dolphin/Data/User/Shaders/sketchy.txt

uniform sampler2D samp9;

out vec4 ocol0;
in vec2 uv0;

uniform vec4 resolution;

void main()
{
  float4 c0 = texture(samp9, uv0).rgba;
  float4 tmp = float4(0, 0, 0, 0);
  tmp += c0 - texture(samp9, uv0 + float2(2, 2)*resolution.zw).rgba;
  tmp += c0 - texture(samp9, uv0 - float2(2, 2)*resolution.zw).rgba;
  tmp += c0 - texture(samp9, uv0 + float2(2, -2)*resolution.zw).rgba;
  tmp += c0 - texture(samp9, uv0 - float2(2, -2)*resolution.zw).rgba;
  float grey = ((0.222 * tmp.r) + (0.707 * tmp.g) + (0.071 * tmp.b));
  // get rid of the bottom line, as it is incorrect.
  if (uv0.y*resolution.y < 163)
    tmp = float4(1.0, 1.0, 1.0, 1.0);
  c0 = c0+1-grey*7.0;
  ocol0 = float4(c0.r, c0.g, c0.b, 1);
}