commit 605c9c8f6b0f5170ea7b6eac3a32440c643614a8
Author: Alexander Rogachev <[email protected]>
Date: Mon Apr 6 20:55:54 2020 +0300
[st][ligatures] Various fixes and improvements:
* Fixed random memory access crash on calling hb_shape().
* Added new patches compatible with Alpha patch.
* Added new patch compatible with Boxdraw patch.
diff --git a/st.suckless.org/patches/ligatures/index.md
b/st.suckless.org/patches/ligatures/index.md
index 1a91dc06..22d3d5de 100644
--- a/st.suckless.org/patches/ligatures/index.md
+++ b/st.suckless.org/patches/ligatures/index.md
@@ -16,13 +16,21 @@ Taken with Fira Code Regular 14pt:
Notes
-----
* The patch adds additional dependency on Harfbuzz library and headers.
-* Original patch was made for clean version of ST from latest master commit.
It is not 100% compatible with Scrollback patches, so I made a modified version
that you can apply on top of a Scrollback patch.
+* Original patch was made for clean version of ST from latest master commit.
It is not 100% compatible with Scrollback and Alpha patches, so I made a
modified versions that you can apply on top of a Scrollback and/or Alpha patch.
* Due to some limitations in drawing engine, ligatures will break when
crossing colors, font styles or selection. They will still render properly as
separate symbols, just not as ligatures.
+boxdraw
+-------
+* The original patch does not work very well with the boxdraw. Since it
requires some additional changes in the code to make ligatures compatible with
boxdraw, a special version of the patch was added, that you can apply on top of
the boxdraw patch.
+* It does not include Alpha or Scrollback patches.
+
Download
--------
-* [st-ligatures](st-ligatures-20200405-28ad288.diff)
-* [st-ligatures-scrollback](st-ligatures-scrollback-20200405-28ad288.diff)
+* [st-ligatures](st-ligatures-20200406-28ad288.diff)
+* [st-ligatures-scrollback](st-ligatures-scrollback-20200406-28ad288.diff)
+* [st-ligatures-alpha](st-ligatures-alpha-20200406-28ad288.diff)
+*
[st-ligatures-alpha-scrollback](st-ligatures-alpha-scrollback-20200406-28ad288.diff)
+* [st-ligatures-boxdraw](st-ligatures-boxdraw-20200407-28ad288.diff)
Authors
-------
diff --git
a/st.suckless.org/patches/ligatures/st-ligatures-20200405-28ad288.diff
b/st.suckless.org/patches/ligatures/st-ligatures-20200406-28ad288.diff
similarity index 97%
rename from st.suckless.org/patches/ligatures/st-ligatures-20200405-28ad288.diff
rename to st.suckless.org/patches/ligatures/st-ligatures-20200406-28ad288.diff
index 830d4f97..8bb26e64 100644
--- a/st.suckless.org/patches/ligatures/st-ligatures-20200405-28ad288.diff
+++ b/st.suckless.org/patches/ligatures/st-ligatures-20200406-28ad288.diff
@@ -31,12 +31,12 @@ index 0cbb002..76c5c4f 100644
`$(PKG_CONFIG) --cflags fontconfig` \
- `$(PKG_CONFIG) --cflags freetype2`
+ `$(PKG_CONFIG) --cflags freetype2` \
-+ `$(PKG_CONFIG) --cflags harfbuzz`
++ `$(PKG_CONFIG) --cflags harfbuzz`
LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
`$(PKG_CONFIG) --libs fontconfig` \
- `$(PKG_CONFIG) --libs freetype2`
+ `$(PKG_CONFIG) --libs freetype2` \
-+ `$(PKG_CONFIG) --libs harfbuzz`
++ `$(PKG_CONFIG) --libs harfbuzz`
# flags
STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
@@ -45,7 +45,7 @@ new file mode 100644
index 0000000..bb0bea8
--- /dev/null
+++ b/hb.c
-@@ -0,0 +1,127 @@
+@@ -0,0 +1,128 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
@@ -67,8 +67,10 @@ index 0000000..bb0bea8
+static HbFontMatch *hbfontcache = NULL;
+
+void hbunloadfonts() {
