.gitignore

.gitignore

@@ -0,0 +1,6 @@
+st
+*.o
+*.orig
+*.regj
+config.h
+*.diff

Makefile

@@ -4,7 +4,7 @@
 
 include config.mk
 
-SRC = st.c x.c
+SRC = st.c x.c hb.c
 OBJ = $(SRC:.c=.o)
 
 all: st
@@ -16,7 +16,8 @@ config.h:
 	$(CC) $(STCFLAGS) -c $<
 
 st.o: config.h st.h win.h
-x.o: arg.h config.h st.h win.h
+x.o: arg.h config.h st.h win.h hb.h
+hb.o: st.h
 
 $(OBJ): config.h config.mk
 

config.def.h

@@ -201,6 +201,8 @@ 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.h

@@ -0,0 +1,475 @@
+/* See LICENSE file for copyright and license details. */
+
+/*
+ * appearance
+ *
+ * font: see http://freedesktop.org/software/fontconfig/fontconfig-user.html
+ */
+static char *font =
+    "JetBrainsMono Nerd Font:pixelsize=18:antialias=true:autohint=true";
+static int borderpx = 2;
+
+/*
+ * What program is execed by st depends of these precedence rules:
+ * 1: program passed with -e
+ * 2: scroll and/or utmp
+ * 3: SHELL environment variable
+ * 4: value of shell in /etc/passwd
+ * 5: value of shell in config.h
+ */
+static char *shell = "/bin/sh";
+char *utmp = NULL;
+/* scroll program: to enable use a string like "scroll" */
+char *scroll = NULL;
+char *stty_args = "stty raw pass8 nl -echo -iexten -cstopb 38400";
+
+/* identification sequence returned in DA and DECID */
+char *vtiden = "\033[?6c";
+
+/* Kerning / character bounding-box multipliers */
+static float cwscale = 1.0;
+static float chscale = 1.0;
+
+/*
+ * word delimiter string
+ *
+ * More advanced example: L" `'\"()[]{}"
+ */
+wchar_t *worddelimiters = L" ";
+
+/* selection timeouts (in milliseconds) */
+static unsigned int doubleclicktimeout = 300;
+static unsigned int tripleclicktimeout = 600;
+
+/* alt screens */
+int allowaltscreen = 1;
+
+/* allow certain non-interactive (insecure) window operations such as:
+   setting the clipboard text */
+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 = 2;
+static double maxlatency = 33;
+
+/*
+ * blinking timeout (set to 0 to disable blinking) for the terminal blinking
+ * attribute.
+ */
+static unsigned int blinktimeout = 800;
+
+/*
+ * thickness of underline and bar cursors
+ */
+static unsigned int cursorthickness = 2;
+
+/*
+ * bell volume. It must be a value between -100 and 100. Use 0 for disabling
+ * it
+ */
+static int bellvolume = 0;
+
+/* default TERM value */
+char *termname = "st-256color";
+
+/*
+ * spaces per tab
+ *
+ * When you are changing this value, don't forget to adapt the »it« value in
+ * the st.info and appropriately install the st.info in the environment where
+ * you use this st version.
+ *
+ *	it#$tabspaces,
+ *
+ * Secondly make sure your kernel is not expanding tabs. When running `stty
+ * -a` »tab0« should appear. You can tell the terminal to not expand tabs by
+ *  running following command:
+ *
+ *	stty tabs
+ */
+unsigned int tabspaces = 8;
+
+/* Terminal colors (16 first used in escape sequence) */
+static const char *colorname[] = {
+    /* 8 normal colors */
+    "black",
+    "red3",
+    "green3",
+    "yellow3",
+    "blue2",
+    "magenta3",
+    "cyan3",
+    "gray90",
+
+    /* 8 bright colors */
+    "gray50",
+    "red",
+    "green",
+    "yellow",
+    "#5c5cff",
+    "magenta",
+    "cyan",
+    "white",
+
+    [255] = 0,
+
+    /* more colors can be added after 255 to use with DefaultXX */
+    "#cccccc",
+    "#555555",
+    "gray90", /* default foreground colour */
+    "black",  /* default background colour */
+};
+
+/*
+ * Default colors (colorname index)
+ * foreground, background, cursor, reverse cursor
+ */
+unsigned int defaultfg = 258;
+unsigned int defaultbg = 259;
+unsigned int defaultcs = 256;
+static unsigned int defaultrcs = 257;
+
+/*
+ * Default shape of cursor
+ * 2: Block ("█")
+ * 4: Underline ("_")
+ * 6: Bar ("|")
+ * 7: Snowman ("☃")
+ */
+static unsigned int cursorshape = 2;
+
+/*
+ * Default columns and rows numbers
+ */
+
+static unsigned int cols = 80;
+static unsigned int rows = 24;
+
+/*
+ * Default colour and shape of the mouse cursor
+ */
+static unsigned int mouseshape = XC_xterm;
+static unsigned int mousefg = 7;
+static unsigned int mousebg = 0;
+
+/*
+ * Color used to display font attributes when fontconfig selected a font which
+ * doesn't match the ones requested.
+ */
+static unsigned int defaultattr = 11;
+
+/*
+ * Force mouse select/shortcuts while mask is active (when MODE_MOUSE is set).
+ * Note that if you want to use ShiftMask with selmasks, set this to an other
+ * modifier, set to 0 to not use it.
+ */
+static uint forcemousemod = ShiftMask;
+
+/*
+ * Internal mouse shortcuts.
+ * Beware that overloading Button1 will disable the selection.
+ */
+static MouseShortcut mshortcuts[] = {
+    /* mask                 button   function        argument       release */
+    {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"}},
+};
+
+/* Internal keyboard shortcuts. */
+#define MODKEY Mod1Mask
+#define TERMMOD (ControlMask | ShiftMask)
+
+static Shortcut shortcuts[] = {
+    /* mask                 keysym          function        argument */
+    {XK_ANY_MOD, XK_Break, sendbreak, {.i = 0}},
+    {ControlMask, XK_Print, toggleprinter, {.i = 0}},
+    {ShiftMask, XK_Print, printscreen, {.i = 0}},
+    {XK_ANY_MOD, XK_Print, printsel, {.i = 0}},
+    {TERMMOD, XK_Prior, zoom, {.f = +1}},
+    {TERMMOD, XK_Next, zoom, {.f = -1}},
+    {TERMMOD, XK_Home, zoomreset, {.f = 0}},
+    {TERMMOD, XK_C, clipcopy, {.i = 0}},
+    {TERMMOD, XK_V, clippaste, {.i = 0}},
+    {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}},
+};
+
+/*
+ * Special keys (change & recompile st.info accordingly)
+ *
+ * Mask value:
+ * * Use XK_ANY_MOD to match the key no matter modifiers state
+ * * Use XK_NO_MOD to match the key alone (no modifiers)
+ * appkey value:
+ * * 0: no value
+ * * > 0: keypad application mode enabled
+ * *   = 2: term.numlock = 1
+ * * < 0: keypad application mode disabled
+ * appcursor value:
+ * * 0: no value
+ * * > 0: cursor application mode enabled
+ * * < 0: cursor application mode disabled
+ *
+ * Be careful with the order of the definitions because st searches in
+ * this table sequentially, so any XK_ANY_MOD must be in the last
+ * position for a key.
+ */
+
+/*
+ * If you want keys other than the X11 function keys (0xFD00 - 0xFFFF)
+ * to be mapped below, add them to this array.
+ */
+static KeySym mappedkeys[] = {-1};
+
+/*
+ * State bits to ignore when matching key or button events.  By default,
+ * numlock (Mod2Mask) and keyboard layout (XK_SWITCH_MOD) are ignored.
+ */
+static uint ignoremod = Mod2Mask | XK_SWITCH_MOD;
+
+/*
+ * This is the huge key array which defines all compatibility to the Linux
+ * world. Please decide about changes wisely.
+ */
+static Key key[] = {
+    /* keysym           mask            string      appkey appcursor */
+    {XK_KP_Home, ShiftMask, "\033[2J", 0, -1},
+    {XK_KP_Home, ShiftMask, "\033[1;2H", 0, +1},
+    {XK_KP_Home, XK_ANY_MOD, "\033[H", 0, -1},
+    {XK_KP_Home, XK_ANY_MOD, "\033[1~", 0, +1},
+    {XK_KP_Up, XK_ANY_MOD, "\033Ox", +1, 0},
+    {XK_KP_Up, XK_ANY_MOD, "\033[A", 0, -1},
+    {XK_KP_Up, XK_ANY_MOD, "\033OA", 0, +1},
+    {XK_KP_Down, XK_ANY_MOD, "\033Or", +1, 0},
+    {XK_KP_Down, XK_ANY_MOD, "\033[B", 0, -1},
+    {XK_KP_Down, XK_ANY_MOD, "\033OB", 0, +1},
+    {XK_KP_Left, XK_ANY_MOD, "\033Ot", +1, 0},
+    {XK_KP_Left, XK_ANY_MOD, "\033[D", 0, -1},
+    {XK_KP_Left, XK_ANY_MOD, "\033OD", 0, +1},
+    {XK_KP_Right, XK_ANY_MOD, "\033Ov", +1, 0},
+    {XK_KP_Right, XK_ANY_MOD, "\033[C", 0, -1},
+    {XK_KP_Right, XK_ANY_MOD, "\033OC", 0, +1},
+    {XK_KP_Prior, ShiftMask, "\033[5;2~", 0, 0},
+    {XK_KP_Prior, XK_ANY_MOD, "\033[5~", 0, 0},
+    {XK_KP_Begin, XK_ANY_MOD, "\033[E", 0, 0},
+    {XK_KP_End, ControlMask, "\033[J", -1, 0},
+    {XK_KP_End, ControlMask, "\033[1;5F", +1, 0},
+    {XK_KP_End, ShiftMask, "\033[K", -1, 0},
+    {XK_KP_End, ShiftMask, "\033[1;2F", +1, 0},
+    {XK_KP_End, XK_ANY_MOD, "\033[4~", 0, 0},
+    {XK_KP_Next, ShiftMask, "\033[6;2~", 0, 0},
+    {XK_KP_Next, XK_ANY_MOD, "\033[6~", 0, 0},
+    {XK_KP_Insert, ShiftMask, "\033[2;2~", +1, 0},
+    {XK_KP_Insert, ShiftMask, "\033[4l", -1, 0},
+    {XK_KP_Insert, ControlMask, "\033[L", -1, 0},
+    {XK_KP_Insert, ControlMask, "\033[2;5~", +1, 0},
+    {XK_KP_Insert, XK_ANY_MOD, "\033[4h", -1, 0},
+    {XK_KP_Insert, XK_ANY_MOD, "\033[2~", +1, 0},
+    {XK_KP_Delete, ControlMask, "\033[M", -1, 0},
+    {XK_KP_Delete, ControlMask, "\033[3;5~", +1, 0},
+    {XK_KP_Delete, ShiftMask, "\033[2K", -1, 0},
+    {XK_KP_Delete, ShiftMask, "\033[3;2~", +1, 0},
+    {XK_KP_Delete, XK_ANY_MOD, "\033[P", -1, 0},
+    {XK_KP_Delete, XK_ANY_MOD, "\033[3~", +1, 0},
+    {XK_KP_Multiply, XK_ANY_MOD, "\033Oj", +2, 0},
+    {XK_KP_Add, XK_ANY_MOD, "\033Ok", +2, 0},
+    {XK_KP_Enter, XK_ANY_MOD, "\033OM", +2, 0},
+    {XK_KP_Enter, XK_ANY_MOD, "\r", -1, 0},
+    {XK_KP_Subtract, XK_ANY_MOD, "\033Om", +2, 0},
+    {XK_KP_Decimal, XK_ANY_MOD, "\033On", +2, 0},
+    {XK_KP_Divide, XK_ANY_MOD, "\033Oo", +2, 0},
+    {XK_KP_0, XK_ANY_MOD, "\033Op", +2, 0},
+    {XK_KP_1, XK_ANY_MOD, "\033Oq", +2, 0},
+    {XK_KP_2, XK_ANY_MOD, "\033Or", +2, 0},
+    {XK_KP_3, XK_ANY_MOD, "\033Os", +2, 0},
+    {XK_KP_4, XK_ANY_MOD, "\033Ot", +2, 0},
+    {XK_KP_5, XK_ANY_MOD, "\033Ou", +2, 0},
+    {XK_KP_6, XK_ANY_MOD, "\033Ov", +2, 0},
+    {XK_KP_7, XK_ANY_MOD, "\033Ow", +2, 0},
+    {XK_KP_8, XK_ANY_MOD, "\033Ox", +2, 0},
+    {XK_KP_9, XK_ANY_MOD, "\033Oy", +2, 0},
+    {XK_Up, ShiftMask, "\033[1;2A", 0, 0},
+    {XK_Up, Mod1Mask, "\033[1;3A", 0, 0},
+    {XK_Up, ShiftMask | Mod1Mask, "\033[1;4A", 0, 0},
+    {XK_Up, ControlMask, "\033[1;5A", 0, 0},
+    {XK_Up, ShiftMask | ControlMask, "\033[1;6A", 0, 0},
+    {XK_Up, ControlMask | Mod1Mask, "\033[1;7A", 0, 0},
+    {XK_Up, ShiftMask | ControlMask | Mod1Mask, "\033[1;8A", 0, 0},
+    {XK_Up, XK_ANY_MOD, "\033[A", 0, -1},
+    {XK_Up, XK_ANY_MOD, "\033OA", 0, +1},
+    {XK_Down, ShiftMask, "\033[1;2B", 0, 0},
+    {XK_Down, Mod1Mask, "\033[1;3B", 0, 0},
+    {XK_Down, ShiftMask | Mod1Mask, "\033[1;4B", 0, 0},
+    {XK_Down, ControlMask, "\033[1;5B", 0, 0},
+    {XK_Down, ShiftMask | ControlMask, "\033[1;6B", 0, 0},
+    {XK_Down, ControlMask | Mod1Mask, "\033[1;7B", 0, 0},
+    {XK_Down, ShiftMask | ControlMask | Mod1Mask, "\033[1;8B", 0, 0},
+    {XK_Down, XK_ANY_MOD, "\033[B", 0, -1},
+    {XK_Down, XK_ANY_MOD, "\033OB", 0, +1},
+    {XK_Left, ShiftMask, "\033[1;2D", 0, 0},
+    {XK_Left, Mod1Mask, "\033[1;3D", 0, 0},
+    {XK_Left, ShiftMask | Mod1Mask, "\033[1;4D", 0, 0},
+    {XK_Left, ControlMask, "\033[1;5D", 0, 0},
+    {XK_Left, ShiftMask | ControlMask, "\033[1;6D", 0, 0},
+    {XK_Left, ControlMask | Mod1Mask, "\033[1;7D", 0, 0},
+    {XK_Left, ShiftMask | ControlMask | Mod1Mask, "\033[1;8D", 0, 0},
+    {XK_Left, XK_ANY_MOD, "\033[D", 0, -1},
+    {XK_Left, XK_ANY_MOD, "\033OD", 0, +1},
+    {XK_Right, ShiftMask, "\033[1;2C", 0, 0},
+    {XK_Right, Mod1Mask, "\033[1;3C", 0, 0},
+    {XK_Right, ShiftMask | Mod1Mask, "\033[1;4C", 0, 0},
+    {XK_Right, ControlMask, "\033[1;5C", 0, 0},
+    {XK_Right, ShiftMask | ControlMask, "\033[1;6C", 0, 0},
+    {XK_Right, ControlMask | Mod1Mask, "\033[1;7C", 0, 0},
+    {XK_Right, ShiftMask | ControlMask | Mod1Mask, "\033[1;8C", 0, 0},
+    {XK_Right, XK_ANY_MOD, "\033[C", 0, -1},
+    {XK_Right, XK_ANY_MOD, "\033OC", 0, +1},
+    {XK_ISO_Left_Tab, ShiftMask, "\033[Z", 0, 0},
+    {XK_Return, Mod1Mask, "\033\r", 0, 0},
+    {XK_Return, XK_ANY_MOD, "\r", 0, 0},
+    {XK_Insert, ShiftMask, "\033[4l", -1, 0},
+    {XK_Insert, ShiftMask, "\033[2;2~", +1, 0},
+    {XK_Insert, ControlMask, "\033[L", -1, 0},
+    {XK_Insert, ControlMask, "\033[2;5~", +1, 0},
+    {XK_Insert, XK_ANY_MOD, "\033[4h", -1, 0},
+    {XK_Insert, XK_ANY_MOD, "\033[2~", +1, 0},
+    {XK_Delete, ControlMask, "\033[M", -1, 0},
+    {XK_Delete, ControlMask, "\033[3;5~", +1, 0},
+    {XK_Delete, ShiftMask, "\033[2K", -1, 0},
+    {XK_Delete, ShiftMask, "\033[3;2~", +1, 0},
+    {XK_Delete, XK_ANY_MOD, "\033[P", -1, 0},
+    {XK_Delete, XK_ANY_MOD, "\033[3~", +1, 0},
+    {XK_BackSpace, XK_NO_MOD, "\177", 0, 0},
+    {XK_BackSpace, Mod1Mask, "\033\177", 0, 0},
+    {XK_Home, ShiftMask, "\033[2J", 0, -1},
+    {XK_Home, ShiftMask, "\033[1;2H", 0, +1},
+    {XK_Home, XK_ANY_MOD, "\033[H", 0, -1},
+    {XK_Home, XK_ANY_MOD, "\033[1~", 0, +1},
+    {XK_End, ControlMask, "\033[J", -1, 0},
+    {XK_End, ControlMask, "\033[1;5F", +1, 0},
+    {XK_End, ShiftMask, "\033[K", -1, 0},
+    {XK_End, ShiftMask, "\033[1;2F", +1, 0},
+    {XK_End, XK_ANY_MOD, "\033[4~", 0, 0},
+    {XK_Prior, ControlMask, "\033[5;5~", 0, 0},
+    {XK_Prior, ShiftMask, "\033[5;2~", 0, 0},
+    {XK_Prior, XK_ANY_MOD, "\033[5~", 0, 0},
+    {XK_Next, ControlMask, "\033[6;5~", 0, 0},
+    {XK_Next, ShiftMask, "\033[6;2~", 0, 0},
+    {XK_Next, XK_ANY_MOD, "\033[6~", 0, 0},
+    {XK_F1, XK_NO_MOD, "\033OP", 0, 0},
+    {XK_F1, /* F13 */ ShiftMask, "\033[1;2P", 0, 0},
+    {XK_F1, /* F25 */ ControlMask, "\033[1;5P", 0, 0},
+    {XK_F1, /* F37 */ Mod4Mask, "\033[1;6P", 0, 0},
+    {XK_F1, /* F49 */ Mod1Mask, "\033[1;3P", 0, 0},
+    {XK_F1, /* F61 */ Mod3Mask, "\033[1;4P", 0, 0},
+    {XK_F2, XK_NO_MOD, "\033OQ", 0, 0},
+    {XK_F2, /* F14 */ ShiftMask, "\033[1;2Q", 0, 0},
+    {XK_F2, /* F26 */ ControlMask, "\033[1;5Q", 0, 0},
+    {XK_F2, /* F38 */ Mod4Mask, "\033[1;6Q", 0, 0},
+    {XK_F2, /* F50 */ Mod1Mask, "\033[1;3Q", 0, 0},
+    {XK_F2, /* F62 */ Mod3Mask, "\033[1;4Q", 0, 0},
+    {XK_F3, XK_NO_MOD, "\033OR", 0, 0},
+    {XK_F3, /* F15 */ ShiftMask, "\033[1;2R", 0, 0},
+    {XK_F3, /* F27 */ ControlMask, "\033[1;5R", 0, 0},
+    {XK_F3, /* F39 */ Mod4Mask, "\033[1;6R", 0, 0},
+    {XK_F3, /* F51 */ Mod1Mask, "\033[1;3R", 0, 0},
+    {XK_F3, /* F63 */ Mod3Mask, "\033[1;4R", 0, 0},
+    {XK_F4, XK_NO_MOD, "\033OS", 0, 0},
+    {XK_F4, /* F16 */ ShiftMask, "\033[1;2S", 0, 0},
+    {XK_F4, /* F28 */ ControlMask, "\033[1;5S", 0, 0},
+    {XK_F4, /* F40 */ Mod4Mask, "\033[1;6S", 0, 0},
+    {XK_F4, /* F52 */ Mod1Mask, "\033[1;3S", 0, 0},
+    {XK_F5, XK_NO_MOD, "\033[15~", 0, 0},
+    {XK_F5, /* F17 */ ShiftMask, "\033[15;2~", 0, 0},
+    {XK_F5, /* F29 */ ControlMask, "\033[15;5~", 0, 0},
+    {XK_F5, /* F41 */ Mod4Mask, "\033[15;6~", 0, 0},
+    {XK_F5, /* F53 */ Mod1Mask, "\033[15;3~", 0, 0},
+    {XK_F6, XK_NO_MOD, "\033[17~", 0, 0},
+    {XK_F6, /* F18 */ ShiftMask, "\033[17;2~", 0, 0},
+    {XK_F6, /* F30 */ ControlMask, "\033[17;5~", 0, 0},
+    {XK_F6, /* F42 */ Mod4Mask, "\033[17;6~", 0, 0},
+    {XK_F6, /* F54 */ Mod1Mask, "\033[17;3~", 0, 0},
+    {XK_F7, XK_NO_MOD, "\033[18~", 0, 0},
+    {XK_F7, /* F19 */ ShiftMask, "\033[18;2~", 0, 0},
+    {XK_F7, /* F31 */ ControlMask, "\033[18;5~", 0, 0},
+    {XK_F7, /* F43 */ Mod4Mask, "\033[18;6~", 0, 0},
+    {XK_F7, /* F55 */ Mod1Mask, "\033[18;3~", 0, 0},
+    {XK_F8, XK_NO_MOD, "\033[19~", 0, 0},
+    {XK_F8, /* F20 */ ShiftMask, "\033[19;2~", 0, 0},
+    {XK_F8, /* F32 */ ControlMask, "\033[19;5~", 0, 0},
+    {XK_F8, /* F44 */ Mod4Mask, "\033[19;6~", 0, 0},
+    {XK_F8, /* F56 */ Mod1Mask, "\033[19;3~", 0, 0},
+    {XK_F9, XK_NO_MOD, "\033[20~", 0, 0},
+    {XK_F9, /* F21 */ ShiftMask, "\033[20;2~", 0, 0},
+    {XK_F9, /* F33 */ ControlMask, "\033[20;5~", 0, 0},
+    {XK_F9, /* F45 */ Mod4Mask, "\033[20;6~", 0, 0},
+    {XK_F9, /* F57 */ Mod1Mask, "\033[20;3~", 0, 0},
+    {XK_F10, XK_NO_MOD, "\033[21~", 0, 0},
+    {XK_F10, /* F22 */ ShiftMask, "\033[21;2~", 0, 0},
+    {XK_F10, /* F34 */ ControlMask, "\033[21;5~", 0, 0},
+    {XK_F10, /* F46 */ Mod4Mask, "\033[21;6~", 0, 0},
+    {XK_F10, /* F58 */ Mod1Mask, "\033[21;3~", 0, 0},
+    {XK_F11, XK_NO_MOD, "\033[23~", 0, 0},
+    {XK_F11, /* F23 */ ShiftMask, "\033[23;2~", 0, 0},
+    {XK_F11, /* F35 */ ControlMask, "\033[23;5~", 0, 0},
+    {XK_F11, /* F47 */ Mod4Mask, "\033[23;6~", 0, 0},
+    {XK_F11, /* F59 */ Mod1Mask, "\033[23;3~", 0, 0},
+    {XK_F12, XK_NO_MOD, "\033[24~", 0, 0},
+    {XK_F12, /* F24 */ ShiftMask, "\033[24;2~", 0, 0},
+    {XK_F12, /* F36 */ ControlMask, "\033[24;5~", 0, 0},
+    {XK_F12, /* F48 */ Mod4Mask, "\033[24;6~", 0, 0},
+    {XK_F12, /* F60 */ Mod1Mask, "\033[24;3~", 0, 0},
+    {XK_F13, XK_NO_MOD, "\033[1;2P", 0, 0},
+    {XK_F14, XK_NO_MOD, "\033[1;2Q", 0, 0},
+    {XK_F15, XK_NO_MOD, "\033[1;2R", 0, 0},
+    {XK_F16, XK_NO_MOD, "\033[1;2S", 0, 0},
+    {XK_F17, XK_NO_MOD, "\033[15;2~", 0, 0},
+    {XK_F18, XK_NO_MOD, "\033[17;2~", 0, 0},
+    {XK_F19, XK_NO_MOD, "\033[18;2~", 0, 0},
+    {XK_F20, XK_NO_MOD, "\033[19;2~", 0, 0},
+    {XK_F21, XK_NO_MOD, "\033[20;2~", 0, 0},
+    {XK_F22, XK_NO_MOD, "\033[21;2~", 0, 0},
+    {XK_F23, XK_NO_MOD, "\033[23;2~", 0, 0},
+    {XK_F24, XK_NO_MOD, "\033[24;2~", 0, 0},
+    {XK_F25, XK_NO_MOD, "\033[1;5P", 0, 0},
+    {XK_F26, XK_NO_MOD, "\033[1;5Q", 0, 0},
+    {XK_F27, XK_NO_MOD, "\033[1;5R", 0, 0},
+    {XK_F28, XK_NO_MOD, "\033[1;5S", 0, 0},
+    {XK_F29, XK_NO_MOD, "\033[15;5~", 0, 0},
+    {XK_F30, XK_NO_MOD, "\033[17;5~", 0, 0},
+    {XK_F31, XK_NO_MOD, "\033[18;5~", 0, 0},
+    {XK_F32, XK_NO_MOD, "\033[19;5~", 0, 0},
+    {XK_F33, XK_NO_MOD, "\033[20;5~", 0, 0},
+    {XK_F34, XK_NO_MOD, "\033[21;5~", 0, 0},
+    {XK_F35, XK_NO_MOD, "\033[23;5~", 0, 0},
+};
+
+/*
+ * Selection types' masks.
+ * Use the same masks as usual.
+ * Button1Mask is always unset, to make masks match between ButtonPress.
+ * ButtonRelease and MotionNotify.
+ * If no match is found, regular selection is used.
+ */
+static uint selmasks[] = {
+    [SEL_RECTANGULAR] = Mod1Mask,
+};
+
+/*
+ * Printable characters in ASCII, used to estimate the advance width
+ * of single wide characters.
+ */
+static char ascii_printable[] = " !\"#$%&'()*+,-./0123456789:;<=>?"
+                                "@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_"
+                                "`abcdefghijklmnopqrstuvwxyz{|}~";

