fixed cursor error

Remove stub code that was used for an experiment of adding sixel code to st
from the commit f7398434.

FAQ

@@ -2,12 +2,14 @@
 
 Use the excellent tool of [utmp](https://git.suckless.org/utmp/) for this task.
 
+
 ## Some _random program_ complains that st is unknown/not recognised/unsupported/whatever!
 
 It means that st doesn’t have any terminfo entry on your system. Chances are
 you did not `make install`. If you just want to test it without installing it,
 you can manually run `tic -sx st.info`.
 
+
 ## Nothing works, and nothing is said about an unknown terminal!
 
 * Some programs just assume they’re running in xterm i.e. they don’t rely on
@@ -15,6 +17,7 @@ you can manually run `tic -sx st.info`.
 * Some programs don’t complain about the lacking st description and default to
   another terminal. In that case see the question about terminfo.
 
+
 ## How do I scroll back up?
 
 * Using a terminal multiplexer.
@@ -23,11 +26,13 @@ you can manually run `tic -sx st.info`.
 * Using the excellent tool of [scroll](https://git.suckless.org/scroll/).
 * Using the scrollback [patch](https://st.suckless.org/patches/scrollback/).
 
+
 ## I would like to have utmp and/or scroll functionality by default
 
 You can add the absolute patch of both programs in your config.h
 file. You only have to modify the value of utmp and scroll variables.
 
+
 ## Why doesn't the Del key work in some programs?
 
 Taken from the terminfo manpage:
@@ -83,12 +88,14 @@ If you are using zsh, then read the zsh FAQ
 
 Putting these lines into your .zshrc will fix the problems.
 
+
 ## How can I use meta in 8bit mode?
 
 St supports meta in 8bit mode, but the default terminfo entry doesn't
 use this capability. If you want it, you have to use the 'st-meta' value
 in TERM.
 
+
 ## I cannot compile st in OpenBSD
 
 OpenBSD lacks librt, despite it being mandatory in POSIX
@@ -97,6 +104,7 @@ If you want to compile st for OpenBSD you have to remove -lrt from config.mk, an
 st will compile without any loss of functionality, because all the functions are
 included in libc on this platform.
 
+
 ## The Backspace Case
 
 St is emulating the Linux way of handling backspace being delete and delete being
@@ -158,19 +166,60 @@ terminal users wants its backspace to be how he feels it:
 	[1] http://www.ibb.net/~anne/keyboard.html
 	[2] http://www.tldp.org/HOWTO/Keyboard-and-Console-HOWTO-5.html
 
+
 ## But I really want the old grumpy behaviour of my terminal
 
 Apply [1].
 
 [1] https://st.suckless.org/patches/delkey
 
-## Why do images not work in st (in programs such as w3m)?
 
-This is a terrible hack that overdraws an image on top of the terminal emulator
+## Why do images not work in st using the w3m image hack?
-window. It also relies on a very specific way the terminal draws it's contents.
+
+w3mimg uses a hack that draws an image on top of the terminal emulator Drawable
+window. The hack relies on the terminal to use a single buffer to draw its
+contents directly.
+
+st uses double-buffered drawing so the image is quickly replaced and may show a
+short flicker effect.
+
+Below is a patch example to change st double-buffering to a single Drawable
+buffer.
+
+diff --git a/x.c b/x.c
+--- a/x.c
++++ b/x.c
+@@ -732,10 +732,6 @@ xresize(int col, int row)
+ 	win.tw = col * win.cw;
+ 	win.th = row * win.ch;
+ 
+-	XFreePixmap(xw.dpy, xw.buf);
+-	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
+-			DefaultDepth(xw.dpy, xw.scr));
+-	XftDrawChange(xw.draw, xw.buf);
+ 	xclear(0, 0, win.w, win.h);
+ 
+ 	/* resize to new width */
+@@ -1148,8 +1144,7 @@ xinit(int cols, int rows)
+ 	gcvalues.graphics_exposures = False;
+ 	dc.gc = XCreateGC(xw.dpy, parent, GCGraphicsExposures,
+ 			&gcvalues);
+-	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
+-			DefaultDepth(xw.dpy, xw.scr));
++	xw.buf = xw.win;
+ 	XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
+ 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
+ 
+@@ -1632,8 +1627,6 @@ xdrawline(Line line, int x1, int y1, int x2)
+ void
+ xfinishdraw(void)
+ {
+-	XCopyArea(xw.dpy, xw.buf, xw.win, dc.gc, 0, 0, win.w,
+-			win.h, 0, 0);
+ 	XSetForeground(xw.dpy, dc.gc,
+ 			dc.col[IS_SET(MODE_REVERSE)?
+ 				defaultfg : defaultbg].pixel);
 
-A more proper (but limited way) would be using sixels. Which st doesn't
-support.
 
 ## BadLength X error in Xft when trying to render emoji
 

LICENSE

@@ -1,6 +1,6 @@
 MIT/X Consortium License
 
-© 2014-2018 Hiltjo Posthuma <hiltjo at codemadness dot org>
+© 2014-2020 Hiltjo Posthuma <hiltjo at codemadness dot org>
 © 2018 Devin J. Pohly <djpohly at gmail dot com>
 © 2014-2017 Quentin Rameau <quinq at fifth dot space>
 © 2009-2012 Aurélien APTEL <aurelien dot aptel at gmail dot com>

config.def.h

@@ -43,9 +43,18 @@ static unsigned int tripleclicktimeout = 600;
 /* alt screens */
 int allowaltscreen = 1;
 
-/* frames per second st should at maximum draw to the screen */
+/* allow certain non-interactive (insecure) window operations such as:
-static unsigned int xfps = 120;
+   setting the clipboard text */
-static unsigned int actionfps = 30;
+int allowwindowops = 0;
+
+/*
+ * 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
@@ -84,6 +93,9 @@ char *termname = "st-256color";
  */
 unsigned int tabspaces = 8;
 
+/* bg opacity */
+float alpha = 0.8;
+
 /* Terminal colors (16 first used in escape sequence) */
 static const char *colorname[] = {
 	/* 8 normal colors */
@@ -111,6 +123,7 @@ static const char *colorname[] = {
 	/* more colors can be added after 255 to use with DefaultXX */
 	"#cccccc",
 	"#555555",
+	"black",
 };
 
 
@@ -118,9 +131,9 @@ static const char *colorname[] = {
  * Default colors (colorname index)
  * foreground, background, cursor, reverse cursor
  */
-unsigned int defaultfg = 7;
+unsigned int defaultfg = 257;
 unsigned int defaultbg = 0;
-static unsigned int defaultcs = 256;
+static unsigned int defaultcs = 257;
 static unsigned int defaultrcs = 257;
 
