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connections.lua

@@ -0,0 +1,300 @@
+
+
+
+local connections = { }
+
+
+
+function connections:new (mod_storage, name)
+	local obj = { }
+
+   setmetatable (obj, self)
+   self.__index = self
+
+   obj.connector_list = { }
+   obj.name = tostring (name)
+   obj.storage = mod_storage
+
+	if mod_storage then
+		local stored = mod_storage:get_string (obj.name)
+
+		if stored == "" then
+			stored = "{ }"
+		end
+
+		obj.connector_list = minetest.deserialize (stored)
+
+		if not obj.connector_list then
+			obj.connector_list = { }
+		end
+	end
+
+	return obj
+end
+
+
+
+function connections:load ()
+	if self.storage then
+		local stored = self.storage:get_string (self.name)
+
+		if stored == "" then
+			stored = "{ }"
+		end
+
+		self.connector_list = minetest.deserialize (stored)
+	end
+end
+
+
+
+function connections:store ()
+	if self.storage then
+		self.storage:set_string (self.name, minetest.serialize (self.connector_list))
+	end
+end
+
+
+
+
+function connections:add_node (pos, id)
+	self.connector_list[minetest.pos_to_string (pos, 0)] =
+	{
+		id = (id and tostring (id)) or nil,
+		checked = false
+	}
+
+	self:store ()
+end
+
+
+
+function connections:remove_node (pos)
+	self.connector_list[minetest.pos_to_string (pos, 0)] = nil
+
+	self:store ()
+end
+
+
+
+function connections:set_id (pos, id)
+	local con = self.connector_list[minetest.pos_to_string (pos, 0)]
+
+	if con then
+		con.id = (id and tostring (id)) or nil
+
+		self:store ()
+
+		return true
+	end
+
+	return false
+end
+
+
+
+local function is_connected (self, pos, id, tally, test_coords)
+	if not id then
+		return nil
+	end
+
+	local con = self.connector_list[minetest.pos_to_string (pos, 0)]
+
+	if con and not con.checked then
+		con.checked = true
+
+		if con.id == id then
+			con.checked = false
+
+			return pos, tally
+		end
+
+		for i = 1, #test_coords do
+			local result, agg = is_connected (self,
+														 {
+															 x = pos.x + test_coords[i].x,
+															 y = pos.y + test_coords[i].y,
+															 z = pos.z + test_coords[i].z
+														 },
+														 id,
+														 tally,
+														 test_coords)
+
+			if result then
+				con.checked = false
+
+				return result, (tally + agg + 1)
+			end
+		end
+
+		con.checked = false
+	end
+
+	return nil, 0
+end
+
+
+
+function connections:is_connected (pos, id)
+	return is_connected (self,
+								pos,
+								tostring (id),
+								0,
+								{
+									{ x =  1, y =  0, z =  0 },
+									{ x = -1, y =  0, z =  0 },
+									{ x =  0, y =  0, z =  1 },
+									{ x =  0, y =  0, z = -1 },
+									{ x =  0, y =  1, z =  0 },
+									{ x =  0, y = -1, z =  0 }
+								})
+end
+
+
+
+function connections:is_connected_horizontal (pos, id)
+	return is_connected (self,
+								pos,
+								tostring (id),
+								0,
+								{
+									{ x =  1, y =  0, z =  0 },
+									{ x = -1, y =  0, z =  0 },
+									{ x =  0, y =  0, z =  1 },
+									{ x =  0, y =  0, z = -1 }
+								})
+end
+
+
+
+function connections:is_connected_vertical (pos, id)
+	return is_connected (self,
+								pos,
+								tostring (id),
+								0,
+								{
+									{ x =  0, y =  1, z =  0 },
+									{ x =  0, y = -1, z =  0 }
+								})
+end
+
+
+
+local function get_connected_ids (self, pos, test_coords, list)
+	local con = self.connector_list[minetest.pos_to_string (pos, 0)]
+
+	if con and not con.checked then
+		con.checked = true
+
+		if con.id then
+			list[#list + 1] =
+			{
+				pos = { x = pos.x, y = pos.y, z = pos.z },
+				id = con.id
+			}
+		end
+
+		for i = 1, #test_coords do
+			get_connected_ids (self,
+									 {
+										  x = pos.x + test_coords[i].x,
+										  y = pos.y + test_coords[i].y,
+										  z = pos.z + test_coords[i].z
+									  },
+									  test_coords,
+									  list)
+		end
+
+		con.checked = false
+	end
+
+	return list
+end
+
+
+
+function connections:get_connected_ids (pos)
+	local list = get_connected_ids (self,
+											  pos,
+											  {
+												  { x =  1, y =  0, z =  0 },
+												  { x = -1, y =  0, z =  0 },
+												  { x =  0, y =  0, z =  1 },
+												  { x =  0, y =  0, z = -1 },
+												  { x =  0, y =  1, z =  0 },
+												  { x =  0, y = -1, z =  0 }
+											  },
+											  { })
+
+	for i = #list, 1, -1 do
+		for j = 1, i - 1, 1 do
+			if list[i].pos.x == list[j].pos.x and
+				list[i].pos.y == list[j].pos.y and
+				list[i].pos.z == list[j].pos.z then
+
+				list[i] = nil
+				break
+			end
+		end
+	end
+
+	return list
+end
+
+
+
+function connections:get_connected_ids_horizontal (pos)
+	return get_connected_ids (self,
+									  pos,
+									  {
+										  { x =  1, y =  0, z =  0 },
+										  { x = -1, y =  0, z =  0 },
+										  { x =  0, y =  0, z =  1 },
+										  { x =  0, y =  0, z = -1 }
+									  },
+									  { })
+end
+
+
+
+function connections:get_connected_ids_vertical (pos)
+	return get_connected_ids (self,
+									  pos,
+									  {
+										  { x =  0, y =  1, z =  0 },
+										  { x =  0, y = -1, z =  0 }
+									  },
+									  { })
+end
+
+
+
+function connections:get_connected_ids_north_south (pos)
+	return get_connected_ids (self,
+									  pos,
+									  {
+										  { x =  0, y =  0, z =  1 },
+										  { x =  0, y =  0, z = -1 }
+									  },
+									  { })
+end
+
+
+
+function connections:get_connected_ids_east_west (pos)
+	return get_connected_ids (self,
+									  pos,
+									  {
+										  { x =  1, y =  0, z =  0 },
+										  { x = -1, y =  0, z =  0 }
+									  },
+									  { })
+end
+
+
+
+return connections
+
+
+
+--