config.mk

@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
 # includes and libs
 INCS = -I$(X11INC) \
        `$(PKG_CONFIG) --cflags fontconfig` \
-       `$(PKG_CONFIG) --cflags freetype2`
+       `$(PKG_CONFIG) --cflags freetype2` \
+       `$(PKG_CONFIG) --cflags harfbuzz`
 LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
        `$(PKG_CONFIG) --libs fontconfig` \
-       `$(PKG_CONFIG) --libs freetype2`
+       `$(PKG_CONFIG) --libs freetype2` \
+       `$(PKG_CONFIG) --libs harfbuzz`
 
 # flags
 STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
@@ -29,8 +31,9 @@ STLDFLAGS = $(LIBS) $(LDFLAGS)
 #CPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600 -D_BSD_SOURCE
 #LIBS = -L$(X11LIB) -lm -lX11 -lutil -lXft \
 #       `$(PKG_CONFIG) --libs fontconfig` \
-#       `$(PKG_CONFIG) --libs freetype2`
+#       `$(PKG_CONFIG) --libs freetype2` \
+#       `$(PKG_CONFIG) --libs harfbuzz`
 #MANPREFIX = ${PREFIX}/man
 
 # compiler and linker
-# CC = c99
+CC = tcc

hb.c

@@ -0,0 +1,136 @@
+// clang-format off
+#include <X11/Xft/Xft.h>
+#include <X11/cursorfont.h>
+#include <hb-ft.h>
+#include <hb.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "st.h"
+#include "hb.h"
+// clang-format on
+
+#define FEATURE(c1, c2, c3, c4)                                                \
+  {.tag = HB_TAG(c1, c2, c3, c4),                                              \
+   .value = 1,                                                                 \
+   .start = HB_FEATURE_GLOBAL_START,                                           \
+   .end = HB_FEATURE_GLOBAL_END}
+#define BUFFER_STEP 256
+
+hb_font_t *hbfindfont(XftFont *match);
+
+typedef struct {
+  XftFont *match;
+  hb_font_t *font;
+} HbFontMatch;
+
+typedef struct {
+  size_t capacity;
+  HbFontMatch *fonts;
+} HbFontCache;
+
+static HbFontCache hbfontcache = {0, NULL};
+
+typedef struct {
+  size_t capacity;
+  Rune *runes;
+} RuneBuffer;
+
+static RuneBuffer hbrunebuffer = {0, NULL};
+
+/*
+ * Poplulate the array with a list of font features, wrapped in FEATURE macro,
+ * e. g.
+ * FEATURE('c', 'a', 'l', 't'), FEATURE('d', 'l', 'i', 'g')
+ */
+hb_feature_t features[] = {FEATURE('c', 'a', 'l', 't'),
+                           FEATURE('d', 'l', 'i', 'g')
+
+};
+
+void hbunloadfonts() {
+  for (int i = 0; i < hbfontcache.capacity; i++) {
+    hb_font_destroy(hbfontcache.fonts[i].font);
+    XftUnlockFace(hbfontcache.fonts[i].match);
+  }
+
+  if (hbfontcache.fonts != NULL) {
+    free(hbfontcache.fonts);
+    hbfontcache.fonts = NULL;
+  }
+  hbfontcache.capacity = 0;
+}
+
+hb_font_t *hbfindfont(XftFont *match) {
+  for (int i = 0; i < hbfontcache.capacity; i++) {
+    if (hbfontcache.fonts[i].match == match)
+      return hbfontcache.fonts[i].font;
+  }
+
+  /* Font not found in cache, caching it now. */
+  hbfontcache.fonts = realloc(hbfontcache.fonts,
+                              sizeof(HbFontMatch) * (hbfontcache.capacity + 1));
+  FT_Face face = XftLockFace(match);
+  hb_font_t *font = hb_ft_font_create(face, NULL);
+  if (font == NULL)
+    die("Failed to load Harfbuzz font.");
+
+  hbfontcache.fonts[hbfontcache.capacity].match = match;
+  hbfontcache.fonts[hbfontcache.capacity].font = font;
+  hbfontcache.capacity += 1;
+
+  return font;
+}
+
+void hbtransform(HbTransformData *data, XftFont *xfont, const Glyph *glyphs,
+                 int start, int length) {
+  ushort mode = USHRT_MAX;
+  unsigned int glyph_count;
+  int rune_idx, glyph_idx, end = start + length;
+
+  hb_font_t *font = hbfindfont(xfont);
+  if (font == NULL)
+    return;
+
+  hb_buffer_t *buffer = hb_buffer_create();
+  hb_buffer_set_direction(buffer, HB_DIRECTION_LTR);
+  hb_buffer_set_cluster_level(buffer,
+                              HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS);
+
+  /* Resize the buffer if required length is larger. */
+  if (hbrunebuffer.capacity < length) {
+    hbrunebuffer.capacity = (length / BUFFER_STEP + 1) * BUFFER_STEP;
+    hbrunebuffer.runes =
+        realloc(hbrunebuffer.runes, hbrunebuffer.capacity * sizeof(Rune));
+  }
+
+  /* Fill buffer with codepoints. */
+  for (rune_idx = 0, glyph_idx = start; glyph_idx < end;
+       glyph_idx++, rune_idx++) {
+    hbrunebuffer.runes[rune_idx] = glyphs[glyph_idx].u;
+    mode = glyphs[glyph_idx].mode;
+    if (mode & ATTR_WDUMMY)
+      hbrunebuffer.runes[rune_idx] = 0x0020;
+  }
+  hb_buffer_add_codepoints(buffer, hbrunebuffer.runes, length, 0, length);
+
+  /* Shape the segment. */
+  hb_shape(font, buffer, features, sizeof(features) / sizeof(hb_feature_t));
+
+  /* Get new glyph info. */
+  hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, &glyph_count);
+  hb_glyph_position_t *pos =
+      hb_buffer_get_glyph_positions(buffer, &glyph_count);
+
+  /* Fill the output. */
+  data->buffer = buffer;
+  data->glyphs = info;
+  data->positions = pos;
+  data->count = glyph_count;
+}
+
+void hbcleanup(HbTransformData *data) {
+  hb_buffer_destroy(data->buffer);
+  memset(data, 0, sizeof(HbTransformData));
+}

