commit ffe921a73bc23ff07321631bd0f4be4def97ffe4
parent a04453e1046155148dcd2c2c5fe94c844ec57377
Author: Alexander Rogachev <sorryforbadname@gmail.com>
Date: Thu, 30 Apr 2020 00:02:36 +0300
[st][ligatures] Improved and simplified ligature drawing logic, removed excessive redraws.
Diffstat:
10 files changed, 1540 insertions(+), 1412 deletions(-)
diff --git a/st.suckless.org/patches/ligatures/st-ligatures-20200406-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-20200406-28ad288.diff
@@ -1,279 +0,0 @@
-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$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
- `$(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 +1,136 @@
-+#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, size_t 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 *, size_t, 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-20200428-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-20200428-28ad288.diff
@@ -0,0 +1,307 @@
+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
+
+ $(OBJ): config.h config.mk
+
+diff --git a/config.mk b/config.mk
+index 0cbb002..a021b2c 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(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..7df2828
+--- /dev/null
++++ b/hb.c
+@@ -0,0 +1,136 @@
++#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, size_t 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..b3e02d0
+--- /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 *, size_t, int, int);
++
+diff --git a/st.c b/st.c
+index 3e48410..e5064d6 100644
+--- a/st.c
++++ b/st.c
+@@ -2585,7 +2585,8 @@ 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();
+ 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/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 4cf6b21..410994d 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;
+ }
+
+@@ -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/st-ligatures-alpha-20200406-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-alpha-20200406-28ad288.diff
@@ -1,279 +0,0 @@
-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 +1,136 @@
-+#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, size_t 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 *, size_t, 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-20200428-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-alpha-20200428-28ad288.diff
@@ -0,0 +1,307 @@
+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 +1,136 @@
++#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, size_t 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 *, size_t, int, int);
++
+diff --git a/st.c b/st.c
+index 3e48410..e5064d6 100644
+--- a/st.c
++++ b/st.c
+@@ -2585,7 +2585,8 @@ 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();
+ 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/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 4cf6b21..410994d 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;
+ }
+
+@@ -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/st-ligatures-alpha-scrollback-20200406-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-alpha-scrollback-20200406-28ad288.diff
@@ -1,285 +0,0 @@
-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 +1,136 @@
-+#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, size_t 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 *, size_t, 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-alpha-scrollback-20200428-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-alpha-scrollback-20200428-28ad288.diff
@@ -0,0 +1,307 @@
+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
+
+ $(OBJ): config.h config.mk
+
+diff --git a/config.mk b/config.mk
+index 1d2f0e2..fd92921 100644
+--- a/config.mk
++++ b/config.mk
+@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
+ # includes and libs
+ INCS = -I$(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 +1,136 @@
++#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, size_t 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 *, size_t, int, int);
++
+diff --git a/st.c b/st.c
+index f8b6f67..a6c3ee7 100644
+--- a/st.c
++++ b/st.c
+@@ -2656,7 +2656,8 @@ 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();
+ xximspot(term.ocx, term.ocy);
+diff --git a/st.h b/st.h
+index c67ebc3..073ae82 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 139f7ff..eaf764f 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 {
+@@ -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/st-ligatures-boxdraw-20200407-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-boxdraw-20200407-28ad288.diff
@@ -1,284 +0,0 @@
-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 +1,140 @@
-+#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, size_t 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 *, size_t, 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-boxdraw-20200428-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-boxdraw-20200428-28ad288.diff
@@ -0,0 +1,312 @@
+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 +1,140 @@
++#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, size_t 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 *, size_t, int, int);
++
+diff --git a/st.c b/st.c
+index 3e48410..e5064d6 100644
+--- a/st.c
++++ b/st.c
+@@ -2585,7 +2585,8 @@ 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();
+ 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/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 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;
+ }
+
+@@ -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/st-ligatures-scrollback-20200406-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-scrollback-20200406-28ad288.diff
@@ -1,285 +0,0 @@
-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$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
- `$(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 +1,136 @@
-+#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, size_t 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 *, size_t, 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-scrollback-20200428-28ad288.diff b/st.suckless.org/patches/ligatures/st-ligatures-scrollback-20200428-28ad288.diff
@@ -0,0 +1,307 @@
+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$(X11LIB) -lm -lrt -lX11 -lutil -lXft \
+ `$(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 +1,136 @@
++#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, size_t 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 *, size_t, int, int);
++
+diff --git a/st.c b/st.c
+index f8b6f67..a6c3ee7 100644
+--- a/st.c
++++ b/st.c
+@@ -2656,7 +2656,8 @@ 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();
+ xximspot(term.ocx, term.ocy);
+diff --git a/st.h b/st.h
+index c67ebc3..073ae82 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 4cf6b21..410994d 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;
+ }
+
+@@ -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;
