commit 4f5468706f3c72a94df41670fda3eb1ee53158f4
parent 73fa348f121e8f9856b4dee9a095937e6c79cdea
Author: Alexander Rogachev <sorryforbadname@gmail.com>
Date: Fri, 27 Aug 2021 20:27:08 +0300
[wiki][patch][st][ligatures] Update for st 0.8.4.
* New patch versions compatible with 0.8.4 release.
* Added an option to enable additional font features.
* Fixed compiler warning at call to calloc with '-O3 -flto'.
Diffstat:
6 files changed, 1583 insertions(+), 0 deletions(-)
diff --git a/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-20210824-0.8.4.diff b/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-20210824-0.8.4.diff
@@ -0,0 +1,315 @@
+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
+
+ $(OBJ): config.h config.mk
+
+diff --git a/config.mk b/config.mk
+index c070a4a..3d236f0 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(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..6389e95
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,145 @@
++#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"
++
++#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 }
++
++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;
++
++/*
++ * Replace 0 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[] = { 0 };
++
++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, size_t len, int x, int y)
++{
++ int start = 0, length = 1, gstart = 0;
++ hb_codepoint_t *codepoints = calloc((unsigned int)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, features, sizeof(features));
++
++ /* 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..07888df
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,6 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++void hbunloadfonts();
++void hbtransform(XftGlyphFontSpec *, const Glyph *, size_t, int, int);
+diff --git a/st.c b/st.c
+index 76b7e0d..e60bf58 100644
+--- a/st.c
++++ b/st.c
+@@ -2581,7 +2581,8 @@ draw(void)
+
+ 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]);
++ term.ocx, term.ocy, term.line[term.ocy][term.ocx],
++ term.line[term.ocy], term.col);
+ term.ocx = cx;
+ term.ocy = term.c.y;
+ xfinishdraw();
+diff --git a/st.h b/st.h
+index 3d351b6..06b115d 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/win.h b/win.h
+index a6ef1b9..bc0d180 100644
+--- a/win.h
++++ b/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);
+diff --git a/x.c b/x.c
+index 210f184..f6d67ef 100644
+--- a/x.c
++++ b/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 {
+@@ -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;
+ }
+
+@@ -1485,14 +1492,17 @@ xdrawglyph(Glyph g, int x, int y)
+ }
+
+ 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;
diff --git a/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-alpha-20210824-0.8.4.diff b/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-alpha-20210824-0.8.4.diff
@@ -0,0 +1,314 @@
+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
+
+ $(OBJ): config.h config.mk
+
+diff --git a/config.mk b/config.mk
+index aaa54ff..1741840 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(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..f9c4f76
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,144 @@
++#include <stdlib.h>
++#include <stdio.h>
++#include <math.h>
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++#include "st.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 }
++
++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;
++
++/*
++ * Replace 0 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[] = { 0 };
++
++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, size_t len, int x, int y)
++{
++ int start = 0, length = 1, gstart = 0;
++ hb_codepoint_t *codepoints = calloc((unsigned int)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, features, sizeof(features));
++
++ /* 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..07888df
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,6 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++void hbunloadfonts();
++void hbtransform(XftGlyphFontSpec *, const Glyph *, size_t, int, int);
+diff --git a/st.c b/st.c
+index 76b7e0d..e60bf58 100644
+--- a/st.c
++++ b/st.c
+@@ -2581,7 +2581,8 @@ draw(void)
+
+ 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]);
++ term.ocx, term.ocy, term.line[term.ocy][term.ocx],
++ term.line[term.ocy], term.col);
+ term.ocx = cx;
+ term.ocy = term.c.y;
+ xfinishdraw();
+diff --git a/st.h b/st.h
+index 9f11a6a..4b72307 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/win.h b/win.h
+index a6ef1b9..bc0d180 100644
+--- a/win.h
++++ b/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);
+diff --git a/x.c b/x.c
+index 73545d8..9e980e3 100644
