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

uniform sampler2D brightTex;

uniform vec4 filterInfo;

varying vec2 screen;
varying vec2 scale;

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

const vec2 offsPix0 = vec2( 1,  0);
const vec2 offsPix1 = vec2(-1,  0);
const vec2 offsPix2 = vec2( 0,  1);
const vec2 offsPix3 = vec2( 0, -1);
const vec2 offsPix4 = vec2( 1,  1);
const vec2 offsPix5 = vec2(-1,  1);
const vec2 offsPix6 = vec2( 1, -1);
const vec2 offsPix7 = vec2(-1, -1);

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

void main(void)
{
    // Main depth and color:

    gl_FragColor = texture2D(brightTex, screen.xy);

    float full = 2.0 * abs(gl_FragColor.x - 0.5);
    float treshold = 0.99;
    float delta = treshold - full;

    if(delta >= 0.0)
    {
        // neightbor texture coordinates:
        vec2 neigh0 = offsPix0 * scale.xy + screen.xy;
        vec2 neigh1 = offsPix1 * scale.xy + screen.xy;
        vec2 neigh2 = offsPix2 * scale.xy + screen.xy;
        vec2 neigh3 = offsPix3 * scale.xy + screen.xy;
        vec2 neigh4 = offsPix4 * scale.xy + screen.xy;
        vec2 neigh5 = offsPix5 * scale.xy + screen.xy;
        vec2 neigh6 = offsPix6 * scale.xy + screen.xy;
        vec2 neigh7 = offsPix7 * scale.xy + screen.xy;

        // Lookup colors:
        
        vec4 colA, colB;
        colA.x = texture2D(brightTex, neigh0).x;
        colA.y = texture2D(brightTex, neigh1).x;
        colA.z = texture2D(brightTex, neigh2).x;
        colA.w = texture2D(brightTex, neigh3).x;
        colB.x = texture2D(brightTex, neigh4).x;
        colB.y = texture2D(brightTex, neigh5).x;
        colB.z = texture2D(brightTex, neigh6).x;
        colB.w = texture2D(brightTex, neigh7).x;

        float sum = gl_FragColor.x 
                + dot(colA + colB, vec4(1.0, 1.0, 1.0, 1.0));
        gl_FragColor = vec4(sum * 0.11111111);
    }
}

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