-+ for (int i = 0; i < hbfontslen; i++)
++ for (int i = 0; i < hbfontslen; i++) {
+ hb_font_destroy(hbfontcache[i].font);
++ XftUnlockFace(hbfontcache[i].match);
++ }
+
+ if (hbfontcache != NULL) {
+ free(hbfontcache);
@@ -89,7 +91,6 @@ index 0000000..bb0bea8
+ hb_font_t *font = hb_ft_font_create(face, NULL);
+ if (font == NULL)
+ die("Failed to load Harfbuzz font.");
-+ XftUnlockFace(match);
+
+ hbfontcache[hbfontslen].match = match;
+ hbfontcache[hbfontslen].font = font;
diff --git
a/st.suckless.org/patches/ligatures/st-ligatures-alpha-20200406-28ad288.diff
b/st.suckless.org/patches/ligatures/st-ligatures-alpha-20200406-28ad288.diff
new file mode 100644
index 00000000..fb0a29ab
--- /dev/null
+++ b/st.suckless.org/patches/ligatures/st-ligatures-alpha-20200406-28ad288.diff
@@ -0,0 +1,271 @@
+diff --git a/Makefile b/Makefile
+index 470ac86..38240da 100644
+--- a/Makefile
++++ b/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: options st
+@@ -22,7 +22,8 @@ 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
+
+ $(OBJ): config.h config.mk
+
+diff --git a/config.mk b/config.mk
+index 0cbb002..76c5c4f 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(X11INC) \
+ `$(PKG_CONFIG) --cflags fontconfig` \
+- `$(PKG_CONFIG) --cflags freetype2`
++ `$(PKG_CONFIG) --cflags freetype2` \
++ `$(PKG_CONFIG) --cflags harfbuzz`
+ LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft -lXrender \
+ `$(PKG_CONFIG) --libs fontconfig` \
+- `$(PKG_CONFIG) --libs freetype2`
++ `$(PKG_CONFIG) --libs freetype2` \
++ `$(PKG_CONFIG) --libs harfbuzz`
+
+ # flags
+ STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
+diff --git a/hb.c b/hb.c
+new file mode 100644
+index 0000000..bb0bea8
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,128 @@
++#include <stdlib.h>
++#include <stdio.h>
++#include <math.h>
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++#include "st.h"
++
++void hbtransformsegment(XftFont *xfont, const Glyph *string, hb_codepoint_t
*codepoints, int start, int length);
++hb_font_t *hbfindfont(XftFont *match);
++
++typedef struct {
++ XftFont *match;
++ hb_font_t *font;
++} HbFontMatch;
++
++static int hbfontslen = 0;
++static HbFontMatch *hbfontcache = NULL;
++
++void hbunloadfonts() {
++ for (int i = 0; i < hbfontslen; i++) {
++ hb_font_destroy(hbfontcache[i].font);
++ XftUnlockFace(hbfontcache[i].match);
++ }
++
++ if (hbfontcache != NULL) {
++ free(hbfontcache);
++ hbfontcache = NULL;
++ }
++ hbfontslen = 0;
++}
++
++hb_font_t *hbfindfont(XftFont *match) {
++ for (int i = 0; i < hbfontslen; i++) {
++ if (hbfontcache[i].match == match)
++ return hbfontcache[i].font;
++ }
++
++ // Font not found in cache, caching it now.
++ hbfontcache = realloc(hbfontcache, sizeof(HbFontMatch) * (hbfontslen +
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[hbfontslen].match = match;
++ hbfontcache[hbfontslen].font = font;
++ hbfontslen += 1;
++
++ return font;
++}
++
++void hbtransform(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int
x, int y) {
++ int start = 0, length = 1, gstart = 0;
++ hb_codepoint_t *codepoints = calloc(len, sizeof(hb_codepoint_t));
++
++ for (int idx = 1, specidx = 1; idx < len; idx++) {
++ if (glyphs[idx].mode & ATTR_WDUMMY) {
++ length += 1;
++ continue;
++ }
++
++ if (specs[specidx].font != specs[start].font ||
ATTRCMP(glyphs[gstart], glyphs[idx]) || selected(x + idx, y) != selected(x +
gstart, y)) {
++ hbtransformsegment(specs[start].font, glyphs,
codepoints, gstart, length);
++
++ // Reset the sequence.
