FXAA integration

[KirillAlekseeenko]

Integrated FXAA as a relatively simple spatial antialiasing algorithm at the end of the frame just before UI rendering

There are multiple presets: 0 -- no FXAA from 1 to 5 -- the higher this number the more expensive filtering is used

To set FXAA preset add "-fxaa preset_num" parameter to the command line arguments

[Try]

Hi, @KirillAlekseeenko and thanks for PR!

Currently busy with gpu-driven, - will look closely into PR afterward.

Some notes in a meantime:

• can you please provide a screen-shoots showcasing visual changes?
• how much performance FXAA takes?
• please provide a link to source of Fxaa3_11.h - for sake of bookkeeping.

And one more thing to note: there was a debate in last release comments about better AA technique, so it best next time to raise ticket and ask. On my end I was looking toward programmable-resolve based AA (can do on Apple, but not yet on Vulkan). It is OK with you, if after 6-12 months this FXAA will be replaced by else algorithm?

[KirillAlekseeenko]

Hi! Accroding to nvidia nsight frame capture FXAA takes from 0.06 to 0.08 ms (depends on quality preset) on nvidia 3070 card with full hd resolution. Source for Fxaa3_11.h can be found here: https://gist.github.com/jwoolston/c96c22473110c9924d831cebb5f2cdb4 Originally it's a part of NVIDIA samples: https://docs.nvidia.com/gameworks/content/gameworkslibrary/graphicssamples/opengl_samples/fxaa.htm https://docs.nvidia.com/gameworks/content/gameworkslibrary/graphicssamples/d3d_samples/fxaa311sample.htm

It's ok if FXAA will be removed in future releases, it's just a starting AA solution and not good comparing to alternatives, but it's cheap and simple though. What did you mean by programmable-resolve based AA?

There are shots before and after applying FXAA

[Try]

What did you mean by programmable-resolve based AA?

This is though direction, rather a complete technique at this point. Basic idea here is to use (or abuse :D ) MSAA rendering with some extensions to get full-res gBuffer + 4x-coverage buffer. This method originally was intended only to deal with sky-to-object aliasing (trees/ship) - coverage buffer is perfect to compose sky on top of scene.

Naturally there are quite a few challenges to make it work, and one of then is to be able to resolve MSAA image into single-sampled image from shader, rather then from fixed-function hardware.

[Try]

There some code-style issues - I'll fix it afterward. Merged, thanks!