builtin/falling.lua

   1 -- Minetest: builtin/item.lua
   2
   3 --
   4 -- Falling stuff
   5 --
   6
   7 minetest.register_entity("__builtin:falling_node", {
   8         initial_properties = {
   9                 physical = true,
  10                 collisionbox = {-0.5,-0.5,-0.5, 0.5,0.5,0.5},
  11                 visual = "wielditem",
  12                 textures = {},
  13                 visual_size = {x=0.667, y=0.667},
  14         },
  15
  16         nodename = "",
  17
  18         set_node = function(self, nodename)
  19                 self.nodename = nodename
  20                 local stack = ItemStack(nodename)
  21                 local itemtable = stack:to_table()
  22                 local itemname = nil
  23                 if itemtable then
  24                         itemname = stack:to_table().name
  25                 end
  26                 local item_texture = nil
  27                 local item_type = ""
  28                 if minetest.registered_items[itemname] then
  29                         item_texture = minetest.registered_items[itemname].inventory_image
  30                         item_type = minetest.registered_items[itemname].type
  31                 end
  32                 prop = {
  33                         is_visible = true,
  34                         textures = {nodename},
  35                 }
  36                 self.object:set_properties(prop)
  37         end,
  38
  39         get_staticdata = function(self)
  40                 return self.nodename
  41         end,
  42
  43         on_activate = function(self, staticdata)
  44                 self.nodename = staticdata
  45                 self.object:set_armor_groups({immortal=1})
  46                 --self.object:setacceleration({x=0, y=-10, z=0})
  47                 self:set_node(self.nodename)
  48         end,
  49
  50         on_step = function(self, dtime)
  51                 -- Set gravity
  52                 self.object:setacceleration({x=0, y=-10, z=0})
  53                 -- Turn to actual sand when collides to ground or just move
  54                 local pos = self.object:getpos()
  55                 local bcp = {x=pos.x, y=pos.y-0.7, z=pos.z} -- Position of bottom center point
  56                 local bcn = minetest.env:get_node(bcp)
  57                 -- Note: walkable is in the node definition, not in item groups
  58                 if minetest.registered_nodes[bcn.name] and
  59                                 minetest.registered_nodes[bcn.name].walkable then
  60                         local np = {x=bcp.x, y=bcp.y+1, z=bcp.z}
  61                         -- Check what's here
  62                         local n2 = minetest.env:get_node(np)
  63                         -- If it's not air or liquid, remove node and replace it with
  64                         -- it's drops
  65                         if n2.name ~= "air" and (not minetest.registered_nodes[n2.name] or
  66                                         minetest.registered_nodes[n2.name].liquidtype == "none") then
  67                                 local drops = minetest.get_node_drops(n2.name, "")
  68                                 minetest.env:remove_node(np)
  69                                 -- Add dropped items
  70                                 local _, dropped_item
  71                                 for _, dropped_item in ipairs(drops) do
  72                                         minetest.env:add_item(np, dropped_item)
  73                                 end
  74                                 -- Run script hook
  75                                 local _, callback
  76                                 for _, callback in ipairs(minetest.registered_on_dignodes) do
  77                                         callback(np, n2, nil)
  78                                 end
  79                         end
  80                         -- Create node and remove entity
  81                         minetest.env:add_node(np, {name=self.nodename})
  82                         self.object:remove()
  83                 else
  84                         -- Do nothing
  85                 end
  86         end
  87 })
  88
  89 function spawn_falling_node(p, nodename)
  90         obj = minetest.env:add_entity(p, "__builtin:falling_node")
  91         obj:get_luaentity():set_node(nodename)
  92 end
  93
  94 --
  95 -- Some common functions
  96 --
  97
  98 function nodeupdate_single(p)
  99         n = minetest.env:get_node(p)
 100         if minetest.get_node_group(n.name, "falling_node") ~= 0 then
 101                 p_bottom = {x=p.x, y=p.y-1, z=p.z}
 102                 n_bottom = minetest.env:get_node(p_bottom)
 103                 -- Note: walkable is in the node definition, not in item groups
 104                 if minetest.registered_nodes[n_bottom.name] and
 105                                 not minetest.registered_nodes[n_bottom.name].walkable then
 106                         minetest.env:remove_node(p)
 107                         spawn_falling_node(p, n.name)
 108                         nodeupdate(p)
 109                 end
 110         end
 111 end
 112
 113 function nodeupdate(p)
 114         -- Round p to prevent falling entities to get stuck
 115         p.x = math.floor(p.x+0.5)
 116         p.y = math.floor(p.y+0.5)
 117         p.z = math.floor(p.z+0.5)
 118
 119         for x = -1,1 do
 120         for y = -1,1 do
 121         for z = -1,1 do
 122                 p2 = {x=p.x+x, y=p.y+y, z=p.z+z}
 123                 nodeupdate_single(p2)
 124         end
 125         end
 126         end
 127 end
 128
 129 --
 130 -- Global callbacks
 131 --
 132
 133 function on_placenode(p, node)
 134         nodeupdate(p)
 135 end
 136 minetest.register_on_placenode(on_placenode)
 137
 138 function on_dignode(p, node)
 139         nodeupdate(p)
 140 end
 141 minetest.register_on_dignode(on_dignode)