float4x4 gLightWorldViewProj : WorldViewProjection;
float4x4 gWorldViewProj: WorldViewProjection; //For compatibility sake

struct VS_Input {
    float3 Position : POSITION;
    float2 TexCoord : TEXCOORD;
    float3 Normal : NORMAL;
    float3 Tangent : TANGENT;
};
struct VS_Output
{
    float4 Position : SV_POSITION;
};

VS_Output VS_Shadow(VS_Input input)
{
    VS_Output output;
    // Transform vertex position to light's clip space
    output.Position = mul(float4(input.Position, 1.0f), gLightWorldViewProj);
    return output;
}

float4 PS_Shadow(VS_Output input) : SV_TARGET
{
    // Output depth information (Z/W in clip space)
    //    // gl_FragDepth = gl_FragCoord.z;
    return float4(input.Position.z / input.Position.w, 0.0f, 0.0f, input.Position.z / input.Position.w);
}

// Rasterizer state for front face culling
RasterizerState FrontFaceCull
{
    FrontCounterClockwise = FALSE;
    CullMode = FRONT;
};

// Technique for rendering shadow map
technique11 DefaultTechnique
{
    pass P0
    {
        //Set FrontFaceCulling
        SetRasterizerState(FrontFaceCull);
        SetVertexShader(CompileShader(vs_5_0, VS_Shadow()));
        SetPixelShader(CompileShader(ps_5_0, PS_Shadow()));
    }
}