///////////////////////////////////////////////////////////////////////////////
//
//      ##  ######
//       ######  ###
//  ## ###############        Shark 3D Engine (www.shark3d.com)
//   ########## # # #
//    ########                Copyright (c) 1996-2006 Spinor GmbH.
//   ######### # # #          All rights reserved.
//  ##   ##########
//      ##
//
///////////////////////////////////////////////////////////////////////////////


#define NITERATION 4

struct PS_INPUT
{
float3 eye     : TEXCOORD0;
float3 normal  : TEXCOORD1;
float3 posView : TEXCOORD2;
};

sampler colorSamp: register(s0);
sampler distanceSamp: register(s1);

float readDistanceCubeMap(samplerCUBE m, float3 r)
{
 float dist = texCUBE(m, r).r;
 if(dist == 0) dist = 10;
 return dist;
}

half3 Hit(samplerCUBE tex, half3 R, half3 p0)
{
        float rl = texCUBE(tex, R).r;
        float dp = rl - dot(p0, R);
        float3 p = p0 + R * dp;
        float ppp = length(p) / texCUBE(tex, p).r;
        float dun = 0, dov = 0, pun = ppp, pov = ppp;
        if (ppp < 1) dun = dp; else dov = dp;
        float dl = max( dp + rl * (1 - ppp), 0);
        float3 RR = p0 + R * dl;

        for(int i = 0; i < NITERATION; i++) {
                float ddl;
                float llp = length(RR) / readDistanceCubeMap(tex, RR);
                if (llp < 1) {
                        dun = dl; pun = llp;
                        ddl = (dov == 0) ? rl * (1 - llp) :
                                (dl - dov) * (1 - llp)/(llp - pov);
                } else {
                        dov = dl; pov = llp;
                        ddl = (dun == 0) ? rl * (1 - llp) :
                                (dl - dun) * (1 - llp)/(llp - pun);
                }
                dl = max(dl + ddl, 0);
                RR = p0 + R * dl;
        }
        return RR;
}



///////////////////////////////////////////////////////////////////////////////
// Pixelshader
// Profile: 3x0
// reflective


float4 main(PS_INPUT input): COLOR0
{
// return  texCUBE(colorSamp, input.normal);
//return float4(input.normal, 1);

const float g_FresnelCoeff = 1.0;
const float g_Transparency = 0.0;
const float g_RefractFactor = 1.0f;

float3 normal = normalize(input.normal);
float3 eye = normalize(input.eye);

float3 r1 = reflect(eye, normal);
float3 RR1 = Hit(distanceSamp, r1, input.posView);

// fresnel
float3 fresnel = saturate(g_FresnelCoeff + (1.0f - g_FresnelCoeff) * pow(1 - dot(normal, -eye), 5));
 
return texCUBE(colorSamp,RR1) * float4(fresnel, 1);
}

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

///////////////////////////////////////////////////////////////////////////////
// Pixelshader
// Profile: 3x0
// refractive

float4 refract(PS_INPUT input): COLOR0
{
// return  texCUBE(colorSamp, input.normal);
//return float4(input.normal, 1);

const float3 g_FresnelCoeff = 0.0;
const float g_Transparency = 0.3;
const float g_RefractFactor = 0.8f;

float3 normal = normalize(input.normal);
float3 eye = normalize(input.eye);

float3 r1 = reflect(eye, normal);
float3 r2 = refract(eye, normal, g_RefractFactor);
float3 RR1 = Hit(distanceSamp, r1, input.posView);
float3 RR2 = Hit(distanceSamp, r2, input.posView);

// fresnel
float3 fresnel = saturate(g_FresnelCoeff + (1.0f - g_FresnelCoeff) * pow(1 - dot(normal, -eye), 5));
 
//return 1;
return texCUBE(colorSamp,RR2)*(1- g_Transparency) + texCUBE(colorSamp, RR1) * g_Transparency;
}

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

///////////////////////////////////////////////////////////////////////////////
// Pixelshader
// Profile: 3x0
// metal
float4 Fresnel;

float4 metal(PS_INPUT input): COLOR0
{

//const float3 g_FresnelCoeff = 0.7;
const float g_Transparency = 0.0;
const float g_RefractFactor = 1.0f;

float3 normal = normalize(input.normal);
float3 eye = normalize(input.eye);

float3 r1 = reflect(eye, normal);
float3 RR1 = Hit(distanceSamp, r1, input.posView);


// fresnel
float4 fresnel = saturate(Fresnel + (1.0f - Fresnel) * pow(1 - dot(normal, -eye), 5));
// fresnel = float4(0.95, 0.63, 0.54,1);
return texCUBE(colorSamp,RR1) * fresnel;
}

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