dolphin/Data/User/Shaders/acidtrip.txt

uniform samplerRECT samp0 : register(s0);

void main(out float4 ocol0 : COLOR0, in float2 uv0 : TEXCOORD0)
{
  ocol0 = (texRECT(samp0, uv0+1).rgba - texRECT(samp0, uv0-1).rgba)*8;
}