uniform sampler2D samp9;

out vec4 ocol0;
in vec2 uv0;

uniform vec4 resolution;

void main()
{
  //variables
  float internalresolution = 1278.0;
  float4 c0 = texture(samp9, uv0).rgba;
  //blur
  float4 blurtotal = float4(0.0, 0.0, 0.0, 0.0);
  float blursize = 1.5;
  blurtotal += texture(samp9, uv0 + float2(-blursize, -blursize)*resolution.zw);
  blurtotal += texture(samp9, uv0 + float2(-blursize,  blursize)*resolution.zw);
  blurtotal += texture(samp9, uv0 + float2( blursize, -blursize)*resolution.zw);
  blurtotal += texture(samp9, uv0 + float2( blursize,  blursize)*resolution.zw);
  blurtotal += texture(samp9, uv0 + float2(-blursize,  0.0)*resolution.zw);
  blurtotal += texture(samp9, uv0 + float2( blursize,  0.0)*resolution.zw);
  blurtotal += texture(samp9, uv0 + float2( 0.0, -blursize)*resolution.zw);
  blurtotal += texture(samp9, uv0 + float2( 0.0,  blursize)*resolution.zw);
  blurtotal *= 0.125;
  c0 = blurtotal;
  //greyscale
  float grey = ((0.3 * c0.r) + (0.4 * c0.g) + (0.3 * c0.b));
  // brighten and apply horizontal scanlines
  // This would have been much simpler if I could get the stupid modulo (%) to work
  // If anyone who is more well versed in Cg knows how to do this it'd be slightly more efficient
  // float lineIntensity = ((uv0[1] % 9) - 4) / 40;
  float vPos = uv0.y*resolution.y / 9.0;
  float lineIntensity = (((vPos - floor(vPos)) * 9.0) - 4.0) / 40.0;
  grey = grey * 0.5 + 0.7 + lineIntensity;
  // darken edges
  float x = uv0.x * resolution.x;
  float y = uv0.y * resolution.y;
  if (x > internalresolution/2.0) x = internalresolution-x;
  if (y > internalresolution/2.0) y = internalresolution-y;
  if (x > internalresolution/2.0*0.95) x = internalresolution/2.0*0.95;
  if (y > internalresolution/2.0*0.95) y = internalresolution/2.0*0.95;
  x = -x + 641.0;
  y = -y + 641.0;
  /*****inline square root routines*****/
  // bit of a performance bottleneck.
  // neccessary to make the darkened area rounded
  // instead of rhombus-shaped.
  float sqrt = x / 10.0;
  while((sqrt*sqrt) < x) sqrt+=0.1;
  x = sqrt;
  sqrt = y / 10.0;
  while((sqrt*sqrt) < y) sqrt+=0.1;
  y = sqrt;
  /*****end of inline square root routines*****/
  x *= 2.0;
  y *= 2.0;
  grey -= x / 200.0;
  grey -= y / 200.0;
  // output
  ocol0 = float4(0.0, grey, 0.0, 1.0);
}