 /*
@@ -159,14 +172,55 @@ static unsigned int defaultattr = 11;
  */
 static uint forcemousemod = ShiftMask;
 
+/*
+ * Xresources preferences to load at startup
+ */
+ResourcePref resources[] = {
+		{ "font",         STRING,  &font },
+		{ "color0",       STRING,  &colorname[0] },
+		{ "color1",       STRING,  &colorname[1] },
+		{ "color2",       STRING,  &colorname[2] },
+		{ "color3",       STRING,  &colorname[3] },
+		{ "color4",       STRING,  &colorname[4] },
+		{ "color5",       STRING,  &colorname[5] },
+		{ "color6",       STRING,  &colorname[6] },
+		{ "color7",       STRING,  &colorname[7] },
+		{ "color8",       STRING,  &colorname[8] },
+		{ "color9",       STRING,  &colorname[9] },
+		{ "color10",      STRING,  &colorname[10] },
+		{ "color11",      STRING,  &colorname[11] },
+		{ "color12",      STRING,  &colorname[12] },
+		{ "color13",      STRING,  &colorname[13] },
+		{ "color14",      STRING,  &colorname[14] },
+		{ "color15",      STRING,  &colorname[15] },
+		{ "background",   STRING,  &colorname[256] },
+		{ "foreground",   STRING,  &colorname[257] },
+		{ "cursorColor",  STRING,  &colorname[258] },
+		{ "termname",     STRING,  &termname },
+		{ "shell",        STRING,  &shell },
+		{ "minlatency",   INTEGER, &minlatency },
+		{ "maxlatency",   INTEGER, &maxlatency },
+		{ "blinktimeout", INTEGER, &blinktimeout },
+		{ "bellvolume",   INTEGER, &bellvolume },
+		{ "tabspaces",    INTEGER, &tabspaces },
+		{ "borderpx",     INTEGER, &borderpx },
+		{ "cwscale",      FLOAT,   &cwscale },
+		{ "chscale",      FLOAT,   &chscale },
+		{ "alpha",        FLOAT,   &alpha },
+};
+
 /*
  * Internal mouse shortcuts.
  * Beware that overloading Button1 will disable the selection.
  */
 static MouseShortcut mshortcuts[] = {
 	/* mask                 button   function        argument       release */
+	{ XK_ANY_MOD,           Button4, kscrollup,      {.i = 1},      0, /* !alt */ -1 },
+	{ XK_ANY_MOD,           Button5, kscrolldown,    {.i = 1},      0, /* !alt */ -1 },
 	{ XK_ANY_MOD,           Button2, selpaste,       {.i = 0},      1 },
+	{ ShiftMask,            Button4, ttysend,        {.s = "\033[5;2~"} },
 	{ XK_ANY_MOD,           Button4, ttysend,        {.s = "\031"} },
+	{ ShiftMask,            Button5, ttysend,        {.s = "\033[6;2~"} },
 	{ XK_ANY_MOD,           Button5, ttysend,        {.s = "\005"} },
 };
 
@@ -188,6 +242,8 @@ static Shortcut shortcuts[] = {
 	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
 	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
 	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
+	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
+	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
 };
 
 /*

config.mk

@@ -1,5 +1,5 @@
 # st version
-VERSION = 0.8.2
+VERSION = 0.8.4
 
 # Customize below to fit your system
 
@@ -16,7 +16,7 @@ PKG_CONFIG = pkg-config
 INCS = -I$(X11INC) \
        `$(PKG_CONFIG) --cflags fontconfig` \
        `$(PKG_CONFIG) --cflags freetype2`
-LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
+LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft -lXrender\
        `$(PKG_CONFIG) --libs fontconfig` \
        `$(PKG_CONFIG) --libs freetype2`
 
@@ -28,8 +28,8 @@ STLDFLAGS = $(LIBS) $(LDFLAGS)
 # OpenBSD:
 #CPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
 #LIBS = -L$(X11LIB) -lm -lX11 -lutil -lXft \
-#       `pkg-config --libs fontconfig` \
+#       `$(PKG_CONFIG) --libs fontconfig` \
-#       `pkg-config --libs freetype2`
+#       `$(PKG_CONFIG) --libs freetype2`
 
 # compiler and linker
 # CC = c99

st.c

@@ -35,13 +35,17 @@
 #define ESC_ARG_SIZ   16
 #define STR_BUF_SIZ   ESC_BUF_SIZ
 #define STR_ARG_SIZ   ESC_ARG_SIZ
+#define HISTSIZE      2000
 
 /* macros */
 #define IS_SET(flag)		((term.mode & (flag)) != 0)
-#define ISCONTROLC0(c)		(BETWEEN(c, 0, 0x1f) || (c) == '\177')
+#define ISCONTROLC0(c)		(BETWEEN(c, 0, 0x1f) || (c) == 0x7f)
 #define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
 #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
 #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
+#define TLINE(y)		((y) < term.scr ? term.hist[((y) + term.histi - \
+				term.scr + HISTSIZE + 1) % HISTSIZE] : \
+				term.line[(y) - term.scr])
 
 enum term_mode {
 	MODE_WRAP        = 1 << 0,
@@ -51,7 +55,6 @@ enum term_mode {
 	MODE_ECHO        = 1 << 4,
 	MODE_PRINT       = 1 << 5,
 	MODE_UTF8        = 1 << 6,
-	MODE_SIXEL       = 1 << 7,
 };
 
 enum cursor_movement {
@@ -78,12 +81,11 @@ enum charset {
 enum escape_state {
 	ESC_START      = 1,
 	ESC_CSI        = 2,
-	ESC_STR        = 4,  /* OSC, PM, APC */
+	ESC_STR        = 4,  /* DCS, OSC, PM, APC */
 	ESC_ALTCHARSET = 8,
 	ESC_STR_END    = 16, /* a final string was encountered */
 	ESC_TEST       = 32, /* Enter in test mode */
 	ESC_UTF8       = 64,
-	ESC_DCS        =128,
 };
 
 typedef struct {
@@ -117,6 +119,9 @@ typedef struct {
 	int col;      /* nb col */
 	Line *line;   /* screen */
 	Line *alt;    /* alternate screen */
+	Line hist[HISTSIZE]; /* history buffer */
+	int histi;    /* history index */
+	int scr;      /* scroll back */
 	int *dirty;   /* dirtyness of lines */
 	TCursor c;    /* cursor */
 	int ocx;      /* old cursor col */
@@ -129,6 +134,7 @@ typedef struct {
 	int charset;  /* current charset */
 	int icharset; /* selected charset for sequence */
 	int *tabs;
+	Rune lastc;   /* last printed char outside of sequence, 0 if control */
 } Term;
 
