cave pearls and spindleshrooms (name subject to change) now are things. Not in mapgen yet.

df_mapitems/cave_coral.lua

@@ -10,6 +10,7 @@ minetest.register_node("df_mapitems:cave_coral_3", {
 	is_ground_content = true,
 	drop = "default:coral_skeleton",
 	light_source = 3,
+	paramtype2 = "facedir",
 	groups = {cracky = 3, dfcaverns_cave_coral = 1},
 	sounds = default.node_sound_stone_defaults(),
 })
@@ -22,6 +23,7 @@ minetest.register_node("df_mapitems:cave_coral_2", {
 	is_ground_content = true,
 	drop = "default:coral_skeleton",
 	light_source = 2,
+	paramtype2 = "facedir",
 	groups = {cracky = 3, dfcaverns_cave_coral = 1},
 	sounds = default.node_sound_stone_defaults(),
 })
@@ -34,6 +36,7 @@ minetest.register_node("df_mapitems:cave_coral_1", {
 	is_ground_content = true,
 	drop = "default:coral_skeleton",
 	light_source = 1,
+	paramtype2 = "facedir",
 	groups = {cracky = 3, dfcaverns_cave_coral = 1},
 	sounds = default.node_sound_stone_defaults(),
 })
@@ -46,7 +49,8 @@ minetest.register_abm{
 	interval = 2,
 	chance = 10,
 	action = function(pos)
-		minetest.swap_node(pos, {name=coral_names[math.random(1,3)]})
+		local node = minetest.get_node(pos)
+		minetest.swap_node(pos, {name=coral_names[math.random(1,3)], param2=node.param2})
 	end,
 }
 

