SRGB gamma correction

[IntegratedQuantum]

fixes #116

@careeoki @ikabod-kee please check if there are any problems with this artistically, I tried to convert all the values, such that no artistic changes are needed. However I may have missed things and there are also some notable differences:

• ambient occlusion acts differently (there is less of it)
• dark lights are brighter (which fixes (0.0.1) Torch light is too dark #2363 and makes Can (and should) we avoid the hue shifting that happens at the edge of light sources? #896 worse)
• Reflection and bloom have changed due to now running on the correct color space

Please tell me if I should try fixing any of these.

Remaining work:

• check performance impact

[ikabod-kee]

Oh man, you weren't kidding about the hue shifting being worse. This should definitely be fixed before merging.

Also, here is a comparison between the old and new versions.

The new version looks good from afar, but is also quite desaturated and not very good up close.
The old version has the saturation, but things from afar look ehhh!

[ikabod-kee]

Old:

New:

Yeah, the fog really desaturates things.

[careeoki]

I definitley prefer the old ambient occlusion.
There appears to be a sharp line where it goes from "dark" to pure black. You can see how it reveals the underlying triangles.

I think the night isn't dark enough. Not advocating for how dark it was before, but it feels oddly bright next to the black night sky.
You can also see how the torch has hardly any effect on the surroundings, which feels wrong.

Other dark lights have nearly no effect at all at night.

This really kills the vibe of night builds.

Like Ikabod said, there's something weird with the fog, it looks like i need to defrost my monitor.

[careeoki]

To compare night darknesses:

old: way too dark

new: too bright, doesn't feel like night

very hasty image edit: somewhere in between the two. bright enough to navigate, but still dark enough for the night vibe and for nice lighting in builds

[careeoki]

Reflection and bloom have changed due to now running on the correct color space

I would probably have to manually go through the reflect/bloom textures to tweak them.

[IntegratedQuantum]

As for the fog I think the fundamental problem is that this is how realistic fog acts, it is desaturating the background:

I do agree that it looks weird though, and I also prefer the more saturated version. So maybe we should just pass out on gamma correction, and keep the current style?

[ikabod-kee]

I think the issue author meant that they wanted a gamma slider, like in Minecraft Legacy Console

[tillpp]

When it is dark, our eyes also see everything less saturated, because the color cones for red,green,blue work worse, but the color cones gray are still functioning.

I would even go so far as to say, that an image, being made black-white, can create the feeling of night without having to dim it.

[IntegratedQuantum]

I think the issue author meant that they wanted a gamma slider, like in Minecraft Legacy Console

Well SRGB is gamma=2.2, if we add a slider for it, that doesn't solve the artistic problems with it.

I would even go so far as to say, that an image, being made black-white, can create the feeling of night without having to dim it.

We could give that a try.

[ikabod-kee]

Here's what high-gamma legacy console looks like

I do honestly think that a lot of the issue with the PR currently is the lesser ambient occlusion and weird lighting bugs 💔

[IntegratedQuantum]

I do honestly think that a lot of the issue with the PR currently is the lesser ambient occlusion and weird lighting bugs

Well, but together with the fog that's basically everything that was affected by gamma correction.

[IntegratedQuantum]

Instead of only focusing on the problems, maybe you could tell me what (if any) you like about this gamma correction PR.
That could help me assess whether it's worth going forward with this or trying a different approach instead.