++ length = 1;
++ start = specidx;
++ gstart = idx;
++ } else {
++ length += 1;
++ }
++
++ specidx++;
++ }
++
++ // EOL.
++ hbtransformsegment(specs[start].font, glyphs, codepoints, gstart,
length);
++
++ // Apply the transformation to glyph specs.
++ for (int i = 0, specidx = 0; i < len; i++) {
++ if (glyphs[i].mode & ATTR_WDUMMY)
++ continue;
++
++ if (codepoints[i] != specs[specidx].glyph)
++ ((Glyph *)glyphs)[i].mode |= ATTR_LIGA;
++
++ specs[specidx++].glyph = codepoints[i];
++ }
++
++ free(codepoints);
++}
++
++void hbtransformsegment(XftFont *xfont, const Glyph *string, hb_codepoint_t
*codepoints, int start, int length) {
++ hb_font_t *font = hbfindfont(xfont);
++ if (font == NULL)
++ return;
++
++ Rune rune;
++ ushort mode = USHRT_MAX;
++ hb_buffer_t *buffer = hb_buffer_create();
++ hb_buffer_set_direction(buffer, HB_DIRECTION_LTR);
++
++ // Fill buffer with codepoints.
++ for (int i = start; i < (start+length); i++) {
++ rune = string[i].u;
++ mode = string[i].mode;
++ if (mode & ATTR_WDUMMY)
++ rune = 0x0020;
++ hb_buffer_add_codepoints(buffer, &rune, 1, 0, 1);
++ }
++
++ // Shape the segment.
++ hb_shape(font, buffer, NULL, 0);
++
++ // Get new glyph info.
++ hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, NULL);
++
++ // Write new codepoints.
++ for (int i = 0; i < length; i++) {
++ hb_codepoint_t gid = info[i].codepoint;
++ codepoints[start+i] = gid;
++ }
++
++ // Cleanup.
++ hb_buffer_destroy(buffer);
++}
+diff --git a/hb.h b/hb.h
+new file mode 100644
+index 0000000..a209238
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,7 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++void hbunloadfonts();
++void hbtransform(XftGlyphFontSpec *, const Glyph *, int, int, int);
++
+diff --git a/st.c b/st.c
+index 3e48410..073e4c7 100644
+--- a/st.c
++++ b/st.c
+@@ -2584,8 +2584,14 @@ draw(void)
+ cx--;
+
+ drawregion(0, 0, term.col, term.row);
++ // Draw current line to format ligatures properly.
++ xdrawline(term.line[term.c.y], 0, term.c.y, term.col);
++
+ xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+ term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
++ // If cursor was on a transformed glyph, we need to redraw the previous
line
++ if (term.ocy != term.c.y && (term.line[term.ocy][term.ocx].mode &
ATTR_LIGA))
++ xdrawline(term.line[term.ocy], 0, term.ocy, term.col);
+ term.ocx = cx, term.ocy = term.c.y;
+ xfinishdraw();
+ xximspot(term.ocx, term.ocy);
+diff --git a/st.h b/st.h
+index a1928ca..07ba678 100644
+--- a/st.h
++++ b/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) & (~ATTR_LIGA)) !=
((b).mode & (~ATTR_WRAP) & (~ATTR_LIGA)) || \
++ (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)
+@@ -33,6 +34,7 @@ enum glyph_attribute {
+ ATTR_WRAP = 1 << 8,
+ ATTR_WIDE = 1 << 9,
+ ATTR_WDUMMY = 1 << 10,
++ ATTR_LIGA = 1 << 11,
+ ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
+ };
+
+diff --git a/x.c b/x.c
+index 4cf6b21..447f475 100644
+--- a/x.c
++++ b/x.c
+@@ -19,6 +19,7 @@ static char *argv0;
+ #include "arg.h"
+ #include "st.h"
+ #include "win.h"
++#include "hb.h"
+
+ /* types used in config.h */
+ typedef struct {
+@@ -1031,6 +1032,9 @@ 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);
+@@ -1229,7 +1233,7 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph
*glyphs, int len, int x
+ mode = glyphs[i].mode;
+
+ /* Skip dummy wide-character spacing. */
+- if (mode == ATTR_WDUMMY)
++ if (mode & ATTR_WDUMMY)
+ continue;
+
+ /* Determine font for glyph if different from previous glyph. */
+@@ -1336,6 +1340,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph
*glyphs, int len, int x
+ numspecs++;
+ }
+
++ // Harfbuzz transformation for ligatures.