hb.h

@@ -0,0 +1,15 @@
+#include <X11/Xft/Xft.h>
+#include <hb.h>
+#include <hb-ft.h>
+
+typedef struct {
+	hb_buffer_t *buffer;
+	hb_glyph_info_t *glyphs;
+	hb_glyph_position_t *positions;
+	unsigned int count;
+} HbTransformData;
+
+void hbunloadfonts();
+void hbtransform(HbTransformData *, XftFont *, const Glyph *, int, int);
+void hbcleanup(HbTransformData *);
+

st-bold-is-not-bright-20190127-3be4cf1.diff

@@ -0,0 +1,27 @@
+From e8f3c86d93613eef5af187dfd2dba9ae9919a2ee Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rapha=C3=ABl=20Proust?= <code@bnwr.net>
+Date: Sun, 27 Jan 2019 13:31:28 +0800
+Subject: [PATCH] Show bold not as bright
+
+---
+ x.c | 4 ----
+ 1 file changed, 4 deletions(-)
+
+diff --git a/x.c b/x.c
+index 0422421..904e1dc 100644
+--- a/x.c
++++ b/x.c
+@@ -1296,10 +1296,6 @@ xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, i
+ 		bg = &dc.col[base.bg];
+ 	}
+ 
+-	/* Change basic system colors [0-7] to bright system colors [8-15] */
+-	if ((base.mode & ATTR_BOLD_FAINT) == ATTR_BOLD && BETWEEN(base.fg, 0, 7))
+-		fg = &dc.col[base.fg + 8];
+-
+ 	if (IS_SET(MODE_REVERSE)) {
+ 		if (fg == &dc.col[defaultfg]) {
+ 			fg = &dc.col[defaultbg];
+-- 
+2.20.1
+