 /* CSI Escape sequence structs */
@@ -185,8 +191,8 @@ static void tnewline(int);
 static void tputtab(int);
 static void tputc(Rune);
 static void treset(void);
-static void tscrollup(int, int);
+static void tscrollup(int, int, int);
-static void tscrolldown(int, int);
+static void tscrolldown(int, int, int);
 static void tsetattr(int *, int);
 static void tsetchar(Rune, Glyph *, int, int);
 static void tsetdirt(int, int);
@@ -415,10 +421,10 @@ tlinelen(int y)
 {
 	int i = term.col;
 
-	if (term.line[y][i - 1].mode & ATTR_WRAP)
+	if (TLINE(y)[i - 1].mode & ATTR_WRAP)
 		return i;
 
-	while (i > 0 && term.line[y][i - 1].u == ' ')
+	while (i > 0 && TLINE(y)[i - 1].u == ' ')
 		--i;
 
 	return i;
@@ -527,7 +533,7 @@ selsnap(int *x, int *y, int direction)
 		 * Snap around if the word wraps around at the end or
 		 * beginning of a line.
 		 */
-		prevgp = &term.line[*y][*x];
+		prevgp = &TLINE(*y)[*x];
 		prevdelim = ISDELIM(prevgp->u);
 		for (;;) {
 			newx = *x + direction;
@@ -542,14 +548,14 @@ selsnap(int *x, int *y, int direction)
 					yt = *y, xt = *x;
 				else
 					yt = newy, xt = newx;
-				if (!(term.line[yt][xt].mode & ATTR_WRAP))
+				if (!(TLINE(yt)[xt].mode & ATTR_WRAP))
 					break;
 			}
 
 			if (newx >= tlinelen(newy))
 				break;
 
-			gp = &term.line[newy][newx];
+			gp = &TLINE(newy)[newx];
 			delim = ISDELIM(gp->u);
 			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
 					|| (delim && gp->u != prevgp->u)))
@@ -570,14 +576,14 @@ selsnap(int *x, int *y, int direction)
 		*x = (direction < 0) ? 0 : term.col - 1;
 		if (direction < 0) {
 			for (; *y > 0; *y += direction) {
-				if (!(term.line[*y-1][term.col-1].mode
+				if (!(TLINE(*y-1)[term.col-1].mode
 						& ATTR_WRAP)) {
 					break;
 				}
 			}
 		} else if (direction > 0) {
 			for (; *y < term.row-1; *y += direction) {
-				if (!(term.line[*y][term.col-1].mode
+				if (!(TLINE(*y)[term.col-1].mode
 						& ATTR_WRAP)) {
 					break;
 				}
@@ -608,13 +614,13 @@ getsel(void)
 		}
 
 		if (sel.type == SEL_RECTANGULAR) {
-			gp = &term.line[y][sel.nb.x];
+			gp = &TLINE(y)[sel.nb.x];
 			lastx = sel.ne.x;
 		} else {
-			gp = &term.line[y][sel.nb.y == y ? sel.nb.x : 0];
+			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
 			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
 		}
-		last = &term.line[y][MIN(lastx, linelen-1)];
+		last = &TLINE(y)[MIN(lastx, linelen-1)];
 		while (last >= gp && last->u == ' ')
 			--last;
 
@@ -634,7 +640,8 @@ getsel(void)
 		 * st.
 		 * FIXME: Fix the computer world.
 		 */
-		if ((y < sel.ne.y || lastx >= linelen) && !(last->mode & ATTR_WRAP))
+		if ((y < sel.ne.y || lastx >= linelen) &&
+		    (!(last->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
 			*ptr++ = '\n';
 	}
 	*ptr = 0;
@@ -730,7 +737,7 @@ sigchld(int a)
 		die("child exited with status %d\n", WEXITSTATUS(stat));
 	else if (WIFSIGNALED(stat))
 		die("child terminated due to signal %d\n", WTERMSIG(stat));
-	exit(0);
+	_exit(0);
 }
 
 void
@@ -841,7 +848,6 @@ ttyread(void)
 		if (buflen > 0)
 			memmove(buf, buf + written, buflen);
 		return ret;
-
 	}
 }
 
@@ -849,6 +855,9 @@ void
 ttywrite(const char *s, size_t n, int may_echo)
 {
 	const char *next;
+	Arg arg = (Arg) { .i = term.scr };
+
+	kscrolldown(&arg);
 
 	if (may_echo && IS_SET(MODE_ECHO))
 		twrite(s, n, 1);
@@ -1048,6 +1057,11 @@ tnew(int col, int row)
 	treset();
 }
 
+int tisaltscr(void)
+{
+	return IS_SET(MODE_ALTSCREEN);
+}
+
 void
 tswapscreen(void)
 {
@@ -1060,13 +1074,53 @@ tswapscreen(void)
 }
 
 void
-tscrolldown(int orig, int n)
+kscrolldown(const Arg* a)
+{
+	int n = a->i;
+
+	if (n < 0)
+		n = term.row + n;
+
+	if (n > term.scr)
+		n = term.scr;
+
+	if (term.scr > 0) {
+		term.scr -= n;
+		selscroll(0, -n);
+		tfulldirt();
+	}
+}
+
+void
+kscrollup(const Arg* a)
+{
+	int n = a->i;
+
+	if (n < 0)
+		n = term.row + n;
+
+	if (term.scr <= HISTSIZE-n) {
+		term.scr += n;
+		selscroll(0, n);
+		tfulldirt();
+	}
+}
+
+void
+tscrolldown(int orig, int n, int copyhist)
 {
 	int i;
 	Line temp;
 
 	LIMIT(n, 0, term.bot-orig+1);
 
+	if (copyhist) {
+		term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
+		temp = term.hist[term.histi];
+		term.hist[term.histi] = term.line[term.bot];
+		term.line[term.bot] = temp;
+	}
+
 	tsetdirt(orig, term.bot-n);
 	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
 
@@ -1076,17 +1130,28 @@ tscrolldown(int orig, int n)
 		term.line[i-n] = temp;
 	}
 
-	selscroll(orig, n);
+	if (term.scr == 0)
+		selscroll(orig, n);
 }
 
 void
-tscrollup(int orig, int n)
+tscrollup(int orig, int n, int copyhist)
 {
 	int i;
 	Line temp;
 
 	LIMIT(n, 0, term.bot-orig+1);
 
