#define min(a,b) ((a) < (b) ？(a) : (b))
#define max(a,v) ((a) > (b) ? (a) : (b))

/*	canonrect函数：将矩形坐标规范化	*/
struct rect canonrect(struct rect r)
{
	struct rect temp;

	temp.pt1.x = min(r.pt1.x,r.pt2.x);
	temp.pt1.y = min(r.pt1.y,r.pt1.y);
	temp.pt2.x = max(r.pt1.x,r.pt2.x);
	temp.pt2.y = max(r.pt1.x,r.pt2.y);
	return temp;
}