tunnelmaker change log
-- Version 2.0-pre-1 (ver-2 git branch)
-- Started with Mikola's update. Changes so far look very good, and they're significant enough to bump version to 2.0.
-- Updated left-click use. Left-click does single node_dig without repeating. Sneak left-click brings up formspec.
-- Added User config formspec with three items: Remove reference nodes, Dig non-train tunnels, and Continuous updown digging.
--   Remove reference nodes replaces chat commands.
--   Dig non-train tunnels allows digging 5x5 unlined tunnels without references, gravel, etc.
-- Changed lights back to torches with option to use mese_post_lights.
-- Prefixed all minetest.conf settings with tunnel_, but didn't update settingtypes.txt.
-- Removed the few characters in comments that linux reported to have encoding problems.
-- Added flip and rotate support to run_list, so one only needs to give the seven base digging patterns, instead of all 32.
-- Still in the process of validation and verification. Each time new options are added, this process gets harder.
-- Added sounds for digging, but need better one for tunneling.
-- Per Mikola's comment, license is TBD. Need reference to code actually borrowed.

-- Version 1.X.X
-- Removed the crafting scheme for the tunnelmaker tool. Normal players do not need to craft the tunnelmaker tool, and the administration can use the command /give <name> tunnelmaker:tool1 .
-- Added the ability to make a mound of gravel (or any other material) and an additional base under the gravel.
-- Custom configurations are made in settingtypes.txt and accessed in the main menu minetest / advanced settings / mods / tunnelmaker.
-- Add additional user configurations.
-- Optionally enable the use of other materials in desert biomes.
-- Optionally disable to replace the coating of tunnels on a specific coating.
-- Optionally disable wide paths in the woods
-- Optionally disable gravel mound and additional base.
-- Optionally disable markup for the railway advtrains.
-- Now you can change any material that is used in the tunnelmaker
-- Added coverage in underwater tunnels
-- When using "Glass walls", underwater tunnels have become completely sealed.
-- Added the function of automatic replacement of material markup on the road surface. Use the remove_marking <on | off> command.
-- Now for the operation of the functions of the mod is not required creative mode.
-- Now on the floor of the tunnel there is always a specific coating.

-- Version 1.0
-- Add two additional user configurations:
-- Set height of tunnels.
-- Optionally disable "arches".
-- Fixed bug in one reference block placement.

-- Version 0.9.9
-- Add additional user configurations.
-- Optionally disable adding torches.
-- Optionally change search distance for torches.
-- Optionally allow continuous up/down digging, without resetting each time.

-- Version 0.9.8
-- Optionally add back in water tunnels.
-- Optionally disable placing cobblestone references on the ground.
-- Edit init.lua to change these configuration variables (near top of file).

-- Version 0.9.7
-- Revert back to checking for dtrack by name, instead of groups.advtrains_track.
-- Groups doesn't work in latest versions of advtrains.
-- Changed left-click digging to steel_pick equivalent instead of wood_pick.

-- Version 0.9.6
-- Delete player's global state when player leaves.

-- Version 0.9.5
-- Add cobble braces for bridges if they would be air.

-- Version 0.9.4
-- Major update to build in support for digging up and down.
-- Digging up and down only supports orthogonal and 45deg directions to match advtrains track.
-- (Note: advtrains track requires at least one horizontal track matching slope before making any turns.)
-- To select updown direction, hold sneak key (shift) while right-clicking tunnelmaker.
-- One click selects up (Yellow 'U' on icon), second click selects down (Yellow 'D' on icon),
-- third click returns back to horizontal (no letter on icon).
-- Updown state can also be reset by rotating to different icon, or moving by some amount (still tuning this).
-- Once updown state is selected, release sneak key and use right-click like normal.
-- After digging, updown state will also be reset to horizontal.
-- Known changes/issues caused by using sneak key:
--   • Can't dig up or down while flying.
--   • Digall won't apply its function when right-clicking tunnelmaker.
--   • Can't sneak right-click on ATC track to dig below them.

-- Version 0.9.3
-- Tweak cdir == 2 (nw) digging pattern.
-- Clean up some old debug statements.

-- Version 0.9.2
-- Continue work making tunnelmaker play nice with advtrains track.
-- Per Orwell's request, changed method for determining if node is advtrains track.
-- Instead of searching for dtrack in name of node,
-- I check whether the node belongs to the advtrains_track group using:
--     if minetest.registered_nodes[name].groups.advtrains_track == 1 then
--
-- Note that one can't right click ATC track with tunnelmaker, that track overrides right click.
-- Trying to right click on slope track probably won't do what is wanted.  Right now it treats
-- it like any other track, and digs the ground level.

-- Version 0.9.1
-- 1. Try to play nicer with already placed advtrains track (dtrack*).
--   A. Don't dig dtrack nodes.
--      This allows expanding or extending tunnels where track has already been laid.
--    However this causes issues when using tunnelmaker to raise or lower track.
--      Trying to dig tunnel one node above track won't fill where placed track exists.
--      Trying to dig tunnel one node below track will cause existing track to drop.
--   B. If pointing to dtrack node, assume user actually wants to point to ground below track.
--      Lower positions of pointed_thing by one node, while keeping name the same.
--      This assumes that existing track is sitting on valid node.
-- 2. Restruction direction code to make it much shorter.
-- 3. Fixed bug in implementation of SSW digging pattern.
--
-- Version 0.9.0
-- 1. Updated digging patterns to fix minor irregularities.
-- 2. Added protections for tunneling in water.
--      Adds glass walls around tunnel whenever there is water.
--      Adds glass endcap at end to protect from flooding while tunneling.
--      Note that this can place undesired glass when digging next to ground-level water. This
--        won't happen as long as you're one node higher than the water.
-- 3. Restructured code again.  Code is longer, but simpler to understand.

-- Version 0.8.1
-- Test if air before digging.  Cleans up air not diggable INFO messages.
-- Added test for desert-type biomes, which lets me start using biome-appropriate fill.
--   needs minetest 0.5.0+ to correctly flag desert biomes
--   however, if api doesn't exist (using 0.4.x), test just always returns false

-- Version 0.8.0
-- Changed from dig_node to node_dig (based on what matyilona200 did for the Tunneltest mod)
-- Places only a single instance of each type of block dug in inventory
-- Doesn't cause blocks to drop in 0.5.0-dev
-- Works with digall mod, but make sure it's deactivated before tunneling!

-- Version 0.7.0
-- Added test for fallable blocks in ceiling and replace them with cobblestone.
-- Fixed bug where I was digging from lower blocks to higher blocks.
-- Simplified and cleaned up tunneling code.

-- Version 0.6.0
-- Increased width and height of tunnel created.