+	if (copyhist) {
+		term.histi = (term.histi + 1) % HISTSIZE;
+		temp = term.hist[term.histi];
+		term.hist[term.histi] = term.line[orig];
+		term.line[orig] = temp;
+	}
+
+	if (term.scr > 0 && term.scr < HISTSIZE)
+		term.scr = MIN(term.scr + n, HISTSIZE-1);
+
 	tclearregion(0, orig, term.col-1, orig+n-1);
 	tsetdirt(orig+n, term.bot);
 
@@ -1096,7 +1161,8 @@ tscrollup(int orig, int n)
 		term.line[i+n] = temp;
 	}
 
-	selscroll(orig, -n);
+	if (term.scr == 0)
+		selscroll(orig, -n);
 }
 
 void
@@ -1105,27 +1171,17 @@ selscroll(int orig, int n)
 	if (sel.ob.x == -1)
 		return;
 
-	if (BETWEEN(sel.ob.y, orig, term.bot) || BETWEEN(sel.oe.y, orig, term.bot)) {
+	if (BETWEEN(sel.nb.y, orig, term.bot) != BETWEEN(sel.ne.y, orig, term.bot)) {
-		if ((sel.ob.y += n) > term.bot || (sel.oe.y += n) < term.top) {
+		selclear();
+	} else if (BETWEEN(sel.nb.y, orig, term.bot)) {
+		sel.ob.y += n;
+		sel.oe.y += n;
+		if (sel.ob.y < term.top || sel.ob.y > term.bot ||
+		    sel.oe.y < term.top || sel.oe.y > term.bot) {
 			selclear();
-			return;
-		}
-		if (sel.type == SEL_RECTANGULAR) {
-			if (sel.ob.y < term.top)
-				sel.ob.y = term.top;
-			if (sel.oe.y > term.bot)
-				sel.oe.y = term.bot;
 		} else {
-			if (sel.ob.y < term.top) {
+			selnormalize();
-				sel.ob.y = term.top;
-				sel.ob.x = 0;
-			}
-			if (sel.oe.y > term.bot) {
-				sel.oe.y = term.bot;
-				sel.oe.x = term.col;
-			}
 		}
-		selnormalize();
 	}
 }
 
@@ -1135,7 +1191,7 @@ tnewline(int first_col)
 	int y = term.c.y;
 
 	if (y == term.bot) {
-		tscrollup(term.top, 1);
+		tscrollup(term.top, 1, 1);
 	} else {
 		y++;
 	}
@@ -1300,14 +1356,14 @@ void
 tinsertblankline(int n)
 {
 	if (BETWEEN(term.c.y, term.top, term.bot))
-		tscrolldown(term.c.y, n);
+		tscrolldown(term.c.y, n, 0);
 }
 
 void
 tdeleteline(int n)
 {
 	if (BETWEEN(term.c.y, term.top, term.bot))
-		tscrollup(term.c.y, n);
+		tscrollup(term.c.y, n, 0);
 }
 
 int32_t
@@ -1657,6 +1713,12 @@ csihandle(void)
 		if (csiescseq.arg[0] == 0)
 			ttywrite(vtiden, strlen(vtiden), 0);
 		break;
+	case 'b': /* REP -- if last char is printable print it <n> more times */
+		DEFAULT(csiescseq.arg[0], 1);
+		if (term.lastc)
+			while (csiescseq.arg[0]-- > 0)
+				tputc(term.lastc);
+		break;
 	case 'C': /* CUF -- Cursor <n> Forward */
 	case 'a': /* HPR -- Cursor <n> Forward */
 		DEFAULT(csiescseq.arg[0], 1);
@@ -1738,11 +1800,11 @@ csihandle(void)
 		break;
 	case 'S': /* SU -- Scroll <n> line up */
 		DEFAULT(csiescseq.arg[0], 1);
-		tscrollup(term.top, csiescseq.arg[0]);
+		tscrollup(term.top, csiescseq.arg[0], 0);
 		break;
 	case 'T': /* SD -- Scroll <n> line down */
 		DEFAULT(csiescseq.arg[0], 1);
-		tscrolldown(term.top, csiescseq.arg[0]);
+		tscrolldown(term.top, csiescseq.arg[0], 0);
 		break;
 	case 'L': /* IL -- Insert <n> blank lines */
 		DEFAULT(csiescseq.arg[0], 1);
@@ -1780,7 +1842,7 @@ csihandle(void)
 		break;
 	case 'n': /* DSR – Device Status Report (cursor position) */
 		if (csiescseq.arg[0] == 6) {
-			len = snprintf(buf, sizeof(buf),"\033[%i;%iR",
+			len = snprintf(buf, sizeof(buf), "\033[%i;%iR",
 					term.c.y+1, term.c.x+1);
 			ttywrite(buf, len, 0);
 		}
@@ -1864,7 +1926,7 @@ strhandle(void)
 				xsettitle(strescseq.args[1]);
 			return;
 		case 52:
-			if (narg > 2) {
+			if (narg > 2 && allowwindowops) {
 				dec = base64dec(strescseq.args[2]);
 				if (dec) {
 					xsetsel(dec);
@@ -1900,7 +1962,6 @@ strhandle(void)
 		xsettitle(strescseq.args[0]);
 		return;
 	case 'P': /* DCS -- Device Control String */
-		term.mode |= ESC_DCS;
 	case '_': /* APC -- Application Program Command */
 	case '^': /* PM -- Privacy Message */
 		return;
@@ -2023,7 +2084,7 @@ tdumpline(int n)
 	bp = &term.line[n][0];
 	end = &bp[MIN(tlinelen(n), term.col) - 1];
 	if (bp != end || bp->u != ' ') {
-		for ( ;bp <= end; ++bp)
+		for ( ; bp <= end; ++bp)
 			tprinter(buf, utf8encode(bp->u, buf));
 	}
 	tprinter("\n", 1);
@@ -2094,12 +2155,9 @@ tdectest(char c)
 void
 tstrsequence(uchar c)
 {
-	strreset();
-
 	switch (c) {
 	case 0x90:   /* DCS -- Device Control String */
 		c = 'P';
-		term.esc |= ESC_DCS;
 		break;
 	case 0x9f:   /* APC -- Application Program Command */
 		c = '_';
@@ -2111,6 +2169,7 @@ tstrsequence(uchar c)
 		c = ']';
 		break;
 	}
+	strreset();
 	strescseq.type = c;
 	term.esc |= ESC_STR;
 }
@@ -2153,6 +2212,7 @@ tcontrolcode(uchar ascii)
 		return;
 	case '\032': /* SUB */
 		tsetchar('?', &term.c.attr, term.c.x, term.c.y);
+		/* FALLTHROUGH */
 	case '\030': /* CAN */
 		csireset();
 		break;
@@ -2248,7 +2308,7 @@ eschandle(uchar ascii)
 		return 0;
 	case 'D': /* IND -- Linefeed */
 		if (term.c.y == term.bot) {
-			tscrollup(term.top, 1);
+			tscrollup(term.top, 1, 1);
 		} else {
 			tmoveto(term.c.x, term.c.y+1);
 		}
@@ -2261,7 +2321,7 @@ eschandle(uchar ascii)
 		break;
 	case 'M': /* RI -- Reverse index */
 		if (term.c.y == term.top) {
-			tscrolldown(term.top, 1);
+			tscrolldown(term.top, 1, 1);
 		} else {
 			tmoveto(term.c.x, term.c.y-1);
 		}
@@ -2307,15 +2367,13 @@ tputc(Rune u)
 	Glyph *gp;
 
