* 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.
The error below was reported, so handle the existence of a mod called "bucket" which doesn't have any liquids field:
Runtime error from mod 'nether' in callback on_mods_loaded(): /mods/environment/nether/nodes.lua:378: attempt to index field 'liquids' (a nil value)
stack traceback:
/mods/environment/nether/nodes.lua:378: in function /mods/environment/nether/nodes.lua:373
/minetest/builtin/game/register.lua:429: in function /minetest/builtin/game/register.lua:413
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.
* textures for new tool items
* axe, shovel, pick, sword based on nether
* run also tools.lua
* Textture for Compressed Netherbrick
* new node "Compressed Netherbrick"
* define how to craft "Compressed Netherbrick"
* change recipe for NetherLump and remove old node
* Delete nether_nether_compressed.png
(new animation by Extex101)
The original texture is now "nether_portal_alt.png", and used to provide a "nether:portal_alt" node, which is used/demoed by the Surface-portal as the original animation still has a "it's full of stars" charm coming out when used for lighter coloured portals.
Improvements found while using the portals API in another mod (cloudlands):
* remote_portal_checkup() will check the whole portal and frame for mapgen overwrites.
* Allow find_realm_anchorPos() to return nil if no realm location could be found (portal will fail to ignite).
* Allow create_book_of_portals() to be invoked [indirectly] by other mods.
Also lowers nether_book_close.png to be 4bpp
Also adds nether.register_wormhole_node(), moving the wormhole node template into portal_api.lua, and allowing wormhole nodes with custom post_effect_color to be more easily created.
UTF-8 with BOM crashes some systems according to 6551f5c120 comment, and there are several cases where Minetest is buggy with files that use CRLF line endings (though none I'm aware that affect these files), so strip CRs and BOM