++ hbtransform(specs, glyphs, len, x, y);
++
+ return numspecs;
+ }
+
diff --git
a/st.suckless.org/patches/ligatures/st-ligatures-alpha-scrollback-20200406-28ad288.diff
b/st.suckless.org/patches/ligatures/st-ligatures-alpha-scrollback-20200406-28ad288.diff
new file mode 100644
index 00000000..e878bde9
--- /dev/null
+++
b/st.suckless.org/patches/ligatures/st-ligatures-alpha-scrollback-20200406-28ad288.diff
@@ -0,0 +1,277 @@
+diff --git a/Makefile b/Makefile
+index 470ac86..38240da 100644
+--- a/Makefile
++++ b/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: options st
+@@ -22,7 +22,8 @@ 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
+
+ $(OBJ): config.h config.mk
+
+diff --git a/config.mk b/config.mk
+index 0cbb002..76c5c4f 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(X11INC) \
+ `$(PKG_CONFIG) --cflags fontconfig` \
+- `$(PKG_CONFIG) --cflags freetype2`
++ `$(PKG_CONFIG) --cflags freetype2` \
++ `$(PKG_CONFIG) --cflags harfbuzz`
+ LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft -lXrender \
+ `$(PKG_CONFIG) --libs fontconfig` \
+- `$(PKG_CONFIG) --libs freetype2`
++ `$(PKG_CONFIG) --libs freetype2` \
++ `$(PKG_CONFIG) --libs harfbuzz`
+
+ # flags
+ STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
+diff --git a/hb.c b/hb.c
+new file mode 100644
+index 0000000..bd3fb71
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,128 @@
++#include <stdlib.h>
++#include <stdio.h>
++#include <math.h>
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++#include "st.h"
++
++void hbtransformsegment(XftFont *xfont, const Glyph *string, hb_codepoint_t
*codepoints, int start, int length);
++hb_font_t *hbfindfont(XftFont *match);
++
++typedef struct {
++ XftFont *match;
++ hb_font_t *font;
++} HbFontMatch;
++
++static int hbfontslen = 0;
++static HbFontMatch *hbfontcache = NULL;
++
++void hbunloadfonts() {
++ for (int i = 0; i < hbfontslen; i++) {
++ hb_font_destroy(hbfontcache[i].font);
++ XftUnlockFace(hbfontcache[i].match);
++ }
++
++ if (hbfontcache != NULL) {
++ free(hbfontcache);
++ hbfontcache = NULL;
++ }
++ hbfontslen = 0;
++}
++
++hb_font_t *hbfindfont(XftFont *match) {
++ for (int i = 0; i < hbfontslen; i++) {
++ if (hbfontcache[i].match == match)
++ return hbfontcache[i].font;
++ }
++
++ // Font not found in cache, caching it now.