 	control = ISCONTROL(u);
-	if (!IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
+	if (u < 127 || !IS_SET(MODE_UTF8)) {
 		c[0] = u;
 		width = len = 1;
 	} else {
 		len = utf8encode(u, c);
-		if (!control && (width = wcwidth(u)) == -1) {
+		if (!control && (width = wcwidth(u)) == -1)
-			memcpy(c, "\357\277\275", 4); /* UTF_INVALID */
 			width = 1;
-		}
 	}
 
 	if (IS_SET(MODE_PRINT))
@@ -2330,23 +2388,11 @@ tputc(Rune u)
 	if (term.esc & ESC_STR) {
 		if (u == '\a' || u == 030 || u == 032 || u == 033 ||
 		   ISCONTROLC1(u)) {
-			term.esc &= ~(ESC_START|ESC_STR|ESC_DCS);
+			term.esc &= ~(ESC_START|ESC_STR);
-			if (IS_SET(MODE_SIXEL)) {
-				/* TODO: render sixel */;
-				term.mode &= ~MODE_SIXEL;
-				return;
-			}
 			term.esc |= ESC_STR_END;
 			goto check_control_code;
 		}
 
-		if (IS_SET(MODE_SIXEL)) {
-			/* TODO: implement sixel mode */
-			return;
-		}
-		if (term.esc&ESC_DCS && strescseq.len == 0 && u == 'q')
-			term.mode |= MODE_SIXEL;
-
 		if (strescseq.len+len >= strescseq.siz) {
 			/*
 			 * Here is a bug in terminals. If the user never sends
@@ -2383,6 +2429,8 @@ check_control_code:
 		/*
 		 * control codes are not shown ever
 		 */
+		if (!term.esc)
+			term.lastc = 0;
 		return;
 	} else if (term.esc & ESC_START) {
 		if (term.esc & ESC_CSI) {
@@ -2413,7 +2461,7 @@ check_control_code:
 		 */
 		return;
 	}
-	if (sel.ob.x != -1 && BETWEEN(term.c.y, sel.ob.y, sel.oe.y))
+	if (selected(term.c.x, term.c.y))
 		selclear();
 
 	gp = &term.line[term.c.y][term.c.x];
@@ -2432,6 +2480,7 @@ check_control_code:
 	}
 
 	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
+	term.lastc = u;
 
 	if (width == 2) {
 		gp->mode |= ATTR_WIDE;
@@ -2455,7 +2504,7 @@ twrite(const char *buf, int buflen, int show_ctrl)
 	int n;
 
 	for (n = 0; n < buflen; n += charsize) {
-		if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
+		if (IS_SET(MODE_UTF8)) {
 			/* process a complete utf8 char */
 			charsize = utf8decode(buf + n, &u, buflen - n);
 			if (charsize == 0)
@@ -2482,7 +2531,7 @@ twrite(const char *buf, int buflen, int show_ctrl)
 void
 tresize(int col, int row)
 {
-	int i;
+	int i, j;
 	int minrow = MIN(row, term.row);
 	int mincol = MIN(col, term.col);
 	int *bp;
@@ -2519,6 +2568,14 @@ tresize(int col, int row)
 	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
 	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
 
+	for (i = 0; i < HISTSIZE; i++) {
+		term.hist[i] = xrealloc(term.hist[i], col * sizeof(Glyph));
+		for (j = mincol; j < col; j++) {
+			term.hist[i][j] = term.c.attr;
+			term.hist[i][j].u = ' ';
+		}
+	}
+
 	/* resize each row to new width, zero-pad if needed */
 	for (i = 0; i < minrow; i++) {
 		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
@@ -2577,7 +2634,7 @@ drawregion(int x1, int y1, int x2, int y2)
 			continue;
 
 		term.dirty[y] = 0;
-		xdrawline(term.line[y], x1, y, x2);
+		xdrawline(TLINE(y), x1, y, x2);
 	}
 }
 
@@ -2598,8 +2655,9 @@ draw(void)
 		cx--;
 
 	drawregion(0, 0, term.col, term.row);
-	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+	if (term.scr == 0)
-			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
+		xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+				term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
 	term.ocx = cx;
 	term.ocy = term.c.y;
 	xfinishdraw();

st.h

@@ -81,12 +81,15 @@ void die(const char *, ...);
 void redraw(void);
 void draw(void);
 
+void kscrolldown(const Arg *);
+void kscrollup(const Arg *);
 void printscreen(const Arg *);
 void printsel(const Arg *);
 void sendbreak(const Arg *);
 void toggleprinter(const Arg *);
 
 int tattrset(int);
+int tisaltscr(void);
 void tnew(int, int);
 void tresize(int, int);
 void tsetdirtattr(int);
@@ -118,7 +121,9 @@ extern char *stty_args;
 extern char *vtiden;
 extern wchar_t *worddelimiters;
 extern int allowaltscreen;
+extern int allowwindowops;
 extern char *termname;
 extern unsigned int tabspaces;
 extern unsigned int defaultfg;
 extern unsigned int defaultbg;
+extern float alpha;

st.info

@@ -158,6 +158,7 @@ st-mono| simpleterm monocolor,
 	rc=\E8,
 	rev=\E[7m,
 	ri=\EM,
+	rin=\E[%p1%dT,
 	ritm=\E[23m,
 	rmacs=\E(B,
 	rmcup=\E[?1049l,
@@ -183,6 +184,8 @@ st-mono| simpleterm monocolor,
 # XTerm extensions
 	rmxx=\E[29m,
 	smxx=\E[9m,
+# disabled rep for now: causes some issues with older ncurses versions.
+#	rep=%p1%c\E[%p2%{1}%-%db,
 # tmux extensions, see TERMINFO EXTENSIONS in tmux(1)
 	Tc,
 	Ms=\E]52;%p1%s;%p2%s\007,

x.c

@@ -14,6 +14,7 @@
 #include <X11/keysym.h>
 #include <X11/Xft/Xft.h>
 #include <X11/XKBlib.h>
+#include <X11/Xresource.h>
 
 char *argv0;
 #include "arg.h"
@@ -34,6 +35,7 @@ typedef struct {
 	void (*func)(const Arg *);
 	const Arg arg;
 	uint  release;
+	int  altscrn;  /* 0: don't care, -1: not alt screen, 1: alt screen */
 } MouseShortcut;
 
 typedef struct {
@@ -45,6 +47,19 @@ typedef struct {
 	signed char appcursor; /* application cursor */
 } Key;
 
