replacing ligatures+scrollback patch w +boxdraw and applying said patch(previous one gave errors even on manual patching w 0 errors)

13 files changed, 211 insertions, 34 deletions

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
 
 $(OBJ): config.h config.mk
diff --git a/config.mk b/config.mk
index ddf278a..49ede7e 100644
--- a/config.mk
+++ b/config.mk
@@ -15,10 +15,12 @@ PKG_CONFIG = pkg-config
 # includes and libs
 INCS = -I$(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..bc204d8
--- /dev/null
+++ b/hb.c
@@ -0,0 +1,149 @@
+#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;
+
+/*
+ * Poplulate the array with a list of font features, wrapped in FEATURE macro,
+ * e. g.
+ * FEATURE('c', 'a', 'l', 't'), FEATURE('d', 'l', 'i', 'g')
+ */
+hb_feature_t features[] = { };
+
+void
+hbunloadfonts()
+{
+	for (int i = 0; i < 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)/sizeof(hb_feature_t));
+
+	/* 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/hb.o b/hb.o
new file mode 100644
index 0000000..bafc199
--- /dev/null
+++ b/hb.o
diff --git a/patches/11th-ligatures-scrollback-20210824-0.8.4.diff b/patches/11th-st-ligatures-boxdraw-20210824-0.8.4.diff
index 94e842a..bc14536 100644
--- a/patches/11th-ligatures-scrollback-20210824-0.8.4.diff
+++ b/patches/11th-st-ligatures-boxdraw-20210824-0.8.4.diff
@@ -1,13 +1,13 @@
 diff --git a/Makefile b/Makefile
-index 470ac86..38240da 100644
+index 6dfa212..2ffd3c8 100644
 --- a/Makefile
 +++ b/Makefile
 @@ -4,7 +4,7 @@
  
  include config.mk
  
--SRC = st.c x.c
-+SRC = st.c x.c hb.c
+-SRC = st.c x.c boxdraw.c
++SRC = st.c x.c boxdraw.c hb.c
  OBJ = $(SRC:.c=.o)
  
  all: options st
@@ -18,9 +18,9 @@ index 470ac86..38240da 100644
 -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
  
  $(OBJ): config.h config.mk
- 
 diff --git a/config.mk b/config.mk
 index c070a4a..3d236f0 100644
 --- a/config.mk
@@ -42,10 +42,10 @@ index c070a4a..3d236f0 100644
  STCPPFLAGS = -DVERSION=\"$(VERSION)\" -D_XOPEN_SOURCE=600
 diff --git a/hb.c b/hb.c
 new file mode 100644
-index 0000000..f9c4f76
+index 0000000..a47300e
 --- /dev/null
 +++ b/hb.c
-@@ -0,0 +1,144 @@
+@@ -0,0 +1,149 @@
 +#include <stdlib.h>
 +#include <stdio.h>
 +#include <math.h>
@@ -69,10 +69,11 @@ index 0000000..f9c4f76
 +static HbFontMatch *hbfontcache = NULL;
 +
 +/*
-+ * Replace 0 with a list of font features, wrapped in FEATURE macro, e.g.
++ * Poplulate the array with a list of font features, wrapped in FEATURE macro,
++ * e. g.
 + * FEATURE('c', 'a', 'l', 't'), FEATURE('d', 'l', 'i', 'g')
 + */
-+hb_feature_t features[] = { 0 };
++hb_feature_t features[] = { };
 +
 +void
 +hbunloadfonts()
@@ -144,6 +145,10 @@ index 0000000..f9c4f76
 +	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;
@@ -176,7 +181,7 @@ index 0000000..f9c4f76
 +	}
 +
 +	/* Shape the segment. */
-+	hb_shape(font, buffer, features, sizeof(features));
++	hb_shape(font, buffer, features, sizeof(features)/sizeof(hb_feature_t));
 +
 +	/* Get new glyph info. */
 +	hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, NULL);
@@ -203,21 +208,21 @@ index 0000000..07888df
 +void hbunloadfonts();
 +void hbtransform(XftGlyphFontSpec *, const Glyph *, size_t, int, int);
 diff --git a/st.c b/st.c
-index edec064..ea13c13 100644
+index 248728f..9101ae8 100644
 --- a/st.c
 +++ b/st.c
-@@ -2652,7 +2652,8 @@ draw(void)
+@@ -2584,7 +2584,8 @@ 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);
+ 	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
+index 8d26273..133dc08 100644
 --- a/st.h
 +++ b/st.h
 @@ -11,7 +11,8 @@
@@ -230,11 +235,11 @@ index f44e1d3..00c796c 100644
  				(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,
+@@ -34,6 +35,7 @@ enum glyph_attribute {
  	ATTR_WIDE       = 1 << 9,
  	ATTR_WDUMMY     = 1 << 10,
-+	ATTR_LIGA       = 1 << 11,
+ 	ATTR_BOXDRAW    = 1 << 11,
++	ATTR_LIGA       = 1 << 12,
  	ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
  };
  
@@ -252,7 +257,7 @@ index a6ef1b9..bc0d180 100644
  void xfinishdraw(void);
  void xloadcols(void);
 diff --git a/x.c b/x.c
-index 210f184..f6d67ef 100644
+index 9b29264..af93cad 100644
 --- a/x.c
 +++ b/x.c
 @@ -19,6 +19,7 @@ char *argv0;
@@ -273,7 +278,7 @@ index 210f184..f6d67ef 100644
  	/* 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
+@@ -1231,7 +1235,7 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
  		mode = glyphs[i].mode;
  
  		/* Skip dummy wide-character spacing. */
@@ -282,7 +287,7 @@ index 210f184..f6d67ef 100644
  			continue;
  
  		/* Determine font for glyph if different from previous glyph. */
-@@ -1336,6 +1340,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
+@@ -1343,6 +1347,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
  		numspecs++;
  	}
  
@@ -292,7 +297,7 @@ index 210f184..f6d67ef 100644
  	return numspecs;
  }
  
-@@ -1485,14 +1492,17 @@ xdrawglyph(Glyph g, int x, int y)
+@@ -1496,14 +1503,17 @@ xdrawglyph(Glyph g, int x, int y)
  }
  
  void
diff --git a/st b/st
index 6216640..5e6fe9d 100755
--- a/st
+++ b/st
diff --git a/st.c b/st.c
index 4f015ed..7d125fd 100644
--- a/st.c
+++ b/st.c
@@ -2714,7 +2714,8 @@ 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 7185544..b5bf895 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/st.o b/st.o
index 3a7884a..dd92628 100644
--- a/st.o
+++ b/st.o
diff --git a/win.h b/win.h
index 6de960d..94679e4 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 0a7a7dc..d312037 100644
--- a/x.c
+++ b/x.c
@@ -20,6 +20,7 @@ char *argv0;
 #include "arg.h"
 #include "st.h"
 #include "win.h"
+#include "hb.h"
 
 /* types used in config.h */
 typedef struct {
@@ -1180,6 +1181,9 @@ 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);
@@ -1382,7 +1386,7 @@ 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. */
@@ -1494,6 +1498,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
 		numspecs++;
 	}
 
+	/* Harfbuzz transformation for ligatures. */
+	hbtransform(specs, glyphs, len, x, y);
+
 	return numspecs;
 }
 
@@ -1663,7 +1670,7 @@ 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;
 	XRenderColor colbg;
@@ -1671,7 +1678,11 @@ xdrawcursor(int cx, int cy, Glyph g, int ox, int oy, Glyph og)
 	/* 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/x.o b/x.o
index 64dd5b1..2279b06 100644
--- a/x.o
+++ b/x.o