ref: aa6a384ff93badad8ea6364f5a5cd8bd9ec77bb0
dir: /sys/src/libdraw/badrect.c/
#include <u.h>
#include <libc.h>
#include <draw.h>
/*
 * check for zero, negative size or insanely huge rectangle.
 */
int
badrect(Rectangle r)
{
	int x, y;
	uint z;
	x = Dx(r);
	y = Dy(r);
	if(x > 0 && y > 0){
		z = x*y;
		if(z/x == y && z < 0x10000000)
			return 0;
	}
	return 1;
}