add simple method for decorating native tunnels

init.lua

@@ -6,9 +6,6 @@
 
 subterrane = {} --create a container for functions and constants
 
--- set subterrane.mitigate_lava to true to attempt to mitigate lava spilling into the caves
--- set subterrane.get_param2_data to true to make this mod read and set param2 data (shaves a few milliseconds off when you don't, so mods that don't make use of this should leave this unset)
-
 --grab a shorthand for the filepath of the mod
 local modpath = minetest.get_modpath(minetest.get_current_modname())
 
@@ -103,9 +100,7 @@ function subterrane:register_cave_layer(cave_layer_def)
 		local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
 		local area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}
 		vm:get_data(data)
-		if subterrane.get_param2_data then
-			vm:get_param2_data(data_param2)
-		end
+		vm:get_param2_data(data_param2)
 	
 		local biomemap = minetest.get_mapgen_object("biomemap")
 		
@@ -219,10 +214,8 @@ function subterrane:register_cave_layer(cave_layer_def)
 								biome._subterrane_floor_decor(area, data, ai, vi, bi, data_param2)
 							end
 							
-						elseif (biome._subterrane_cave_floor_decor or biome._subterrane_cave_ceiling_decor)
-								and (nvals_cave[index_3d] + nvals_wave[index_3d])/2 <= tcave --if node falls outside cave threshold
-							then
-						-- decorate other "native" caves and tunnels
+						elseif (nvals_cave[index_3d] + nvals_wave[index_3d])/2 <= tcave then --if node falls outside cave threshold
+							-- decorate other "native" caves and tunnels
 							if biome._subterrane_cave_fill_node then
 								cave_fill_node = biome._subterrane_cave_fill_node
 								if data[vi] == c_air then
@@ -261,9 +254,7 @@ function subterrane:register_cave_layer(cave_layer_def)
 		
 		--send data back to voxelmanip
 		vm:set_data(data)
-		if subterrane.get_param2_data then
-			vm:set_param2_data(data_param2)
-		end
+		vm:set_param2_data(data_param2)
 		--calc lighting
 		vm:set_lighting({day = 0, night = 0})
 		vm:calc_lighting()
@@ -273,7 +264,109 @@ function subterrane:register_cave_layer(cave_layer_def)
 		local chunk_generation_time = math.ceil((os.clock() - t_start) * 1000) --grab how long it took
 		print ("[subterrane] "..chunk_generation_time.." ms") --tell people how long
 	end)
+end
 
+
+function subterrane:register_cave_decor(minimum_depth, maximum_depth)
+
+	-- On generated function
+	minetest.register_on_generated(function(minp, maxp, seed)
+		--if out of range of cave definition limits, abort
+		if minp.y > minimum_depth or maxp.y < maximum_depth then
+			return
+		end
+		
+		-- Create a table of biome ids for use with the biomemap.
+		if not subterrane.biome_ids then
+			subterrane.biome_ids = {}
+			for name, desc in pairs(minetest.registered_biomes) do
+				local i = minetest.get_biome_id(desc.name)
+				subterrane.biome_ids[i] = desc.name
+			end
+		end
+	
+		--easy reference to commonly used values
+		local t_start = os.clock()
+		local x_max = maxp.x
+		local y_max = maxp.y
+		local z_max = maxp.z
+		local x_min = minp.x
+		local y_min = minp.y
+		local z_min = minp.z
+		
+		print ("[subterrane] chunk minp ("..x_min.." "..y_min.." "..z_min..")") --tell people you are generating a chunk
+		
+		local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
+		local area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}
+		vm:get_data(data)
+		vm:get_param2_data(data_param2)
+	
+		local biomemap = minetest.get_mapgen_object("biomemap")
+		
+		local sidelen = x_max - x_min + 1 --length of a mapblock
+	
+		local index_3d = 1 --3D node index
+		local index_2d = 1 --2D node index
+		
+		for z = z_min, z_max do -- for each xy plane progressing northwards
+			--decoration loop, places nodes on floor and ceiling
+			for y = y_min, y_max do -- for each x row progressing upwards
+				local vi = area:index(x_min, y, z)
+				for x = x_min, x_max do -- for each node do
+				
+					local biome_name = subterrane.biome_ids[biomemap[index_2d]]
+					local biome = minetest.registered_biomes[biome_name]
+					local cave_fill_node = c_air
+	
+					if biome then
+						-- decorate "native" caves and tunnels
+						if biome._subterrane_cave_fill_node then
+							cave_fill_node = biome._subterrane_cave_fill_node
+							if data[vi] == c_air then
+								data[vi] = cave_fill_node
+							end
+						end
+
+						local ai = area:index(x,y+1,z) --above index
+						local bi = area:index(x,y-1,z) --below index
+
+						if biome._subterrane_cave_ceiling_decor
+							and data[ai] ~= cave_fill_node
+							and data[vi] == cave_fill_node
+							and y < y_max
+							then --ceiling
+							biome._subterrane_cave_ceiling_decor(area, data, ai, vi, bi, data_param2)
+						end
+						--ground
+						if biome._subterrane_cave_floor_decor
+							and data[bi] ~= cave_fill_node
+							and data[vi] == cave_fill_node
+							and y > y_min
+							then --ground
+							biome._subterrane_cave_floor_decor(area, data, ai, vi, bi, data_param2)
+						end
+					end	
+					index_3d = index_3d + 1
+					index_2d = index_2d + 1
+					vi = vi + 1
+				end
+				index_2d = index_2d - sidelen --shift the 2D index back
+			end
+			index_2d = index_2d + sidelen --shift the 2D index up a layer
+		end
+		
+		--send data back to voxelmanip
+		vm:set_data(data)
+		vm:set_param2_data(data_param2)
+		--calc lighting
+		vm:set_lighting({day = 0, night = 0})
+		vm:calc_lighting()
+		--write it to world
+		vm:write_to_map(data)
+	
+		local chunk_generation_time = math.ceil((os.clock() - t_start) * 1000) --grab how long it took
+		print ("[subterrane] "..chunk_generation_time.." ms") --tell people how long
+	end)
 end
 
 print("[Subterrane] loaded!")