Implement Blur Busters CRT beam simulator shader

[mdrejhon]

Hey Tom,
You've heard about it by now -- my CRT simulation shader.

You do things pretty spatially accurately; why not also do things temporally accurately too?
Add accuracy to another dimension.

HLSL and GLSL source code -- https://github.com/blurbusters/crt-beam-simulator/
Article -- https://blurbusters.com/crt

P.S. Wondering how to sequence the shaders? Being the (display+tempral) expert here, Think temporally like a CRT. Signal processing (brightness/contrast/composite artifacts), then electron beam, then phosphor masks. Sequence your shaders the same orthographical order for best results. Your composite filters will look perfect too, but only if done before beam simulation.