Add atmospheric scattering

[natalieeatscats]

This is the version that I like quite a bit more than my first PR, both visually and in the code, but there is a pitfal I've yet to overcome: during thunderstorms, half of the game's "visual sphere" (not sure how else to call it) furthest from the location of the sun turns completely black, and comes back only when a lightning strikes.

Screenshots of it functioning normally:

[natalieeatscats]

Fixed the thunderstorm bug. Phew!

[natalieeatscats]

Did some optimizations and cleaned up the code quite a bit I think, also made the output more manageable (values of scattering 1.0 and mist 0.5 don't look completely whacked anymore). Some screens: Considering making a backup of my weather settings to make screenshots of the thing in combination with Vurt's weathers, as a point of reference

[natalieeatscats]

Here are the screenshots with Vurt's weather settings: (I might actually keep them over my own...)

[zesterer]

I definitely agree that Vurt's settings are an improvement here: the prior screenshots look bright purple, which I don't think is too desirable. The more configurable it is, the better, IMO. I'll try to find time to do another review tomorrow with a view toward getting this merged!

[natalieeatscats]

The more configurable it is, the better, IMO.

I agree, which is why I think it's better to take values from ini, which already has established presets and is easily configurable, than to hardcode them

[natalieeatscats]

Alright, I think I brought it to the look I am satisfied with:

[natalieeatscats]

Also, there is a dilemma looming over the shader: it might be more artistic if original sun color is used more, but then it is not dynamic and the quality of the look is, obviously, dependent on the color in the ini. I think it would be a great compromise to have a slider that blends between purely modified sunlight and the original sun color in the scatterring. I might even try adding that slider myself, though I'm not promising anything

[natalieeatscats]

Yup, added the slider! Now it is up to the user how much the sun color is modified by the scattering. Default is 0.5, which I feel is a nice balance between realism and artistry/configurability.

[natalieeatscats]

Anyone here? 😅

[zesterer]

Apologies: I've not forgotten about this, I've just been very busy with other commitments over the past few weeks. I'll try to get this reviewed over the weekend.