[hackers] [st] Adding a more efficient drawing code. || Christoph Lohmann

From: <git_AT_suckless.org>
Date: Fri, 15 Feb 2013 19:14:40 +0100

commit 95033753be32e93915ddce14ea41b8765b665771
Author: Christoph Lohmann <20h_AT_r-36.net>
Date: Fri Feb 15 19:10:22 2013 +0100

    Adding a more efficient drawing code.
    
    Thanks Mihail Zenkov <mihail.zenkov_AT_gmail.com> for giving the hint!

diff --git a/config.def.h b/config.def.h
index 684adf7..8732ca3 100644
--- a/config.def.h
+++ b/config.def.h
_AT_@ -9,10 +9,13 @@ static char font[] = "Liberation Mono:pixelsize=12:antialias=false:autohint=fals
 static int borderpx = 2;
 static char shell[] = "/bin/sh";
 
-/* double-click timeout (in milliseconds) between clicks for selection */
+/* timeouts (in milliseconds) */
 static unsigned int doubleclicktimeout = 300;
 static unsigned int tripleclicktimeout = 600;
 
+/* frames per second st should at maximum draw to the screen */
+static unsigned int framespersecond = 60;
+
 /* TERM value */
 static char termname[] = "st-256color";
 
diff --git a/st.c b/st.c
index 8206001..f4b419e 100644
--- a/st.c
+++ b/st.c
_AT_@ -3166,10 +3166,12 @@ void
 run(void) {
         XEvent ev;
         fd_set rfd;
- int xfd = XConnectionNumber(xw.dpy), i;
- struct timeval drawtimeout, *tv = NULL;
+ int xfd = XConnectionNumber(xw.dpy);
+ struct timeval drawtimeout, *tv = NULL, now, last;
 
- for(i = 0;; i++) {
+ gettimeofday(&last, NULL);
+
+ for(;;) {
                 FD_ZERO(&rfd);
                 FD_SET(cmdfd, &rfd);
                 FD_SET(xfd, &rfd);
_AT_@ -3179,35 +3181,44 @@ run(void) {
                         die("select failed: %s
", SERRNO);
                 }
 
- /*
- * Stop after a certain number of reads so the user does not
- * feel like the system is stuttering.
- */
- if(i < 1000 && FD_ISSET(cmdfd, &rfd)) {
- ttyread();
+ gettimeofday(&now, NULL);
+ /* usecs until (next) frame */
+ drawtimeout.tv_sec = 0;
+ drawtimeout.tv_usec = \
+ ((1000/framespersecond) - TIMEDIFF(now, last)) * 1000;
 
- /*
- * Just wait a bit so it isn't disturbing the
- * user and the system is able to write something.
- */
- drawtimeout.tv_sec = 0;
- drawtimeout.tv_usec = 5;
- tv = &drawtimeout;
- continue;
+ /* Let us draw a frame. */
+ if(drawtimeout.tv_usec <= 0) {
+ draw();
+ XFlush(xw.dpy);
+
+ last = now;
+ tv = NULL;
                 }
- i = 0;
- tv = NULL;
 
- while(XPending(xw.dpy)) {
- XNextEvent(xw.dpy, &ev);
- if(XFilterEvent(&ev, None))
- continue;
- if(handler[ev.type])
- (handler[ev.type])(&ev);
+ if(FD_ISSET(cmdfd, &rfd))
+ ttyread();
+
+ if(FD_ISSET(xfd, &rfd)) {
+ while(XPending(xw.dpy)) {
+ XNextEvent(xw.dpy, &ev);
+ if(XFilterEvent(&ev, None))
+ continue;
+ if(handler[ev.type])
+ (handler[ev.type])(&ev);
+ }
+
+ if(drawtimeout.tv_usec <= 0) {
+ draw();
+ XFlush(xw.dpy);
+ }
                 }
 
- draw();
- XFlush(xw.dpy);
+ /* There is still some time to wait until next frame. */
+ if(drawtimeout.tv_usec > 0) {
+ tv = &drawtimeout;
+ continue;
+ }
         }
 }
 
Received on Fri Feb 15 2013 - 19:14:40 CET