+/* Xresources preferences */
+enum resource_type {
+	STRING = 0,
+	INTEGER = 1,
+	FLOAT = 2
+};
+
+typedef struct {
+	char *name;
+	enum resource_type type;
+	void *dst;
+} ResourcePref;
+
 /* X modifiers */
 #define XK_ANY_MOD    UINT_MAX
 #define XK_NO_MOD     0
@@ -81,6 +96,7 @@ typedef XftGlyphFontSpec GlyphFontSpec;
 typedef struct {
 	int tw, th; /* tty width and height */
 	int w, h; /* window width and height */
+	int hborderpx, vborderpx;
 	int ch; /* char height */
 	int cw; /* char width  */
 	int mode; /* window state/mode flags */
@@ -105,6 +121,7 @@ typedef struct {
 	XSetWindowAttributes attrs;
 	int scr;
 	int isfixed; /* is fixed geometry? */
+	int depth; /* bit depth */
 	int l, t; /* left and top offset */
 	int gm; /* geometry mask */
 } XWindow;
@@ -243,6 +260,7 @@ static char *usedfont = NULL;
 static double usedfontsize = 0;
 static double defaultfontsize = 0;
 
+static char *opt_alpha = NULL;
 static char *opt_class = NULL;
 static char **opt_cmd  = NULL;
 static char *opt_embed = NULL;
@@ -331,7 +349,7 @@ ttysend(const Arg *arg)
 int
 evcol(XEvent *e)
 {
-	int x = e->xbutton.x - borderpx;
+	int x = e->xbutton.x - win.hborderpx;
 	LIMIT(x, 0, win.tw - 1);
 	return x / win.cw;
 }
@@ -339,7 +357,7 @@ evcol(XEvent *e)
 int
 evrow(XEvent *e)
 {
-	int y = e->xbutton.y - borderpx;
+	int y = e->xbutton.y - win.vborderpx;
 	LIMIT(y, 0, win.th - 1);
 	return y / win.ch;
 }
@@ -446,6 +464,7 @@ mouseaction(XEvent *e, uint release)
 	for (ms = mshortcuts; ms < mshortcuts + LEN(mshortcuts); ms++) {
 		if (ms->release == release &&
 		    ms->button == e->xbutton.button &&
+		    (!ms->altscrn || (ms->altscrn == (tisaltscr() ? 1 : -1))) &&
 		    (match(ms->mod, state) ||  /* exact or forced */
 		     match(ms->mod, state & ~forcemousemod))) {
 			ms->func(&(ms->arg));
@@ -721,6 +740,9 @@ cresize(int width, int height)
 	col = MAX(1, col);
 	row = MAX(1, row);
 
+	win.hborderpx = (win.w - col * win.cw) / 2;
+	win.vborderpx = (win.h - row * win.ch) / 2;
+
 	tresize(col, row);
 	xresize(col, row);
 	ttyresize(win.tw, win.th);
@@ -734,7 +756,7 @@ xresize(int col, int row)
 
 	XFreePixmap(xw.dpy, xw.buf);
 	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
-			DefaultDepth(xw.dpy, xw.scr));
+			xw.depth);
 	XftDrawChange(xw.draw, xw.buf);
 	xclear(0, 0, win.w, win.h);
 
@@ -794,6 +816,13 @@ xloadcols(void)
 			else
 				die("could not allocate color %d\n", i);
 		}
+
+	/* set alpha value of bg color */
+	if (opt_alpha)
+		alpha = strtof(opt_alpha, NULL);
+	dc.col[defaultbg].color.alpha = (unsigned short)(0xffff * alpha);
+	dc.col[defaultbg].pixel &= 0x00FFFFFF;
+	dc.col[defaultbg].pixel |= (unsigned char)(0xff * alpha) << 24;
 	loaded = 1;
 }
 
@@ -828,8 +857,8 @@ xclear(int x1, int y1, int x2, int y2)
 void
 xhints(void)
 {
-	XClassHint class = {opt_name ? opt_name : termname,
+	XClassHint class = {opt_name ? opt_name : "st",
-	                    opt_class ? opt_class : termname};
+	                    opt_class ? opt_class : "St"};
 	XWMHints wm = {.flags = InputHint, .input = 1};
 	XSizeHints *sizeh;
 
@@ -838,8 +867,8 @@ xhints(void)
 	sizeh->flags = PSize | PResizeInc | PBaseSize | PMinSize;
 	sizeh->height = win.h;
 	sizeh->width = win.w;
-	sizeh->height_inc = win.ch;
+	sizeh->height_inc = 1;
-	sizeh->width_inc = win.cw;
+	sizeh->width_inc = 1;
 	sizeh->base_height = 2 * borderpx;
 	sizeh->base_width = 2 * borderpx;
 	sizeh->min_height = win.ch + 2 * borderpx;
@@ -1103,11 +1132,21 @@ xinit(int cols, int rows)
 	Window parent;
 	pid_t thispid = getpid();
 	XColor xmousefg, xmousebg;
+	XWindowAttributes attr;
+	XVisualInfo vis;
 
-	if (!(xw.dpy = XOpenDisplay(NULL)))
-		die("can't open display\n");
 	xw.scr = XDefaultScreen(xw.dpy);
-	xw.vis = XDefaultVisual(xw.dpy, xw.scr);
+
+	if (!(opt_embed && (parent = strtol(opt_embed, NULL, 0)))) {
+		parent = XRootWindow(xw.dpy, xw.scr);
+		xw.depth = 32;
+	} else {
+		XGetWindowAttributes(xw.dpy, parent, &attr);
+		xw.depth = attr.depth;
+	}
+
+	XMatchVisualInfo(xw.dpy, xw.scr, xw.depth, TrueColor, &vis);
+	xw.vis = vis.visual;
 
 	/* font */
 	if (!FcInit())
@@ -1117,12 +1156,12 @@ xinit(int cols, int rows)
 	xloadfonts(usedfont, 0);
 
