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_caverns/level3.lua

@@ -28,7 +28,7 @@ if minetest.get_modpath("ice_sprites") then
 	c_sprite = minetest.get_content_id("ice_sprites:ice_sprite")
 end
 
-local subsea_level = df_caverns.config.level3_min - (df_caverns.config.level3_min - df_caverns.config.level2_min) * 0.33
+local subsea_level = math.floor(df_caverns.config.level3_min - (df_caverns.config.level3_min - df_caverns.config.level2_min) * 0.33)
 local flooding_threshold = math.min(df_caverns.config.tunnel_flooding_threshold, df_caverns.config.cavern_threshold)
 
 local ice_thickness = 3
@@ -165,7 +165,7 @@ local blood_thorn_cavern_floor = function(abs_cracks, vert_rand, vi, area, data,
 	if abs_cracks < 0.075 then
 		if vert_rand < 0.004 then
 			subterrane.big_stalagmite(ai, area, data, 6, 15, c_dry_flowstone, c_dry_flowstone, c_dry_flowstone)
-		elseif data[vi] ~= air and math.random() < 0.5 then
+		elseif data[vi] ~= c_air and math.random() < 0.5 then
 			data[vi] = c_salty_cobble
 			if data[ai] == c_air and math.random() < 0.25 then
 				data[ai] = c_salt_crystal
@@ -207,25 +207,25 @@ local decorate_level_3 = function(minp, maxp, seed, vm, node_arrays, area, data)
 	
 	-- Partly fill flooded caverns and warrens
 	if minp.y <= subsea_level then
-		for vi in area:iterp(minp, maxp) do
-			local y = area:get_y(vi)
-			if y <= subsea_level and nvals_cave[cave_area:transform(area, vi)] < -flooding_threshold then
+		for vi, x, y, z in area:iterp_yxz(area.MinEdge, area.MaxEdge) do
+			local cave = nvals_cave[vi]
+			if y <= subsea_level and cave < -flooding_threshold then
 				if data[vi] == c_air and y <= subsea_level then
 					data[vi] = c_water
 				end
 				
-				local index2d = mapgen_helper.index2di(minp, maxp, area, vi)
-				local biome_name = get_biome(heatmap[index2d], humiditymap[index2d])
-				
-				if biome_name == "blackcap" then
-					-- oil slick
-					local cave = math.abs(nvals_cave[cave_area:transform(area, vi)])
-					if y == subsea_level and data[vi] == c_water and cave + nvals_cracks[index2d]*0.025 < cavern_def.cave_threshold + 0.1 then
-						data[vi] = c_oil
+				if (mapgen_helper.is_pos_within_box({x=x, y=y, z=z}, minp, maxp)) then				
+					local index2d = mapgen_helper.index2di(minp, maxp, area, vi)
+					local biome_name = get_biome(heatmap[index2d], humiditymap[index2d])
+					if biome_name == "blackcap" then
+						-- oil slick
+						if y == subsea_level and data[vi] == c_water and math.abs(cave) + nvals_cracks[index2d]*0.025 < cavern_def.cave_threshold + 0.1 then
+							data[vi] = c_oil
+						end
+					elseif biome_name == "bloodnether" and y <= subsea_level and y > subsea_level - ice_thickness and data[vi] == c_water then
+						-- floating ice
+						data[vi] = c_ice
 					end
-				elseif biome_name == "bloodnether" and y <= subsea_level and y > subsea_level - ice_thickness and data[vi] == c_water then
-					-- floating ice
-					data[vi] = c_ice
 				end
 			end
 		end
@@ -240,7 +240,7 @@ local decorate_level_3 = function(minp, maxp, seed, vm, node_arrays, area, data)
 		local biome_name = get_biome(heatmap[index2d], humiditymap[index2d])
 		local cracks = nvals_cracks[index2d]
 		local abs_cracks = math.abs(cracks)
-		local flooded_caverns = nvals_cave[cave_area:transform(area, vi)] < 0 -- this indicates if we're in the "flooded" set of caves or not.
+		local flooded_caverns = nvals_cave[vi] < 0 -- this indicates if we're in the "flooded" set of caves or not.
 
 		if flooded_caverns and minp.y < subsea_level and area:get_y(vi) < subsea_level then
 			-- underwater floor
@@ -285,7 +285,7 @@ local decorate_level_3 = function(minp, maxp, seed, vm, node_arrays, area, data)
 		local index2d = mapgen_helper.index2di(minp, maxp, area, vi)
 		local biome_name = get_biome(heatmap[index2d], humiditymap[index2d])
 		local abs_cracks = math.abs(nvals_cracks[index2d])
-		local flooded_caverns = nvals_cave[cave_area:transform(area, vi)] < 0 -- this indicates if we're in the "flooded" set of caves or not.
+		local flooded_caverns = nvals_cave[vi] < 0 -- this indicates if we're in the "flooded" set of caves or not.
 