+--- a/x.c
++++ b/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 {
+@@ -1040,6 +1041,9 @@ 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);
+@@ -1246,7 +1250,7 @@ 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. */
+@@ -1353,6 +1357,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
+ numspecs++;
+ }
+
++ /* Harfbuzz transformation for ligatures. */
++ hbtransform(specs, glyphs, len, x, y);
++
+ return numspecs;
+ }
+
+@@ -1502,14 +1509,17 @@ xdrawglyph(Glyph g, int x, int y)
+ }
+
+ 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;
diff --git a/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-alpha-scrollback-20210824-0.8.4.diff b/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-alpha-scrollback-20210824-0.8.4.diff
@@ -0,0 +1,314 @@
+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
+
+ $(OBJ): config.h config.mk
+
+diff --git a/config.mk b/config.mk
+index aaa54ff..1741840 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(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..f9c4f76
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,144 @@
++#include <stdlib.h>
++#include <stdio.h>
++#include <math.h>
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++#include "st.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 }
++
++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;
++
++/*
++ * Replace 0 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[] = { 0 };
++
++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, size_t len, int x, int y)
++{
++ int start = 0, length = 1, gstart = 0;
++ hb_codepoint_t *codepoints = calloc((unsigned int)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, features, sizeof(features));
++
++ /* 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..07888df
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,6 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++void hbunloadfonts();
++void hbtransform(XftGlyphFontSpec *, const Glyph *, size_t, int, int);
+diff --git a/st.c b/st.c
+index edec064..ea13c13 100644
+--- a/st.c
++++ b/st.c
+@@ -2652,7 +2652,8 @@ draw(void)
+ 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]);
++ term.ocx, term.ocy, term.line[term.ocy][term.ocx],
++ term.line[term.ocy], term.col);
+ term.ocx = cx;
+ term.ocy = term.c.y;
+ xfinishdraw();
+diff --git a/st.h b/st.h
+index 7ea2fd3..089b92d 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/win.h b/win.h
+index a6ef1b9..bc0d180 100644
+--- a/win.h
++++ b/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);
+diff --git a/x.c b/x.c
+index 73545d8..9e980e3 100644
+--- a/x.c
++++ b/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 {
+@@ -1040,6 +1041,9 @@ 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);
+@@ -1246,7 +1250,7 @@ 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. */
+@@ -1353,6 +1357,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
+ numspecs++;
+ }
+
++ /* Harfbuzz transformation for ligatures. */
++ hbtransform(specs, glyphs, len, x, y);
++
+ return numspecs;
+ }
+
+@@ -1502,14 +1509,17 @@ xdrawglyph(Glyph g, int x, int y)
+ }
+
+ 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;
diff --git a/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-boxdraw-20210824-0.8.4.diff b/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-boxdraw-20210824-0.8.4.diff
@@ -0,0 +1,318 @@
+diff --git a/Makefile b/Makefile
+index 6dfa212..2ffd3c8 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
+
+ $(OBJ): config.h config.mk
+diff --git a/config.mk b/config.mk
+index c070a4a..3d236f0 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(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..a47300e
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,148 @@
++#include <stdlib.h>
++#include <stdio.h>
++#include <math.h>
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++#include "st.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 }
++
++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;
++
++/*
++ * Replace 0 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[] = { 0 };
++
++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, size_t len, int x, int y)
++{
++ int start = 0, length = 1, gstart = 0;
++ hb_codepoint_t *codepoints = calloc((unsigned int)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, features, sizeof(features));
++
++ /* 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..07888df
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,6 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++void hbunloadfonts();
++void hbtransform(XftGlyphFontSpec *, const Glyph *, size_t, int, int);
+diff --git a/st.c b/st.c
+index 248728f..9101ae8 100644