 	/* colors */
-	xw.cmap = XDefaultColormap(xw.dpy, xw.scr);
+	xw.cmap = XCreateColormap(xw.dpy, parent, xw.vis, None);
 	xloadcols();
 
 	/* adjust fixed window geometry */
-	win.w = 2 * borderpx + cols * win.cw;
+	win.w = 2 * win.hborderpx + cols * win.cw;
-	win.h = 2 * borderpx + rows * win.ch;
+	win.h = 2 * win.vborderpx + rows * win.ch;
 	if (xw.gm & XNegative)
 		xw.l += DisplayWidth(xw.dpy, xw.scr) - win.w - 2;
 	if (xw.gm & YNegative)
@@ -1137,19 +1176,15 @@ xinit(int cols, int rows)
 		| ButtonMotionMask | ButtonPressMask | ButtonReleaseMask;
 	xw.attrs.colormap = xw.cmap;
 
-	if (!(opt_embed && (parent = strtol(opt_embed, NULL, 0))))
-		parent = XRootWindow(xw.dpy, xw.scr);
 	xw.win = XCreateWindow(xw.dpy, parent, xw.l, xw.t,
-			win.w, win.h, 0, XDefaultDepth(xw.dpy, xw.scr), InputOutput,
+			win.w, win.h, 0, xw.depth, InputOutput,
 			xw.vis, CWBackPixel | CWBorderPixel | CWBitGravity
 			| CWEventMask | CWColormap, &xw.attrs);
 
 	memset(&gcvalues, 0, sizeof(gcvalues));
 	gcvalues.graphics_exposures = False;
-	dc.gc = XCreateGC(xw.dpy, parent, GCGraphicsExposures,
+	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h, xw.depth);
-			&gcvalues);
+	dc.gc = XCreateGC(xw.dpy, xw.buf, GCGraphicsExposures, &gcvalues);
-	xw.buf = XCreatePixmap(xw.dpy, xw.win, win.w, win.h,
-			DefaultDepth(xw.dpy, xw.scr));
 	XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
 
@@ -1210,7 +1245,7 @@ xinit(int cols, int rows)
 int
 xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x, int y)
 {
-	float winx = borderpx + x * win.cw, winy = borderpx + y * win.ch, xp, yp;
+	float winx = win.hborderpx + x * win.cw, winy = win.vborderpx + y * win.ch, xp, yp;
 	ushort mode, prevmode = USHRT_MAX;
 	Font *font = &dc.font;
 	int frcflags = FRC_NORMAL;
@@ -1343,7 +1378,7 @@ void
 xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y)
 {
 	int charlen = len * ((base.mode & ATTR_WIDE) ? 2 : 1);
-	int winx = borderpx + x * win.cw, winy = borderpx + y * win.ch,
+	int winx = win.hborderpx + x * win.cw, winy = win.vborderpx + y * win.ch,
 	    width = charlen * win.cw;
 	Color *fg, *bg, *temp, revfg, revbg, truefg, truebg;
 	XRenderColor colfg, colbg;
@@ -1433,17 +1468,17 @@ xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, i
 
 	/* Intelligent cleaning up of the borders. */
 	if (x == 0) {
-		xclear(0, (y == 0)? 0 : winy, borderpx,
+		xclear(0, (y == 0)? 0 : winy, win.vborderpx,
 			winy + win.ch +
-			((winy + win.ch >= borderpx + win.th)? win.h : 0));
+			((winy + win.ch >= win.vborderpx + win.th)? win.h : 0));
 	}
-	if (winx + width >= borderpx + win.tw) {
+	if (winx + width >= win.hborderpx + win.tw) {
 		xclear(winx + width, (y == 0)? 0 : winy, win.w,
-			((winy + win.ch >= borderpx + win.th)? win.h : (winy + win.ch)));
+			((winy + win.ch >= win.vborderpx + win.th)? win.h : (winy + win.ch)));
 	}
 	if (y == 0)
-		xclear(winx, 0, winx + width, borderpx);
+		xclear(winx, 0, winx + width, win.hborderpx);
-	if (winy + win.ch >= borderpx + win.th)
+	if (winy + win.ch >= win.vborderpx + win.th)
 		xclear(winx, winy + win.ch, winx + width, win.h);
 
 	/* Clean up the region we want to draw to. */
@@ -1526,8 +1561,9 @@ xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
 	/* draw the new one */
 	if (IS_SET(MODE_FOCUSED)) {
 		switch (win.cursor) {
-		case 7: /* st extension: snowman (U+2603) */
+		case 7: /* st extension */
-			g.u = 0x2603;
+			g.u = 0x2603; /* snowman (U+2603) */
+			/* FALLTHROUGH */
 		case 0: /* Blinking Block */
 		case 1: /* Blinking Block (Default) */
 		case 2: /* Steady Block */
@@ -1536,35 +1572,35 @@ xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
 		case 3: /* Blinking Underline */
 		case 4: /* Steady Underline */
 			XftDrawRect(xw.draw, &drawcol,
-					borderpx + cx * win.cw,
+					win.hborderpx + cx * win.cw,
-					borderpx + (cy + 1) * win.ch - \
+					win.vborderpx + (cy + 1) * win.ch - \
 						cursorthickness,
 					win.cw, cursorthickness);
 			break;
 		case 5: /* Blinking bar */
 		case 6: /* Steady bar */
 			XftDrawRect(xw.draw, &drawcol,
-					borderpx + cx * win.cw,
+					win.hborderpx + cx * win.cw,
-					borderpx + cy * win.ch,
+					win.vborderpx + cy * win.ch,
 					cursorthickness, win.ch);
 			break;
 		}
 	} else {
 		XftDrawRect(xw.draw, &drawcol,
-				borderpx + cx * win.cw,
+				win.hborderpx + cx * win.cw,
-				borderpx + cy * win.ch,
+				win.vborderpx + cy * win.ch,
 				win.cw - 1, 1);
 		XftDrawRect(xw.draw, &drawcol,
-				borderpx + cx * win.cw,
+				win.hborderpx + cx * win.cw,
-				borderpx + cy * win.ch,
+				win.vborderpx + cy * win.ch,
 				1, win.ch - 1);
 		XftDrawRect(xw.draw, &drawcol,
-				borderpx + (cx + 1) * win.cw - 1,
+				win.hborderpx + (cx + 1) * win.cw - 1,
-				borderpx + cy * win.ch,
+				win.vborderpx + cy * win.ch,
 				1, win.ch - 1);
 		XftDrawRect(xw.draw, &drawcol,
-				borderpx + cx * win.cw,
+				win.hborderpx + cx * win.cw,
-				borderpx + (cy + 1) * win.ch - 1,
+				win.vborderpx + (cy + 1) * win.ch - 1,
 				win.cw, 1);
 	}
 }
@@ -1689,8 +1725,7 @@ xsetmode(int set, unsigned int flags)
 int
 xsetcursor(int cursor)
 {
-	DEFAULT(cursor, 1);
+	if (!BETWEEN(cursor, 0, 7)) /* 7: st extension */
-	if (!BETWEEN(cursor, 0, 6))
 		return 1;
 	win.cursor = cursor;
 	return 0;
@@ -1867,10 +1902,9 @@ 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 xfd = XConnectionNumber(xw.dpy), ttyfd, xev, drawing;
-	int ttyfd;
+	struct timespec seltv, *tv, now, lastblink, trigger;
-	struct timespec drawtimeout, *tv = NULL, now, last, lastblink;
+	double timeout;
-	long deltatime;
 
