Quad
Syntax
type Quad = [
[ number,number ], // Point one. The unit is pixel.
[ number,number ], // Point two. The unit is pixel.
[ number,number ], // Point three. The unit is pixel.
[ number,number ], // Point four. The unit is pixel.
];
Remark
The four points should be arranged in a clockwise or counterclockwise order.