Primordial cavern layer (#12)

* bring in the art assets from ClockGen's "better_caves_modpack" under CC BY 4.0,, code written from scratch.

* update mapgen_helper

* import ClockGen's giant mushroom schematics, make them and giant ferns growable

* add giant jungle mushroom, rough out actual cavern layer code framework

* fungal ceiling decorations

* decorate fungal floor a bit

* update mapgen_helper

* update primordial mushroom schematic placement to ensure it fits

* add giant mycelium fungoidal structure

* add giant mycelium to mapgen

* fix settings for giant mycelium

* make mycelium grow when players aren't present

* allow mycelium growth to pause when it hits unloaded areas

* add a use for giant mycelium

* make giant mushrooms edible, make jungle trees growable

* rough out the jungle biome

* Make a spectrum of jungle growth

* optimize pngs, add is_ground_content to everything

* use custom is_ground_content method

* fix a crash with veinstone, and simplify nvals_cave lookup now that overgen covers the same area

* more fixes for overgen support

* remove unintentional airspace from underside of slade

* fix for overgen crash in level 2

* primordial column material, add sealed shafts to underworld

* add seal block

* Set up puzzle seals to be able to dig a staircase shaft through the slade layer. TODO: the puzzle to guard the trigger.

* puzzle seals now fully functional. Need to add clues for decoding the keys next.

* add a small bit of anti-griefing - the seal breach bell only tolls globally 13 times per activation

* add flowers to the underworld warrior bones

* switch to a different key bell

* fancy up the puzzle seal temples with some custom blocks, add sub-slade grid passages

* add a clue to the seal formspec

* tweak background of inscription 2 so it's less obviously a copy of the background for inscription 1

* switch to compositing to save a few bytes

* fancy up the seal's upper surface with inscriptions to make the formspec feel consistent

* puzzle particle, bones were only spawning on top of structures

* fix ice/oil on level 3, tweak some loot probabilities

* add trail mod support

* remove deprecated files

* boost default plant growth delay, add growing selection boxes

* update map colours

* add named waypoints to the underworld

* try a more efficient way of changing the interiors of columns

* polishing up the Primordial layer

* update guide with some Primordial teasers

* updated magma sea screenshot

* update mapgen_helper and subterrane

* reduce density of megaflora a bit - was too hard to walk through

* spreading_dirt_type depends on light, create my own ABM instead

* add names to the glowing pits and some of the ruins

* separate setting for ruin markers

* record identity of slade-breachers

* make mycelia climbable

* update subterrane

* change surface tunnel detection to allow above-ground stalactites and stalagmites

* add rare thicker Goblin Caps, suitable for use as huts.

* better goblin cap schematics

* update colours

* make it slightly harder to dig down through amethyst sheathing of pits

* fixing up fungus light sensitivity, tree growth code

* fix a few minor bugs

* update deprecated functions

* add various eating sounds

* make mapping kit requirement more flexible

* update spindlestem growth code, remove deprecated functions

* fix leftover undefined variable

* add fireflies to primordial, spread out the post-mapgen node timer for plant matter a bit more.

* fix bones formspec

* add lbm to upgrade old bones

* fix slade undiggability

* make torchspines smokey and manually lightable

* fix drop definitions

* generate dry stalactites in near-surface caverns.

* caverns become far too smokey, alas

* add pitter patter of spore tree spores, alternate paper recipe

* new mapgen_helper metrics

* add smokey back to torchspine now that it can be dialed down a bit

* replace glowstone texture with a new animated one

* switch from ABM to node timer for mapgen mycelium growth

* make mapgen mycelium timer delay configurable

* improve the efficiency of giant mycelium growth using flat node array, fewer dereferences

* remove the smoke from torchspines again - it doesn't dissipate that deep underground

* give slade a more muted, gloomy hue to differentiate it from nether stone

* update screenshots with new slade colors

* update mapgen_helper

df_trees/tower_cap.lua

@@ -8,7 +8,7 @@ minetest.register_node("df_trees:tower_cap_stem", {
 	_doc_items_longdesc = df_trees.doc.tower_cap_desc,
 	_doc_items_usagehelp = df_trees.doc.tower_cap_usage,
 	tiles = {"dfcaverns_tower_cap.png"},
-	is_ground_content = true,
+	is_ground_content = false,
 	groups = {tree = 1, choppy = 2, oddly_breakable_by_hand = 1, flammable = 2, tower_cap = 1},
 	sounds = df_trees.node_sound_tree_soft_fungus_defaults(),
 })
@@ -19,7 +19,7 @@ minetest.register_node("df_trees:tower_cap", {
 	_doc_items_longdesc = df_trees.doc.tower_cap_desc,
 	_doc_items_usagehelp = df_trees.doc.tower_cap_usage,
 	tiles = {"dfcaverns_tower_cap.png"},
-	is_ground_content = true,
+	is_ground_content = false,
 	groups = {tree = 1, choppy = 2, oddly_breakable_by_hand = 1, flammable = 2, tower_cap = 1},
 	sounds = df_trees.node_sound_tree_soft_fungus_defaults(),
 })
@@ -30,7 +30,7 @@ minetest.register_node("df_trees:tower_cap_gills", {
 	_doc_items_longdesc = df_trees.doc.tower_cap_desc,
 	_doc_items_usagehelp = df_trees.doc.tower_cap_usage,
 	tiles = {"dfcaverns_tower_cap_gills.png"},
-	is_ground_content = true,
+	is_ground_content = false,
 	groups = {snappy = 3, leafdecay = 3, flammable = 2, leaves = 1, tower_cap = 1},
 	sounds = default.node_sound_leaves_defaults(),
 	drawtype = "plantlike",
@@ -125,6 +125,7 @@ minetest.register_node("df_trees:tower_cap_sapling", {
 	wield_image = "dfcaverns_tower_cap_sapling.png",
 	paramtype = "light",
 	sunlight_propagates = true,
+	is_ground_content = false,
 	walkable = false,
 	floodable = true,
 	selection_box = {
@@ -136,15 +137,21 @@ minetest.register_node("df_trees:tower_cap_sapling", {
 	sounds = default.node_sound_leaves_defaults(),
 
 	on_construct = function(pos)
-		local below_node = minetest.get_node(vector.add(pos, {x=0,y=-1,z=0}))
-		if minetest.get_item_group(below_node.name, "soil") > 0 then
-			minetest.get_node_timer(pos):start(math.random(
-				df_trees.config.tower_cap_delay_multiplier*df_trees.config.tree_min_growth_delay,
-				df_trees.config.tower_cap_delay_multiplier*df_trees.config.tree_max_growth_delay))
+		if minetest.get_item_group(minetest.get_node({x=pos.x, y=pos.y-1, z=pos.z}).name, "soil") == 0 then
+			return
 		end
+		minetest.get_node_timer(pos):start(math.random(
+			df_trees.config.tower_cap_delay_multiplier*df_trees.config.tree_min_growth_delay,
+			df_trees.config.tower_cap_delay_multiplier*df_trees.config.tree_max_growth_delay))
+	end,
+	on_destruct = function(pos)
+		minetest.get_node_timer(pos):stop()
 	end,
 	
 	on_timer = function(pos)
+		if df_farming and df_farming.kill_if_sunlit(pos) then
+			return
+		end
 		minetest.set_node(pos, {name="air"})
 		df_trees.spawn_tower_cap(pos)
 	end,