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

struct PS_INPUT
{
    float2 screen: TEXCOORD0;
    float2 scale: TEXCOORD1;
};

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

sampler brightTex: register(s0);

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

const float2 offsPix0 = float2( 1,  0);
const float2 offsPix1 = float2( 0,  1);
const float2 offsPix2 = float2( 1,  1);
const float2 offsPix3 = float2(-1,  1);

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

float4 main(PS_INPUT input): COLOR0
{
    // Main color:
    
    float4 result = tex2D(brightTex, input.screen.xy);
    
    float full = abs(2 * result.x - 1);
    float treshold = 0.99;
    float delta = treshold - full;

    if(delta >= 0)
    {
        // Lookup colors:
        
        float4 colA, colB;
        float2 offs0 = offsPix0 * input.scale.xy;
        colA.x = tex2D(brightTex, input.screen.xy + offs0).x;
        colB.x = tex2D(brightTex, input.screen.xy - offs0).x;
        float2 offs1 = offsPix1 * input.scale.xy;
        colA.y = tex2D(brightTex, input.screen.xy + offs1).x;
        colB.y = tex2D(brightTex, input.screen.xy - offs1).x;
        float2 offs2 = offsPix2 * input.scale.xy;
        colA.z = tex2D(brightTex, input.screen.xy + offs2).x;
        colB.z = tex2D(brightTex, input.screen.xy - offs2).x;
        float2 offs3 = offsPix3 * input.scale.xy;
        colA.w = tex2D(brightTex, input.screen.xy + offs3).x;
        colB.w = tex2D(brightTex, input.screen.xy - offs3).x;
           
        // Calculate average:
        
        float sum = result.x + dot(colA + colB, float4(1, 1, 1, 1));
        result.xyz = sum * 0.11111111;
    }
        
    return result;
}

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