MinecraftForge/MinecraftForge — pull request #467 by Crudedragos (2013-03-20 01:14:29+00:00)
Title: Add Event to Tweak max creature spawn in chunk during spawning

* LivingMaxCanSpawnEvent
Allows overriding of the getMaxSpawnedInChunk. Required by spawn control mods to allow users to actually control the distrbution of spawned mobs similar to what minGroupCount/maxGroupCount do for chunk spawned creatures.

Primarily, this is to allow for additional control of mob spawns for spawn control mods such as Mob Spawn Control. The advantage or need of the non-creature mods having access is to allow a single UI to tweak and balance worlds utilizing several creature mods. The balancing with respect to several mod combinations cannot be balanced from the single mod authors perspective and the single UI is typically outside the scope of the individual mods.

It could obviously also be used to tweak vanilla spawn distribution.