Default: Convert saplings to use node timers

Each sapling is given a single node timer that is between
2 and 4 days of game play time (40-80 minutes). If you walk out
of the zone, and come back later, the tree will always grow
to full if the timer has elapsed.

Because trees.lua is all functions, it needs to be parsed before
nodes.lua, since that references some of its functions. Hence,
change the order of parsing here. Otherwise saplings would not
grow to full.

mods/default/init.lua

@@ -36,6 +36,7 @@ default.gui_survival_form = "size[8,8.5]"..
 
 -- Load files
 dofile(minetest.get_modpath("default").."/functions.lua")
+dofile(minetest.get_modpath("default").."/trees.lua")
 dofile(minetest.get_modpath("default").."/nodes.lua")
 dofile(minetest.get_modpath("default").."/furnace.lua")
 dofile(minetest.get_modpath("default").."/tools.lua")
@@ -43,6 +44,5 @@ dofile(minetest.get_modpath("default").."/craftitems.lua")
 dofile(minetest.get_modpath("default").."/crafting.lua")
 dofile(minetest.get_modpath("default").."/mapgen.lua")
 dofile(minetest.get_modpath("default").."/player.lua")
-dofile(minetest.get_modpath("default").."/trees.lua")
 dofile(minetest.get_modpath("default").."/aliases.lua")
 dofile(minetest.get_modpath("default").."/legacy.lua")

mods/default/nodes.lua

@@ -455,6 +455,10 @@ minetest.register_node("default:sapling", {
 	paramtype = "light",
 	sunlight_propagates = true,
 	walkable = false,
+	on_timer = default.grow_sapling,
+	on_construct = function(pos)
+		minetest.get_node_timer(pos):start(math.random(2400,4800))
+	end,
 	selection_box = {
 		type = "fixed",
 		fixed = {-0.3, -0.5, -0.3, 0.3, 0.35, 0.3}
@@ -573,6 +577,10 @@ minetest.register_node("default:junglesapling", {
 	paramtype = "light",
 	sunlight_propagates = true,
 	walkable = false,
+	on_timer = default.grow_sapling,
+	on_construct = function(pos)
+		minetest.get_node_timer(pos):start(math.random(2400,4800))
+	end,
 	selection_box = {
 		type = "fixed",
 		fixed = {-0.3, -0.5, -0.3, 0.3, 0.35, 0.3}
@@ -634,6 +642,10 @@ minetest.register_node("default:pine_sapling", {
 	paramtype = "light",
 	sunlight_propagates = true,
 	walkable = false,
+	on_timer = default.grow_sapling,
+	on_construct = function(pos)
+		minetest.get_node_timer(pos):start(math.random(2400,4800))
+	end,
 	selection_box = {
 		type = "fixed",
 		fixed = {-0.3, -0.5, -0.3, 0.3, 0.35, 0.3}
@@ -695,6 +707,10 @@ minetest.register_node("default:acacia_sapling", {
 	paramtype = "light",
 	sunlight_propagates = true,
 	walkable = false,
+	on_timer = default.grow_sapling,
+	on_construct = function(pos)
+		minetest.get_node_timer(pos):start(math.random(2400,4800))
+	end,
 	selection_box = {
 		type = "fixed",
 		fixed = {-0.3, -0.5, -0.3, 0.3, 0.35, 0.3}
@@ -755,6 +771,10 @@ minetest.register_node("default:aspen_sapling", {
 	paramtype = "light",
 	sunlight_propagates = true,
 	walkable = false,
+	on_timer = default.grow_sapling,
+	on_construct = function(pos)
+		minetest.get_node_timer(pos):start(math.random(2400,4800))
+	end,
 	selection_box = {
 		type = "fixed",
 		fixed = {-0.3, -0.5, -0.3, 0.3, 0.35, 0.3}

mods/default/trees.lua

@@ -59,18 +59,15 @@ end
 
 -- Sapling ABM
 
-minetest.register_abm({
+function default.grow_sapling(pos)
-	nodenames = {"default:sapling", "default:junglesapling",
-		"default:pine_sapling", "default:acacia_sapling",
-		"default:aspen_sapling"},
-	interval = 10,
-	chance = 50,
-	action = function(pos, node)
 	if not default.can_grow(pos) then
+		-- try a bit later again
+		minetest.get_node_timer(pos):start(math.random(240, 600))
 		return
 	end
 
 	local mapgen = minetest.get_mapgen_params().mgname
+	local node = minetest.get_node(pos)
 	if node.name == "default:sapling" then
 		minetest.log("action", "A sapling grows into a tree at "..
 			minetest.pos_to_string(pos))
@@ -108,8 +105,16 @@ minetest.register_abm({
 		default.grow_new_aspen_tree(pos)
 	end
 end
-})
 
+minetest.register_lbm({
+	name = "default:convert_saplings_to_node_timer",
+	nodenames = {"default:sapling", "default:junglesapling",
+			"default:pine_sapling", "default:acacia_sapling",
+			"default:aspen_sapling"},
+	action = function(pos)
+		minetest.get_node_timer(pos):start(math.random(1200, 2400))
+	end
+})
 
 --
 -- Tree generation