Skylight Hooks for Minecraft Forge

World Hooks on sky light, which can provide sunlight / moon factor from the Worldprovider.
mainly for Solar/Lunar Eclipse.

getSunBrightnessFactor is for getting sun brightness, i think it is better than just using getCelestialAngle.. I don't see any problem on it.
I'm pretty sure Lex is saying that you shouldn't just copy/paste code all over. If there's ever a reason that someone needs to make a change to your code they would need to know to make that change everywhere else that you copy/pasted to. The code should live in a single place and you should call that code rather than copying the code.