Some semi-random thoughts on terrain generation

[xoft]

I found out why the jungle trees are so slow-generating. It's because they're huge, and the algorithm was O(N^2) due to checking blocks for duplicates. Without checking, the generator runs fast again, but we get the "leaves overwrite logs" problem. I'll need to figure something out against this.

Also, I've notices that some of the jungle trees grow in thin air. No idea what's going on there yet. It seems to happen only at biome transitions, especially jungle-ocean edge.