#include "SkyPreetham.h"
#include "common.h"
#include "Vector3.h"


//#include <rendering/effect/FEffect.h>
//#include <rendering/FVertexbuffer.h>


inline float CBQ(float x)
{
	return x * x * x;
}


inline float SQR(float x)
{
	return x * x ;
}


using namespace CHCDemoEngine;


SkyPreetham::SkyPreetham(float turbitity):
//	mEffect(NULL),
	mTurbidity(turbitity)
//	mSunEffect(NULL),
//	mSunTexture(NULL),
//	mSunQuad(NULL)
{
/*	mEffect = D().getScene().getEffect("../effects/sky_preetham.fx");

	mVertexBuffer = D().getScene().getVertexBuffer("../models/sky.vbo");

	mSunEffect = D().getScene().getEffect("../effects/sky_sun.fx");
	mSunTexture = D().getScene().getTexture2D("../textures/sky_sun.png");
*/
	CreateSunQuad();
}


SkyPreetham::~SkyPreetham()
{
	//DEL_PTR(mSunQuad);
}



void SkyPreetham::Compute(const Vector3 &sunDir)
{
	float sun_theta[2];

	sun_theta[0] = acos(sunDir.y);

	const float cos_theta =  cos(sun_theta[0]);
	sun_theta[1] = cos_theta * cos_theta;

	Vector3 zenithColor;

	zenithColor.x = ( 0.00165f * CBQ(sun_theta[0]) - 0.00374f * SQR(sun_theta[0]) + 0.00208f * sun_theta[0] + 0.0f)     * SQR(mTurbidity) +	
				    (-0.02902f * CBQ(sun_theta[0]) + 0.06377f * SQR(sun_theta[0]) - 0.03202f * sun_theta[0] + 0.00394f) * mTurbidity +
					( 0.11693f * CBQ(sun_theta[0]) - 0.21196f * SQR(sun_theta[0]) + 0.06052f * sun_theta[0] + 0.25885f);

	zenithColor.y = (0.00275f  * CBQ(sun_theta[0]) - 0.00610f * SQR(sun_theta[0]) + 0.00316f * sun_theta[0] + 0.0f)     * SQR(mTurbidity) +
	                (-0.04214f * CBQ(sun_theta[0]) + 0.08970f * SQR(sun_theta[0]) - 0.04153f * sun_theta[0] + 0.00515f) * mTurbidity +
		            ( 0.15346f * CBQ(sun_theta[0]) - 0.26756f * SQR(sun_theta[0]) + 0.06669f * sun_theta[0] + 0.26688f);
	
	zenithColor.z  = (float)((4.0453f * mTurbidity - 4.9710f) *	tan((4.0f / 9.0f - mTurbidity / 120.0f) * 
							 (M_PI - 2.0f * sun_theta[0])) - 0.2155f * mTurbidity + 2.4192f);

	// convert kcd/mē to cd/mē
	zenithColor.z *= 1000.0f;

	double ABCDE_x[5], ABCDE_y[5], ABCDE_Y[5];

	ABCDE_x[0] = -0.01925 * mTurbidity - 0.25922;
	ABCDE_x[1] = -0.06651 * mTurbidity + 0.00081;
	ABCDE_x[2] = -0.00041 * mTurbidity + 0.21247;
	ABCDE_x[3] = -0.06409 * mTurbidity - 0.89887;
	ABCDE_x[4] = -0.00325 * mTurbidity + 0.04517;

	ABCDE_y[0] = -0.01669 * mTurbidity - 0.26078;
	ABCDE_y[1] = -0.09495 * mTurbidity + 0.00921;
	ABCDE_y[2] = -0.00792 * mTurbidity + 0.21023;
	ABCDE_y[3] = -0.04405 * mTurbidity - 1.65369;
	ABCDE_y[4] = -0.01092 * mTurbidity + 0.05291;

	ABCDE_Y[0] =  0.17872 * mTurbidity - 1.46303;
	ABCDE_Y[1] = -0.35540 * mTurbidity + 0.42749;
	ABCDE_Y[2] = -0.02266 * mTurbidity + 5.32505;
	ABCDE_Y[3] =  0.12064 * mTurbidity - 2.57705;
	ABCDE_Y[4] = -0.06696 * mTurbidity + 0.37027;

/*
	F().getRenderDevice().setDefaultDepthStencilMode(FRenderDevice::DEPTHSTENCIL_TEST_NO_OVERWRITE);

