[UtterInanity]

From liberscribble's driver.c:

void erscribble_driver_update_display()
{
    // Send update message to display manager
    //
    //   Syntax: !I,cmd,pid,x,y,w,h,ignore,window,type,widget,focus
    //   - paint full screen (w=768,h=1024)
    //   - skip the normal rules (ignore=1)
    //   - special widget (widget=erscribble)
    //   - rest unused (0)
    const char *msg = "!I,0,0,0,768,1024,1,0,0,erscribble,0";
    sendto(fd, msg, strlen(msg), 0, (struct sockaddr*) &server_addr, sizeof(server_addr));
    LOGPRINTF("Sent message `%s` to display manager", msg);
}

So it seems as though it wouldn't be horribly difficult to send a refresh to the framebuffer. If I could figure out where the pen is pointing, it looks as though it could even be a small local refresh. Maybe I'll look at that this weekend.