++ hbfontcache = realloc(hbfontcache, sizeof(HbFontMatch) * (hbfontslen +
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[hbfontslen].match = match;
++ hbfontcache[hbfontslen].font = font;
++ hbfontslen += 1;
++
++ return font;
++}
++
++void hbtransform(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int
x, int y) {
++ int start = 0, length = 1, gstart = 0;
++ hb_codepoint_t *codepoints = calloc(len, sizeof(hb_codepoint_t));
++
++ for (int idx = 1, specidx = 1; idx < len; idx++) {
++ if (glyphs[idx].mode & ATTR_WDUMMY) {
++ length += 1;
++ continue;
++ }
++
++ if (specs[specidx].font != specs[start].font ||
ATTRCMP(glyphs[gstart], glyphs[idx]) || selected(x + idx, y) != selected(x +
gstart, y)) {
++ hbtransformsegment(specs[start].font, glyphs,
codepoints, gstart, length);
++
++ // Reset the sequence.
++ length = 1;
++ start = specidx;
++ gstart = idx;
++ } else {
++ length += 1;
++ }
++
++ specidx++;
++ }
++
++ // EOL.
++ hbtransformsegment(specs[start].font, glyphs, codepoints, gstart,
length);
++
++ // Apply the transformation to glyph specs.
++ for (int i = 0, specidx = 0; i < len; i++) {
++ if (glyphs[i].mode & ATTR_WDUMMY)
++ continue;
++
++ if (codepoints[i] != specs[specidx].glyph)
++ ((Glyph *)glyphs)[i].mode |= ATTR_LIGA;
++
++ specs[specidx++].glyph = codepoints[i];
++ }
++
++ free(codepoints);
++}
++
++void hbtransformsegment(XftFont *xfont, const Glyph *string, hb_codepoint_t
*codepoints, int start, int length) {
++ hb_font_t *font = hbfindfont(xfont);
++ if (font == NULL)
++ return;
++
++ Rune rune;
++ ushort mode = USHRT_MAX;
++ hb_buffer_t *buffer = hb_buffer_create();
++ hb_buffer_set_direction(buffer, HB_DIRECTION_LTR);
++
++ // Fill buffer with codepoints.
++ for (int i = start; i < (start+length); i++) {
++ rune = string[i].u;
++ mode = string[i].mode;
++ if (mode & ATTR_WDUMMY)
++ rune = 0x0020;
++ hb_buffer_add_codepoints(buffer, &rune, 1, 0, 1);
++ }
++
++ // Shape the segment.
++ hb_shape(font, buffer, NULL, 0);
++
++ // Get new glyph info.
++ hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, NULL);
++
++ // Write new codepoints.
++ for (int i = 0; i < length; i++) {
++ hb_codepoint_t gid = info[i].codepoint;
++ codepoints[start+i] = gid;
++ }
++
++ // Cleanup.
++ hb_buffer_destroy(buffer);
++}
+diff --git a/hb.h b/hb.h
+new file mode 100644
+index 0000000..4505444
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,7 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++void hbunloadfonts();
++void hbtransform(XftGlyphFontSpec *, const Glyph *, int, int, int);
++
+diff --git a/st.c b/st.c
+index 130bf22..07b2f3b 100644
+--- a/st.c
++++ b/st.c
+@@ -2652,9 +2652,17 @@ draw(void)
+ cx--;
+
+ drawregion(0, 0, term.col, term.row);
+- if (term.scr == 0)
+- xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+- term.ocx, term.ocy,
term.line[term.ocy][term.ocx]);
++ if (term.scr == 0) {
++ // Draw current line to format ligatures properly.