 		if flooded_caverns and minp.y < subsea_level and area:get_y(vi) < subsea_level then
 			-- underwater ceiling, do nothing
@@ -321,7 +321,7 @@ local decorate_level_3 = function(minp, maxp, seed, vm, node_arrays, area, data)
 			else
 				-- bloodthorn ceiling
 				if abs_cracks < 0.075 then
-					if data[vi] ~= air and math.random() < 0.5 then
+					if data[vi] ~= c_air and math.random() < 0.5 then
 						data[vi] = c_salty_cobble
 						local bi = vi - area.ystride
 						if data[bi] == c_air and math.random() < 0.25 then
@@ -346,7 +346,7 @@ local decorate_level_3 = function(minp, maxp, seed, vm, node_arrays, area, data)
 	for _, vi in ipairs(node_arrays.tunnel_floor_nodes) do
 		local index2d = mapgen_helper.index2di(minp, maxp, area, vi)
 		local biome_name = get_biome(heatmap[index2d], humiditymap[index2d])
-		local flooded_caverns = nvals_cave[cave_area:transform(area, vi)] < 0 -- this indicates if we're in the "flooded" set of caves or not.
+		local flooded_caverns = nvals_cave[vi] < 0 -- this indicates if we're in the "flooded" set of caves or not.
 
 		if not (flooded_caverns and minp.y < subsea_level and area:get_y(vi) < subsea_level) then
 			if flooded_caverns or biome_name == "blackcap" then		
@@ -364,7 +364,7 @@ local decorate_level_3 = function(minp, maxp, seed, vm, node_arrays, area, data)
 	for _, vi in ipairs(node_arrays.tunnel_ceiling_nodes) do
 		local index2d = mapgen_helper.index2di(minp, maxp, area, vi)
 		local biome_name = get_biome(heatmap[index2d], humiditymap[index2d])
-		local flooded_caverns = nvals_cave[cave_area:transform(area, vi)] < 0 -- this indicates if we're in the "flooded" set of caves or not.
+		local flooded_caverns = nvals_cave[vi] < 0 -- this indicates if we're in the "flooded" set of caves or not.
 		
 		if not (flooded_caverns and minp.y < subsea_level and area:get_y(vi) < subsea_level) then
 			if flooded_caverns or biome_name == "blackcap" then
@@ -393,7 +393,7 @@ local decorate_level_3 = function(minp, maxp, seed, vm, node_arrays, area, data)
 	for _, vi in ipairs(node_arrays.warren_ceiling_nodes) do
 		local index2d = mapgen_helper.index2di(minp, maxp, area, vi)
 		local biome_name = get_biome(heatmap[index2d], humiditymap[index2d])
-		local flooded_caverns = nvals_cave[cave_area:transform(area, vi)] < 0 -- this indicates if we're in the "flooded" set of caves or not.
+		local flooded_caverns = nvals_cave[vi] < 0 -- this indicates if we're in the "flooded" set of caves or not.
 		
 		if flooded_caverns and minp.y < subsea_level and area:get_y(vi) < subsea_level then
 			-- underwater ceiling, do nothing
@@ -431,7 +431,7 @@ local decorate_level_3 = function(minp, maxp, seed, vm, node_arrays, area, data)
 	for _, vi in ipairs(node_arrays.warren_floor_nodes) do
 		local index2d = mapgen_helper.index2di(minp, maxp, area, vi)
 		local biome_name = get_biome(heatmap[index2d], humiditymap[index2d])
-		local flooded_caverns = nvals_cave[cave_area:transform(area, vi)] < 0 -- this indicates if we're in the "flooded" set of caves or not.
+		local flooded_caverns = nvals_cave[vi] < 0 -- this indicates if we're in the "flooded" set of caves or not.
 		
 		if minp.y < subsea_level and area:get_y(vi) < subsea_level and flooded_caverns then
 			-- underwater floor, do nothing
@@ -473,7 +473,7 @@ local decorate_level_3 = function(minp, maxp, seed, vm, node_arrays, area, data)
 	for _, vi in ipairs(node_arrays.column_nodes) do
 		local index2d = mapgen_helper.index2di(minp, maxp, area, vi)
 		local biome_name = get_biome(heatmap[index2d], humiditymap[index2d])
-		local flooded_caverns = nvals_cave[cave_area:transform(area, vi)] < 0
+		local flooded_caverns = nvals_cave[vi] < 0
 
 		if biome_name == "bloodnether" and data[vi] == c_wet_flowstone then
 			if not flooded_caverns then
@@ -527,4 +527,5 @@ subterrane.register_layer({
 	decorate = decorate_level_3,
 	warren_region_variability_threshold = 0.33,
 	double_frequency = true,
+	is_ground_content = df_caverns.is_ground_content,
 })