ref: f3503fdab5a4c0b950772d0d5d862bee98d0d199
dir: /sys/src/libdraw/debug.c/
#include <u.h>
#include <libc.h>
#include <draw.h>
void
drawsetdebug(int v)
{
uchar *a;
a = bufimage(display, 1+1);
if(a == 0){
fprint(2, "drawsetdebug: %r\n");
return;
}
a[0] = 'D';
a[1] = v;
}