function boost_cart:get_sign(z) if z == 0 then return 0 else return z / math.abs(z) end end function boost_cart:velocity_to_dir(v) if math.abs(v.x) > math.abs(v.z) then return {x=boost_cart:get_sign(v.x), y=boost_cart:get_sign(v.y), z=0} else return {x=0, y=boost_cart:get_sign(v.y), z=boost_cart:get_sign(v.z)} end end function boost_cart:is_rail(pos) 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 return minetest.get_item_group(node, "rail") ~= 0 end function boost_cart:check_front_up_down(pos, dir, onlyDown) local cur = nil -- Front dir.y = 0 cur = vector.add(pos, dir) if boost_cart:is_rail(cur) then return dir end -- Up if not onlyDown then dir.y = 1 cur = vector.add(pos, dir) if boost_cart:is_rail(cur) then return dir end end -- Down dir.y = -1 cur = vector.add(pos, dir) if boost_cart:is_rail(cur) then return dir end return nil end function boost_cart:get_rail_direction(pos_, dir_, ctrl, old_switch) local pos = vector.round(pos_) local dir = vector.new(dir_) local cur = nil local left_check, right_check = true, true old_switch = old_switch or 0 -- 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 = boost_cart:check_front_up_down(pos, left, true) if cur then return cur, 1 end left_check = false end if ctrl.right and right_check then cur = boost_cart:check_front_up_down(pos, right, true) if cur then return cur, 2 end right_check = true end end -- Normal cur = boost_cart:check_front_up_down(pos, dir) if cur then return cur end -- Left, if not already checked if left_check then cur = boost_cart:check_front_up_down(pos, left, true) if cur then return cur end end -- Right, if not already checked if right_check then cur = boost_cart:check_front_up_down(pos, right, true) if cur then return cur end end return {x=0, y=0, z=0} end