dolphin/Data/User/Shaders/fire.txt

uniform samplerRECT samp0 : register(s0);

void main(out float4 ocol0 : COLOR0, in float2 uv0 : TEXCOORD0)
{
  float4 c0 = texRECT(samp0, uv0).rgba;
  float red   = 0.0;
  float green = 0.0;
  float blue  = 0.0;

  red = c0.r;

  if (c0.r > 0.0)
  {
    if (c0.g > c0.r)
    {
 	green = (c0.g - (c0.g - c0.r)) / 3;
    }
  }

  ocol0 = float4(red, green, blue, 1.0);
}