++ xdrawline(term.line[term.c.y], 0, term.c.y, term.col);
++
++ xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
++ term.ocx, term.ocy,
term.line[term.ocy][term.ocx]);
++
++ // If cursor was on a transformed glyph, we need to redraw the
previous line
++ if (term.ocy != term.c.y && (term.line[term.ocy][term.ocx].mode
& ATTR_LIGA))
++ xdrawline(term.line[term.ocy], 0, term.ocy, term.col);
++ }
+ term.ocx = cx, term.ocy = term.c.y;
+ xfinishdraw();
+ xximspot(term.ocx, term.ocy);
+diff --git a/st.h b/st.h
+index 1332cf1..6b5218d 100644
+--- a/st.h
++++ b/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) & (~ATTR_LIGA)) !=
((b).mode & (~ATTR_WRAP) & (~ATTR_LIGA)) || \
++ (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)
+@@ -33,6 +34,7 @@ enum glyph_attribute {
+ ATTR_WRAP = 1 << 8,
+ ATTR_WIDE = 1 << 9,
+ ATTR_WDUMMY = 1 << 10,
++ ATTR_LIGA = 1 << 11,
+ ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
+ };
+
+diff --git a/x.c b/x.c
+index 4cf6b21..f6b09da 100644
+--- a/x.c
++++ b/x.c
+@@ -19,6 +19,7 @@ static char *argv0;
+ #include "arg.h"
+ #include "st.h"
+ #include "win.h"
++#include "hb.h"
+
+ /* types used in config.h */
+ typedef struct {
+@@ -1031,6 +1032,9 @@ 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);
+@@ -1229,7 +1233,7 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph
*glyphs, int len, int x
+ mode = glyphs[i].mode;
+
+ /* Skip dummy wide-character spacing. */
+- if (mode == ATTR_WDUMMY)
++ if (mode & ATTR_WDUMMY)
+ continue;
+
+ /* Determine font for glyph if different from previous glyph. */
+@@ -1336,6 +1340,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph
*glyphs, int len, int x
+ numspecs++;
+ }
+
++ // Harfbuzz transformation for ligatures.
++ hbtransform(specs, glyphs, len, x, y);
++
+ return numspecs;
+ }
+
diff --git
a/st.suckless.org/patches/ligatures/st-ligatures-boxdraw-20200407-28ad288.diff
b/st.suckless.org/patches/ligatures/st-ligatures-boxdraw-20200407-28ad288.diff
new file mode 100644
index 00000000..86d8e8b1
--- /dev/null
+++
b/st.suckless.org/patches/ligatures/st-ligatures-boxdraw-20200407-28ad288.diff
@@ -0,0 +1,276 @@
+diff --git a/Makefile b/Makefile
+index 470ac86..38240da 100644
+--- a/Makefile
++++ b/Makefile
+@@ -4,7 +4,7 @@
+
+ include config.mk
+
+-SRC = st.c x.c boxdraw.c
++SRC = st.c x.c boxdraw.c hb.c
+ OBJ = $(SRC:.c=.o)
+
+ all: options st
+@@ -22,7 +22,8 @@ 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
+ boxdraw.o: config.h st.h boxdraw_data.h
+
+ $(OBJ): config.h config.mk
+diff --git a/config.mk b/config.mk
+index 0cbb002..76c5c4f 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(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
+diff --git a/hb.c b/hb.c
+new file mode 100644
+index 0000000..bb0bea8
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,132 @@
++#include <stdlib.h>
++#include <stdio.h>
++#include <math.h>
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++#include "st.h"
++
++void hbtransformsegment(XftFont *xfont, const Glyph *string, hb_codepoint_t
*codepoints, int start, int length);
++hb_font_t *hbfindfont(XftFont *match);
++
++typedef struct {
++ XftFont *match;
++ hb_font_t *font;
++} HbFontMatch;
++
++static int hbfontslen = 0;
++static HbFontMatch *hbfontcache = NULL;
++
++void hbunloadfonts() {
++ for (int i = 0; i < hbfontslen; i++) {
++ hb_font_destroy(hbfontcache[i].font);
++ XftUnlockFace(hbfontcache[i].match);
++ }
++
++ if (hbfontcache != NULL) {
++ free(hbfontcache);
++ hbfontcache = NULL;
++ }
++ hbfontslen = 0;
++}
++
++hb_font_t *hbfindfont(XftFont *match) {
++ for (int i = 0; i < hbfontslen; i++) {
++ if (hbfontcache[i].match == match)
++ return hbfontcache[i].font;
++ }
++
++ // Font not found in cache, caching it now.
