Add FXAA 3.11 in shaders menu

[CaptTatsu]

I just found out that the FXAA used by Optifine and me is kind of old. It creates noticeable artifacts at somewhat detailed texture in distance (i'll use Jappa's oak leaves as the example), and it only does a little bit of smoothing in near horizontal / vertical lines.
I tried using FXAA 3.11 and most of the issues above are resolved. However, it's obviously a bit more expensive and doesn't work in lower render quality (below 1x)
Here's the article which includes somewhat easy to implement FXAA 3.11 here.

Here's some comparison between old FXAA with FXAA 3.11 (using BSL)
Jappa's oak leaves

(left : old, right : 3.11, more noticeable in darker spots)

Near horizontal line

(top : old, bottom : 3.11)

[sp614x]

The FXAA configuration and shaders are in assets/minecraft/shaders/post and assets/minecraft/shaders/program in the OptiFine JAR (export to see the patched result). These can be customized with a resource pack.
If you make a resource pack that replaces one of the FXAAs with 3.11 it can be added to OptiFine.

[CaptTatsu]

It seems that i can't do much due to the lack of bilinear filtering.
Here's the pack, it replaces FXAA 2x
FXAA 3.11.zip

[sp614x]

The 3.11 in the resource pack is correctly loaded, but it doesn't seem to work.
It was vertically mirrored in 1.13 (simple fix).

3.11 RP

current 2x

[CaptTatsu]

it was due to the lack of bilinear filtering
i tried to add one this time, but the anti aliasing only seem to show once i zoom in. otherwise it doesn't work.

1x zoom, no aa

1x zoom, 3.11

2x zoom, no aa

2x zoom, aa

this time it replaces super secret setting's fxaa(1.8.9, click the button twice), and 2x zoom is applied.
FXAA 3.11.zip

[sp614x]

Looks very smooth, but the zoom dependency is strange.

[CaptTatsu]

just found a fix for 1x zoom, turns out that i need to apply half a pixel coordinate shift. here's the result

no aa

3.11

no aa

3.11

now it replaces 2x again. i can't guarantee if it's artifact free
FXAA 3.11.zip

[sp614x]

The current 2x FXAA uses SubPixelShift in the .vsh:

    posPos.xy = texCoord.xy + (0.5/OutSize * vec2(0.5 - SubPixelShift));
    posPos.zw = texCoord.xy - (0.5/OutSize * vec2(0.5 + SubPixelShift));

[sp614x]

The last fxaa 3.11 works without zoom, but it has a lot of artifacts and can't be added like that:

fxaa 3.11

fxaa 4x

This looks like a problem with the subpixel accuracy, maybe SubPixelShift can fix it.

[sp614x]

@CaptTatsu can you fix the artifacts (subpixel shift)?