ref: 75a2b0366b646d4633c4f0bd44790c760973e2c8
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;
}