MinecraftForge/MinecraftForge — pull request #1181 by Abastro (2014-06-26 06:31:50+00:00)
Title: 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.