	// Move skybox with camera.
	mPosition = D().getScene().getCamera().getPosition();

	mPosition.y -= 2.0;

	setTransform();

	mEffect->setVariableVector3("LightDirection", D().getScene().getLight().getDirection());
	mEffect->setVariableVector2("ThetaSun", sun_theta);
	mEffect->setVariableVector3("ZenithColor", zenithColor);
	mEffect->setVariableVector3("AColor",FVector3((FFloat)ABCDE_x[0], (FFloat)ABCDE_y[0], (FFloat)ABCDE_Y[0]));
	mEffect->setVariableVector3("BColor",FVector3((FFloat)ABCDE_x[1], (FFloat)ABCDE_y[1], (FFloat)ABCDE_Y[1]));
	mEffect->setVariableVector3("CColor",FVector3((FFloat)ABCDE_x[2], (FFloat)ABCDE_y[2], (FFloat)ABCDE_Y[2]));
	mEffect->setVariableVector3("DColor",FVector3((FFloat)ABCDE_x[3], (FFloat)ABCDE_y[3], (FFloat)ABCDE_Y[3]));
	mEffect->setVariableVector3("EColor",FVector3((FFloat)ABCDE_x[4], (FFloat)ABCDE_y[4], (FFloat)ABCDE_Y[4]));


	mEffect->activate();

	F().getRenderDevice().setDefaultPolygonMode(true, FRenderDevice::CULL_NONE);

	// Render sky dome.
	mVertexBuffer->render();

	// Render additively blended sun disc.
	renderSunDisk();

	F().getRenderDevice().setDefaultPolygonMode(true, FRenderDevice::CULL_BACKFACES);


	F().getRenderDevice().setDefaultDepthStencilMode(FRenderDevice::DEPTHSTENCIL_TEST_AND_OVERWRITE);
	*/
}


void SkyPreetham::RenderSunDisk()
{
	/*
	F().getRenderDevice().setDefaultBlendingMode(FRenderDevice::BLENDING_ADDITIVE);

	// Set world matrix to sun disc position.
	FMatrix4 sunposition;
	sunposition.translate(D().getScene().getCamera().getPosition());
	sunposition.rotateAroundY(-D().getScene().getLight().getHorizontalOrientation() + 90.0f);
	sunposition.rotateAroundX(-D().getScene().getLight().getVerticalOrientation());
	F().getRenderDevice().getTransform().setWorldMatrix(sunposition);

	FVector3 lightdirection = D().getScene().getLight().getDirection();
	FFloat size = 0.5f + (1.0f - lightdirection.y) * 0.5f;

	mSunEffect->setVariableVector3("LightDiffuseColor", D().getScene().getLight().getDiffuseColor());
	mSunEffect->setVariableFloat("SunSize", size);
	mSunEffect->setVariableTexture2D("SunTexture", mSunTexture);

	mSunEffect->activate();
	
	mSunQuad->render();

	mSunEffect->deactivate();

	F().getRenderDevice().setDefaultBlendingMode(FRenderDevice::BLENDING_NONE);
	*/
}


void SkyPreetham::CreateSunQuad()
{
	/*
	mSunQuad = new FVertexBuffer();
	mSunQuad->setupPrimitiveType(FVertexBuffer::PRIMITIVES_TRIANGLES);
	mSunQuad->setupVertexFormat(3, 0, 0, true);
	mSunQuad->setupTexCoordSet(0, 2);
	mSunQuad->setVertexBufferSize(4, 6);

	mSunQuad->setVertexPosition(0, FVector3(-0.1f,  0.1f, 1.0f));
	mSunQuad->setVertexPosition(1, FVector3( 0.1f,  0.1f, 1.0f));
	mSunQuad->setVertexPosition(2, FVector3(-0.1f, -0.1f, 1.0f));
	mSunQuad->setVertexPosition(3, FVector3( 0.1f, -0.1f, 1.0f));
	mSunQuad->setVertexTexCoord(0, 0, FVector2(0.0f, 0.0f));
	mSunQuad->setVertexTexCoord(1, 0, FVector2(1.0f, 0.0f));
	mSunQuad->setVertexTexCoord(2, 0, FVector2(0.0f, 1.0f));
	mSunQuad->setVertexTexCoord(3, 0, FVector2(1.0f, 1.0f));

	mSunQuad->setIndex(0, 0);
	mSunQuad->setIndex(1, 1);
	mSunQuad->setIndex(2, 2);
	mSunQuad->setIndex(3, 2);
	mSunQuad->setIndex(4, 1);
	mSunQuad->setIndex(5, 3);
	*/
}