	cgGLSetParameterArray2f(sDownSampleOffsetParam, 0, NUM_DOWNSAMPLES, (const float *)downSampleOffsets);

	mDownSampleFbo->Bind();
	glDrawBuffers(1, mrt + downSampleBufferIdx);

	cgGLBindProgram(sCgDownSampleProgram);
	
	const float offs = 0.5f;

	glBegin(GL_QUADS);

	glTexCoord2f(0, 0); glVertex3f(-offs, -offs, -0.5f);
	glTexCoord2f(1, 0); glVertex3f( offs, -offs, -0.5f);
	glTexCoord2f(1, 1); glVertex3f( offs,  offs, -0.5f);
	glTexCoord2f(0, 1); glVertex3f(-offs,  offs, -0.5f);

	glEnd();

	cgGLDisableTextureParameter(sColorsTexDownSampleParam);

	/*float *data = (float *)mDownSampleFbo->GetColorBuffer(0)->ReadTexture();
	ExportData(data, mWidth / 2, mHeight / 2);
	delete [] data;*/

	glPopAttrib();
	
	PrintGLerror("downsample");
}


void DeferredRenderer::ToneMap(FrameBufferObject *fbo,
							   float imageKey, 
							   float whiteLum,
							   float middleGrey)
{
	ColorBufferObject *colorBuffer = fbo->GetColorBuffer(colorBufferIdx);
	GLuint colorsTex = colorBuffer->GetTexture();

	fbo->Bind();
#if 1
	colorBufferIdx = 3 - colorBufferIdx;
	glDrawBuffers(1, mrt + colorBufferIdx);

	cgGLBindProgram(sCgToneProgram);

	cgGLSetTextureParameter(sColorsTexToneParam, colorsTex);
	cgGLEnableTextureParameter(sColorsTexToneParam);

	cgGLSetParameter1f(sImageKeyParam, imageKey);
	cgGLSetParameter1f(sWhiteLumParam, whiteLum);
	cgGLSetParameter1f(sMiddleGreyParam, middleGrey);

	glColor3f(1.0f, 1.0f, 1.0f);


	glBegin(GL_QUADS);

	const float offs = 0.5f;


	glTexCoord2f(0, 0); glVertex3f(-offs, -offs, -0.5f);
	glTexCoord2f(1, 0); glVertex3f( offs, -offs, -0.5f);
	glTexCoord2f(1, 1); glVertex3f( offs,  offs, -0.5f);
	glTexCoord2f(0, 1); glVertex3f(-offs,  offs, -0.5f);

	glEnd();
#endif

	cgGLDisableTextureParameter(sColorsTexToneParam);

	PrintGLerror("ToneMap");
}




} // namespace