function carts:get_sign(z) if z == 0 then return 0 else return z / math.abs(z) end end function carts:manage_attachment(player, obj) if not player then return end local status = obj ~= nil local player_name = player:get_player_name() if default.player_attached[player_name] == status then return end default.player_attached[player_name] = status if status then player:set_attach(obj, "", {x=0, y=6, z=0}, {x=0, y=0, z=0}) player:set_eye_offset({x=0, y=-4, z=0},{x=0, y=-4, z=0}) else player:set_detach() player:set_eye_offset({x=0, y=0, z=0},{x=0, y=0, z=0}) end end function carts:velocity_to_dir(v) if math.abs(v.x) > math.abs(v.z) then return {x=carts:get_sign(v.x), y=carts:get_sign(v.y), z=0} else return {x=0, y=carts:get_sign(v.y), z=carts:get_sign(v.z)} end end function carts:is_rail(pos, railtype) local node = minetest.get_node(pos).name if node == "ignore" then local vm = minetest.get_voxel_manip() local emin, emax = vm:read_from_map(pos, pos) local area = VoxelArea:new{ MinEdge = emin, MaxEdge = emax, } local data = vm:get_data() local vi = area:indexp(pos) node = minetest.get_name_from_content_id(data[vi]) end if minetest.get_item_group(node, "rail") == 0 then return false end if not railtype then return true end return minetest.get_item_group(node, "connect_to_raillike") == railtype end function carts:check_front_up_down(pos, dir_, check_up, railtype) local dir = vector.new(dir_) local cur -- Front dir.y = 0 cur = vector.add(pos, dir) if carts:is_rail(cur, railtype) then return dir end -- Up if check_up then dir.y = 1 cur = vector.add(pos, dir) if carts:is_rail(cur, railtype) then return dir end end -- Down dir.y = -1 cur = vector.add(pos, dir) if carts:is_rail(cur, railtype) then return dir end return nil end function carts:get_rail_direction(pos_, dir, ctrl, old_switch, railtype) local pos = vector.round(pos_) local cur local left_check, right_check = true, true -- Check left and right local left = {x=0, y=0, z=0} local right = {x=0, y=0, z=0} if dir.z ~= 0 and dir.x == 0 then left.x = -dir.z right.x = dir.z elseif dir.x ~= 0 and dir.z == 0 then left.z = dir.x right.z = -dir.x end if ctrl then if old_switch == 1 then left_check = false elseif old_switch == 2 then right_check = false end if ctrl.left and left_check then cur = carts:check_front_up_down(pos, left, false, railtype) if cur then return cur, 1 end left_check = false end if ctrl.right and right_check then cur = carts:check_front_up_down(pos, right, false, railtype) if cur then return cur, 2 end right_check = true end end -- Normal cur = carts:check_front_up_down(pos, dir, true, railtype) if cur then return cur end -- Left, if not already checked if left_check then cur = carts:check_front_up_down(pos, left, false, railtype) if cur then return cur end end -- Right, if not already checked if right_check then cur = carts:check_front_up_down(pos, right, false, railtype) if cur then return cur end end -- Backwards if not old_switch then cur = carts:check_front_up_down(pos, { x = -dir.x, y = dir.y, z = -dir.z }, true, railtype) if cur then return cur end end return {x=0, y=0, z=0} end function carts:pathfinder(pos_, old_pos, old_dir, ctrl, pf_switch, railtype) local pos = vector.round(pos_) local pf_pos = vector.round(old_pos) local pf_dir = vector.new(old_dir) for i = 1, 3 do if vector.equals(pf_pos, pos) then -- Success! Cart moved on correctly return true end pf_dir, pf_switch = carts:get_rail_direction(pf_pos, pf_dir, ctrl, pf_switch, railtype) if vector.equals(pf_dir, {x=0, y=0, z=0}) then -- No way forwards return false end pf_pos = vector.add(pf_pos, pf_dir) end -- Cart not found return false end function carts:register_rail(name, def_overwrite, railparams) local def = { drawtype = "raillike", paramtype = "light", sunlight_propagates = true, is_ground_content = false, walkable = false, selection_box = { type = "fixed", fixed = {-1/2, -1/2, -1/2, 1/2, -1/2+1/16, 1/2}, }, sounds = default.node_sound_metal_defaults() } for k, v in pairs(def_overwrite) do def[k] = v end if not def.inventory_image then def.wield_image = def.tiles[1] def.inventory_image = def.tiles[1] end if railparams then carts.railparams[name] = table.copy(railparams) end minetest.register_node(name, def) end function carts:get_rail_groups(additional_groups) -- Get the default rail groups and add more when a table is given local groups = {dig_immediate = 2, attached_node = 1, rail = 1, connect_to_raillike = 1} if type(additional_groups) == "table" then for k, v in pairs(additional_groups) do groups[k] = v end end return groups end