Add more pure_gamma steps

[birdybro]

https://github.com/MiSTer-devel/Filters_MiSTer/issues/14 - as mentioned here

[ghogan42]

Well to display colors meant for a 2.5 gamma crt on a 2.2 gamma hdtv you only want 2.5/2.2 = 1.136 gamma. So we originally made them up to 1.4 because that was already darker than we would need for anything.

So we could add these. It's no problem. But these are applied then the effect is applied to the already gamma 2.2 (or possibly around 2.5) that the cores already produce high gammas like the following example:

gamma 1.45 to the output of a console core meant for a crt would result in something like gamma 2.2*1.45=3.19. And gamma 3.19 is going to be a lot darker than it should be because the console was meant for a crt with around 2.5 gamma

I guess I'm asking what the use case for gamma files 1.5 to 2.0?

[birdybro]

I think I agree with your assessment. Closed!