1 files changed, 141 insertions, 0 deletions
diff --git a/builtin/falling.lua b/builtin/falling.lua
new file mode 100644
index 000000000..82b360152
--- /dev/null
+++ b/builtin/falling.lua
@@ -0,0 +1,141 @@
+-- Minetest: builtin/item.lua
+
+--
+-- Falling nodes
+-- 
+
+
+--
+-- Falling stuff
+--
+
+minetest.register_entity("__builtin:falling_node", {
+	initial_properties = {
+		physical = true,
+		collisionbox = {-0.5,-0.5,-0.5, 0.5,0.5,0.5},
+		visual = "wielditem",
+		textures = {},
+		visual_size = {x=0.667, y=0.667},
+	},
+
+	nodename = "",
+
+	set_node = function(self, nodename)
+		self.nodename = nodename
+		local stack = ItemStack(nodename)
+		local itemtable = stack:to_table()
+		local itemname = nil
+		if itemtable then
+			itemname = stack:to_table().name
+		end
+		local item_texture = nil
+		local item_type = ""
+		if minetest.registered_items[itemname] then
+			item_texture = minetest.registered_items[itemname].inventory_image
+			item_type = minetest.registered_items[itemname].type
+		end
+		prop = {
+			is_visible = true,
+			textures = {nodename},
+		}
+		self.object:set_properties(prop)
+	end,
+
+	get_staticdata = function(self)
+		return self.nodename
+	end,
+
+	on_activate = function(self, staticdata)
+		self.nodename = staticdata
+		self.object:set_armor_groups({immortal=1})
+		--self.object:setacceleration({x=0, y=-10, z=0})
+		self:set_node(self.nodename)
+	end,
+
+	on_step = function(self, dtime)
+		-- Set gravity
+		self.object:setacceleration({x=0, y=-10, z=0})
+		-- Turn to actual sand when collides to ground or just move
+		local pos = self.object:getpos()
+		local bcp = {x=pos.x, y=pos.y-0.7, z=pos.z} -- Position of bottom center point
+		local bcn = minetest.env:get_node(bcp)
+		-- Note: walkable is in the node definition, not in item groups
+		if minetest.registered_nodes[bcn.name] and
+				minetest.registered_nodes[bcn.name].walkable then
+			local np = {x=bcp.x, y=bcp.y+1, z=bcp.z}
+			-- Check what's here
+			local n2 = minetest.env:get_node(np)
+			-- If it's not air or liquid, remove node and replace it with
+			-- it's drops
+			if n2.name ~= "air" and (not minetest.registered_nodes[n2.name] or
+					minetest.registered_nodes[n2.name].liquidtype == "none") then
+				local drops = minetest.get_node_drops(n2.name, "")
+				minetest.env:remove_node(np)
+				-- Add dropped items
+				local _, dropped_item
+				for _, dropped_item in ipairs(drops) do
+					minetest.env:add_item(np, dropped_item)
+				end
+				-- Run script hook
+				local _, callback
+				for _, callback in ipairs(minetest.registered_on_dignodes) do
+					callback(np, n2, nil)
+				end
+			end
+			-- Create node and remove entity
+			minetest.env:add_node(np, {name=self.nodename})
+			self.object:remove()
+		else
+			-- Do nothing
+		end
+	end
+})
+
+function spawn_falling_node(p, nodename)
+	obj = minetest.env:add_entity(p, "__builtin:falling_node")
+	obj:get_luaentity():set_node(nodename)
+end
+
+--
+-- Some common functions
+--
+
+function nodeupdate_single(p)
+	n = minetest.env:get_node(p)
+	if minetest.get_node_group(n.name, "falling_node") ~= 0 then
+		p_bottom = {x=p.x, y=p.y-1, z=p.z}
+		n_bottom = minetest.env:get_node(p_bottom)
+		-- Note: walkable is in the node definition, not in item groups
+		if minetest.registered_nodes[n_bottom.name] and
+				not minetest.registered_nodes[n_bottom.name].walkable then
+			minetest.env:remove_node(p)
+			spawn_falling_node(p, n.name)
+			nodeupdate(p)
+		end
+	end
+end
+
+function nodeupdate(p)
+	for x = -1,1 do
+	for y = -1,1 do
+	for z = -1,1 do
+		p2 = {x=p.x+x, y=p.y+y, z=p.z+z}
+		nodeupdate_single(p2)
+	end
+	end
+	end
+end
+
+--
+-- Global callbacks
+--
+
+function on_placenode(p, node)
+	nodeupdate(p)
+end
+minetest.register_on_placenode(on_placenode)
+
+function on_dignode(p, node)
+	nodeupdate(p)
+end
+minetest.register_on_dignode(on_dignode)