FXAA

Option test

extern NumVar ContrastThreshold;    // Default = 0.166
extern NumVar ContrastThresholdMin;    // Default = 0.0833
extern NumVar SubpixelRemoval;        // Default = 0.75

1. FXAA_GREEN_AS_LUMA

There's no mentional changes on simple screen

1. LogLumiance

// Another optimization is in the generation of perceived brightness (luma) of pixels.

// The original implementation used sRGB as a good approximation of log-luminance. A

// more precise representation of log-luminance allows the algorithm to operate with a

// higher threshold value while still finding perceivable edges across the full range

// of brightness. The approximation used here is (1 - 2^(-4L)) * 16/15, where L =

// dot( LinearRGB, float3(0.212671, 0.715160, 0.072169) ). A threshold of 0.2 is

// recommended with log-luminance computed this way.

Test needed