Reply To: help with OpelGL / barrel distortion

[dankcushions]

but my understanding is that these shaders split all the various functions into different passes – one shader preset is a load of separate passes, each with a different utility; eg, in a CRT shader, one pass will add scanlines, one will add blurring, one will add the curvature, etc. you can turn off all but the curvature pass, and achieve what the post is describing without touching any code. you can even save that as a new preset. this is exactly what i did when i wanted to use a LCD-type filter for GBA games, without killing my performance by including a load of extra passes i didn’t care for.

you might be in luck in that your project only needs a small resolution, i guess? if you set your retroarch output to that resolution (through the retropie launch menu), it may well cope with a single pass shader ok!