st-ligatures-scrollback-ringbuffer-20251007-0.9.3.diff

@@ -0,0 +1,651 @@
+diff --git a/Makefile b/Makefile
+index 15db421..dfcea0f 100644
+--- a/Makefile
++++ b/Makefile
+@@ -3,9 +3,9 @@
+ .POSIX:
+ 
+ include config.mk
+ 
+-SRC = st.c x.c
++SRC = st.c x.c hb.c
+ OBJ = $(SRC:.c=.o)
+ 
+ all: st
+ 
+@@ -15,9 +15,10 @@ config.h:
+ .c.o:
+ 	$(CC) $(STCFLAGS) -c $<
+ 
+ st.o: config.h st.h win.h
+-x.o: arg.h config.h st.h win.h
++x.o: arg.h config.h st.h win.h hb.h
++hb.o: st.h
+ 
+ $(OBJ): config.h config.mk
+ 
+ st: $(OBJ)
+diff --git a/config.mk b/config.mk
+index 2fc854e..ec69d1a 100644
+--- a/config.mk
++++ b/config.mk
+@@ -14,12 +14,14 @@ PKG_CONFIG = pkg-config
+ 
+ # includes and libs
+ INCS = -I$(X11INC) \
+        `$(PKG_CONFIG) --cflags fontconfig` \
+-       `$(PKG_CONFIG) --cflags freetype2`
++       `$(PKG_CONFIG) --cflags freetype2` \
++       `$(PKG_CONFIG) --cflags harfbuzz`
+ LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
+        `$(PKG_CONFIG) --libs fontconfig` \
+-       `$(PKG_CONFIG) --libs freetype2`
++       `$(PKG_CONFIG) --libs freetype2` \
++       `$(PKG_CONFIG) --libs harfbuzz`
+ 
+ # flags
+ STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
+ STCFLAGS = $(INCS) $(STCPPFLAGS) $(CPPFLAGS) $(CFLAGS)
+@@ -28,9 +30,10 @@ 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` \
+-#       `$(PKG_CONFIG) --libs freetype2`
++#       `$(PKG_CONFIG) --libs freetype2` \
++#       `$(PKG_CONFIG) --libs harfbuzz`
+ #MANPREFIX = ${PREFIX}/man
+ 
+ # compiler and linker
+ # CC = c99
+diff --git a/hb.c b/hb.c
+new file mode 100644
+index 0000000..99412c8
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,125 @@
++#include <stdlib.h>
++#include <stdio.h>
++#include <math.h>
++#include <X11/Xft/Xft.h>
++#include <X11/cursorfont.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++#include "st.h"
++#include "hb.h"
++
++#define FEATURE(c1,c2,c3,c4) { .tag = HB_TAG(c1,c2,c3,c4), .value = 1, .start = HB_FEATURE_GLOBAL_START, .end = HB_FEATURE_GLOBAL_END }
++#define BUFFER_STEP 256
++
++hb_font_t *hbfindfont(XftFont *match);
++
++typedef struct {
++	XftFont *match;
++	hb_font_t *font;
++} HbFontMatch;
++
++typedef struct {
++	size_t capacity;
++	HbFontMatch *fonts;
++} HbFontCache;
++
++static HbFontCache hbfontcache = { 0, NULL };
++
++typedef struct {
++	size_t capacity;
++	Rune *runes;
++} RuneBuffer;
++
++static RuneBuffer hbrunebuffer = { 0, NULL };
++
++/*
++ * Poplulate the array with a list of font features, wrapped in FEATURE macro,
++ * e. g.
++ * FEATURE('c', 'a', 'l', 't'), FEATURE('d', 'l', 'i', 'g')
++ */
++hb_feature_t features[] = { };
++
++void
++hbunloadfonts()
++{
++	for (int i = 0; i < hbfontcache.capacity; i++) {
++		hb_font_destroy(hbfontcache.fonts[i].font);
++		XftUnlockFace(hbfontcache.fonts[i].match);
++	}
++
++	if (hbfontcache.fonts != NULL) {
++		free(hbfontcache.fonts);
++		hbfontcache.fonts = NULL;
++	}
++	hbfontcache.capacity = 0;
++}
++
++hb_font_t *
++hbfindfont(XftFont *match)
++{
++	for (int i = 0; i < hbfontcache.capacity; i++) {
++		if (hbfontcache.fonts[i].match == match)
++			return hbfontcache.fonts[i].font;
++	}
++
++	/* Font not found in cache, caching it now. */
++	hbfontcache.fonts = realloc(hbfontcache.fonts, sizeof(HbFontMatch) * (hbfontcache.capacity + 1));
++	FT_Face face = XftLockFace(match);
++	hb_font_t *font = hb_ft_font_create(face, NULL);
++	if (font == NULL)
++		die("Failed to load Harfbuzz font.");
++
++	hbfontcache.fonts[hbfontcache.capacity].match = match;
++	hbfontcache.fonts[hbfontcache.capacity].font = font;
++	hbfontcache.capacity += 1;
++
++	return font;
++}
++
++void hbtransform(HbTransformData *data, XftFont *xfont, const Glyph *glyphs, int start, int length) {
++	ushort mode = USHRT_MAX;
++	unsigned int glyph_count;
++	int rune_idx, glyph_idx, end = start + length;
++
++	hb_font_t *font = hbfindfont(xfont);
++	if (font == NULL)
++		return;
++
++	hb_buffer_t *buffer = hb_buffer_create();
++	hb_buffer_set_direction(buffer, HB_DIRECTION_LTR);
++	hb_buffer_set_cluster_level(buffer, HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS);
++
++	/* Resize the buffer if required length is larger. */
++	if (hbrunebuffer.capacity < length) {
++		hbrunebuffer.capacity = (length / BUFFER_STEP + 1) * BUFFER_STEP;
++		hbrunebuffer.runes = realloc(hbrunebuffer.runes, hbrunebuffer.capacity * sizeof(Rune));
++	}
++
++	/* Fill buffer with codepoints. */
++	for (rune_idx = 0, glyph_idx = start; glyph_idx < end; glyph_idx++, rune_idx++) {
++		hbrunebuffer.runes[rune_idx] = glyphs[glyph_idx].u;
++		mode = glyphs[glyph_idx].mode;
++		if (mode & ATTR_WDUMMY)
++			hbrunebuffer.runes[rune_idx] = 0x0020;
++	}
++	hb_buffer_add_codepoints(buffer, hbrunebuffer.runes, length, 0, length);
++
++	/* Shape the segment. */
++	hb_shape(font, buffer, features, sizeof(features)/sizeof(hb_feature_t));
++
++	/* Get new glyph info. */
++	hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, &glyph_count);
++	hb_glyph_position_t *pos = hb_buffer_get_glyph_positions(buffer, &glyph_count);
++
++	/* Fill the output. */
++	data->buffer = buffer;
++	data->glyphs = info;
++	data->positions = pos;
++	data->count = glyph_count;
++}
++
++void hbcleanup(HbTransformData *data) {
++	hb_buffer_destroy(data->buffer);
++	memset(data, 0, sizeof(HbTransformData));
++}
+diff --git a/hb.h b/hb.h
+new file mode 100644
+index 0000000..96e808b
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,15 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++typedef struct {
++	hb_buffer_t *buffer;
++	hb_glyph_info_t *glyphs;
++	hb_glyph_position_t *positions;
++	unsigned int count;
++} HbTransformData;
++
++void hbunloadfonts();
++void hbtransform(HbTransformData *, XftFont *, const Glyph *, int, int);
++void hbcleanup(HbTransformData *);
++
+diff --git a/st.c b/st.c
+index 0074ec7..fc916e9 100644
+--- a/st.c
++++ b/st.c
+@@ -2803,9 +2803,10 @@ draw(void)
+ 
+ 	drawregion(0, 0, term.col, term.row);
+ 	if (TSCREEN.off == 0)
+ 		xdrawcursor(cx, term.c.y, TLINE(term.c.y)[cx],
+-				term.ocx, term.ocy, TLINE(term.ocy)[term.ocx]);
++			term.ocx, term.ocy, TLINE(term.ocy)[term.ocx],
++			TLINE(term.ocy), term.col);
+ 	term.ocx = cx;
+ 	term.ocy = term.c.y;
+ 	xfinishdraw();
+ 	if (ocx != term.ocx || ocy != term.ocy)
+diff --git a/st.h b/st.h
+index 3cea73b..709a369 100644
+--- a/st.h
++++ b/st.h
+@@ -10,9 +10,10 @@
+ #define BETWEEN(x, a, b)	((a) <= (x) && (x) <= (b))
+ #define DIVCEIL(n, d)		(((n) + ((d) - 1)) / (d))
+ #define DEFAULT(a, b)		(a) = (a) ? (a) : (b)
+ #define LIMIT(x, a, b)		(x) = (x) < (a) ? (a) : (x) > (b) ? (b) : (x)
+-#define ATTRCMP(a, b)		((a).mode != (b).mode || (a).fg != (b).fg || \
++#define ATTRCMP(a, b)		(((a).mode & (~ATTR_WRAP)) != ((b).mode & (~ATTR_WRAP)) || \
++				(a).fg != (b).fg || \
+ 				(a).bg != (b).bg)
+ #define TIMEDIFF(t1, t2)	((t1.tv_sec-t2.tv_sec)*1000 + \
+ 				(t1.tv_nsec-t2.tv_nsec)/1E6)
+ #define MODBIT(x, set, bit)	((set) ? ((x) |= (bit)) : ((x) &= ~(bit)))
+diff --git a/win.h b/win.h
+index 6de960d..94679e4 100644
+--- a/win.h
++++ b/win.h
+@@ -24,9 +24,9 @@ enum win_mode {
+ };
+ 
+ void xbell(void);
+ void xclipcopy(void);
+-void xdrawcursor(int, int, Glyph, int, int, Glyph);
++void xdrawcursor(int, int, Glyph, int, int, Glyph, Line, int);
+ void xdrawline(Line, int, int, int);
+ void xfinishdraw(void);
+ void xloadcols(void);
+ int xsetcolorname(int, const char *);
+diff --git a/x.c b/x.c
+index 1e4bdf5..f8372ba 100644
+--- a/x.c
++++ b/x.c
+@@ -18,8 +18,9 @@
+ char *argv0;
+ #include "arg.h"
+ #include "st.h"
+ #include "win.h"
++#include "hb.h"
+ 
+ /* types used in config.h */
+ typedef struct {
+ 	uint mod;
+@@ -142,10 +143,11 @@ typedef struct {
+ 	GC gc;
+ } DC;
+ 
+ static inline ushort sixd_to_16bit(int);
++static void xresetfontsettings(ushort mode, Font **font, int *frcflags);
+ static int xmakeglyphfontspecs(XftGlyphFontSpec *, const Glyph *, int, int, int);
+-static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int);
++static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int, int);
+ static void xdrawglyph(Glyph, int, int);
+ static void xclear(int, int, int, int);
+ static int xgeommasktogravity(int);
+ static int ximopen(Display *);
+@@ -758,9 +760,9 @@ xresize(int col, int row)
+ 	XftDrawChange(xw.draw, xw.buf);
+ 	xclear(0, 0, win.w, win.h);
+ 
+ 	/* resize to new width */
+-	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec));
++	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec) * 4);
+ }
+ 
+ ushort
+ sixd_to_16bit(int x)
+@@ -1063,8 +1065,11 @@ xunloadfont(Font *f)
+ 
+ void
+ xunloadfonts(void)
+ {
++	/* Clear Harfbuzz font cache. */
++	hbunloadfonts();
++
+ 	/* Free the loaded fonts in the font cache.  */
+ 	while (frclen > 0)
+ 		XftFontClose(xw.dpy, frc[--frclen].font);
+ 
+@@ -1189,9 +1194,9 @@ xinit(int cols, int rows)
+ 	XSetForeground(xw.dpy, dc.gc, dc.col[defaultbg].pixel);
+ 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
+ 
+ 	/* font spec buffer */
+-	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec));
++	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec) * 4);
+ 
+ 	/* Xft rendering context */
+ 	xw.draw = XftDrawCreate(xw.dpy, xw.buf, xw.vis, xw.cmap);
+ 
+@@ -1243,144 +1248,155 @@ xinit(int cols, int rows)
+ 	if (xsel.xtarget == None)
+ 		xsel.xtarget = XA_STRING;
+ }
+ 
++void
++xresetfontsettings(ushort mode, Font **font, int *frcflags)
++{
++	*font = &dc.font;
++	if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
++		*font = &dc.ibfont;
++		*frcflags = FRC_ITALICBOLD;
++	} else if (mode & ATTR_ITALIC) {
++		*font = &dc.ifont;
++		*frcflags = FRC_ITALIC;
++	} else if (mode & ATTR_BOLD) {
++		*font = &dc.bfont;
++		*frcflags = FRC_BOLD;
++	}
++}
++
+ 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;
+-	ushort mode, prevmode = USHRT_MAX;
++	ushort mode = glyphs[0].mode & ~ATTR_WRAP;
+ 	Font *font = &dc.font;
+ 	int frcflags = FRC_NORMAL;
+-	float runewidth = win.cw;
++	float runewidth = win.cw * ((glyphs[0].mode & ATTR_WIDE) ? 2.0f : 1.0f);
+ 	Rune rune;
+ 	FT_UInt glyphidx;
+ 	FcResult fcres;
+ 	FcPattern *fcpattern, *fontpattern;
+ 	FcFontSet *fcsets[] = { NULL };
+ 	FcCharSet *fccharset;
+-	int i, f, numspecs = 0;
++	int f, code_idx, numspecs = 0;
++	float cluster_xp = xp, cluster_yp = yp;
++	HbTransformData shaped = { 0 };
+ 
+-	for (i = 0, xp = winx, yp = winy + font->ascent; i < len; ++i) {
+-		/* Fetch rune and mode for current glyph. */
+-		rune = glyphs[i].u;
+-		mode = glyphs[i].mode;
++	/* Initial values. */
++	xresetfontsettings(mode, &font, &frcflags);
+ 
+-		/* Skip dummy wide-character spacing. */
+-		if (mode == ATTR_WDUMMY)
++	/* Shape the segment. */
++	hbtransform(&shaped, font->match, glyphs, 0, len);
++	xp = winx; yp = winy + font->ascent;
++	cluster_xp = xp; cluster_yp = yp;
++
++	for (code_idx = 0; code_idx < shaped.count; code_idx++) {
++		int idx = shaped.glyphs[code_idx].cluster;
++
++		if (glyphs[idx].mode & ATTR_WDUMMY)
+ 			continue;
+ 
+-		/* Determine font for glyph if different from previous glyph. */
+-		if (prevmode != mode) {
+-			prevmode = mode;
+-			font = &dc.font;
+-			frcflags = FRC_NORMAL;
+-			runewidth = win.cw * ((mode & ATTR_WIDE) ? 2.0f : 1.0f);
+-			if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
+-				font = &dc.ibfont;
+-				frcflags = FRC_ITALICBOLD;
+-			} else if (mode & ATTR_ITALIC) {
+-				font = &dc.ifont;
+-				frcflags = FRC_ITALIC;
+-			} else if (mode & ATTR_BOLD) {
+-				font = &dc.bfont;
+-				frcflags = FRC_BOLD;
+-			}
+-			yp = winy + font->ascent;
++		/* Advance the drawing cursor if we've moved to a new cluster */
++		if (code_idx > 0 && (idx != shaped.glyphs[code_idx - 1].cluster)) {
++			xp += runewidth * (idx - shaped.glyphs[code_idx - 1].cluster);
++			cluster_xp = xp;
++			cluster_yp = yp;
+ 		}
+ 
+-		/* Lookup character index with default font. */
+-		glyphidx = XftCharIndex(xw.dpy, font->match, rune);
+-		if (glyphidx) {
++		if (shaped.glyphs[code_idx].codepoint != 0) {
++			/* If symbol is found, put it into the specs. */
+ 			specs[numspecs].font = font->match;
+-			specs[numspecs].glyph = glyphidx;
+-			specs[numspecs].x = (short)xp;
+-			specs[numspecs].y = (short)yp;
+-			xp += runewidth;
++			specs[numspecs].glyph = shaped.glyphs[code_idx].codepoint;
++			specs[numspecs].x = cluster_xp + (short)(shaped.positions[code_idx].x_offset / 64.);
++			specs[numspecs].y = cluster_yp - (short)(shaped.positions[code_idx].y_offset / 64.);
++			cluster_xp += shaped.positions[code_idx].x_advance / 64.;
++			cluster_yp += shaped.positions[code_idx].y_advance / 64.;
+ 			numspecs++;
+-			continue;
+-		}
+-
+-		/* Fallback on font cache, search the font cache for match. */
+-		for (f = 0; f < frclen; f++) {
+-			glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
+-			/* Everything correct. */
+-			if (glyphidx && frc[f].flags == frcflags)
+-				break;
+-			/* We got a default font for a not found glyph. */
+-			if (!glyphidx && frc[f].flags == frcflags
+-					&& frc[f].unicodep == rune) {
+-				break;
++		} else {
++			/* If it's not found, try to fetch it through the font cache. */
++			rune = glyphs[idx].u;
++			for (f = 0; f < frclen; f++) {
++				glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
++				/* Everything correct. */
++				if (glyphidx && frc[f].flags == frcflags)
++					break;
++				/* We got a default font for a not found glyph. */
++				if (!glyphidx && frc[f].flags == frcflags
++						&& frc[f].unicodep == rune) {
++					break;
++				}
+ 			}
+-		}
+-
+-		/* Nothing was found. Use fontconfig to find matching font. */
+-		if (f >= frclen) {
+-			if (!font->set)
+-				font->set = FcFontSort(0, font->pattern,
+-				                       1, 0, &fcres);
+-			fcsets[0] = font->set;
+ 
+-			/*
+-			 * Nothing was found in the cache. Now use
+-			 * some dozen of Fontconfig calls to get the
+-			 * font for one single character.
+-			 *
+-			 * Xft and fontconfig are design failures.
+-			 */
+-			fcpattern = FcPatternDuplicate(font->pattern);
+-			fccharset = FcCharSetCreate();
+-
+-			FcCharSetAddChar(fccharset, rune);
+-			FcPatternAddCharSet(fcpattern, FC_CHARSET,
+-					fccharset);
+-			FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
+-
+-			FcConfigSubstitute(0, fcpattern,
+-					FcMatchPattern);
+-			FcDefaultSubstitute(fcpattern);
+-
+-			fontpattern = FcFontSetMatch(0, fcsets, 1,
+-					fcpattern, &fcres);
+-
+-			/* Allocate memory for the new cache entry. */
+-			if (frclen >= frccap) {
+-				frccap += 16;
+-				frc = xrealloc(frc, frccap * sizeof(Fontcache));
++			/* Nothing was found. Use fontconfig to find matching font. */
++			if (f >= frclen) {
++				if (!font->set)
++					font->set = FcFontSort(0, font->pattern,
++							       1, 0, &fcres);
++				fcsets[0] = font->set;
++
++				/*
++				 * Nothing was found in the cache. Now use
++				 * some dozen of Fontconfig calls to get the
++				 * font for one single character.
++				 *
++				 * Xft and fontconfig are design failures.
++				 */
++				fcpattern = FcPatternDuplicate(font->pattern);
++				fccharset = FcCharSetCreate();
++
++				FcCharSetAddChar(fccharset, rune);
++				FcPatternAddCharSet(fcpattern, FC_CHARSET,
++						fccharset);
++				FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
++
++				FcConfigSubstitute(0, fcpattern,
++						FcMatchPattern);
++				FcDefaultSubstitute(fcpattern);
++
++				fontpattern = FcFontSetMatch(0, fcsets, 1,
++						fcpattern, &fcres);
++
++				/* Allocate memory for the new cache entry. */
++				if (frclen >= frccap) {
++					frccap += 16;
++					frc = xrealloc(frc, frccap * sizeof(Fontcache));
++				}
++
++				frc[frclen].font = XftFontOpenPattern(xw.dpy,
++						fontpattern);
++				if (!frc[frclen].font)
++					die("XftFontOpenPattern failed seeking fallback font: %s\n",
++						strerror(errno));
++				frc[frclen].flags = frcflags;
++				frc[frclen].unicodep = rune;
++
++				glyphidx = XftCharIndex(xw.dpy, frc[frclen].font, rune);
++
++				f = frclen;
++				frclen++;
++
++				FcPatternDestroy(fcpattern);
++				FcCharSetDestroy(fccharset);
+ 			}
+ 
+-			frc[frclen].font = XftFontOpenPattern(xw.dpy,
+-					fontpattern);
+-			if (!frc[frclen].font)
+-				die("XftFontOpenPattern failed seeking fallback font: %s\n",
+-					strerror(errno));
+-			frc[frclen].flags = frcflags;
+-			frc[frclen].unicodep = rune;
+-
+-			glyphidx = XftCharIndex(xw.dpy, frc[frclen].font, rune);
+-
+-			f = frclen;
+-			frclen++;
+-
+-			FcPatternDestroy(fcpattern);
+-			FcCharSetDestroy(fccharset);
++			specs[numspecs].font = frc[f].font;
++			specs[numspecs].glyph = glyphidx;
++			specs[numspecs].x = (short)xp;
++			specs[numspecs].y = (short)yp;
++			numspecs++;
+ 		}
+-
+-		specs[numspecs].font = frc[f].font;
+-		specs[numspecs].glyph = glyphidx;
+-		specs[numspecs].x = (short)xp;
+-		specs[numspecs].y = (short)yp;
+-		xp += runewidth;
+-		numspecs++;
+ 	}
+ 
++	/* Cleanup and get ready for next segment. */
++	hbcleanup(&shaped);
+ 	return numspecs;
+ }
+ 
+ void
+-xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y)
++xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y, int charlen)
+ {
+-	int charlen = len * ((base.mode & ATTR_WIDE) ? 2 : 1);
+ 	int winx = borderpx + x * win.cw, winy = borderpx + y * win.ch,
+ 	    width = charlen * win.cw;
+ 	Color *fg, *bg, *temp, revfg, revbg, truefg, truebg;
+ 	XRenderColor colfg, colbg;
+@@ -1514,23 +1530,26 @@ xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, i
+ void
+ xdrawglyph(Glyph g, int x, int y)
+ {
+ 	int numspecs;
+-	XftGlyphFontSpec spec;
++	XftGlyphFontSpec *specs = xw.specbuf;
+ 
+-	numspecs = xmakeglyphfontspecs(&spec, &g, 1, x, y);
+-	xdrawglyphfontspecs(&spec, g, numspecs, x, y);
++	numspecs = xmakeglyphfontspecs(specs, &g, 1, x, y);
++	xdrawglyphfontspecs(specs, g, numspecs, x, y, (g.mode & ATTR_WIDE) ? 2 : 1);
+ }
+ 
+ void
+-xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
++xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og, Line line, int len)
+ {
+ 	Color drawcol;
+ 
+ 	/* remove the old cursor */
+ 	if (selected(ox, oy))
+ 		og.mode ^= ATTR_REVERSE;
+-	xdrawglyph(og, ox, oy);
++
++	/* Redraw the line where cursor was previously.
++	 * It will restore the ligatures broken by the cursor. */
++	xdrawline(line, 0, oy, len);
+ 
+ 	if (IS_SET(MODE_HIDE))
+ 		return;
+ 
+@@ -1662,30 +1681,30 @@ xdrawline(Line line, int x1, int y1, int x2)
+ 	int i, x, ox, numspecs;
+ 	Glyph base, new;
+ 	XftGlyphFontSpec *specs = xw.specbuf;
+ 
+-	numspecs = xmakeglyphfontspecs(specs, &line[x1], x2 - x1, x1, y1);
+ 	i = ox = 0;
+-	for (x = x1; x < x2 && i < numspecs; x++) {
++	for (x = x1; x < x2; x++) {
+ 		new = line[x];
+ 		if (new.mode == ATTR_WDUMMY)
+ 			continue;
+ 		if (selected(x, y1))
+ 			new.mode ^= ATTR_REVERSE;
+-		if (i > 0 && ATTRCMP(base, new)) {
+-			xdrawglyphfontspecs(specs, base, i, ox, y1);
+-			specs += i;
+-			numspecs -= i;
++		if ((i > 0) && ATTRCMP(base, new)) {
++			numspecs = xmakeglyphfontspecs(specs, &line[ox], x - ox, ox, y1);
++			xdrawglyphfontspecs(specs, base, numspecs, ox, y1, x - ox);
+ 			i = 0;
+ 		}
+ 		if (i == 0) {
+ 			ox = x;
+ 			base = new;
+ 		}
+ 		i++;
+ 	}
+-	if (i > 0)
+-		xdrawglyphfontspecs(specs, base, i, ox, y1);
++	if (i > 0) {
++		numspecs = xmakeglyphfontspecs(specs, &line[ox], x2 - ox, ox, y1);
++		xdrawglyphfontspecs(specs, base, numspecs, ox, y1, x2 - ox);
++	}
+ }
+ 
+ void
+ xfinishdraw(void)

