0.5.0 Tracking Issue

[JonahPlusPlus]

Things to do when Bevy 0.9 is released.

• Update to be 0.9 compliant

QOL changes:

• Remove AtmosphereSkyBoxMaterial (unnecessary newtype) or make it an alias (Bevy 0.9 now requires impl Resource, so the Handle can't be used directly)
• Add default procedural feature (controls whether the AtmospherePlugin adds the AtmospherePipelinePlugin) (Fixes Custom skybox texture? #29)
• Add removal detection to detection feature
• Remove dithering (Bevy 0.9 now adds dithering by default) (dithering is still necessary, it seems banding still occurs)
• Explore compile time vs run time discrepancy (see more below)
• Rename compute shader "time" variables to "depth" (to make it more accurate to the source literature)
• Add more images to README

Potential Features:

• Alternative sky models (Added Gradient model)
• Night sky model (Fixes Starry starry night #27)

Compile time vs run time discrepancy

As more features get added in, I should put more consideration into how things are organized. Sky models, for instance, can be organized into an enum and the variants can be feature-gated. In that case, the enum should be marked non-exhaustive, so changing the variant features won't cause a compile error. Besides that, it allows for adding new sky models in the future.

On that note, I should probably see if current features can receive the same treatment (allow for changing behavior at compile time and run time) to make them more flexible.