CRT Geom Flat to crop black bars - img adj

RetroArch Additions Shaders
#1

So I was using Crt geom with curvature ON for a while but I felt like using a flat version again. The issue is that when curvature is disabled, so are the overscan options.

I changed the parameters to obtain a flat version while keeping the curvature switch ON (had to find the maximum you can put for distance and radius). I also added an image adjustment pass (which had conflicting names I changed).

So let’s say you have that game that has unequal black bars, you can: -center it with “img- X/Y modifiers” (that’s the image adjustment shader) -stretch it over the black bars with “Crt Geom Horiz/Vert. Overscan %”

The Crt-geom shader parameters have been changed to use the Gaussian Beam, disable 3x Oversample, and not use the Dotmask. That’s probably the best setting to go the fullscreen/non-integer way.

Should be like adjusting your old (flat) CRT.

#2

since you added an image-adjustment pass, is there a reason you opted to use crt-geom’s overscan cropping instead of image-adjustment’s?

#3

Crt-geom is far better at stretching the picture in this profile.

Img-adj makes some horrible distortion.

#4

Those extreme curvature values to make it flat are causing an issue…

A small part in the center of the screen is slightly rounded (makes the scanlines a bit off). This is hard to see in 240p, becomes obvious at 360p. :frowning:

Any idea to change the code to have the same behaviour if Curvature is ON or OFF?

#5

You could move the overscan bits outside of the curvature functions, but that’s basically what I did with the image-adjustment shader, so I assume the stretching looks bad because of a lack of anti-aliasing…?

#6

I tried my luck with the code I don’t have enough understanding of… got a lot of black screens.

Then I did what I’m good at: throwing random numbers and observe. A Curvature Radius of 10.5 is the magical number. Can’t see any difference even at 360p.

480p shows a slight difference vs a “curvature OFF” version but it’s useless anyway on a 1080p screen (that I have). Guess it’s good enough for now…