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.
(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
Currently proof of concept: Removes wormhole colour from .png texture and specifies it through MT API instead. The post_effect_color may call for registering a separate node per portal colour.
Palette 0 will have to be the traditional portal magenta (instead of 0 being black) for map compatibility with mod when colour was in the texture and not param2.
Goal: make caves a lot brighter, accentuating glowstone and lava
accents, making walking around without torches possible. The old
light level was barely enough to walk and see edges. This level
feels adequate.
Gimp settings: brightness + 40, contrast + 20.
