Mushroom spread: Optimise and make overridable

Move mushroom spread ABM action into a global and overridable function.
Optimise spread code.
Reduce spread range to reduce spread through walls.

diff --git a/mods/flowers/init.lua b/mods/flowers/init.lua
index cb5b21930cb2cfe624fae75f095fcbd9f93677c6..57112c16bc5fdb7fe7d93c5e28bad63ce77a27eb 100644 (file)
--- a/mods/flowers/init.lua
+++ b/mods/flowers/init.lua
@@ -204,38 +204,34 @@ minetest.register_node("flowers:mushroom_brown", {
 
 -- Mushroom spread and death
 
+function flowers.mushroom_spread(pos, node)
+       if minetest.get_node_light(pos, nil) == 15 then
+               minetest.remove_node(pos)
+               return
+       end
+       local positions = minetest.find_nodes_in_area_under_air(
+               {x = pos.x - 1, y = pos.y - 2, z = pos.z - 1},
+               {x = pos.x + 1, y = pos.y + 1, z = pos.z + 1},
+               {"group:soil", "group:tree"})
+       if #positions == 0 then
+               return
+       end
+       local pos2 = positions[math.random(#positions)]
+       pos2.y = pos2.y + 1
+       if minetest.get_node_light(pos, 0.5) <= 3 and
+                       minetest.get_node_light(pos2, 0.5) <= 3 then
+               minetest.set_node(pos2, {name = node.name})
+       end
+end
+
 minetest.register_abm({
        label = "Mushroom spread",
        nodenames = {"flowers:mushroom_brown", "flowers:mushroom_red"},
        interval = 11,
-       chance = 50,
-       action = function(pos, node)
-               if minetest.get_node_light(pos, nil) == 15 then
-                       minetest.remove_node(pos)
-                       return
-               end
-               local random = {
-                       x = pos.x + math.random(-2, 2),
-                       y = pos.y + math.random(-1, 1),
-                       z = pos.z + math.random(-2, 2)
-               }
-               local random_node = minetest.get_node_or_nil(random)
-               if not random_node or random_node.name ~= "air" then
-                       return
-               end
-               local node_under = minetest.get_node_or_nil({x = random.x,
-                       y = random.y - 1, z = random.z})
-               if not node_under then
-                       return
-               end
-
-               if (minetest.get_item_group(node_under.name, "soil") ~= 0 or
-                               minetest.get_item_group(node_under.name, "tree") ~= 0) and
-                               minetest.get_node_light(pos, 0.5) <= 3 and
-                               minetest.get_node_light(random, 0.5) <= 3 then
-                       minetest.set_node(random, {name = node.name})
-               end
-       end
+       chance = 150,
+       action = function(...)
+               flowers.mushroom_spread(...)
+       end,
 })