++ hbfontcache = realloc(hbfontcache, sizeof(HbFontMatch) * (hbfontslen +
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[hbfontslen].match = match;
++ hbfontcache[hbfontslen].font = font;
++ hbfontslen += 1;
++
++ return font;
++}
++
++void hbtransform(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int
x, int y) {
++ int start = 0, length = 1, gstart = 0;
++ hb_codepoint_t *codepoints = calloc(len, sizeof(hb_codepoint_t));
++
++ for (int idx = 1, specidx = 1; idx < len; idx++) {
++ if (glyphs[idx].mode & ATTR_WDUMMY) {
++ length += 1;
++ continue;
++ }
++
++ if (specs[specidx].font != specs[start].font ||
ATTRCMP(glyphs[gstart], glyphs[idx]) || selected(x + idx, y) != selected(x +
gstart, y)) {
++ hbtransformsegment(specs[start].font, glyphs,
codepoints, gstart, length);
++
++ // Reset the sequence.
++ length = 1;
++ start = specidx;
++ gstart = idx;
++ } else {
++ length += 1;
++ }
++
++ specidx++;
++ }
++
++ // EOL.
++ hbtransformsegment(specs[start].font, glyphs, codepoints, gstart,
length);
++
++ // Apply the transformation to glyph specs.
++ for (int i = 0, specidx = 0; i < len; i++) {
++ if (glyphs[i].mode & ATTR_WDUMMY)
++ continue;
++ if (glyphs[i].mode & ATTR_BOXDRAW) {
++ specidx++;
++ continue;
++ }
++
++ if (codepoints[i] != specs[specidx].glyph)
++ ((Glyph *)glyphs)[i].mode |= ATTR_LIGA;
++
++ specs[specidx++].glyph = codepoints[i];
++ }
++
++ free(codepoints);
++}
++
++void hbtransformsegment(XftFont *xfont, const Glyph *string, hb_codepoint_t
*codepoints, int start, int length) {
++ hb_font_t *font = hbfindfont(xfont);
++ if (font == NULL)
++ return;
++
++ Rune rune;
++ ushort mode = USHRT_MAX;
++ hb_buffer_t *buffer = hb_buffer_create();
++ hb_buffer_set_direction(buffer, HB_DIRECTION_LTR);
++
++ // Fill buffer with codepoints.
++ for (int i = start; i < (start+length); i++) {
++ rune = string[i].u;
++ mode = string[i].mode;
++ if (mode & ATTR_WDUMMY)
++ rune = 0x0020;
++ hb_buffer_add_codepoints(buffer, &rune, 1, 0, 1);
++ }
++
++ // Shape the segment.
++ hb_shape(font, buffer, NULL, 0);
++
++ // Get new glyph info.
++ hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, NULL);
++
++ // Write new codepoints.
++ for (int i = 0; i < length; i++) {
++ hb_codepoint_t gid = info[i].codepoint;
++ codepoints[start+i] = gid;
++ }
++
++ // Cleanup.
++ hb_buffer_destroy(buffer);
++}
+diff --git a/hb.h b/hb.h
+new file mode 100644
+index 0000000..a209238
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,7 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++void hbunloadfonts();
++void hbtransform(XftGlyphFontSpec *, const Glyph *, int, int, int);
++
+diff --git a/st.c b/st.c
+index 3e48410..073e4c7 100644
+--- a/st.c
++++ b/st.c
+@@ -2584,8 +2584,14 @@ draw(void)
+ cx--;
+
+ drawregion(0, 0, term.col, term.row);
++ // Draw current line to format ligatures properly.
