Here's the basic idea: I've got a Rogue-ish, perhaps Dwarf Fortress-ish game, with a randomly generated overworld and several dungeon entrances scattered around it. I already have the dungeons basically covered, but I'm stuck on an aspect of the overworld.
Said overworld, considered as a 2D map of screens, should have a perhaps blob-like distribution of four different themes or biomes -- grasslands, desert, snow and swamp, each with their own total amount of screens. Let's say the map is 8x8, which gives 64 unique screens. Half of those could be grasslands, a quarter desert, and swamp and snow get a quarter each:
It seems palette reduction has made snow the same color as swamp. Originally, there were eight snow screens in the bottom corner, and a slightly staggered eight-screen swamp area in the middle. Sorry 'bout that, and please ignore the location markers.
The best I could get was some snaking shapes, and often enough with nonsensical combinations like desert snaking through snow (or vice versa). I can't for the life of me figure out how to get it nice and blobby, let alone having it make climatical (?) sense. So how do I generate a biome map like in the mockup?
Okay, by request: the world really isn't much bigger than that example, and what I need is just a way to spread some blobs that determine thematic appearances, with the extra limitation that snow can't touch desert. Screens don't scroll, and if a screen is set to "desert", there'll be no grass anywhere on it.