st-scrollback-ringbuffer-0.9.2.diff

@@ -0,0 +1,730 @@
+commit 0663bdf11a409961da5b1120741a69814da8ce65
+Author: Timo Röhling <timo@gaussglocke.de>
+Date:   Tue Nov 23 19:45:33 2021 +0100
+
+    Terminal scrollback with ring buffer
+    
+    This patch adds a ring buffer for scrollback to the terminal.  The
+    advantage of using a ring buffer is that the common case, scrolling with
+    no static screen content, can be achieved very efficiently by
+    incrementing and decrementing the starting line (modulo buffer size).
+    
+    The scrollback buffer is limited to HISTSIZE lines in order to bound
+    memory usage. As the lines are allocated on demand, it is possible to
+    implement unlimited scrollback with few changes.  If the terminal is
+    reset, the scroll back buffer is reset, too.
+
+diff --git a/config.def.h b/config.def.h
+index 2cd740a..8b25d40 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -201,6 +201,8 @@ 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} },
+ };
+ 
+ /*
+diff --git a/st.c b/st.c
+index b9f66e7..d9b163e 100644
+--- a/st.c
++++ b/st.c
+@@ -43,6 +43,10 @@
+ #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
+ #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
+ 
++#define TSCREEN term.screen[IS_SET(MODE_ALTSCREEN)]
++#define TLINEOFFSET(y) (((y) + TSCREEN.cur - TSCREEN.off + TSCREEN.size) % TSCREEN.size)
++#define TLINE(y) (TSCREEN.buffer[TLINEOFFSET(y)])
++
+ enum term_mode {
+ 	MODE_WRAP        = 1 << 0,
+ 	MODE_INSERT      = 1 << 1,
+@@ -109,12 +113,21 @@ typedef struct {
+ 	int alt;
+ } Selection;
+ 
++/* Screen lines */
++typedef struct {
++	Line* buffer;  /* ring buffer */
++	int size;      /* size of buffer */
++	int cur;       /* start of active screen */
++	int off;       /* scrollback line offset */
++	TCursor sc;    /* saved cursor */
++} LineBuffer;
++
+ /* Internal representation of the screen */
+ typedef struct {
+ 	int row;      /* nb row */
+ 	int col;      /* nb col */
+-	Line *line;   /* screen */
+-	Line *alt;    /* alternate screen */
++	LineBuffer screen[2]; /* screen and alternate screen */
++	int linelen;  /* allocated line length */
+ 	int *dirty;   /* dirtyness of lines */
+ 	TCursor c;    /* cursor */
+ 	int ocx;      /* old cursor col */
+@@ -203,6 +216,8 @@ static void tdeftran(char);
+ static void tstrsequence(uchar);
+ 
+ static void drawregion(int, int, int, int);
++static void clearline(Line, Glyph, int, int);
++static Line ensureline(Line);
+ 
+ static void selnormalize(void);
+ static void selscroll(int, int);
+@@ -408,11 +423,12 @@ int
+ tlinelen(int y)
+ {
+ 	int i = term.col;
++	Line line = TLINE(y);
+ 
+-	if (term.line[y][i - 1].mode & ATTR_WRAP)
++	if (line[i - 1].mode & ATTR_WRAP)
+ 		return i;
+ 
+-	while (i > 0 && term.line[y][i - 1].u == ' ')
++	while (i > 0 && line[i - 1].u == ' ')
+ 		--i;
+ 
+ 	return i;
+@@ -521,7 +537,7 @@ 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;
+@@ -536,14 +552,14 @@ 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)))
+@@ -564,14 +580,14 @@ 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;
+ 				}
+@@ -602,13 +618,13 @@ 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;
+ 
+@@ -949,12 +965,15 @@ int
+ tattrset(int attr)
+ {
+ 	int i, j;
++	int y = TLINEOFFSET(0);
+ 
+ 	for (i = 0; i < term.row-1; i++) {
++		Line line = TSCREEN.buffer[y];
+ 		for (j = 0; j < term.col-1; j++) {
+-			if (term.line[i][j].mode & attr)
++			if (line[j].mode & attr)
+ 				return 1;
+ 		}
++		y = (y+1) % TSCREEN.size;
+ 	}
+ 
+ 	return 0;
+@@ -976,14 +995,17 @@ void
+ tsetdirtattr(int attr)
+ {
+ 	int i, j;
++	int y = TLINEOFFSET(0);
+ 
+ 	for (i = 0; i < term.row-1; i++) {
++		Line line = TSCREEN.buffer[y];
+ 		for (j = 0; j < term.col-1; j++) {
+-			if (term.line[i][j].mode & attr) {
++			if (line[j].mode & attr) {
+ 				tsetdirt(i, i);
+ 				break;
+ 			}
+ 		}
++		y = (y+1) % TSCREEN.size;
+ 	}
+ }
+ 
+@@ -996,27 +1018,19 @@ tfulldirt(void)
+ void
+ tcursor(int mode)
+ {
+-	static TCursor c[2];
+-	int alt = IS_SET(MODE_ALTSCREEN);
+-
+ 	if (mode == CURSOR_SAVE) {
+-		c[alt] = term.c;
++		TSCREEN.sc = term.c;
+ 	} else if (mode == CURSOR_LOAD) {
+-		term.c = c[alt];
+-		tmoveto(c[alt].x, c[alt].y);
++		term.c = TSCREEN.sc;
++		tmoveto(term.c.x, term.c.y);
+ 	}
+ }
+ 
+ void
+ treset(void)
+ {
+-	uint i;
+-
+-	term.c = (TCursor){{
+-		.mode = ATTR_NULL,
+-		.fg = defaultfg,
+-		.bg = defaultbg
+-	}, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
++	int i, j;
++	Glyph g = (Glyph){ .fg = defaultfg, .bg = defaultbg};
+ 
+ 	memset(term.tabs, 0, term.col * sizeof(*term.tabs));
+ 	for (i = tabspaces; i < term.col; i += tabspaces)
+@@ -1028,17 +1042,37 @@ treset(void)
+ 	term.charset = 0;
+ 
+ 	for (i = 0; i < 2; i++) {
+-		tmoveto(0, 0);
+-		tcursor(CURSOR_SAVE);
+-		tclearregion(0, 0, term.col-1, term.row-1);
+-		tswapscreen();
++		term.screen[i].sc = (TCursor){{
++			.fg = defaultfg,
++			.bg = defaultbg
++		}};
++		term.screen[i].cur = 0;
++		term.screen[i].off = 0;
++		for (j = 0; j < term.row; ++j) {
++			if (term.col != term.linelen)
++				term.screen[i].buffer[j] = xrealloc(term.screen[i].buffer[j], term.col * sizeof(Glyph));
++			clearline(term.screen[i].buffer[j], g, 0, term.col);
++		}
++		for (j = term.row; j < term.screen[i].size; ++j) {
++			free(term.screen[i].buffer[j]);
++			term.screen[i].buffer[j] = NULL;
++		}
+ 	}
++	tcursor(CURSOR_LOAD);
++	term.linelen = term.col;
++	tfulldirt();
+ }
+ 
+ void
+ tnew(int col, int row)
+ {
+-	term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
++	int i;
++	term = (Term){};
++	term.screen[0].buffer = xmalloc(HISTSIZE * sizeof(Line));
++	term.screen[0].size = HISTSIZE;
++	term.screen[1].buffer = NULL;
++	for (i = 0; i < HISTSIZE; ++i) term.screen[0].buffer[i] = NULL;
++
+ 	tresize(col, row);
+ 	treset();
+ }
+@@ -1046,14 +1080,42 @@ tnew(int col, int row)
+ void
+ tswapscreen(void)
+ {
+-	Line *tmp = term.line;
+-
+-	term.line = term.alt;
+-	term.alt = tmp;
+ 	term.mode ^= MODE_ALTSCREEN;
+ 	tfulldirt();
+ }
+ 
++void
++kscrollup(const Arg *a)
++{
++	int n = a->i;
++
++	if (IS_SET(MODE_ALTSCREEN))
++		return;
++
++	if (n < 0) n = (-n) * term.row;
++	if (n > TSCREEN.size - term.row - TSCREEN.off) n = TSCREEN.size - term.row - TSCREEN.off;
++	while (!TLINE(-n)) --n;
++	TSCREEN.off += n;
++	selscroll(0, n);
++	tfulldirt();
++}
++
++void
++kscrolldown(const Arg *a)
++{
++
++	int n = a->i;
++
++	if (IS_SET(MODE_ALTSCREEN))
++		return;
++
++	if (n < 0) n = (-n) * term.row;
++	if (n > TSCREEN.off) n = TSCREEN.off;
++	TSCREEN.off -= n;
++	selscroll(0, -n);
++	tfulldirt();
++}
++
+ void
+ tscrolldown(int orig, int n)
+ {
+@@ -1062,15 +1124,29 @@ tscrolldown(int orig, int n)
+ 
+ 	LIMIT(n, 0, term.bot-orig+1);
+ 
+-	tsetdirt(orig, term.bot-n);
+-	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
++	/* Ensure that lines are allocated */
++	for (i = -n; i < 0; i++) {
++		TLINE(i) = ensureline(TLINE(i));
++	}
+ 
+-	for (i = term.bot; i >= orig+n; i--) {
+-		temp = term.line[i];
+-		term.line[i] = term.line[i-n];
+-		term.line[i-n] = temp;
++	/* Shift non-scrolling areas in ring buffer */
++	for (i = term.bot+1; i < term.row; i++) {
++		temp = TLINE(i);
++		TLINE(i) = TLINE(i-n);
++		TLINE(i-n) = temp;
++	}
++	for (i = 0; i < orig; i++) {
++		temp = TLINE(i);
++		TLINE(i) = TLINE(i-n);
++		TLINE(i-n) = temp;
+ 	}
+ 
++	/* Scroll buffer */
++	TSCREEN.cur = (TSCREEN.cur + TSCREEN.size - n) % TSCREEN.size;
++	/* Clear lines that have entered the view */
++	tclearregion(0, orig, term.linelen-1, orig+n-1);
++	/* Redraw portion of the screen that has scrolled */
++	tsetdirt(orig+n-1, term.bot);
+ 	selscroll(orig, n);
+ }
+ 
+@@ -1082,15 +1158,29 @@ tscrollup(int orig, int n)
+ 
+ 	LIMIT(n, 0, term.bot-orig+1);
+ 
+-	tclearregion(0, orig, term.col-1, orig+n-1);
+-	tsetdirt(orig+n, term.bot);
++	/* Ensure that lines are allocated */
++	for (i = term.row; i < term.row + n; i++) {
++		TLINE(i) = ensureline(TLINE(i));
++	}
+ 
+-	for (i = orig; i <= term.bot-n; i++) {
+-		temp = term.line[i];
+-		term.line[i] = term.line[i+n];
+-		term.line[i+n] = temp;
++	/* Shift non-scrolling areas in ring buffer */
++	for (i = orig-1; i >= 0; i--) {
++		temp = TLINE(i);
++		TLINE(i) = TLINE(i+n);
++		TLINE(i+n) = temp;
++	}
++	for (i = term.row-1; i >term.bot; i--) {
++		temp = TLINE(i);
++		TLINE(i) = TLINE(i+n);
++		TLINE(i+n) = temp;
+ 	}
+ 
++	/* Scroll buffer */
++	TSCREEN.cur = (TSCREEN.cur + n) % TSCREEN.size;
++	/* Clear lines that have entered the view */
++	tclearregion(0, term.bot-n+1, term.linelen-1, term.bot);
++	/* Redraw portion of the screen that has scrolled */
++	tsetdirt(orig, term.bot-n+1);
+ 	selscroll(orig, -n);
+ }
+ 
+@@ -1194,6 +1284,7 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
+ 		"⎻", "─", "⎼", "⎽", "├", "┤", "┴", "┬", /* p - w */
+ 		"│", "≤", "≥", "π", "≠", "£", "·", /* x - ~ */
+ 	};
++	Line line = TLINE(y);
+ 
+ 	/*
+ 	 * The table is proudly stolen from rxvt.
+@@ -1202,25 +1293,25 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
+ 	   BETWEEN(u, 0x41, 0x7e) && vt100_0[u - 0x41])
+ 		utf8decode(vt100_0[u - 0x41], &u, UTF_SIZ);
+ 
+-	if (term.line[y][x].mode & ATTR_WIDE) {
++	if (line[x].mode & ATTR_WIDE) {
+ 		if (x+1 < term.col) {
+-			term.line[y][x+1].u = ' ';
+-			term.line[y][x+1].mode &= ~ATTR_WDUMMY;
++			line[x+1].u = ' ';
++			line[x+1].mode &= ~ATTR_WDUMMY;
+ 		}
+-	} else if (term.line[y][x].mode & ATTR_WDUMMY) {
+-		term.line[y][x-1].u = ' ';
+-		term.line[y][x-1].mode &= ~ATTR_WIDE;
++	} else if (line[x].mode & ATTR_WDUMMY) {
++		line[x-1].u = ' ';
++		line[x-1].mode &= ~ATTR_WIDE;
+ 	}
+ 
+ 	term.dirty[y] = 1;
+-	term.line[y][x] = *attr;
+-	term.line[y][x].u = u;
++	line[x] = *attr;
++	line[x].u = u;
+ }
+ 
+ void
+ tclearregion(int x1, int y1, int x2, int y2)
+ {
+-	int x, y, temp;
++	int x, y, L, S, temp;
+ 	Glyph *gp;
+ 
+ 	if (x1 > x2)
+@@ -1228,15 +1319,16 @@ tclearregion(int x1, int y1, int x2, int y2)
+ 	if (y1 > y2)
+ 		temp = y1, y1 = y2, y2 = temp;
+ 
+-	LIMIT(x1, 0, term.col-1);
+-	LIMIT(x2, 0, term.col-1);
++	LIMIT(x1, 0, term.linelen-1);
++	LIMIT(x2, 0, term.linelen-1);
+ 	LIMIT(y1, 0, term.row-1);
+ 	LIMIT(y2, 0, term.row-1);
+ 
++	L = TLINEOFFSET(y1);
+ 	for (y = y1; y <= y2; y++) {
+ 		term.dirty[y] = 1;
+ 		for (x = x1; x <= x2; x++) {
+-			gp = &term.line[y][x];
++			gp = &TSCREEN.buffer[L][x];
+ 			if (selected(x, y))
+ 				selclear();
+ 			gp->fg = term.c.attr.fg;
+@@ -1244,6 +1336,7 @@ tclearregion(int x1, int y1, int x2, int y2)
+ 			gp->mode = 0;
+ 			gp->u = ' ';
+ 		}
++		L = (L + 1) % TSCREEN.size;
+ 	}
+ }
+ 
+@@ -1258,7 +1351,7 @@ tdeletechar(int n)
+ 	dst = term.c.x;
+ 	src = term.c.x + n;
+ 	size = term.col - src;
+-	line = term.line[term.c.y];
++	line = TLINE(term.c.y);
+ 
+ 	memmove(&line[dst], &line[src], size * sizeof(Glyph));
+ 	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
+@@ -1275,7 +1368,7 @@ tinsertblank(int n)
+ 	dst = term.c.x + n;
+ 	src = term.c.x;
+ 	size = term.col - dst;
+-	line = term.line[term.c.y];
++	line = TLINE(term.c.y);
+ 
+ 	memmove(&line[dst], &line[src], size * sizeof(Glyph));
+ 	tclearregion(src, term.c.y, dst - 1, term.c.y);
+@@ -2079,7 +2172,7 @@ tdumpline(int n)
+ 	char buf[UTF_SIZ];
+ 	const Glyph *bp, *end;
+ 
+-	bp = &term.line[n][0];
++	bp = &TLINE(n)[0];
+ 	end = &bp[MIN(tlinelen(n), term.col) - 1];
+ 	if (bp != end || bp->u != ' ') {
+ 		for ( ; bp <= end; ++bp)
+@@ -2466,11 +2559,11 @@ check_control_code:
+ 	if (selected(term.c.x, term.c.y))
+ 		selclear();
+ 
+-	gp = &term.line[term.c.y][term.c.x];
++	gp = &TLINE(term.c.y)[term.c.x];
+ 	if (IS_SET(MODE_WRAP) && (term.c.state & CURSOR_WRAPNEXT)) {
+ 		gp->mode |= ATTR_WRAP;
+ 		tnewline(1);
+-		gp = &term.line[term.c.y][term.c.x];
++		gp = &TLINE(term.c.y)[term.c.x];
+ 	}
+ 
+ 	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col) {
+@@ -2483,7 +2576,7 @@ check_control_code:
+ 			tnewline(1);
+ 		else
+ 			tmoveto(term.col - width, term.c.y);
+-		gp = &term.line[term.c.y][term.c.x];
++		gp = &TLINE(term.c.y)[term.c.x];
+ 	}
+ 
+ 	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
+@@ -2514,6 +2607,11 @@ twrite(const char *buf, int buflen, int show_ctrl)
+ 	Rune u;
+ 	int n;
+ 
++	if (TSCREEN.off) {
++		TSCREEN.off = 0;
++		tfulldirt();
++	}
++
+ 	for (n = 0; n < buflen; n += charsize) {
+ 		if (IS_SET(MODE_UTF8)) {
+ 			/* process a complete utf8 char */
+@@ -2540,56 +2638,85 @@ twrite(const char *buf, int buflen, int show_ctrl)
+ }
+ 
+ void
+-tresize(int col, int row)
++clearline(Line line, Glyph g, int x, int xend)
+ {
+ 	int i;
++	g.mode = 0;
++	g.u = ' ';
++	for (i = x; i < xend; ++i) {
++		line[i] = g;
++	}
++}
++
++Line
++ensureline(Line line)
++{
++	if (!line) {
++		line = xmalloc(term.linelen * sizeof(Glyph));
++	}
++	return line;
++}
++
++void
++tresize(int col, int row)
++{
++	int i, j;
+ 	int minrow = MIN(row, term.row);
+ 	int mincol = MIN(col, term.col);
++	int linelen = MAX(col, term.linelen);
+ 	int *bp;
+-	TCursor c;
+ 
+-	if (col < 1 || row < 1) {
++	if (col < 1 || row < 1 || row > HISTSIZE) {
+ 		fprintf(stderr,
+ 		        "tresize: error resizing to %dx%d\n", col, row);
+ 		return;
+ 	}
+ 
+-	/*
+-	 * slide screen to keep cursor where we expect it -
+-	 * tscrollup would work here, but we can optimize to
+-	 * memmove because we're freeing the earlier lines
+-	 */
+-	for (i = 0; i <= term.c.y - row; i++) {
+-		free(term.line[i]);
+-		free(term.alt[i]);
++	/* Shift buffer to keep the cursor where we expect it */
++	if (row <= term.c.y) {
++		term.screen[0].cur = (term.screen[0].cur - row + term.c.y + 1) % term.screen[0].size;
++	}
++
++	/* Resize and clear line buffers as needed */
++	if (linelen > term.linelen) {
++		for (i = 0; i < term.screen[0].size; ++i) {
++			if (term.screen[0].buffer[i]) {
++				term.screen[0].buffer[i] = xrealloc(term.screen[0].buffer[i], linelen * sizeof(Glyph));
++				clearline(term.screen[0].buffer[i], term.c.attr, term.linelen, linelen);
++			}
++		}
++		for (i = 0; i < minrow; ++i) {
++			term.screen[1].buffer[i] = xrealloc(term.screen[1].buffer[i], linelen * sizeof(Glyph));
++			clearline(term.screen[1].buffer[i], term.c.attr, term.linelen, linelen);
++		}
+ 	}
+-	/* ensure that both src and dst are not NULL */
+-	if (i > 0) {
+-		memmove(term.line, term.line + i, row * sizeof(Line));
+-		memmove(term.alt, term.alt + i, row * sizeof(Line));
++	/* Allocate all visible lines for regular line buffer */
++	for (j = term.screen[0].cur, i = 0; i < row; ++i, j = (j + 1) % term.screen[0].size)
++	{
++		if (!term.screen[0].buffer[j]) {
++			term.screen[0].buffer[j] = xmalloc(linelen * sizeof(Glyph));
++		}
++		if (i >= term.row) {
++			clearline(term.screen[0].buffer[j], term.c.attr, 0, linelen);
++		}
+ 	}
+-	for (i += row; i < term.row; i++) {
+-		free(term.line[i]);
+-		free(term.alt[i]);
++	/* Resize alt screen */
++	term.screen[1].cur = 0;
++	term.screen[1].size = row;
++	for (i = row; i < term.row; ++i) {
++		free(term.screen[1].buffer[i]);
++	}
++	term.screen[1].buffer = xrealloc(term.screen[1].buffer, row * sizeof(Line));
++	for (i = term.row; i < row; ++i) {
++		term.screen[1].buffer[i] = xmalloc(linelen * sizeof(Glyph));
++		clearline(term.screen[1].buffer[i], term.c.attr, 0, linelen);
+ 	}
+ 
+ 	/* resize to new height */
+-	term.line = xrealloc(term.line, row * sizeof(Line));
+-	term.alt  = xrealloc(term.alt,  row * sizeof(Line));
+ 	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
+ 	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
+ 
+-	/* 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));
+-		term.alt[i]  = xrealloc(term.alt[i],  col * sizeof(Glyph));
+-	}
+-
+-	/* allocate any new rows */
+-	for (/* i = minrow */; i < row; i++) {
+-		term.line[i] = xmalloc(col * sizeof(Glyph));
+-		term.alt[i] = xmalloc(col * sizeof(Glyph));
+-	}
++	/* fix tabstops */
+ 	if (col > term.col) {
+ 		bp = term.tabs + term.col;
+ 
+@@ -2599,26 +2726,16 @@ tresize(int col, int row)
+ 		for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
+ 			*bp = 1;
+ 	}
++
+ 	/* update terminal size */
+ 	term.col = col;
+ 	term.row = row;
++	term.linelen = linelen;
+ 	/* reset scrolling region */
+ 	tsetscroll(0, row-1);
+ 	/* make use of the LIMIT in tmoveto */
+ 	tmoveto(term.c.x, term.c.y);
+-	/* Clearing both screens (it makes dirty all lines) */
+-	c = term.c;
+-	for (i = 0; i < 2; i++) {
+-		if (mincol < col && 0 < minrow) {
+-			tclearregion(mincol, 0, col - 1, minrow - 1);
+-		}
+-		if (0 < col && minrow < row) {
+-			tclearregion(0, minrow, col - 1, row - 1);
+-		}
+-		tswapscreen();
+-		tcursor(CURSOR_LOAD);
+-	}
+-	term.c = c;
++	tfulldirt();
+ }
+ 
+ void
+@@ -2630,14 +2747,15 @@ resettitle(void)
+ void
+ drawregion(int x1, int y1, int x2, int y2)
+ {
+-	int y;
++	int y, L;
+ 
++	L = TLINEOFFSET(y1);
+ 	for (y = y1; y < y2; y++) {
+-		if (!term.dirty[y])
+-			continue;
+-
+-		term.dirty[y] = 0;
+-		xdrawline(term.line[y], x1, y, x2);
++		if (term.dirty[y]) {
++			term.dirty[y] = 0;
++			xdrawline(TSCREEN.buffer[L], x1, y, x2);
++		}
++		L = (L + 1) % TSCREEN.size;
+ 	}
+ }
+ 
+@@ -2652,14 +2770,15 @@ draw(void)
+ 	/* adjust cursor position */
+ 	LIMIT(term.ocx, 0, term.col-1);
+ 	LIMIT(term.ocy, 0, term.row-1);
+-	if (term.line[term.ocy][term.ocx].mode & ATTR_WDUMMY)
++	if (TLINE(term.ocy)[term.ocx].mode & ATTR_WDUMMY)
+ 		term.ocx--;
+-	if (term.line[term.c.y][cx].mode & ATTR_WDUMMY)
++	if (TLINE(term.c.y)[cx].mode & ATTR_WDUMMY)
+ 		cx--;
+ 
+ 	drawregion(0, 0, term.col, term.row);
+-	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+-			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
++	if (TSCREEN.off == 0)
++		xdrawcursor(cx, term.c.y, TLINE(term.c.y)[cx],
++				term.ocx, term.ocy, TLINE(term.ocy)[term.ocx]);
+ 	term.ocx = cx;
+ 	term.ocy = term.c.y;
+ 	xfinishdraw();
+diff --git a/st.h b/st.h
+index fd3b0d8..3cea73b 100644
+--- a/st.h
++++ b/st.h
+@@ -19,6 +19,7 @@
+ 
+ #define TRUECOLOR(r,g,b)	(1 << 24 | (r) << 16 | (g) << 8 | (b))
+ #define IS_TRUECOL(x)		(1 << 24 & (x))
++#define HISTSIZE            2000
+ 
+ enum glyph_attribute {
+ 	ATTR_NULL       = 0,
+diff --git a/x.c b/x.c
+index bd23686..25785a6 100644
+--- a/x.c
++++ b/x.c
+@@ -59,6 +59,8 @@ static void zoom(const Arg *);
+ static void zoomabs(const Arg *);
+ static void zoomreset(const Arg *);
+ static void ttysend(const Arg *);
++void kscrollup(const Arg *);
++void kscrolldown(const Arg *);
+ 
+ /* config.h for applying patches and the configuration. */
+ #include "config.h"