++ xdrawline(term.line[term.c.y], 0, term.c.y, term.col);
++
+ xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+ term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
++ // If cursor was on a transformed glyph, we need to redraw the previous
line
++ if (term.ocy != term.c.y && (term.line[term.ocy][term.ocx].mode &
ATTR_LIGA))
++ xdrawline(term.line[term.ocy], 0, term.ocy, term.col);
+ term.ocx = cx, term.ocy = term.c.y;
+ xfinishdraw();
+ xximspot(term.ocx, term.ocy);
+diff --git a/st.h b/st.h
+index a1928ca..07ba678 100644
+--- a/st.h
++++ b/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) & (~ATTR_LIGA)) !=
((b).mode & (~ATTR_WRAP) & (~ATTR_LIGA)) || \
++ (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)
+@@ -33,6 +34,7 @@ enum glyph_attribute {
+ ATTR_WRAP = 1 << 8,
+ ATTR_WIDE = 1 << 9,
+ ATTR_WDUMMY = 1 << 10,
+ ATTR_BOXDRAW = 1 << 11,
++ ATTR_LIGA = 1 << 12,
+ ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
+ };
+
+diff --git a/x.c b/x.c
+index 4cf6b21..447f475 100644
+--- a/x.c
++++ b/x.c
+@@ -19,6 +19,7 @@ static char *argv0;
+ #include "arg.h"
+ #include "st.h"
+ #include "win.h"
++#include "hb.h"
+
+ /* types used in config.h */
+ typedef struct {
+@@ -1031,6 +1032,9 @@ 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);
+@@ -1229,7 +1233,7 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph
*glyphs, int len, int x
+ mode = glyphs[i].mode;
+
+ /* Skip dummy wide-character spacing. */
+- if (mode == ATTR_WDUMMY)
++ if (mode & ATTR_WDUMMY)
+ continue;
+
+ /* Determine font for glyph if different from previous glyph. */
+@@ -1336,6 +1340,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph
*glyphs, int len, int x
+ numspecs++;
+ }
+
++ // Harfbuzz transformation for ligatures.
++ hbtransform(specs, glyphs, len, x, y);
++
+ return numspecs;
+ }
+
diff --git
a/st.suckless.org/patches/ligatures/st-ligatures-scrollback-20200405-28ad288.diff
b/st.suckless.org/patches/ligatures/st-ligatures-scrollback-20200406-28ad288.diff
similarity index 97%
rename from
st.suckless.org/patches/ligatures/st-ligatures-scrollback-20200405-28ad288.diff
rename to
st.suckless.org/patches/ligatures/st-ligatures-scrollback-20200406-28ad288.diff
index 815df913..439b63c8 100644
---
a/st.suckless.org/patches/ligatures/st-ligatures-scrollback-20200405-28ad288.diff
+++
b/st.suckless.org/patches/ligatures/st-ligatures-scrollback-20200406-28ad288.diff
@@ -31,12 +31,12 @@ index 0cbb002..76c5c4f 100644
`$(PKG_CONFIG) --cflags fontconfig` \
- `$(PKG_CONFIG) --cflags freetype2`
+ `$(PKG_CONFIG) --cflags freetype2` \
-+ `$(PKG_CONFIG) --cflags harfbuzz`
++ `$(PKG_CONFIG) --cflags harfbuzz`
LIBS = -L$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
`$(PKG_CONFIG) --libs fontconfig` \
- `$(PKG_CONFIG) --libs freetype2`
+ `$(PKG_CONFIG) --libs freetype2` \
-+ `$(PKG_CONFIG) --libs harfbuzz`
++ `$(PKG_CONFIG) --libs harfbuzz`
# flags
STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
@@ -45,7 +45,7 @@ new file mode 100644
index 0000000..bd3fb71
--- /dev/null
+++ b/hb.c
-@@ -0,0 +1,127 @@
+@@ -0,0 +1,128 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
@@ -67,8 +67,10 @@ index 0000000..bd3fb71
+static HbFontMatch *hbfontcache = NULL;
+
+void hbunloadfonts() {
-+ for (int i = 0; i < hbfontslen; i++)
++ for (int i = 0; i < hbfontslen; i++) {
+ hb_font_destroy(hbfontcache[i].font);
++ XftUnlockFace(hbfontcache[i].match);
++ }
+
+ if (hbfontcache != NULL) {
+ free(hbfontcache);
@@ -89,7 +91,6 @@ index 0000000..bd3fb71
+ hb_font_t *font = hb_ft_font_create(face, NULL);
+ if (font == NULL)
+ die("Failed to load Harfbuzz font.");
-+ XftUnlockFace(match);
+
+ hbfontcache[hbfontslen].match = match;
+ hbfontcache[hbfontslen].font = font;