df_mapitems/cave_pearls.lua

@@ -0,0 +1,154 @@
+-- internationalization boilerplate
+local MP = minetest.get_modpath(minetest.get_current_modname())
+local S, NS = dofile(MP.."/intllib.lua")
+
+local pearl_on_place = function(itemstack, placer, pointed_thing)
+	local pt = pointed_thing
+	-- check if pointing at a node
+	if not pt then
+		return itemstack
+	end
+	if pt.type ~= "node" then
+		return itemstack
+	end
+	
+	local under_pos = pt.under
+	local above_pos = pt.above
+
+	local under_node = minetest.get_node(under_pos)
+	local above_node = minetest.get_node(above_pos)
+
+	if minetest.is_protected(above_pos, placer:get_player_name()) then
+		minetest.record_protection_violation(above_pos, placer:get_player_name())
+		return
+	end
+
+	local under_name = under_node.name
+	local above_name = above_node.name
+	local under_def = minetest.registered_nodes[under_name]
+	local above_def = minetest.registered_nodes[above_name]
+	
+	-- return if any of the nodes is not registered
+	if not under_def or not above_def then
+		return itemstack
+	end
+	-- check if you can replace the node above the pointed node
+	if not above_def.buildable_to then
+		return itemstack
+	end
+
+	local dir = vector.subtract(under_pos, above_pos)
+	local param2
+	if dir.x > 0 then
+		--facing +x: 16, 17, 18, 19,
+		param2 = 15 + math.random(1,4)
+	elseif dir.x < 0 then
+		--facing -x: 12, 13, 14, 15
+		param2 = 11 + math.random(1,4)
+	elseif dir.z > 0 then
+		--facing +z: 8, 9, 10, 11
+		param2 = 7 + math.random(1,4)
+	elseif dir.z < 0 then
+		--facing -z: 4, 5, 6, 7
+		param2 = 3 + math.random(1,4)
+	elseif dir.y > 0 then
+		--facing -y: 20, 21, 22, 23 (ceiling)
+		param2 = 19 + math.random(1,4)
+	else
+		--facing +y: 0, 1, 2, 3 (floor)
+		param2 = math.random(1,4) - 1
+	end
+
+	-- add the node and remove 1 item from the itemstack
+	minetest.add_node(above_pos, {name = itemstack:get_name(), param2 = param2})
+	if not minetest.setting_getbool("creative_mode") and not minetest.check_player_privs(placer, "creative") then
+		itemstack:take_item()
+	end
+	return itemstack
+end
+
+local valid_mounting_node = function(pos)
+	local node = minetest.get_node(pos)
+	if not node then return false end
+	local def = minetest.registered_nodes[node.name]
+	if not def then return false end
+	if def.buildable_to then return false end
+	return true
+end
+
+local add_to_table = function(dest, source)
+	for _, val in ipairs(source) do
+		table.insert(dest, val)
+	end
+end
+
+local get_valid_facedirs = function(pos)
+	local dirs = {}
+	if valid_mounting_node(vector.add(pos, {x=1,y=0,z=0})) then
+		add_to_table(dirs, {16, 17, 18, 19})
+	end
+	if valid_mounting_node(vector.add(pos, {x=-1,y=0,z=0})) then
+		add_to_table(dirs, {12, 13, 14, 15})
+	end
+	if valid_mounting_node(vector.add(pos, {x=0,y=1,z=0})) then
+		add_to_table(dirs, {0, 1, 2, 3})
+	end
+	if valid_mounting_node(vector.add(pos, {x=0,y=-1,z=0})) then
+		add_to_table(dirs, {20, 21, 22, 23})
+	end
+	if valid_mounting_node(vector.add(pos, {x=0,y=0,z=1})) then
+		add_to_table(dirs, {8, 9, 10, 11})
+	end
+	if valid_mounting_node(vector.add(pos, {x=0,y=0,z=-1})) then
+		add_to_table(dirs, {4, 5, 6, 7})
+	end
+end
+
+minetest.register_node("df_mapitems:wall_pearls", {
+	description = S("Cave Pearls"),
+	tiles = {"dfcaverns_cave_pearl.png"},
+	drawtype = "nodebox",
+	paramtype = "light",
+	paramtype2 = "facedir",
+	groups = {cracky = 2},
+	walkable = false,
+	climbable = true,
+	light_source = 4,
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{-0.375, -0.5, -0.375, -0.125, -0.3125, -0.125}, -- NodeBox1
+			{0.125, -0.5, -0.1875, 0.3125, -0.375, 0}, -- NodeBox2
+			{-0.125, -0.5, 0.25, 0.0625, -0.375, 0.4375}, -- NodeBox3
+		}
+	},
+	on_place = pearl_on_place,
+})
+
+local c_air = minetest.get_content_id("air")
+local c_stone = minetest.get_content_id("default:stone")
+local c_pearls = minetest.get_content_id("df_mapitems:wall_pearls")
+
+--facing +x: 16, 17, 18, 19, 
+--facing -x: 12, 13, 14, 15
+--facing +z: 8, 9, 10, 11
+--facing -z: 4, 5, 6, 7
+--facing -y: 20, 21, 22, 23, (ceiling)
+df_mapitems.place_wall_pearls = function(vi, area, data, data_param2)
+	if data[vi] == c_air then
+		if data[vi+1] == c_stone then -- positive X
+			data[vi] = c_pearls
+			data_param2[vi] = 15 + math.random(1,4)
+		elseif data[vi-1] == c_stone then -- negative X
+			data[vi] = c_pearls
+			data_param2[vi] = 11 + math.random(1,4)
+		elseif data[vi+area.zstride] == c_stone then -- positive Z
+			data[vi] = c_pearls
+			data_param2[vi] = 7 + math.random(1,4)
+		elseif data[vi-area.zstride] == c_stone then -- negative Z
+			data[vi] = c_pearls
+			data_param2[vi] = 3 + math.random(1,4)
+		end
+	end
+end
+

df_mapitems/init.lua

@@ -17,4 +17,5 @@ dofile(modpath.."/cave_coral.lua")
 dofile(modpath.."/crystals_mese.lua")
 dofile(modpath.."/crystals_ruby.lua")
 
-dofile(modpath.."/veinstone.lua")
+dofile(modpath.."/veinstone.lua")
+dofile(modpath.."/cave_pearls.lua")