Leaf decay, based on the groups 'leafdecay' and 'tree'

diff --git a/mods/default/init.lua b/mods/default/init.lua
index bd17d6869ac12328925b5921d7f26655f241972c..fda4ee1c6c2c3b7ca2a088052a54f1605bb162ff 100644 (file)
--- a/mods/default/init.lua
+++ b/mods/default/init.lua
@@ -11,8 +11,9 @@ LIGHT_MAX = 14
 -- Definitions made by this mod that other mods can use too
 default = {}
 
--- Register and define map generator stuff
+-- Load other files
 dofile(minetest.get_modpath("default").."/mapgen.lua")
+dofile(minetest.get_modpath("default").."/leafdecay.lua")
 
 --
 -- Tool definition
@@ -808,7 +809,7 @@ minetest.register_node("default:tree", {
        description = "Tree",
        tile_images = {"default_tree_top.png", "default_tree_top.png", "default_tree.png"},
        is_ground_content = true,
-       groups = {snappy=2,choppy=2,oddly_breakable_by_hand=1},
+       groups = {tree=1,snappy=2,choppy=2,oddly_breakable_by_hand=1},
        sounds = default.node_sound_wood_defaults(),
 })
 
@@ -816,7 +817,7 @@ minetest.register_node("default:jungletree", {
        description = "Jungle Tree",
        tile_images = {"default_jungletree_top.png", "default_jungletree_top.png", "default_jungletree.png"},
        is_ground_content = true,
-       groups = {snappy=2,choppy=2,oddly_breakable_by_hand=1},
+       groups = {tree=1,snappy=2,choppy=2,oddly_breakable_by_hand=1},
        sounds = default.node_sound_wood_defaults(),
 })
 
@@ -839,7 +840,7 @@ minetest.register_node("default:leaves", {
        visual_scale = 1.3,
        tile_images = {"default_leaves.png"},
        paramtype = "light",
-       groups = {snappy=3},
+       groups = {snappy=3, leafdecay=3},
        drop = {
                max_items = 1,
                items = {

diff --git a/mods/default/leafdecay.lua b/mods/default/leafdecay.lua
new file mode 100644 (file)
index 0000000..0fa894a
--- /dev/null
+++ b/mods/default/leafdecay.lua
@@ -0,0 +1,76 @@
+-- minetest/default/leafdecay.lua
+
+-- To enable leaf decay for a node, add it to the "leafdecay" group.
+--
+-- The rating of the group determines how far from a node in the group "tree"
+-- the node can be without decaying.
+--
+-- If param2 of the node is ~= 0, the node will always be preserved. Thus, if
+-- the player places a node of that kind, you will want to set param2=1 or so.
+
+default.leafdecay_trunk_cache = {}
+default.leafdecay_enable_cache = true
+
+minetest.register_abm({
+       nodenames = {"group:leafdecay"},
+       neighbors = {"air", "group:liquid"},
+       -- A low interval and a high inverse chance spreads the load
+       interval = 2,
+       chance = 5,
+
+       action = function(p0, node, _, _)
+               --print("leafdecay ABM at "..p0.x..", "..p0.y..", "..p0.z..")")
+               local do_preserve = false
+               local d = minetest.registered_nodes[node.name].groups.leafdecay
+               if not d or d == 0 then
+                       --print("not groups.leafdecay")
+                       return
+               end
+               local n0 = minetest.env:get_node(p0)
+               if n0.param2 ~= 0 then
+                       --print("param2 ~= 0")
+                       return
+               end
+               local p0_hash = nil
+               if default.leafdecay_enable_cache then
+                       p0_hash = minetest.hash_node_position(p0)
+                       local trunkp = default.leafdecay_trunk_cache[p0_hash]
+                       if trunkp then
+                               local n = minetest.env:get_node(trunkp)
+                               local reg = minetest.registered_nodes[n.name]
+                               if reg.groups.tree and reg.groups.tree ~= 0 then
+                                       --print("cached trunk still exists")
+                                       return
+                               end
+                               --print("cached trunk is invalid")
+                               -- Cache is invalid
+                               table.remove(default.leafdecay_trunk_cache, p0_hash)
+                       end
+               end
+               for dx = -d, d do if do_preserve then break end
+               for dy = -d, d do if do_preserve then break end
+               for dz = -d, d do if do_preserve then break end
+                       local p = {
+                               x = p0.x + dx,
+                               y = p0.y + dy,
+                               z = p0.z + dz,
+                       }
+                       local n = minetest.env:get_node(p)
+                       local reg = minetest.registered_nodes[n.name]
+                       if reg.groups.tree and reg.groups.tree ~= 0 then
+                               do_preserve = true
+                               if default.leafdecay_enable_cache then
+                                       --print("caching trunk")
+                                       -- Cache the trunk
+                                       default.leafdecay_trunk_cache[p0_hash] = p
+                               end
+                       end
+               end
+               end
+               end
+               if not do_preserve then
+                       minetest.env:remove_node(p0)
+               end
+       end
+})
+