枚举成员
BOTTOM_CORNER
BOTTOM_CORNER: 5
BOTTOM_LEFT_CORNER
BOTTOM_LEFT_CORNER: 7
BOTTOM_LEFT_SIDE
BOTTOM_LEFT_SIDE: 6
BOTTOM_RIGHT_CORNER
BOTTOM_RIGHT_CORNER: 3
BOTTOM_RIGHT_SIDE
BOTTOM_RIGHT_SIDE: 2
BOTTOM_SIDE
BOTTOM_SIDE: 4
LEFT_CORNER
LEFT_CORNER: 9
RIGHT_CORNER
RIGHT_CORNER: 1
TOP_LEFT_CORNER
TOP_LEFT_CORNER: 11
TOP_LEFT_SIDE
TOP_LEFT_SIDE: 10
TOP_RIGHT_CORNER
TOP_RIGHT_CORNER: 15
TOP_RIGHT_SIDE
TOP_RIGHT_SIDE: 14