Match colors of real GBA

[vanjac]

Colors look very different on an original GBA than on mGBA. They are much more muted and some hues are shifted. No$gba emulates the colors of the GBA pretty accurately, and even has an option to switch between GBA / GBA SP / NDS / NDS-Lite modes. There should be a similar option for mGBA.

mGBA on the left, no$ on the right. The right is much closer to what appears on my gba.

[vanjac]

According to this the gba display has a Gamma of 3 to 4 https://pineight.com/gba/#static

[themalu866]

There's a shader on Mgba for that but personally I don't like it.
I think they tried to remove the grey from it but ended making the red colors more like pinks.

It's pretty inaccurate if you compare with No$gba or the older version of VisualBoyAdvance.

[LimitCrown]

mGBA doesn't perform any automatic color correction, but it does come with the gba-color shader. I think it works well. The one that comes with mGBA is outdated though, unless it was recently updated, so I had needed to change the values in the shader's files to match its most recent version at some point.

I personally like it. I use it the most frequently and I have the darken screen parameter set to 1.5, its max-allowed value and which corresponds to a target gamma of 3.7. An example of Mario Kart Super Circuit's title screen with the shader in use:

[vanjac]

I didn't know about that shader, thanks. I still think it's not quite as accurate as no$, like themalu866 said the reds are a bit too light.

Where could I find the most recent version?

[LimitCrown]

The most recent version of the shader can be found in this link: https://github.com/libretro/glsl-shaders/blob/master/handheld/shaders/color/gba-color.glsl

However, the formating used with mGBA's shaders is different, so instead of directly using the glsl file I changed the values and the last line that differed in mGBA's to match the latest one.

[ghost]

@LimitCrown

Hi

Would you please consider post the final gba-color.fs code here?

I have tried changing it according to your instructions but I'm not sure I have done it right and frankly I'm not good at these things.

All I get is a black screen with sound basically.

Thank you in advance!

[LimitCrown]

@RokkumanX Ah, sorry for not responding sooner. Here is a link to an updated version of the gba-color shader for mGBA. https://www.dropbox.com/sh/fd6d4tq6hsp6hav/AABhUfi1mMoyKuAaVmRmliL6a?dl=0

[ghost]

@LimitCrown

Much obliged, thank you very much!

[Squall-Leonhart]

The retroarch shader has been updated since.
shaders.zip