1 -- Minetest: builtin/item.lua
7 core.register_entity(":__builtin:falling_node", {
10 visual_size = {x = 0.667, y = 0.667},
14 collide_with_objects = false,
15 collisionbox = {-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
20 set_node = function(self, node)
22 self.object:set_properties({
24 textures = {node.name},
28 get_staticdata = function(self)
29 return core.serialize(self.node)
32 on_activate = function(self, staticdata)
33 self.object:set_armor_groups({immortal = 1})
35 local node = core.deserialize(staticdata)
38 elseif staticdata ~= "" then
39 self:set_node({name = staticdata})
43 on_step = function(self, dtime)
45 local acceleration = self.object:getacceleration()
46 if not vector.equals(acceleration, {x = 0, y = -10, z = 0}) then
47 self.object:setacceleration({x = 0, y = -10, z = 0})
49 -- Turn to actual sand when collides to ground or just move
50 local pos = self.object:getpos()
51 local bcp = {x = pos.x, y = pos.y - 0.7, z = pos.z} -- Position of bottom center point
52 local bcn = core.get_node(bcp)
53 local bcd = core.registered_nodes[bcn.name]
54 -- Note: walkable is in the node definition, not in item groups
57 (core.get_item_group(self.node.name, "float") ~= 0 and
58 bcd.liquidtype ~= "none")) then
59 if bcd and bcd.leveled and
60 bcn.name == self.node.name then
61 local addlevel = self.node.level
62 if not addlevel or addlevel <= 0 then
63 addlevel = bcd.leveled
65 if core.add_node_level(bcp, addlevel) == 0 then
69 elseif bcd and bcd.buildable_to and
70 (core.get_item_group(self.node.name, "float") == 0 or
71 bcd.liquidtype == "none") then
75 local np = {x = bcp.x, y = bcp.y + 1, z = bcp.z}
77 local n2 = core.get_node(np)
78 -- If it's not air or liquid, remove node and replace it with
80 if n2.name ~= "air" and (not core.registered_nodes[n2.name] or
81 core.registered_nodes[n2.name].liquidtype == "none") then
83 if core.registered_nodes[n2.name].buildable_to == false then
85 local drops = core.get_node_drops(n2.name, "")
86 for _, dropped_item in ipairs(drops) do
87 core.add_item(np, dropped_item)
91 for _, callback in ipairs(core.registered_on_dignodes) do
95 -- Create node and remove entity
96 if core.registered_nodes[self.node.name] then
97 core.add_node(np, self.node)
103 local vel = self.object:getvelocity()
104 if vector.equals(vel, {x = 0, y = 0, z = 0}) then
105 local npos = self.object:getpos()
106 self.object:setpos(vector.round(npos))
111 function spawn_falling_node(p, node)
112 local obj = core.add_entity(p, "__builtin:falling_node")
113 obj:get_luaentity():set_node(node)
116 function drop_attached_node(p)
117 local nn = core.get_node(p).name
119 for _, item in ipairs(core.get_node_drops(nn, "")) do
121 x = p.x + math.random()/2 - 0.25,
122 y = p.y + math.random()/2 - 0.25,
123 z = p.z + math.random()/2 - 0.25,
125 core.add_item(pos, item)
129 function check_attached_node(p, n)
130 local def = core.registered_nodes[n.name]
131 local d = {x = 0, y = 0, z = 0}
132 if def.paramtype2 == "wallmounted" then
133 d = core.wallmounted_to_dir(n.param2)
137 local p2 = vector.add(p, d)
138 local nn = core.get_node(p2).name
139 local def2 = core.registered_nodes[nn]
140 if def2 and not def2.walkable then
147 -- Some common functions
150 function nodeupdate_single(p)
151 local n = core.get_node(p)
152 if core.get_item_group(n.name, "falling_node") ~= 0 then
153 local p_bottom = {x = p.x, y = p.y - 1, z = p.z}
154 local n_bottom = core.get_node(p_bottom)
155 -- Note: walkable is in the node definition, not in item groups
156 if core.registered_nodes[n_bottom.name] and
157 (core.get_item_group(n.name, "float") == 0 or
158 core.registered_nodes[n_bottom.name].liquidtype == "none") and
159 (n.name ~= n_bottom.name or (core.registered_nodes[n_bottom.name].leveled and
160 core.get_node_level(p_bottom) < core.get_node_max_level(p_bottom))) and
161 (not core.registered_nodes[n_bottom.name].walkable or
162 core.registered_nodes[n_bottom.name].buildable_to) then
163 n.level = core.get_node_level(p)
165 spawn_falling_node(p, n)
170 if core.get_item_group(n.name, "attached_node") ~= 0 then
171 if not check_attached_node(p, n) then
172 drop_attached_node(p)
180 -- This table is specifically ordered.
181 -- We don't walk diagonals, only our direct neighbors, and self.
182 -- Down first as likely case, but always before self. The same with sides.
183 -- Up must come last, so that things above self will also fall all at once.
184 local nodeupdate_neighbors = {
185 {x = 0, y = -1, z = 0},
186 {x = -1, y = 0, z = 0},
187 {x = 1, y = 0, z = 0},
188 {x = 0, y = 0, z = 1},
189 {x = 0, y = 0, z = -1},
190 {x = 0, y = 0, z = 0},
191 {x = 0, y = 1, z = 0},
194 function nodeupdate(p)
195 -- Round p to prevent falling entities to get stuck.
198 -- We make a stack, and manually maintain size for performance.
199 -- Stored in the stack, we will maintain tables with pos, and
200 -- last neighbor visited. This way, when we get back to each
201 -- node, we know which directions we have already walked, and
202 -- which direction is the next to walk.
205 -- The neighbor order we will visit from our table.
209 -- Push current pos onto the stack.
211 s[n] = {p = p, v = v}
212 -- Select next node from neighbor list.
213 p = vector.add(p, nodeupdate_neighbors[v])
214 -- Now we check out the node. If it is in need of an update,
215 -- it will let us know in the return value (true = updated).
216 if not nodeupdate_single(p) then
217 -- If we don't need to "recurse" (walk) to it then pop
218 -- our previous pos off the stack and continue from there,
219 -- with the v value we were at when we last were at that
227 -- If there's nothing left on the stack, and no
228 -- more sides to walk to, we're done and can exit
229 if n == 0 and v == 7 then
233 -- The next round walk the next neighbor in list.
236 -- If we did need to walk the neighbor, then
237 -- start walking it from the walk order start (1),
238 -- and not the order we just pushed up the stack.
248 function on_placenode(p, node)
251 core.register_on_placenode(on_placenode)
253 function on_dignode(p, node)
256 core.register_on_dignode(on_dignode)