From 7482a4bf5f58274f7f0c032b91c18c673375b277 Mon Sep 17 00:00:00 2001
From: Anders Eurenius <aes@spotify.com>
Date: Sun, 22 Jun 2014 16:02:06 +0200
Subject: [PATCH 6/6] Refactor mainloop, add fast blink support

---
 st.c | 136 ++++++++++++++++++++++++++++++++++++++++++-------------------------
 1 file changed, 86 insertions(+), 50 deletions(-)

diff --git a/st.c b/st.c
index 1621352..f256528 100644
--- a/st.c
+++ b/st.c
@@ -3244,6 +3244,9 @@ xdraws(char *s, Glyph base, int x, int y, int charlen, int bytelen) {
 	if(base.mode & ATTR_BLINK && term.mode & MODE_BLINK)
 		fg = bg;
 
+	if(base.mode & ATTR_FASTBLINK && term.mode & MODE_FBLINK)
+		fg = bg;
+
 	if(base.mode & ATTR_INVISIBLE)
 		fg = bg;
 
@@ -3752,12 +3755,10 @@ resize(XEvent *e) {
 }
 
 void
-run(void) {
+init(void)
+{
 	XEvent ev;
 	int w = xw.w, h = xw.h;
-	fd_set rfd;
-	int xfd = XConnectionNumber(xw.dpy), xev, blinkset = 0, dodraw = 0;
-	struct timeval drawtimeout, *tv = NULL, now, last, lastblink;
 
 	/* Waiting for window mapping */
 	while(1) {
@@ -3772,32 +3773,75 @@ run(void) {
 
 	ttynew();
 	cresize(w, h);
+}
+
+const int xev_activity = 1;
+const int cmd_activity = 2;
+
+int do_select(struct timeval *tv)
+{
+	int xfd = XConnectionNumber(xw.dpy);
+	fd_set rfd;
+
+	FD_ZERO(&rfd);
+	FD_SET(cmdfd, &rfd);
+	FD_SET(xfd, &rfd);
+
+	while(select(MAX(xfd, cmdfd)+1, &rfd, NULL, NULL, tv) < 0) {
+		if(errno == EINTR)
+			continue;
+		die("select failed: %s\n", strerror(errno));
+	}
+
+	return (FD_ISSET(xfd, &rfd)? xev_activity: 0) |
+		(FD_ISSET(cmdfd, &rfd)? cmd_activity: 0);
+}
+
+int
+setblinks(struct timeval *now)
+{
+	unsigned long long int t = now->tv_sec * 1000 + now->tv_usec / 1000;
+	int blink, fblink, change = 0;
+
+	blink = (t / blinktimeout) & 1;
+	if(!!(term.mode & MODE_BLINK) != blink)
+		change = 1;
+
+	fblink = (t / (blinktimeout / 4)) & 1;
+	if(!!(term.mode & MODE_FBLINK) != fblink)
+		change = 1;
+
+	MODBIT(term.mode, blink, MODE_BLINK);
+	MODBIT(term.mode, fblink, MODE_FBLINK);
+
+	return change;
+}
+
+void
+run(void) {
+	XEvent ev;
+	int s, xev, blinkset = 0, dodraw = 0;
+	struct timeval drawtimeout, *tv = NULL, now, last;
+
+	init();
 
 	gettimeofday(&last, NULL);
-	lastblink = last;
+	xev = actionfps;
 
-	for(xev = actionfps;;) {
+	for(;;) {
 		long deltatime;
 
-		FD_ZERO(&rfd);
-		FD_SET(cmdfd, &rfd);
-		FD_SET(xfd, &rfd);
+		s = do_select(tv);
 
-		if(select(MAX(xfd, cmdfd)+1, &rfd, NULL, NULL, tv) < 0) {
-			if(errno == EINTR)
-				continue;
-			die("select failed: %s\n", strerror(errno));
-		}
-		if(FD_ISSET(cmdfd, &rfd)) {
+		if(s & cmd_activity) {
 			ttyread();
 			if(blinktimeout) {
-				blinkset = tattrset(ATTR_BLINK);
-				if(!blinkset)
-					MODBIT(term.mode, 0, MODE_BLINK);
+				blinkset = tattrset(ATTR_BLINK) |
+					tattrset(ATTR_FASTBLINK);
 			}
 		}
 
-		if(FD_ISSET(xfd, &rfd))
+		if(s & xev_activity)
 			xev = actionfps;
 
 		gettimeofday(&now, NULL);
@@ -3806,10 +3850,9 @@ run(void) {
 		tv = &drawtimeout;
 
 		dodraw = 0;
-		if(blinktimeout && TIMEDIFF(now, lastblink) > blinktimeout) {
+		if(blinktimeout && blinkset && setblinks(&now)) {
 			tsetdirtattr(ATTR_BLINK);
-			term.mode ^= MODE_BLINK;
-			lastblink = now;
+			tsetdirtattr(ATTR_FASTBLINK);
 			dodraw = 1;
 		}
 		deltatime = TIMEDIFF(now, last);
@@ -3819,35 +3862,28 @@ run(void) {
 			last = now;
 		}
 
-		if(dodraw) {
-			while(XPending(xw.dpy)) {
-				XNextEvent(xw.dpy, &ev);
-				if(XFilterEvent(&ev, None))
-					continue;
-				if(handler[ev.type])
-					(handler[ev.type])(&ev);
-			}
+		if(!dodraw)
+			continue;
 
-			draw();
-			XFlush(xw.dpy);
-
-			if(xev && !FD_ISSET(xfd, &rfd))
-				xev--;
-			if(!FD_ISSET(cmdfd, &rfd) && !FD_ISSET(xfd, &rfd)) {
-				if(blinkset) {
-					if(TIMEDIFF(now, lastblink) \
-							> blinktimeout) {
-						drawtimeout.tv_usec = 1;
-					} else {
-						drawtimeout.tv_usec = (1000 * \
-							(blinktimeout - \
-							TIMEDIFF(now,
-								lastblink)));
-					}
-				} else {
-					tv = NULL;
-				}
-			}
+		while(XPending(xw.dpy)) {
+			XNextEvent(xw.dpy, &ev);
+			if(XFilterEvent(&ev, None))
+				continue;
+			if(handler[ev.type])
+				(handler[ev.type])(&ev);
+		}
+
+		draw();
+		XFlush(xw.dpy);
+
+		if(xev && !(s & xev_activity))
+			xev--;
+		if(blinkset) {
+			drawtimeout.tv_sec = 0;
+			drawtimeout.tv_usec = blinktimeout / 2;
+			tv = &drawtimeout;
+		} else {
+			tv = NULL;
 		}
 	}
 }
-- 
2.0.0