st.c

@@ -43,6 +43,10 @@
 #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
 #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
 
+#define TSCREEN term.screen[IS_SET(MODE_ALTSCREEN)]
+#define TLINEOFFSET(y) (((y) + TSCREEN.cur - TSCREEN.off + TSCREEN.size) % TSCREEN.size)
+#define TLINE(y) (TSCREEN.buffer[TLINEOFFSET(y)])
+
 enum term_mode {
 	MODE_WRAP        = 1 << 0,
 	MODE_INSERT      = 1 << 1,
@@ -109,12 +113,21 @@ typedef struct {
 	int alt;
 } Selection;
 
+/* Screen lines */
+typedef struct {
+	Line* buffer;  /* ring buffer */
+	int size;      /* size of buffer */
+	int cur;       /* start of active screen */
+	int off;       /* scrollback line offset */
+	TCursor sc;    /* saved cursor */
+} LineBuffer;
+
 /* Internal representation of the screen */
 typedef struct {
 	int row;      /* nb row */
 	int col;      /* nb col */
-	Line *line;   /* screen */
+	LineBuffer screen[2]; /* screen and alternate screen */
-	Line *alt;    /* alternate screen */
+	int linelen;  /* allocated line length */
 	int *dirty;   /* dirtyness of lines */
 	TCursor c;    /* cursor */
 	int ocx;      /* old cursor col */
@@ -203,6 +216,8 @@ static void tdeftran(char);
 static void tstrsequence(uchar);
 
 static void drawregion(int, int, int, int);
+static void clearline(Line, Glyph, int, int);
+static Line ensureline(Line);
 
 static void selnormalize(void);
 static void selscroll(int, int);
@@ -408,11 +423,12 @@ int
 tlinelen(int y)
 {
 	int i = term.col;
+	Line line = TLINE(y);
 
-	if (term.line[y][i - 1].mode & ATTR_WRAP)
+	if (line[i - 1].mode & ATTR_WRAP)
 		return i;
 
-	while (i > 0 && term.line[y][i - 1].u == ' ')
+	while (i > 0 && line[i - 1].u == ' ')
 		--i;
 
 	return i;
@@ -521,7 +537,7 @@ 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;
@@ -536,14 +552,14 @@ 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)))
@@ -564,14 +580,14 @@ 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;
 				}
@@ -602,13 +618,13 @@ 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;
 
@@ -949,12 +965,15 @@ int
 tattrset(int attr)
 {
 	int i, j;
+	int y = TLINEOFFSET(0);
 
 	for (i = 0; i < term.row-1; i++) {
+		Line line = TSCREEN.buffer[y];
 		for (j = 0; j < term.col-1; j++) {
-			if (term.line[i][j].mode & attr)
+			if (line[j].mode & attr)
 				return 1;
 		}
+		y = (y+1) % TSCREEN.size;
 	}
 
 	return 0;
@@ -976,14 +995,17 @@ void
 tsetdirtattr(int attr)
 {
 	int i, j;
+	int y = TLINEOFFSET(0);
 
 	for (i = 0; i < term.row-1; i++) {
+		Line line = TSCREEN.buffer[y];
 		for (j = 0; j < term.col-1; j++) {
-			if (term.line[i][j].mode & attr) {
+			if (line[j].mode & attr) {
 				tsetdirt(i, i);
 				break;
 			}
 		}
+		y = (y+1) % TSCREEN.size;
 	}
 }
 
@@ -996,27 +1018,19 @@ tfulldirt(void)
 void
 tcursor(int mode)
 {
-	static TCursor c[2];
-	int alt = IS_SET(MODE_ALTSCREEN);
-
 	if (mode == CURSOR_SAVE) {
-		c[alt] = term.c;
+		TSCREEN.sc = term.c;
 	} else if (mode == CURSOR_LOAD) {
-		term.c = c[alt];
+		term.c = TSCREEN.sc;
-		tmoveto(c[alt].x, c[alt].y);
+		tmoveto(term.c.x, term.c.y);
 	}
 }
 
 void
 treset(void)
 {
-	uint i;
+	int i, j;
-
+	Glyph g = (Glyph){ .fg = defaultfg, .bg = defaultbg};
-	term.c = (TCursor){{
-		.mode = ATTR_NULL,
-		.fg = defaultfg,
-		.bg = defaultbg
-	}, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
 
 	memset(term.tabs, 0, term.col * sizeof(*term.tabs));
 	for (i = tabspaces; i < term.col; i += tabspaces)
@@ -1028,17 +1042,37 @@ treset(void)
 	term.charset = 0;
 
 	for (i = 0; i < 2; i++) {
-		tmoveto(0, 0);
+		term.screen[i].sc = (TCursor){{
-		tcursor(CURSOR_SAVE);
+			.fg = defaultfg,
-		tclearregion(0, 0, term.col-1, term.row-1);
+			.bg = defaultbg
-		tswapscreen();
+		}};
+		term.screen[i].cur = 0;
+		term.screen[i].off = 0;
+		for (j = 0; j < term.row; ++j) {
+			if (term.col != term.linelen)
+				term.screen[i].buffer[j] = xrealloc(term.screen[i].buffer[j], term.col * sizeof(Glyph));
+			clearline(term.screen[i].buffer[j], g, 0, term.col);
+		}
+		for (j = term.row; j < term.screen[i].size; ++j) {
+			free(term.screen[i].buffer[j]);
+			term.screen[i].buffer[j] = NULL;
+		}
 	}
+	tcursor(CURSOR_LOAD);
+	term.linelen = term.col;
+	tfulldirt();
 }
 
 void
 tnew(int col, int row)
 {
-	term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
+	int i;
+	term = (Term){};
+	term.screen[0].buffer = xmalloc(HISTSIZE * sizeof(Line));
+	term.screen[0].size = HISTSIZE;
+	term.screen[1].buffer = NULL;
+	for (i = 0; i < HISTSIZE; ++i) term.screen[0].buffer[i] = NULL;
+
 	tresize(col, row);
 	treset();
 }
@@ -1046,14 +1080,42 @@ tnew(int col, int row)
 void
 tswapscreen(void)
 {
-	Line *tmp = term.line;
-
-	term.line = term.alt;
-	term.alt = tmp;
 	term.mode ^= MODE_ALTSCREEN;
 	tfulldirt();
 }
 
+void
+kscrollup(const Arg *a)
+{
+	int n = a->i;
+
+	if (IS_SET(MODE_ALTSCREEN))
+		return;
+
+	if (n < 0) n = (-n) * term.row;
+	if (n > TSCREEN.size - term.row - TSCREEN.off) n = TSCREEN.size - term.row - TSCREEN.off;
+	while (!TLINE(-n)) --n;
+	TSCREEN.off += n;
+	selscroll(0, n);
+	tfulldirt();
+}
+
+void
+kscrolldown(const Arg *a)
+{
+
+	int n = a->i;
+
+	if (IS_SET(MODE_ALTSCREEN))
+		return;
+
+	if (n < 0) n = (-n) * term.row;
+	if (n > TSCREEN.off) n = TSCREEN.off;
+	TSCREEN.off -= n;
+	selscroll(0, -n);
+	tfulldirt();
+}
+
 void
 tscrolldown(int orig, int n)
 {
@@ -1062,15 +1124,29 @@ tscrolldown(int orig, int n)
 
 	LIMIT(n, 0, term.bot-orig+1);
 
