auto-sync patch

This commit is contained in:
Luke Smith 2020-05-06 13:58:09 -04:00
parent b35e4f5727
commit 4f44d2d13f
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GPG Key ID: 4C50B54A911F6252
2 changed files with 65 additions and 68 deletions

View File

@ -42,9 +42,14 @@ static unsigned int tripleclicktimeout = 600;
/* alt screens */
int allowaltscreen = 1;
/* frames per second st should at maximum draw to the screen */
static unsigned int xfps = 120;
static unsigned int actionfps = 30;
/*
* draw latency range in ms - from new content/keypress/etc until drawing.
* within this range, st draws when content stops arriving (idle). mostly it's
* near minlatency, but it waits longer for slow updates to avoid partial draw.
* low minlatency will tear/flicker more, as it can "detect" idle too early.
*/
static double minlatency = 8;
static double maxlatency = 33;
/*
* blinking timeout (set to 0 to disable blinking) for the terminal blinking
@ -197,8 +202,6 @@ ResourcePref resources[] = {
{ "cursorColor", STRING, &colorname[256] },
{ "termname", STRING, &termname },
{ "shell", STRING, &shell },
{ "xfps", INTEGER, &xfps },
{ "actionfps", INTEGER, &actionfps },
{ "blinktimeout", INTEGER, &blinktimeout },
{ "bellvolume", INTEGER, &bellvolume },
{ "tabspaces", INTEGER, &tabspaces },

110
x.c
View File

@ -1956,10 +1956,9 @@ run(void)
XEvent ev;
int w = win.w, h = win.h;
fd_set rfd;
int xfd = XConnectionNumber(xw.dpy), xev, blinkset = 0, dodraw = 0;
int ttyfd;
struct timespec drawtimeout, *tv = NULL, now, last, lastblink;
long deltatime;
int xfd = XConnectionNumber(xw.dpy), ttyfd, xev, drawing;
struct timespec seltv, *tv, now, lastblink, trigger;
double timeout;
/* Waiting for window mapping */
do {
@ -1980,51 +1979,31 @@ run(void)
ttyfd = ttynew(opt_line, shell, opt_io, opt_cmd);
cresize(w, h);
clock_gettime(CLOCK_MONOTONIC, &last);
lastblink = last;
for (xev = actionfps;;) {
for (timeout = -1, drawing = 0, lastblink = (struct timespec){0};;) {
FD_ZERO(&rfd);
FD_SET(ttyfd, &rfd);
FD_SET(xfd, &rfd);
if (XPending(xw.dpy))
timeout = 0; /* existing events might not set xfd */
seltv.tv_sec = timeout / 1E3;
seltv.tv_nsec = 1E6 * (timeout - 1E3 * seltv.tv_sec);
tv = timeout >= 0 ? &seltv : NULL;
if (pselect(MAX(xfd, ttyfd)+1, &rfd, NULL, NULL, tv, NULL) < 0) {
if (errno == EINTR)
continue;
die("select failed: %s\n", strerror(errno));
}
if (FD_ISSET(ttyfd, &rfd)) {
ttyread();
if (blinktimeout) {
blinkset = tattrset(ATTR_BLINK);
if (!blinkset)
MODBIT(win.mode, 0, MODE_BLINK);
}
}
if (FD_ISSET(xfd, &rfd))
xev = actionfps;
clock_gettime(CLOCK_MONOTONIC, &now);
drawtimeout.tv_sec = 0;
drawtimeout.tv_nsec = (1000 * 1E6)/ xfps;
tv = &drawtimeout;
dodraw = 0;
if (blinktimeout && TIMEDIFF(now, lastblink) > blinktimeout) {
tsetdirtattr(ATTR_BLINK);
win.mode ^= MODE_BLINK;
lastblink = now;
dodraw = 1;
}
deltatime = TIMEDIFF(now, last);
if (deltatime > 1000 / (xev ? xfps : actionfps)) {
dodraw = 1;
last = now;
}
if (FD_ISSET(ttyfd, &rfd))
ttyread();
if (dodraw) {
xev = 0;
while (XPending(xw.dpy)) {
xev = 1;
XNextEvent(xw.dpy, &ev);
if (XFilterEvent(&ev, None))
continue;
@ -2032,30 +2011,45 @@ run(void)
(handler[ev.type])(&ev);
}
/*
* To reduce flicker and tearing, when new content or event
* triggers drawing, we first wait a bit to ensure we got
* everything, and if nothing new arrives - we draw.
* We start with trying to wait minlatency ms. If more content
* arrives sooner, we retry with shorter and shorter preiods,
* and eventually draw even without idle after maxlatency ms.
* Typically this results in low latency while interacting,
* maximum latency intervals during `cat huge.txt`, and perfect
* sync with periodic updates from animations/key-repeats/etc.
*/
if (FD_ISSET(ttyfd, &rfd) || xev) {
if (!drawing) {
trigger = now;
drawing = 1;
}
timeout = (maxlatency - TIMEDIFF(now, trigger)) \
/ maxlatency * minlatency;
if (timeout > 0)
continue; /* we have time, try to find idle */
}
/* idle detected or maxlatency exhausted -> draw */
timeout = -1;
if (blinktimeout && tattrset(ATTR_BLINK)) {
timeout = blinktimeout - TIMEDIFF(now, lastblink);
if (timeout <= 0) {
if (-timeout > blinktimeout) /* start visible */
win.mode |= MODE_BLINK;
win.mode ^= MODE_BLINK;
tsetdirtattr(ATTR_BLINK);
lastblink = now;
timeout = blinktimeout;
}
}
draw();
XFlush(xw.dpy);
if (xev && !FD_ISSET(xfd, &rfd))
xev--;
if (!FD_ISSET(ttyfd, &rfd) && !FD_ISSET(xfd, &rfd)) {
if (blinkset) {
if (TIMEDIFF(now, lastblink) \
> blinktimeout) {
drawtimeout.tv_nsec = 1000;
} else {
drawtimeout.tv_nsec = (1E6 * \
(blinktimeout - \
TIMEDIFF(now,
lastblink)));
}
drawtimeout.tv_sec = \
drawtimeout.tv_nsec / 1E9;
drawtimeout.tv_nsec %= (long)1E9;
} else {
tv = NULL;
}
}
}
drawing = 0;
}
}