source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/normalMapping.cg @ 3131

/*******************************************/
/*    Shader for normal mapped geoemtry    */
/*******************************************/

/**************************************************************/
/* Shader computing the MRT output for normal mapped geoemtry */
/**************************************************************/


// input
struct vtxin 
{
  float4 position: POSITION;
  float4 normal: NORMAL;
  float4 tangent: COLOR0;
  float4 texCoord: TEXCOORD0;
};


// vtx output
struct vtxout
{
        float4 position: POSITION;
        float4 texCoord: TEXCOORD0;    

        float4 tangent: COLOR0;  
         // eye position
        float4 eyePos: TEXCOORD1;
        float4 normal: TEXCOORD2;

        float4 worldPos: TEXCOORD3;
        float4 oldWorldPos: TEXCOORD4;
        float4 bitangent: TEXCOORD5
};


// fragment input
struct fragin
{
        float4 tangent: COLOR0;  
        float4 texCoord: TEXCOORD0;    

        float4 winPos: WPOS;
        // eye position
        float4 eyePos: TEXCOORD1;
        float4 normal: TEXCOORD2;
        float4 worldPos: TEXCOORD3;
        float4 oldWorldPos: TEXCOORD4;
        float4 bitangent: TEXCOORD5
};


struct pixel
{
        float4 color: COLOR0;
        float3 normal: COLOR1;
        float3 offsVec: COLOR2;
};


#pragma position_invariant vtx

vtxout vtx(vtxin IN, 
                   uniform float4x4 viewMatrix,
                   uniform float4x4 modelMatrix,
                   uniform float4x4 oldModelMatrix
                   )
{
        vtxout OUT;

        OUT.color = IN.color;
        OUT.texCoord = IN.texCoord;

        // transform the vertex position into eye space
        OUT.eyePos = mul(glstate.matrix.modelview[0], IN.position);
        // transform the vertex position into post projection space
        OUT.position = mul(glstate.matrix.mvp, IN.position);
        // transform the old vertex position into world space
        OUT.worldPos = mul(modelMatrix, IN.position);
        // transform the old vertex position into world space
        OUT.oldWorldPos = mul(oldModelMatrix, IN.position);
        // the normal has to be correctly transformed with the inverse transpose
        OUT.normal = mul(glstate.matrix.invtrans.modelview[0], IN.normal);
        OUT.tangent = mul(glstate.matrix.invtrans.modelview[0], IN.color); 

        OUT.bitangent = cross(IN.tangent, IN.normal);

        return OUT;
}


pixel fragtex(fragin IN, 
                          uniform sampler2D tex: TEXUNIT0,
                          uniform float4x4 viewMatrix,
                          uniform sampler2D normalMap: TEXUNIT1
                          )
{
        float4 texColor = tex2D(tex, IN.texCoord.xy);

        // account for alpha blending
        if (texColor.w < 0.5f) discard;

        pixel pix;

        // save color in first render target
        // hack: use combination of emmisive + diffuse (emmisive used as constant ambient term)
        pix.color = (glstate.material.emission + glstate.material.diffuse) * texColor; 
        
        // compute eye linear depth
        pix.color.w = length(IN.eyePos.xyz);

        // the scene entity id
        //pix.id = glstate.fog.color.xyz;
        // the offset to the world pos from old frame
        pix.offsVec = IN.oldWorldPos.xyz - IN.worldPos.xyz;

        // compute tanget space in world space => transform basis vectors back into world space by
        // multiplying with inverse view. since transforming normal with T means to 
        // multiply with the inverse transpose of T, we multiple with 
        // Transp(Inv(Inv(view))) = Transp(view)
        float3 normal = mul(transpose(viewMatrix), IN.normal).xyz;
        float3 tangent = mul(transpose(viewMatrix), IN.tangent).xyz;
        float3 bitangent = mul(transpose(viewMatrix), IN.bitangent).xyz;

        // compute tangent space - world space transform which is the transpose,
        // as it is the inverse of a rotation matrix 
        float3x3 tangToWorldTrafo = transpose(float3x3(IN.tangent, IN.bitangent, IN.normal));
        const float3 tangentSpaceNorm = tex2Dlod(normalMap, float4(IN.texCoord.xy).xyz);
        pix.normal = mul(tangToWorldTrafo, tangentSpaceNorm);

        return pix;
}


pixel frag(fragin IN, uniform float4x4 viewMatrix)
{
        pixel pix;
        // hack: use comination of emmisive + diffuse (emmisive used as constant ambient term)
        pix.col = glstate.material.diffuse + glstate.material.emission;
        // save world space normal in rt => transform back into world space by
        // multiplying with inverse view. since transforming normal with T means to 
        // multiply with the inverse transpose of T, we multiple with Transp(Inv(Inv(view))) = Transp(view)
        pix.norm = mul(transpose(viewMatrix), IN.normal).xyz;
        // eye space depth
        pix.col.w = length(IN.eyePos.xyz);
        // the scene entity id
        //pix.id = glstate.fog.color.xyz;
        // the offset to the world pos from old frame
        pix.offsVec = IN.oldWorldPos.xyz - IN.worldPos.xyz;

        pixel pix;
        // compute tanget space in world space => transform basis vectors back into world space by
        // multiplying with inverse view. since transforming normal with T means to 
        // multiply with the inverse transpose of T, we multiple with 
        // Transp(Inv(Inv(view))) = Transp(view)
        float3 normal = mul(transpose(viewMatrix), IN.normal).xyz;
        float3 tangent = mul(transpose(viewMatrix), IN.tangent).xyz;
        float3 bitangent = mul(transpose(viewMatrix), IN.bitangent).xyz;

        // compute tangent space - world space transform which is the transpose,
        // as it is the inverse of a rotation matrix 
        float3x3 tangToWorldTrafo = transpose(float3x3(IN.tangent, IN.bitangent, IN.normal));
        const float3 tangentSpaceNorm = tex2Dlod(normalMap, float4(IN.texCoord.xy).xyz);
        pix.normal = mul(tangToWorldTrafo, tangentSpaceNorm);

        return pix;
}