-	tsetdirt(orig, term.bot-n);
+	/* Ensure that lines are allocated */
-	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
+	for (i = -n; i < 0; i++) {
-
+		TLINE(i) = ensureline(TLINE(i));
-	for (i = term.bot; i >= orig+n; i--) {
-		temp = term.line[i];
-		term.line[i] = term.line[i-n];
-		term.line[i-n] = temp;
 	}
 
+	/* Shift non-scrolling areas in ring buffer */
+	for (i = term.bot+1; i < term.row; i++) {
+		temp = TLINE(i);
+		TLINE(i) = TLINE(i-n);
+		TLINE(i-n) = temp;
+	}
+	for (i = 0; i < orig; i++) {
+		temp = TLINE(i);
+		TLINE(i) = TLINE(i-n);
+		TLINE(i-n) = temp;
+	}
+
+	/* Scroll buffer */
+	TSCREEN.cur = (TSCREEN.cur + TSCREEN.size - n) % TSCREEN.size;
+	/* Clear lines that have entered the view */
+	tclearregion(0, orig, term.linelen-1, orig+n-1);
+	/* Redraw portion of the screen that has scrolled */
+	tsetdirt(orig+n-1, term.bot);
 	selscroll(orig, n);
 }
 
@@ -1082,15 +1158,29 @@ tscrollup(int orig, int n)
 
 	LIMIT(n, 0, term.bot-orig+1);
 
-	tclearregion(0, orig, term.col-1, orig+n-1);
+	/* Ensure that lines are allocated */
-	tsetdirt(orig+n, term.bot);
+	for (i = term.row; i < term.row + n; i++) {
-
+		TLINE(i) = ensureline(TLINE(i));
-	for (i = orig; i <= term.bot-n; i++) {
-		temp = term.line[i];
-		term.line[i] = term.line[i+n];
-		term.line[i+n] = temp;
 	}
 
+	/* Shift non-scrolling areas in ring buffer */
+	for (i = orig-1; i >= 0; i--) {
+		temp = TLINE(i);
+		TLINE(i) = TLINE(i+n);
+		TLINE(i+n) = temp;
+	}
+	for (i = term.row-1; i >term.bot; i--) {
+		temp = TLINE(i);
+		TLINE(i) = TLINE(i+n);
+		TLINE(i+n) = temp;
+	}
+
+	/* Scroll buffer */
+	TSCREEN.cur = (TSCREEN.cur + n) % TSCREEN.size;
+	/* Clear lines that have entered the view */
+	tclearregion(0, term.bot-n+1, term.linelen-1, term.bot);
+	/* Redraw portion of the screen that has scrolled */
+	tsetdirt(orig, term.bot-n+1);
 	selscroll(orig, -n);
 }
 
@@ -1197,6 +1287,7 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
 		"⎻", "─", "⎼", "⎽", "├", "┤", "┴", "┬", /* p - w */
 		"│", "≤", "≥", "π", "≠", "£", "·", /* x - ~ */
 	};
+	Line line = TLINE(y);
 
 	/*
 	 * The table is proudly stolen from rxvt.
@@ -1205,25 +1296,25 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
 	   BETWEEN(u, 0x41, 0x7e) && vt100_0[u - 0x41])
 		utf8decode(vt100_0[u - 0x41], &u, UTF_SIZ);
 
-	if (term.line[y][x].mode & ATTR_WIDE) {
+	if (line[x].mode & ATTR_WIDE) {
 		if (x+1 < term.col) {
-			term.line[y][x+1].u = ' ';
+			line[x+1].u = ' ';
-			term.line[y][x+1].mode &= ~ATTR_WDUMMY;
+			line[x+1].mode &= ~ATTR_WDUMMY;
 		}
-	} else if (term.line[y][x].mode & ATTR_WDUMMY) {
+	} else if (line[x].mode & ATTR_WDUMMY) {
-		term.line[y][x-1].u = ' ';
+		line[x-1].u = ' ';
-		term.line[y][x-1].mode &= ~ATTR_WIDE;
+		line[x-1].mode &= ~ATTR_WIDE;
 	}
 
 	term.dirty[y] = 1;
-	term.line[y][x] = *attr;
+	line[x] = *attr;
-	term.line[y][x].u = u;
+	line[x].u = u;
 }
 
 void
 tclearregion(int x1, int y1, int x2, int y2)
 {
-	int x, y, temp;
+	int x, y, L, S, temp;
 	Glyph *gp;
 
 	if (x1 > x2)
@@ -1231,15 +1322,16 @@ tclearregion(int x1, int y1, int x2, int y2)
 	if (y1 > y2)
 		temp = y1, y1 = y2, y2 = temp;
 
-	LIMIT(x1, 0, term.col-1);
+	LIMIT(x1, 0, term.linelen-1);
-	LIMIT(x2, 0, term.col-1);
+	LIMIT(x2, 0, term.linelen-1);
 	LIMIT(y1, 0, term.row-1);
 	LIMIT(y2, 0, term.row-1);
 
+	L = TLINEOFFSET(y1);
 	for (y = y1; y <= y2; y++) {
 		term.dirty[y] = 1;
 		for (x = x1; x <= x2; x++) {
-			gp = &term.line[y][x];
+			gp = &TSCREEN.buffer[L][x];
 			if (selected(x, y))
 				selclear();
 			gp->fg = term.c.attr.fg;
@@ -1247,6 +1339,7 @@ tclearregion(int x1, int y1, int x2, int y2)
 			gp->mode = 0;
 			gp->u = ' ';
 		}
+		L = (L + 1) % TSCREEN.size;
 	}
 }
 
@@ -1261,7 +1354,7 @@ tdeletechar(int n)
 	dst = term.c.x;
 	src = term.c.x + n;
 	size = term.col - src;
-	line = term.line[term.c.y];
+	line = TLINE(term.c.y);
 
 	memmove(&line[dst], &line[src], size * sizeof(Glyph));
 	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
@@ -1278,7 +1371,7 @@ tinsertblank(int n)
 	dst = term.c.x + n;
 	src = term.c.x;
 	size = term.col - dst;
-	line = term.line[term.c.y];
+	line = TLINE(term.c.y);
 
 	memmove(&line[dst], &line[src], size * sizeof(Glyph));
 	tclearregion(src, term.c.y, dst - 1, term.c.y);
@@ -2105,7 +2198,7 @@ tdumpline(int n)
 	char buf[UTF_SIZ];
 	const Glyph *bp, *end;
 
-	bp = &term.line[n][0];
+	bp = &TLINE(n)[0];
 	end = &bp[MIN(tlinelen(n), term.col) - 1];
 	if (bp != end || bp->u != ' ') {
 		for ( ; bp <= end; ++bp)
@@ -2493,11 +2586,11 @@ check_control_code:
 	if (selected(term.c.x, term.c.y))
 		selclear();
 
-	gp = &term.line[term.c.y][term.c.x];
+	gp = &TLINE(term.c.y)[term.c.x];
 	if (IS_SET(MODE_WRAP) && (term.c.state & CURSOR_WRAPNEXT)) {
 		gp->mode |= ATTR_WRAP;
 		tnewline(1);
-		gp = &term.line[term.c.y][term.c.x];
+		gp = &TLINE(term.c.y)[term.c.x];
 	}
 
 	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col) {
@@ -2510,7 +2603,7 @@ check_control_code:
 			tnewline(1);
 		else
 			tmoveto(term.col - width, term.c.y);
-		gp = &term.line[term.c.y][term.c.x];
+		gp = &TLINE(term.c.y)[term.c.x];
 	}
 
 	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
@@ -2541,6 +2634,11 @@ twrite(const char *buf, int buflen, int show_ctrl)
 	Rune u;
 	int n;
 
+	if (TSCREEN.off) {
+		TSCREEN.off = 0;
+		tfulldirt();
+	}
+
 	for (n = 0; n < buflen; n += charsize) {
 		if (IS_SET(MODE_UTF8)) {
 			/* process a complete utf8 char */
@@ -2567,56 +2665,85 @@ twrite(const char *buf, int buflen, int show_ctrl)
 }
 
 void
-tresize(int col, int row)
+clearline(Line line, Glyph g, int x, int xend)
 {
 	int i;
+	g.mode = 0;
+	g.u = ' ';
+	for (i = x; i < xend; ++i) {
+		line[i] = g;
+	}
+}
+
+Line
+ensureline(Line line)
+{
+	if (!line) {
+		line = xmalloc(term.linelen * sizeof(Glyph));
+	}
+	return line;
+}
+
+void
+tresize(int col, int row)
+{
+	int i, j;
 	int minrow = MIN(row, term.row);
 	int mincol = MIN(col, term.col);
+	int linelen = MAX(col, term.linelen);
 	int *bp;
-	TCursor c;
 
-	if (col < 1 || row < 1) {
+	if (col < 1 || row < 1 || row > HISTSIZE) {
 		fprintf(stderr,
 		        "tresize: error resizing to %dx%d\n", col, row);
 		return;
 	}
 
-	/*
+	/* Shift buffer to keep the cursor where we expect it */
-	 * slide screen to keep cursor where we expect it -
+	if (row <= term.c.y) {
-	 * tscrollup would work here, but we can optimize to
+		term.screen[0].cur = (term.screen[0].cur - row + term.c.y + 1) % term.screen[0].size;
-	 * memmove because we're freeing the earlier lines
-	 */
-	for (i = 0; i <= term.c.y - row; i++) {
-		free(term.line[i]);
-		free(term.alt[i]);
 	}
-	/* ensure that both src and dst are not NULL */
+
-	if (i > 0) {
+	/* Resize and clear line buffers as needed */
-		memmove(term.line, term.line + i, row * sizeof(Line));
+	if (linelen > term.linelen) {
-		memmove(term.alt, term.alt + i, row * sizeof(Line));
+		for (i = 0; i < term.screen[0].size; ++i) {
+			if (term.screen[0].buffer[i]) {
+				term.screen[0].buffer[i] = xrealloc(term.screen[0].buffer[i], linelen * sizeof(Glyph));
+				clearline(term.screen[0].buffer[i], term.c.attr, term.linelen, linelen);
+			}
+		}
+		for (i = 0; i < minrow; ++i) {
+			term.screen[1].buffer[i] = xrealloc(term.screen[1].buffer[i], linelen * sizeof(Glyph));
+			clearline(term.screen[1].buffer[i], term.c.attr, term.linelen, linelen);
+		}
 	}
-	for (i += row; i < term.row; i++) {
+	/* Allocate all visible lines for regular line buffer */
-		free(term.line[i]);
+	for (j = term.screen[0].cur, i = 0; i < row; ++i, j = (j + 1) % term.screen[0].size)
-		free(term.alt[i]);
+	{
+		if (!term.screen[0].buffer[j]) {
+			term.screen[0].buffer[j] = xmalloc(linelen * sizeof(Glyph));
+		}
+		if (i >= term.row) {
+			clearline(term.screen[0].buffer[j], term.c.attr, 0, linelen);
+		}
+	}
+	/* Resize alt screen */
+	term.screen[1].cur = 0;
+	term.screen[1].size = row;
+	for (i = row; i < term.row; ++i) {
+		free(term.screen[1].buffer[i]);
+	}
+	term.screen[1].buffer = xrealloc(term.screen[1].buffer, row * sizeof(Line));
+	for (i = term.row; i < row; ++i) {
+		term.screen[1].buffer[i] = xmalloc(linelen * sizeof(Glyph));
+		clearline(term.screen[1].buffer[i], term.c.attr, 0, linelen);
 	}
 
 	/* resize to new height */
-	term.line = xrealloc(term.line, row * sizeof(Line));
-	term.alt  = xrealloc(term.alt,  row * sizeof(Line));
 	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
 	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
 
-	/* resize each row to new width, zero-pad if needed */
+	/* fix tabstops */
-	for (i = 0; i < minrow; i++) {
-		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
-		term.alt[i]  = xrealloc(term.alt[i],  col * sizeof(Glyph));
-	}
-
-	/* allocate any new rows */
-	for (/* i = minrow */; i < row; i++) {
-		term.line[i] = xmalloc(col * sizeof(Glyph));
-		term.alt[i] = xmalloc(col * sizeof(Glyph));
-	}
 	if (col > term.col) {
 		bp = term.tabs + term.col;
 
@@ -2626,26 +2753,16 @@ tresize(int col, int row)
 		for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
 			*bp = 1;
 	}
+
 	/* update terminal size */
 	term.col = col;
 	term.row = row;
+	term.linelen = linelen;
 	/* reset scrolling region */
 	tsetscroll(0, row-1);
 	/* make use of the LIMIT in tmoveto */
 	tmoveto(term.c.x, term.c.y);
-	/* Clearing both screens (it makes dirty all lines) */
+	tfulldirt();
-	c = term.c;
-	for (i = 0; i < 2; i++) {
-		if (mincol < col && 0 < minrow) {
-			tclearregion(mincol, 0, col - 1, minrow - 1);
-		}
-		if (0 < col && minrow < row) {
-			tclearregion(0, minrow, col - 1, row - 1);
-		}
-		tswapscreen();
-		tcursor(CURSOR_LOAD);
-	}
-	term.c = c;
 }
 
 void
@@ -2657,14 +2774,15 @@ resettitle(void)
 void
 drawregion(int x1, int y1, int x2, int y2)
 {
-	int y;
+	int y, L;
 
+	L = TLINEOFFSET(y1);
 	for (y = y1; y < y2; y++) {
-		if (!term.dirty[y])
+		if (term.dirty[y]) {
-			continue;
+			term.dirty[y] = 0;
-
+			xdrawline(TSCREEN.buffer[L], x1, y, x2);
-		term.dirty[y] = 0;
+		}
-		xdrawline(term.line[y], x1, y, x2);
+		L = (L + 1) % TSCREEN.size;
 	}
 }
 
@@ -2679,14 +2797,16 @@ draw(void)
 	/* adjust cursor position */
 	LIMIT(term.ocx, 0, term.col-1);
 	LIMIT(term.ocy, 0, term.row-1);
-	if (term.line[term.ocy][term.ocx].mode & ATTR_WDUMMY)
+	if (TLINE(term.ocy)[term.ocx].mode & ATTR_WDUMMY)
 		term.ocx--;
-	if (term.line[term.c.y][cx].mode & ATTR_WDUMMY)
+	if (TLINE(term.c.y)[cx].mode & ATTR_WDUMMY)
 		cx--;
 
 	drawregion(0, 0, term.col, term.row);
-	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+	if (TSCREEN.off == 0)
-			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
+		xdrawcursor(cx, term.c.y, TLINE(term.c.y)[cx],
+			term.ocx, term.ocy, TLINE(term.ocy)[term.ocx],
+			TLINE(term.ocy), term.col);
 	term.ocx = cx;
 	term.ocy = term.c.y;
 	xfinishdraw();

st.h

@@ -11,7 +11,8 @@
 #define DIVCEIL(n, d)		(((n) + ((d) - 1)) / (d))
 #define DEFAULT(a, b)		(a) = (a) ? (a) : (b)
 #define LIMIT(x, a, b)		(x) = (x) < (a) ? (a) : (x) > (b) ? (b) : (x)
-#define ATTRCMP(a, b)		((a).mode != (b).mode || (a).fg != (b).fg || \
+#define ATTRCMP(a, b)		(((a).mode & (~ATTR_WRAP)) != ((b).mode & (~ATTR_WRAP)) || \
+				(a).fg != (b).fg || \
 				(a).bg != (b).bg)
 #define TIMEDIFF(t1, t2)	((t1.tv_sec-t2.tv_sec)*1000 + \
 				(t1.tv_nsec-t2.tv_nsec)/1E6)
@@ -19,6 +20,7 @@
 
