#include <u.h>#include <libc.h>#include <draw.h> voiddrawsetdebug(int v){	uchar *a; 	_lockdisplay(display);	a = bufimage(display, 1+1);	if(a == nil){		_unlockdisplay(display);		fprint(2, "drawsetdebug: %r\n");		return;	}	a[0] = 'D';	a[1] = v;	_unlockdisplay(display);}