ApelGammaShader

// Apel's gamma correction shader

//tweakables
static float gamma = 0.859;
static float saturation = 1.0;
static float luminance = 1.0;
//tweakables

texture lastshader;
sampler s0 = sampler_state { texture = <lastshader>; minfilter = none; magfilter = none; };

float3 grayscale(float3 col)
{
return dot(col.rgb, float3(0.3, 0.59, 0.11));
}

float4 gammatoo(float2 tex : TEXCOORD) : COLOR0
{
float3 c = tex2D(s0, tex).rgb;
c = lerp(grayscale(c), c, saturation); // Apply saturation
c = pow(c, gamma); // Apply gamma

return float4(saturate(c * luminance ), 1.0);
}

technique T0 < string MGEinterface = "MGE XE 0"; >
{
pass { PixelShader = compile ps_3_0 gammatoo(); }