final.fsh

#version 120
/*
* Simple outline postprocessing effect
* Author: nyuuzero
*/

#define LINE_THICKNESS 1

uniform sampler2D composite;
uniform sampler2D gdepth;
uniform float viewWidth;
uniform float viewHeight;
uniform float near;
uniform float far;
varying vec4 texcoord;

float getLinearDepth(vec2 coords)
{
   return (2 * near) / (far + near - texture2D( gdepth, coords ).x * (far - near));
}

float generateOutline(vec2 coords)
{
   // pixelsize
   float horizontalPixelSize = 1.0 / viewWidth * LINE_THICKNESS;
   float verticalPixelSize = 1.0 / viewHeight * LINE_THICKNESS;

   // generate outline
   float tempDepth =
      getLinearDepth(coords + vec2(horizontalPixelSize,verticalPixelSize)) +
      getLinearDepth(coords + vec2(-horizontalPixelSize,verticalPixelSize)) +
      getLinearDepth(coords + vec2(0.0,-verticalPixelSize));

   tempDepth /= 3;

   return getLinearDepth(coords)-tempDepth;
}

void main()
{
    vec4 color;
    color = mix(texture2D( composite, texcoord.st ),vec4(0.0,0.0,0.0,1.0),clamp(generateOutline(texcoord.st)*100,0.0,0.999));
    //color *= 1.0 - clamp(generateOutline(texcoord.st)*100,0.0,1.0);
    gl_FragColor = color;
}