 #define TRUECOLOR(r,g,b)	(1 << 24 | (r) << 16 | (g) << 8 | (b))
 #define IS_TRUECOL(x)		(1 << 24 & (x))
+#define HISTSIZE            2000
 
 enum glyph_attribute {
 	ATTR_NULL       = 0,

win.h

@@ -25,7 +25,7 @@ enum win_mode {
 
 void xbell(void);
 void xclipcopy(void);
-void xdrawcursor(int, int, Glyph, int, int, Glyph);
+void xdrawcursor(int, int, Glyph, int, int, Glyph, Line, int);
 void xdrawline(Line, int, int, int);
 void xfinishdraw(void);
 void xloadcols(void);

x.c

@@ -19,6 +19,7 @@ char *argv0;
 #include "arg.h"
 #include "st.h"
 #include "win.h"
+#include "hb.h"
 
 /* types used in config.h */
 typedef struct {
@@ -59,6 +60,8 @@ static void zoom(const Arg *);
 static void zoomabs(const Arg *);
 static void zoomreset(const Arg *);
 static void ttysend(const Arg *);
+void kscrollup(const Arg *);
+void kscrolldown(const Arg *);
 
 /* config.h for applying patches and the configuration. */
 #include "config.h"
@@ -141,8 +144,9 @@ typedef struct {
 } DC;
 
 static inline ushort sixd_to_16bit(int);
+static void xresetfontsettings(ushort mode, Font **font, int *frcflags);
 static int xmakeglyphfontspecs(XftGlyphFontSpec *, const Glyph *, int, int, int);
-static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int);
+static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int, int);
 static void xdrawglyph(Glyph, int, int);
 static void xclear(int, int, int, int);
 static int xgeommasktogravity(int);
@@ -757,7 +761,7 @@ xresize(int col, int row)
 	xclear(0, 0, win.w, win.h);
 
 	/* resize to new width */
-	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec));
+	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec) * 4);
 }
 
 ushort
@@ -1062,6 +1066,9 @@ xunloadfont(Font *f)
 void
 xunloadfonts(void)
 {
+	/* Clear Harfbuzz font cache. */
+	hbunloadfonts();
+
 	/* Free the loaded fonts in the font cache.  */
 	while (frclen > 0)
 		XftFontClose(xw.dpy, frc[--frclen].font);
@@ -1188,7 +1195,7 @@ xinit(int cols, int rows)
 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
 
 	/* font spec buffer */
-	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec));
+	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec) * 4);
 
 	/* Xft rendering context */
 	xw.draw = XftDrawCreate(xw.dpy, xw.buf, xw.vis, xw.cmap);
@@ -1242,142 +1249,153 @@ xinit(int cols, int rows)
 		xsel.xtarget = XA_STRING;
 }
 
+void
+xresetfontsettings(ushort mode, Font **font, int *frcflags)
+{
+	*font = &dc.font;
+	if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
+		*font = &dc.ibfont;
+		*frcflags = FRC_ITALICBOLD;
+	} else if (mode & ATTR_ITALIC) {
+		*font = &dc.ifont;
+		*frcflags = FRC_ITALIC;
+	} else if (mode & ATTR_BOLD) {
+		*font = &dc.bfont;
+		*frcflags = FRC_BOLD;
+	}
+}
+
 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;
-	ushort mode, prevmode = USHRT_MAX;
+	ushort mode = glyphs[0].mode & ~ATTR_WRAP;
 	Font *font = &dc.font;
 	int frcflags = FRC_NORMAL;
-	float runewidth = win.cw;
+	float runewidth = win.cw * ((glyphs[0].mode & ATTR_WIDE) ? 2.0f : 1.0f);
 	Rune rune;
 	FT_UInt glyphidx;
 	FcResult fcres;
 	FcPattern *fcpattern, *fontpattern;
 	FcFontSet *fcsets[] = { NULL };
 	FcCharSet *fccharset;
-	int i, f, numspecs = 0;
+	int f, code_idx, numspecs = 0;
+	float cluster_xp = xp, cluster_yp = yp;
+	HbTransformData shaped = { 0 };
 
-	for (i = 0, xp = winx, yp = winy + font->ascent; i < len; ++i) {
+	/* Initial values. */
-		/* Fetch rune and mode for current glyph. */
+	xresetfontsettings(mode, &font, &frcflags);
-		rune = glyphs[i].u;
-		mode = glyphs[i].mode;
 
-		/* Skip dummy wide-character spacing. */
+	/* Shape the segment. */
-		if (mode == ATTR_WDUMMY)
+	hbtransform(&shaped, font->match, glyphs, 0, len);
+	xp = winx; yp = winy + font->ascent;
+	cluster_xp = xp; cluster_yp = yp;
+
+	for (code_idx = 0; code_idx < shaped.count; code_idx++) {
+		int idx = shaped.glyphs[code_idx].cluster;
+
+		if (glyphs[idx].mode & ATTR_WDUMMY)
 			continue;
 
-		/* Determine font for glyph if different from previous glyph. */
+		/* Advance the drawing cursor if we've moved to a new cluster */
-		if (prevmode != mode) {
+		if (code_idx > 0 && (idx != shaped.glyphs[code_idx - 1].cluster)) {
-			prevmode = mode;
+			xp += runewidth * (idx - shaped.glyphs[code_idx - 1].cluster);
-			font = &dc.font;
+			cluster_xp = xp;
-			frcflags = FRC_NORMAL;
+			cluster_yp = yp;
-			runewidth = win.cw * ((mode & ATTR_WIDE) ? 2.0f : 1.0f);
-			if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
-				font = &dc.ibfont;
-				frcflags = FRC_ITALICBOLD;
-			} else if (mode & ATTR_ITALIC) {
-				font = &dc.ifont;
-				frcflags = FRC_ITALIC;
-			} else if (mode & ATTR_BOLD) {
-				font = &dc.bfont;
-				frcflags = FRC_BOLD;
-			}
-			yp = winy + font->ascent;
 		}
 
-		/* Lookup character index with default font. */
+		if (shaped.glyphs[code_idx].codepoint != 0) {
-		glyphidx = XftCharIndex(xw.dpy, font->match, rune);
+			/* If symbol is found, put it into the specs. */
-		if (glyphidx) {
 			specs[numspecs].font = font->match;
+			specs[numspecs].glyph = shaped.glyphs[code_idx].codepoint;
+			specs[numspecs].x = cluster_xp + (short)(shaped.positions[code_idx].x_offset / 64.);
+			specs[numspecs].y = cluster_yp - (short)(shaped.positions[code_idx].y_offset / 64.);
+			cluster_xp += shaped.positions[code_idx].x_advance / 64.;
+			cluster_yp += shaped.positions[code_idx].y_advance / 64.;
+			numspecs++;
+		} else {
+			/* If it's not found, try to fetch it through the font cache. */
+			rune = glyphs[idx].u;
+			for (f = 0; f < frclen; f++) {
+				glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
+				/* Everything correct. */
+				if (glyphidx && frc[f].flags == frcflags)
+					break;
+				/* We got a default font for a not found glyph. */
+				if (!glyphidx && frc[f].flags == frcflags
+						&& frc[f].unicodep == rune) {
+					break;
+				}
+			}
+
+			/* Nothing was found. Use fontconfig to find matching font. */
+			if (f >= frclen) {
+				if (!font->set)
+					font->set = FcFontSort(0, font->pattern,
+							       1, 0, &fcres);
+				fcsets[0] = font->set;
+
+				/*
+				 * Nothing was found in the cache. Now use
+				 * some dozen of Fontconfig calls to get the
+				 * font for one single character.
+				 *
+				 * Xft and fontconfig are design failures.
+				 */
+				fcpattern = FcPatternDuplicate(font->pattern);
+				fccharset = FcCharSetCreate();
+
+				FcCharSetAddChar(fccharset, rune);
+				FcPatternAddCharSet(fcpattern, FC_CHARSET,
+						fccharset);
+				FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
+
+				FcConfigSubstitute(0, fcpattern,
+						FcMatchPattern);
+				FcDefaultSubstitute(fcpattern);
+
+				fontpattern = FcFontSetMatch(0, fcsets, 1,
+						fcpattern, &fcres);
+
+				/* Allocate memory for the new cache entry. */
+				if (frclen >= frccap) {
+					frccap += 16;
+					frc = xrealloc(frc, frccap * sizeof(Fontcache));
+				}
+
+				frc[frclen].font = XftFontOpenPattern(xw.dpy,
+						fontpattern);
+				if (!frc[frclen].font)
+					die("XftFontOpenPattern failed seeking fallback font: %s\n",
+						strerror(errno));
+				frc[frclen].flags = frcflags;
+				frc[frclen].unicodep = rune;
+
+				glyphidx = XftCharIndex(xw.dpy, frc[frclen].font, rune);
+
+				f = frclen;
+				frclen++;
+
+				FcPatternDestroy(fcpattern);
+				FcCharSetDestroy(fccharset);
+			}
+
+			specs[numspecs].font = frc[f].font;
 			specs[numspecs].glyph = glyphidx;
 			specs[numspecs].x = (short)xp;
 			specs[numspecs].y = (short)yp;
-			xp += runewidth;
 			numspecs++;
-			continue;
 		}
-
-		/* Fallback on font cache, search the font cache for match. */
-		for (f = 0; f < frclen; f++) {
-			glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
-			/* Everything correct. */
-			if (glyphidx && frc[f].flags == frcflags)
-				break;
-			/* We got a default font for a not found glyph. */
-			if (!glyphidx && frc[f].flags == frcflags
-					&& frc[f].unicodep == rune) {
-				break;
-			}
-		}
-
-		/* Nothing was found. Use fontconfig to find matching font. */
-		if (f >= frclen) {
-			if (!font->set)
-				font->set = FcFontSort(0, font->pattern,
-				                       1, 0, &fcres);
-			fcsets[0] = font->set;
-
-			/*
-			 * Nothing was found in the cache. Now use
-			 * some dozen of Fontconfig calls to get the
-			 * font for one single character.
-			 *
-			 * Xft and fontconfig are design failures.
-			 */
-			fcpattern = FcPatternDuplicate(font->pattern);
-			fccharset = FcCharSetCreate();
-
-			FcCharSetAddChar(fccharset, rune);
-			FcPatternAddCharSet(fcpattern, FC_CHARSET,
-					fccharset);
-			FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
-
-			FcConfigSubstitute(0, fcpattern,
-					FcMatchPattern);
-			FcDefaultSubstitute(fcpattern);
-
-			fontpattern = FcFontSetMatch(0, fcsets, 1,
-					fcpattern, &fcres);
-
-			/* Allocate memory for the new cache entry. */
-			if (frclen >= frccap) {
-				frccap += 16;
-				frc = xrealloc(frc, frccap * sizeof(Fontcache));
-			}
-
-			frc[frclen].font = XftFontOpenPattern(xw.dpy,
-					fontpattern);
-			if (!frc[frclen].font)
-				die("XftFontOpenPattern failed seeking fallback font: %s\n",
-					strerror(errno));
-			frc[frclen].flags = frcflags;
-			frc[frclen].unicodep = rune;
-
-			glyphidx = XftCharIndex(xw.dpy, frc[frclen].font, rune);
-
-			f = frclen;
-			frclen++;
-
-			FcPatternDestroy(fcpattern);
-			FcCharSetDestroy(fccharset);
-		}
-
-		specs[numspecs].font = frc[f].font;
-		specs[numspecs].glyph = glyphidx;
-		specs[numspecs].x = (short)xp;
-		specs[numspecs].y = (short)yp;
-		xp += runewidth;
-		numspecs++;
 	}
 
+	/* Cleanup and get ready for next segment. */
+	hbcleanup(&shaped);
 	return numspecs;
 }
 
 void
-xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y)
+xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, int y, int charlen)
 {
-	int charlen = len * ((base.mode & ATTR_WIDE) ? 2 : 1);
 	int winx = borderpx + x * win.cw, winy = borderpx + y * win.ch,
 	    width = charlen * win.cw;
 	Color *fg, *bg, *temp, revfg, revbg, truefg, truebg;
@@ -1415,10 +1433,6 @@ xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, i
 		bg = &dc.col[base.bg];
 	}
 
-	/* Change basic system colors [0-7] to bright system colors [8-15] */
-	if ((base.mode & ATTR_BOLD_FAINT) == ATTR_BOLD && BETWEEN(base.fg, 0, 7))
-		fg = &dc.col[base.fg + 8];
-
 	if (IS_SET(MODE_REVERSE)) {
 		if (fg == &dc.col[defaultfg]) {
 			fg = &dc.col[defaultbg];
@@ -1513,21 +1527,24 @@ void
 xdrawglyph(Glyph g, int x, int y)
 {
 	int numspecs;
-	XftGlyphFontSpec spec;
+	XftGlyphFontSpec *specs = xw.specbuf;
 
-	numspecs = xmakeglyphfontspecs(&spec, &g, 1, x, y);
+	numspecs = xmakeglyphfontspecs(specs, &g, 1, x, y);
-	xdrawglyphfontspecs(&spec, g, numspecs, x, y);
+	xdrawglyphfontspecs(specs, g, numspecs, x, y, (g.mode & ATTR_WIDE) ? 2 : 1);
 }
 
 void
-xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
+xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og, Line line, int len)
 {
 	Color drawcol;
 
 	/* remove the old cursor */
 	if (selected(ox, oy))
 		og.mode ^= ATTR_REVERSE;
-	xdrawglyph(og, ox, oy);
+
+	/* Redraw the line where cursor was previously.
+	 * It will restore the ligatures broken by the cursor. */
+	xdrawline(line, 0, oy, len);
 
 	if (IS_SET(MODE_HIDE))
 		return;
@@ -1661,18 +1678,16 @@ xdrawline(Line line, int x1, int y1, int x2)
 	Glyph base, new;
 	XftGlyphFontSpec *specs = xw.specbuf;
 
-	numspecs = xmakeglyphfontspecs(specs, &line[x1], x2 - x1, x1, y1);
 	i = ox = 0;
-	for (x = x1; x < x2 && i < numspecs; x++) {
+	for (x = x1; x < x2; x++) {
 		new = line[x];
 		if (new.mode == ATTR_WDUMMY)
 			continue;
 		if (selected(x, y1))
 			new.mode ^= ATTR_REVERSE;
-		if (i > 0 && ATTRCMP(base, new)) {
+		if ((i > 0) && ATTRCMP(base, new)) {
-			xdrawglyphfontspecs(specs, base, i, ox, y1);
+			numspecs = xmakeglyphfontspecs(specs, &line[ox], x - ox, ox, y1);
-			specs += i;
+			xdrawglyphfontspecs(specs, base, numspecs, ox, y1, x - ox);
-			numspecs -= i;
 			i = 0;
 		}
 		if (i == 0) {
@@ -1681,8 +1696,10 @@ xdrawline(Line line, int x1, int y1, int x2)
 		}
 		i++;
 	}
-	if (i > 0)
+	if (i > 0) {
-		xdrawglyphfontspecs(specs, base, i, ox, y1);
+		numspecs = xmakeglyphfontspecs(specs, &line[ox], x2 - ox, ox, y1);
+		xdrawglyphfontspecs(specs, base, numspecs, ox, y1, x2 - ox);
+	}
 }
 
 void