start working on leveled nodes.

start working on generalizing registration of leveled nodes. currently
broken.

mods/bg_api/init.lua

@@ -23,6 +23,7 @@ load_file("random_tick")
 load_file("increasing_abm")
 load_file("loose_node")
 load_file("fall_fix")
+load_file("leveled_node")
 
 load_file("privs")
 

mods/bg_api/leveled_node.lua

@@ -0,0 +1,85 @@
+local decomposing_leaves_layers = 4
+
+local function is_same_kind (pos, basename)
+	local node = minetest.get_node(pos)
+	local node_basename = minetest.registered_items[node.name].basename
+	return basename == node_basename
+end
+
+local function after_place_stack (pos)
+	local node = minetest.get_node(pos)
+	if not blockgame.item_matches(node.name, {"groups:leveled"}) then return end
+	local def = minetest.registered_nodes[node.name]
+	local basename = def.basename
+	local level_max = def.level_max
+
+	local below = pos + blockgame.vector.dirs.down
+	if is_same_kind(below, basename) then
+		local below_node = minetest.get_node(pos)
+		local below_def = minetest.registered_nodes[below_node.name]
+
+		if below_def.level ~= level_max then
+			local max_diff = level_max - below_def.level
+			local diff = math.min(max_diff, def.level)
+
+			minetest.swap_node(below, {name = basename .. "_" .. (below_def.level + diff)})
+			if diff == def.level then
+				minetest.remove_node(pos)
+			else
+				minetest.swap_node(pos, {name = basename .. "_" .. (def.level - diff)})
+			end
+		end
+	end
+
+	local above = pos:offset(0, 1, 0)
+	if is_same_kind(above, basename) then
+		after_place_stack(above)
+	end
+end
+
+local function register_layer (basename, def, level)
+	local description = def.description .. " (" .. level .. "/" .. def.level_max .. ")"
+	if level == level_max then description = def.description end
+	def.description = description
+
+	local height = level / def.level_max
+
+	local drawtype = "nodebox"
+	local node_box = {
+		["type"] = "fixed",
+		fixed = { -0.5, -0.5, -0.5, 0.5, -0.5 + height, 0.5 },
+	}
+	if level == level_max then
+		drawtype = def.drawtype
+		node_box = nil
+	end
+	def.drawtype = drawtype
+	def.node_box = node_box
+
+	def.on_construct = after_place_stack
+	def.after_place_node = after_place_stack
+	def.after_land = after_place_stack
+
+	def.groups = def.groups or {}
+	def.groups = blockgame.underride(def.groups, {
+		leveled = level,
+	})
+
+	local layer_modname = minetest.get_current_modname()
+	def.drop = def.drop or layer_modname .. ":" .. basename .. "_1 " .. level
+
+	blockgame.register_node(basename .. "_" .. level, def)
+end
+
+function blockgame.register_leveled_node (basename, def)
+	local level_max = def.level_max
+	if not level_max then return false end
+
+	def.basename = basename
+
+	for level=1, level_max do
+		register_layer(basename, def, level)
+	end
+	minetest.register_alias(basename, basename .. "_" .. level_max)
+	return true
+end

mods/bg_api/util_table.lua

@@ -16,6 +16,18 @@ function blockgame.shallow_copy_table (tab)
 	return result
 end
 
+function blockgame.naive_deep_copy (tab)
+	local result = {}
+	for key, value in pairs(tab) do
+		if type(value) == "table" then
+			result[key] = blockgame.naive_deep_copy(value)
+		else
+			result[key] = value
+		end
+	end
+	return result
+end
+
 function blockgame.shuffle (tab)
 	local keys = blockgame.get_keys(tab)
 	local result = {}
@@ -43,9 +55,13 @@ end
 
 function blockgame.underride (tab, template)
 	local tab = tab or {}
-	local result = blockgame.shallow_copy_table(template)
+	local result = blockgame.naive_deep_copy(template)
 	for key, value in pairs(tab) do
+		if type(value) == "table" then
+			result[key] = blockgame.underride(value, template[key] or {})
+		else
 			result[key] = value
 		end
+	end
 	return result
 end

mods/bg_tree/node_leaves.lua

@@ -1,24 +1,25 @@
 local modname = minetest.get_current_modname()
 
-local function reg_leaves (name, def)
+local base_def = {
-	local texture = def.texture or name
-
-	def = blockgame.underride(def, {
-		description = name,
-
-		texture = texture,
-		tiles = {modname .. "_" .. texture .. ".png"},
-
 	drawtype = "allfaces_optional",
 	paramtype = "light",
 	sunlight_propagates = true,
-	})
+	groups = {
-
-	def.groups = blockgame.underride(def.groups, {
 		planty = 1,
 		extends_leaves_support = 1,
 		air_flowable = 1,
 		falling_node = 1,
+	},
+}
+
+local function reg_leaves (name, def)
+	def = blockgame.underride(def, base_def)
+
+	local texture = def.texture or name
+	def = blockgame.underride(def, {
+		description = name,
+		tiles = {modname .. "_" .. texture .. ".png"},
+
 	})
 
 	blockgame.register_node(name, def)
@@ -63,14 +64,17 @@ reg_leaves("leaves_alive", {
 	},
 })
 
+--[[
 local function check_decompose (pos)
 	local node = minetest.get_node(pos)
 	return blockgame.item_matches(node.name, {"group:leaves_decomposing"})
 end
+]]--
 
 -- TODO: generalize stacking node registration and put into API.
 local decomposing_leaves_layers = 4
 
+--[[
 local function after_place_stack (pos)
 	if not check_decompose(pos) then return end
 
@@ -117,26 +121,24 @@ local function reg_decomposing (level)
 		node_box = nil
 	end
 
-	reg_leaves("leaves_decomposing_" .. level, {
+	reg_leaves("leaves_decomposing_" .. level, )
-		description = description,
-		level = level,
-		level_max = decomposing_leaves_layers,
-		texture = "leaves_decomposing",
-		drawtype = drawtype,
-		node_box = node_box,
-		on_construct = after_place_stack,
-		after_place_node = after_place_stack,
-		after_land = after_place_stack,
-		drop = modname .. ":leaves_decomposing_1 " .. level,
-		groups = {
-			leaves_decomposing = level,
-		},
-		walkable = false,
-		supports_falling = true,
-	})
 end
 for level=1, decomposing_leaves_layers do
 	reg_decomposing(level)
 end
 
 minetest.register_alias(modname .. ":leaves_decomposing", modname .. ":leaves_decomposing_" .. decomposing_leaves_layers)
+]]--
+
+blockgame.register_leveled_node("leaves_decomposing", blockgame.underride({
+	description = "Decomposing Leaves",
+	level_max = decomposing_leaves_layers,
+	tiles = {
+		modname .. "_leaves_decomposing.png",
+	},
+	groups = {
+		leaves_decomposing = level,
+	},
+	walkable = false,
+	supports_falling = true,
+}, base_def))