struct Vertex
{
  float4 position   : POSITION;     // Fragment position in screen-space
  float4 color      : COLOR;        // Fragment color
  float2 texCoords  : TEXCOORD0;    // Fragment's Texture Coordinates
  float depth       : TEXCOORD1;    // Fragment depth in eye-space
};

struct Fragment
{
    float4 color  : COLOR0;
};

Fragment main(Vertex p_In
              
            #ifdef STORE_NORMALIZED_DEPTH
              ,uniform float p_Near // Near distance
              ,uniform float p_Far  // Far distance
            #endif

              ,uniform float p_DepthOffset  // Depth offset
              )
{
    Fragment l_Out;

#ifdef STORE_NORMALIZED_DEPTH

    // Store normalized depth in [0,1] to avoid overflowing,
    // even when using half precision floating point render target
    float l_Depth = (1.0/p_Near - 1.0/p_In.depth) / (1.0/p_Near - 1.0/p_Far);

    // Use some bias to avoid precision issue
    // TODO : As depth is not distributed uniformly across the range
    // we should bias proportionately to the depth value itself.
    // The absolute bias closer to the camera is lower than the bias further away.
    l_Depth += p_DepthOffset;

#else

    // Store non-normalized depth
    float l_Depth = p_In.depth;
    
    // Use some bias to avoid precision issue
    l_Depth += p_DepthOffset;

#endif
    
    // Write the depth value to the depth map
    l_Out.color.r = l_Depth;
    
    return l_Out;
}