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
The round ones look nice and cartoony, but not the right art direction for Minetest Nether.
Making use of the existing default_item_smoke.png is also a close contender for smoke puffs, but it's not translucent and I think the roundness of it reduces how much the puffs form into plumes.
Portals will now fail to ignite instead of defaulting to a fallback depth of (starty - 256) when no unprotected target can be found.
The search depth is also increased from (starty - 256) to (starty - 646)
This is to properly handle large protected areas that are sometimes set up at spawn - see issue #26
* 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
The second argument of minetest.settings:get_bool is the default value (for when the configuration value is not set). Remove the superfluous `or nether.NETHER_REALM_ENABLED` which rendered the config option useless, because it always forced the variable to true.
(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
If a portal is being ignited and portal frame near-but-not-at its destination was found that was active and already linked back to the local portal, it would cause the local portal to be extinguished. (Required the remote portal to somehow be in a different state from the portal it was linking to)
https://forum.minetest.net/viewtopic.php?t=15912
Don't place Book of Portals in dungeon chests if its contents can be written in the help modpack Encyclopedia instead, and don't add Book of Portals to dungeon chests if Nether portals are the only type of portal - A Nether mod doesn't need a Book of Portals if it's only being used to provide a Nether portal.
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.
When a surface level was known, only the volume_is_natural check was being performed, this fixes that.
Also fixes bug where LBM didn't start the timer of example portals that had been disabled.
Allows portal ignite to repair a stopped timer.
Other misc cleanup - paramat's new Floatlands won't have lakes so I removed that from the flavortext.
give nether_portal_circular.mts a flat floor - the new nether_portal_circular.mts allows its bottom nodes to be sunk into the ground.
Example portal basic behavior and book_of_portals_pagetext implemented.
Other changes are allowing portals corrupted by ABMs to be repaired, finding better ground level of surface portals.
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
