* bug fixes
Fixes wrong new_y_min when shift_existing_biomes() shifts a biome below the nether floor,
find_surface_anchorPos() no longer assumes y=0 will be outside the nether.
Nil-reference fixed when a mods tries to register a portal after mods are finished loading, but the portal shape+material was already registered by another mod.
* Make ShiftExistingBiomes available via API
makes the ShiftExistingBiomes function available to other mods via the nether global, since it's not a simple function and biomes would also need to be shifted if another mod wants to add a second nether layer.
* Allow layers to extend the depth of nether effects
Mods can set/lower nether.DEPTH_FLOOR_LAYERS when creating a layer under the nether. This allows multiple layer mods to know where their ceiling should start, and to be included in the effects which only happen in the nether.
* document nether API
More of a tentative interop guide than an API.
Use snake_case for API functions.
* clears netherrack from dungeon stairways
* Adds pillars or mezzanine floors to large rooms
* slightly more careful with window placement
* glowstone sometimes added behind in windows
Add more appropriate/atmosphere distance fog to the nether, via climate_api mod to avoid conflicting with other mods.
Any game or server with climate_api mod installed will be expecting climate_api to take control of sky values.
Adds a magma oceans region to the nether outside the existing nether caverns, which can be reached via tunnels.
Other misc changes:
* chatcomment nether_whereami, a debug aid for knowing which perlin-noise region you are in
* Nether ores no longer obtainable on the ceiling
* Move crafts into crafts.lua
* Add steam to lava cooling, and play bubbling lava upon death by lava
* Add cracked netherbrick
a decorative node which can only be obtained from dungeons or structures
I encourage someone to improve or replace the cracked netherbrick texture. For copyright purposes it's currently a derivative work (by me, 2020) from nether_brick.png, which is licensed under CC BY-SA 3.0 by PilzAdam, so it can fall under the "All other media" PilzAdam's credit in readme.md rather than need its own entry.
* respect protected areas when spawning remote portals
* Use portal_shape to determine area to check for natural/protected
* Log warning on deprecated function call
The biomes-based mapgen was creating the same amount of lava as the original nether mapgen, but it doesn't have the same issue of chunk emerge order sometimes causing lava in the overdraw regions to get removed. This adjustment will hopefully balance that a little.
Also makes glowstone stalactite a bit rarer.
Adjusting lava ore scarcity in the biomes-mapgen doesn't cause forwards or backwards compatibilty issues with existing maps, likewise with schematic rarety like glowstone stalactites, so can afford to fiddle and tune.
Prevents the c++/native mapgen from placing ores or decorations (when useBiomes is true).
The biomes-based implementation is faster, more deterministic, and keeps its dungeons, but requires MT 5.1 features to work.
Also
* Glowstone & Netherrack stalactites
* Include the new decorations in mapgen_nobiomes
* Decorate dungeons - Add windows and glowstone "chandeliers" to some rooms
* Configurable Nether floor and ceiling depths
