///////////////////////////////////////////////////////////////////////////////
//
//      ##  ######
//       ######  ###
//  ## ###############        Shark 3D Engine (www.shark3d.com)
//   ########## # # #
//    ########                Copyright (c) 1996-2006 Spinor GmbH.
//   ######### # # #          All rights reserved.
//  ##   ##########
//      ##
//
///////////////////////////////////////////////////////////////////////////////

struct PS_INPUT
{
    float2 mainTexCoord: TEXCOORD0;
    float4 baseVec: TEXCOORD2;
};

///////////////////////////////////////////////////////////////////////////////

sampler tex0: register(s0);

///////////////////////////////////////////////////////////////////////////////
// Pixelshader
// Profile: 2x0

float4 main(PS_INPUT input): COLOR0
{
    float2 mainTexCoord = input.mainTexCoord;
    float2 offsPix0 = input.baseVec.xy;
    float2 offsPix1 = input.baseVec.zw;
    float2 offsPix2 = offsPix0 + offsPix1;
    float2 offsPix3 = offsPix0 - offsPix1;

    float4 val = tex2D(tex0, mainTexCoord);
    float4 val0 = tex2D(tex0, mainTexCoord.xy + offsPix0);
    float4 val1 = tex2D(tex0, mainTexCoord.xy + offsPix1);
    float4 val2 = tex2D(tex0, mainTexCoord.xy + offsPix2);
    float4 val3 = tex2D(tex0, mainTexCoord.xy + offsPix3);
    float4 val4 = tex2D(tex0, mainTexCoord.xy - offsPix0);
    float4 val5 = tex2D(tex0, mainTexCoord.xy - offsPix1);
    float4 val6 = tex2D(tex0, mainTexCoord.xy - offsPix2);
    float4 val7 = tex2D(tex0, mainTexCoord.xy - offsPix3);

    float4 sum
        = (val * val + val0 * val0 + val1 * val1 + val2 * val2 + val3 * val3
        + 0.5 * (val4 * val4 + val5 * val5 + val6 * val6 + val7 * val7))
        * 0.142857f; // = approx. 1.0 / 7.0

    return sqrt(sum);
}

///////////////////////////////////////////////////////////////////////////////