source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/normalMapping.cg @ 3163

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

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


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

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

        float4 worldPos: TEXCOORD3;
        float4 oldWorldPos: TEXCOORD4;
        float4 tangent: TEXCOORD5;  
        float4 bitangent: TEXCOORD6;
};


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

        float4 winPos: WPOS;
        // eye position
        float4 eyePos: TEXCOORD1;
        float4 normal: TEXCOORD2;
        float4 worldPos: TEXCOORD3;
        float4 oldWorldPos: TEXCOORD4;
        float4 tangent: TEXCOORD5;  
        float4 bitangent: TEXCOORD6;
};


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;

        float4 tangent = float4(IN.color.xyz * 2.0f - float3(1.0f), 1.0f);
        //float4 tangent = IN.color;

        //float4 tangent = 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
        // convert to view space
        OUT.normal = mul(glstate.matrix.invtrans.modelview[0], IN.normal);
        OUT.tangent = mul(glstate.matrix.invtrans.modelview[0], tangent); 
        
        OUT.bitangent = float4(cross(OUT.tangent.xyz, OUT.normal.xyz), 1);
        //OUT.bitangent = float4(cross(OUT.normal.xyz, OUT.tangent.xyz), 1);

        return OUT;
}



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


pixel frag(fragin IN,
                   uniform float4x4 viewMatrix,
                   uniform sampler2D normalMap: TEXUNIT0)
{
        pixel pix;
        // hack: use comination of emmisive + diffuse (emmisive used as constant ambient term)
        pix.color = glstate.material.diffuse + glstate.material.emission;
        
        // eye space 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 to world space trafo =>
        // 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)
        const float3 normal = normalize(mul(transpose(viewMatrix), IN.normal).xyz);
        const float3 tangent = normalize(mul(transpose(viewMatrix), IN.tangent).xyz);
        const float3 bitangent = normalize(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(tangent, bitangent, normal));
        //float3x3 tangToWorldTrafo = transpose(float3x3(bitangent, tangent, normal));
        //float3x3 tangToWorldTrafo = transpose(float3x3(tangent, normal, bitangent));
        //float3x3 tangToWorldTrafo = transpose(float3x3(normal, bitangent, tangent));
        //float3x3 tangToWorldTrafo = transpose(float3x3(normal, tangent, bitangent));

        const float3 tangentSpaceNorm = tex2Dlod(normalMap, float4(IN.texCoord.xy, 0, 0)).xyz * 2.0f - float3(1.0f);
        //const float3 tangentSpaceNorm = float3(0, 1, 0);
        //const float3 tangentSpaceNorm = float3(0, 0, 1);
        
        pix.normal = normalize(mul(tangToWorldTrafo, tangentSpaceNorm));
        //pix.normal = normalize(tangentSpaceNorm);
        //pix.color.xyz = float3(abs(dot(tangent.xyz, normal.xyz)));
        //pix.color.xyz = float3(abs(dot(bitangent.xyz, tangent.xyz)));
        //pix.color.xyz = float3(abs(dot(normalize(IN.normal.xyz), normalize(IN.tangent.xyz))));
        //pix.color.xyz = float3(abs(dot(IN.normal.xyz, IN.tangent.xyz)));
        //pix.color.xyz = normal.xyz;
        //pix.color.xyz = IN.tangent.xyz;
        //pix.color.xyz = float3(IN.texCoord.x,0,0);
        //pix.color.xyz = float3(0,IN.texCoord.y,0);
        
        return pix;
}



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.xyz, IN.bitangent.xyz, IN.normal.xyz));
        const float3 tangentSpaceNorm = tex2Dlod(normalMap, float4(IN.texCoord.xy, 0, 0)).xyz;
        pix.normal = mul(tangToWorldTrafo, tangentSpaceNorm);

        return pix;
}