//shading:         flat
//lighting model:  blinn
//lighting type:   directional

// --------------------------------------------------------------------------------------------------
// PARAMETERS:
// --------------------------------------------------------------------------------------------------

//transforms
float4x4 tW: WORLD;        //the models world matrix
float4x4 tV: VIEW;         //view matrix as set via Renderer (EX9)
float4x4 tP: PROJECTION;   //projection matrix as set via Renderer (EX9)
float4x4 tWVP: WORLDVIEWPROJECTION;

//material properties
float4 cAmb : COLOR <String uiname="Color";>  = {1, 1, 1, 1};
float4 cFog : COLOR <String uiname="Fog Color";>  = {0, 0, 0, 1};

//texture
texture Tex <string uiname="Texture";>;
sampler Samp = sampler_state    //sampler for doing the texture-lookup
{
    Texture   = (Tex);          //apply a texture to the sampler
    MipFilter = LINEAR;         //sampler states
    MinFilter = LINEAR;
    MagFilter = LINEAR;
};

float4x4 tTex: TEXTUREMATRIX <string uiname="Texture Transform";>;
float3 point1, point2, gamma;
float width, maxdepth;
//the data structure: "vertexshader to pixelshader"
//used as output data with the VS function
//and as input data with the PS function
struct vs2ps
{
    float4 Pos : POSITION;
    float4 TexCd : TEXCOORD0;
    float depth : TEXCOORD1;
};

// --------------------------------------------------------------------------------------------------
// VERTEXSHADERS
// --------------------------------------------------------------------------------------------------

vs2ps VS(
    float4 Pos : POSITION,
    float4 TexCd : TEXCOORD0,
    float depth : TEXCOORD1)
{
    //inititalize all fields of output struct with 0
    vs2ps Out = (vs2ps)0;

    //transform position
    float range=Pos.x+0.5;
    float3 curve=point1+((point2-point1)*range)+(range-pow(range,2))*gamma;
    curve.y+=Pos.y*width;
    Pos.xyz=curve;

    depth=saturate(maxdepth-mul(Pos,tWVP).z);//maxdepth);
    Out.depth=depth-(depth-pow(depth,2));
    Out.Pos = mul(Pos, tWVP);

    //transform texturecoordinates
    Out.TexCd = mul(TexCd, tTex);

    return Out;
}

// --------------------------------------------------------------------------------------------------
// PIXELSHADERS:
// --------------------------------------------------------------------------------------------------

float4 PS(vs2ps In): COLOR
{
    //In.TexCd = In.TexCd / In.TexCd.w; // for perpective texture projections (e.g. shadow maps) ps_2_0

    float4 col =  cAmb;
    col.a=cAmb.a;
    if (maxdepth != 0.) {
    col.rgb=lerp(cFog.rgb,col.rgb,In.depth);
    }
    return col;
}

// --------------------------------------------------------------------------------------------------
// TECHNIQUES:
// --------------------------------------------------------------------------------------------------

technique TConstant
{
    pass P0
    {
        //Wrap0 = U;  // useful when mesh is round like a sphere
        VertexShader = compile vs_1_0 VS();
        PixelShader = compile ps_1_0 PS();
    }
}

technique TConstantFF
{
    pass P0
    {
        //transformations
        WorldTransform[0]   = (tW);
        ViewTransform       = (tV);
        ProjectionTransform = (tP);

        //material
        MaterialAmbient  = {1, 1, 1, 1};
        MaterialDiffuse  = {1, 1, 1, 1};

        //texturing
        Sampler[0] = (Samp);
        TextureTransform[0] = (tTex);
        TexCoordIndex[0] = 0;
        TextureTransformFlags[0] = COUNT4 | PROJECTED;
        //Wrap0 = U;  // useful when mesh is round like a sphere

        //lighting
        LightEnable[0] = TRUE;
        Lighting       = TRUE;
        SpecularEnable = FALSE;

        LightType[0]     = DIRECTIONAL;
        LightAmbient[0]  = (cAmb);
        LightDiffuse[0]  = {0, 0, 0, 0};
        LightDirection[0] = {0, 0, 1, 1};

        //shading
        ShadeMode = FLAT;
        VertexShader = NULL;
        PixelShader  = NULL;
    }
}