 	/* Waiting for window mapping */
 	do {
@@ -1891,85 +1925,133 @@ run(void)
 	ttyfd = ttynew(opt_line, shell, opt_io, opt_cmd);
 	cresize(w, h);
 
-	clock_gettime(CLOCK_MONOTONIC, &last);
+	for (timeout = -1, drawing = 0, lastblink = (struct timespec){0};;) {
-	lastblink = last;
-
-	for (xev = actionfps;;) {
 		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 (FD_ISSET(ttyfd, &rfd))
-		if (blinktimeout && TIMEDIFF(now, lastblink) > blinktimeout) {
+			ttyread();
-			tsetdirtattr(ATTR_BLINK);
+
-			win.mode ^= MODE_BLINK;
+		xev = 0;
-			lastblink = now;
+		while (XPending(xw.dpy)) {
-			dodraw = 1;
+			xev = 1;
-		}
+			XNextEvent(xw.dpy, &ev);
-		deltatime = TIMEDIFF(now, last);
+			if (XFilterEvent(&ev, None))
-		if (deltatime > 1000 / (xev ? xfps : actionfps)) {
+				continue;
-			dodraw = 1;
+			if (handler[ev.type])
-			last = now;
+				(handler[ev.type])(&ev);
 		}
 
-		if (dodraw) {
+		/*
-			while (XPending(xw.dpy)) {
+		 * To reduce flicker and tearing, when new content or event
-				XNextEvent(xw.dpy, &ev);
+		 * triggers drawing, we first wait a bit to ensure we got
-				if (XFilterEvent(&ev, None))
+		 * everything, and if nothing new arrives - we draw.
-					continue;
+		 * We start with trying to wait minlatency ms. If more content
-				if (handler[ev.type])
+		 * arrives sooner, we retry with shorter and shorter periods,
-					(handler[ev.type])(&ev);
+		 * 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 */
+		}
 
-			draw();
+		/* idle detected or maxlatency exhausted -> draw */
-			XFlush(xw.dpy);
+		timeout = -1;
-
+		if (blinktimeout && tattrset(ATTR_BLINK)) {
-			if (xev && !FD_ISSET(xfd, &rfd))
+			timeout = blinktimeout - TIMEDIFF(now, lastblink);
-				xev--;
+			if (timeout <= 0) {
-			if (!FD_ISSET(ttyfd, &rfd) && !FD_ISSET(xfd, &rfd)) {
+				if (-timeout > blinktimeout) /* start visible */
-				if (blinkset) {
+					win.mode |= MODE_BLINK;
-					if (TIMEDIFF(now, lastblink) \
+				win.mode ^= MODE_BLINK;
-							> blinktimeout) {
+				tsetdirtattr(ATTR_BLINK);
-						drawtimeout.tv_nsec = 1000;
+				lastblink = now;
-					} else {
+				timeout = blinktimeout;
-						drawtimeout.tv_nsec = (1E6 * \
-							(blinktimeout - \
-							TIMEDIFF(now,
-								lastblink)));
-					}
-					drawtimeout.tv_sec = \
-					    drawtimeout.tv_nsec / 1E9;
-					drawtimeout.tv_nsec %= (long)1E9;
-				} else {
-					tv = NULL;
-				}
 			}
 		}
+
+		draw();
+		XFlush(xw.dpy);
+		drawing = 0;
 	}
 }
 
+int
+resource_load(XrmDatabase db, char *name, enum resource_type rtype, void *dst)
+{
+	char **sdst = dst;
+	int *idst = dst;
+	float *fdst = dst;
+
+	char fullname[256];
+	char fullclass[256];
+	char *type;
+	XrmValue ret;
+
+	snprintf(fullname, sizeof(fullname), "%s.%s",
+			opt_name ? opt_name : "st", name);
+	snprintf(fullclass, sizeof(fullclass), "%s.%s",
+			opt_class ? opt_class : "St", name);
+	fullname[sizeof(fullname) - 1] = fullclass[sizeof(fullclass) - 1] = '\0';
+
+	XrmGetResource(db, fullname, fullclass, &type, &ret);
+	if (ret.addr == NULL || strncmp("String", type, 64))
+		return 1;
+
+	switch (rtype) {
+	case STRING:
+		*sdst = ret.addr;
+		break;
+	case INTEGER:
+		*idst = strtoul(ret.addr, NULL, 10);
+		break;
+	case FLOAT:
+		*fdst = strtof(ret.addr, NULL);
+		break;
+	}
+	return 0;
+}
+
+void
+config_init(void)
+{
+	char *resm;
+	XrmDatabase db;
+	ResourcePref *p;
+
+	XrmInitialize();
+	resm = XResourceManagerString(xw.dpy);
+	if (!resm)
+		return;
+
+	db = XrmGetStringDatabase(resm);
+	for (p = resources; p < resources + LEN(resources); p++)
+		resource_load(db, p->name, p->type, p->dst);
+}
+
 void
 usage(void)
 {
@@ -1988,12 +2070,15 @@ main(int argc, char *argv[])
 {
 	xw.l = xw.t = 0;
 	xw.isfixed = False;
-	win.cursor = cursorshape;
+	xsetcursor(cursorshape);
 
 	ARGBEGIN {
 	case 'a':
 		allowaltscreen = 0;
 		break;
+	case 'A':
+		opt_alpha = EARGF(usage());
+		break;
 	case 'c':
 		opt_class = EARGF(usage());
 		break;
@@ -2043,6 +2128,11 @@ run:
 
 	setlocale(LC_CTYPE, "");
 	XSetLocaleModifiers("");
+
+	if(!(xw.dpy = XOpenDisplay(NULL)))
+		die("Can't open display\n");
+
+	config_init();
 	cols = MAX(cols, 1);
 	rows = MAX(rows, 1);
 	tnew(cols, rows);