Trackdir Direction
TRACKDIR_X_NE = 0, DIR_NE = 1,
TRACKDIR_Y_SE = 1, DIR_SE = 3,
TRACKDIR_UPPER_E = 2, DIR_E = 2,
TRACKDIR_LOWER_E = 3, DIR_E = 2,
TRACKDIR_LEFT_S = 4, DIR_S = 4,
TRACKDIR_RIGHT_S = 5, DIR_S = 4,
TRACKDIR_X_SW = 8, DIR_SW = 5,
TRACKDIR_Y_NW = 9, DIR_NW = 7,
TRACKDIR_UPPER_W = 10, DIR_W = 6,
TRACKDIR_LOWER_W = 11, DIR_W = 6,
TRACKDIR_LEFT_N = 12, DIR_N = 0,
TRACKDIR_RIGHT_N = 13, DIR_N = 0,