@clayote making it a cylinder segment shouldn't be a problem
@noiob I have an LCD panel that definitely does a weird row-by-row dithering thing that really screws with scanline-type imagery. Fortunately, this doesn't seem to mess up CRT shaders for low-res systems, but for higher-res stuff with thinner horizontal lines, it can be a bit noticeable.
And yes, everything's better with scanline effects. I highly recommend this for TMNT: Shredder's Revenge, for example. Perhaps even on an OLED!
@noiob sounds like integer scaling with lower N pixels of the square turned off.
E.g.: 320x240 interlaced signal upscaled 4x to 1280x960 and with zero-indexed lines line%4==3 (3, 7, 11, 15, 19, ..., 955, 959) being completely shut down, line%4==0 being updated every even (frame_no%2==0) frame and going black otherwise, line%4==1 being updated every frame, and line%4==2 being updated every odd frame (frame_no%2==1) and going black otherwise. This way you'd get really intense CRT feelings.
@sfner no, I want the panel to have actual black lines
@sfner also you don't get scan lines in your example, it's specifically a 240p thing
@noiob make it convex.