+--- a/st.c
++++ b/st.c
+@@ -2584,7 +2584,8 @@ draw(void)
+
+ 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]);
++ term.ocx, term.ocy, term.line[term.ocy][term.ocx],
++ term.line[term.ocy], term.col);
+ term.ocx = cx;
+ term.ocy = term.c.y;
+ xfinishdraw();
+diff --git a/st.h b/st.h
+index 8d26273..133dc08 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)
+@@ -34,6 +35,7 @@ enum glyph_attribute {
+ 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/win.h b/win.h
+index a6ef1b9..bc0d180 100644
+--- a/win.h
++++ b/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);
+diff --git a/x.c b/x.c
+index 9b29264..af93cad 100644
+--- a/x.c
++++ b/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 {
+@@ -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);
+@@ -1231,7 +1235,7 @@ 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. */
+@@ -1343,6 +1347,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
+ numspecs++;
+ }
+
++ /* Harfbuzz transformation for ligatures. */
++ hbtransform(specs, glyphs, len, x, y);
++
+ return numspecs;
+ }
+
+@@ -1496,14 +1503,17 @@ xdrawglyph(Glyph g, int x, int y)
+ }
+
+ 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;
diff --git a/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-scrollback-20210824-0.8.4.diff b/st.suckless.org/patches/ligatures/0.8.4/st-ligatures-scrollback-20210824-0.8.4.diff
@@ -0,0 +1,314 @@
+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
+
+ $(OBJ): config.h config.mk
+
+diff --git a/config.mk b/config.mk
+index c070a4a..3d236f0 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(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..f9c4f76
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,144 @@
++#include <stdlib.h>
++#include <stdio.h>
++#include <math.h>
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++#include "st.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 }
++
++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;
++
++/*
++ * Replace 0 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[] = { 0 };
++
++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, size_t len, int x, int y)
++{
++ int start = 0, length = 1, gstart = 0;
++ hb_codepoint_t *codepoints = calloc((unsigned int)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, features, sizeof(features));
++
++ /* 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..07888df
+--- /dev/null
++++ b/hb.h
+@@ -0,0 +1,6 @@
++#include <X11/Xft/Xft.h>
++#include <hb.h>
++#include <hb-ft.h>
++
++void hbunloadfonts();
++void hbtransform(XftGlyphFontSpec *, const Glyph *, size_t, int, int);
+diff --git a/st.c b/st.c
+index edec064..ea13c13 100644
+--- a/st.c
++++ b/st.c
+@@ -2652,7 +2652,8 @@ draw(void)
+ 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]);
++ term.ocx, term.ocy, term.line[term.ocy][term.ocx],
++ term.line[term.ocy], term.col);
+ term.ocx = cx;
+ term.ocy = term.c.y;
+ xfinishdraw();
+diff --git a/st.h b/st.h
+index f44e1d3..00c796c 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/win.h b/win.h
+index a6ef1b9..bc0d180 100644
+--- a/win.h
++++ b/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);
+diff --git a/x.c b/x.c
+index 210f184..f6d67ef 100644
+--- a/x.c
++++ b/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 {
+@@ -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;
+ }
+
+@@ -1485,14 +1492,17 @@ xdrawglyph(Glyph g, int x, int y)
+ }
+
+ 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;
diff --git a/st.suckless.org/patches/ligatures/index.md b/st.suckless.org/patches/ligatures/index.md
@@ -18,6 +18,7 @@ Notes
* The patch adds additional dependency on Harfbuzz library and headers.
* Original patch was made for vanilla version of ST from latest master commit. It is not 100% compatible with Scrollback and Alpha patches, so I made 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.
+* Since 0.8.4 patch, there's now a way to enable additional font rendering features. Look into `features` array in `hb.c` for details.
Boxdraw
-------
@@ -26,6 +27,13 @@ Boxdraw
Download
--------
+**0.8.4**:
+* [st-ligatures-0.8.4](0.8.4/st-ligatures-20210824-0.8.4.diff)
+* [st-ligatures-scrollback-0.8.4](0.8.4/st-ligatures-scrollback-20210824-0.8.4.diff)
+* [st-ligatures-alpha-0.8.4](0.8.4/st-ligatures-alpha-20210824-0.8.4.diff)
+* [st-ligatures-alpha-scrollback-0.8.4](0.8.4/st-ligatures-alpha-scrollback-20210824-0.8.4.diff)
+* [st-ligatures-boxdraw-0.8.4](0.8.4/st-ligatures-boxdraw-20210824-0.8.4.diff)
+
**0.8.3**:
* [st-ligatures-0.8.3](0.8.3/st-ligatures-20200430-0.8.3.diff)
* [st-ligatures-scrollback-0.8.3](0.8.3/st-ligatures-scrollback-20200430-0.8.3.diff)
