Apply ligatures patch

diff --git a/Makefile b/Makefile
index 470ac86407bbd2876e3ee997e04e57649b51da9f..38240da745340dc0beac7f518deb206ab3d4b852 100644 (file)
--- 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 c070a4ac49d199e4e2525bd11fc528f3a3422571..3d236f0a2dbd217689010df2a3ecc6010e0fb113 100644 (file)
--- 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 (file)
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 (file)
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 ebdf3609b6a8eb6605791a91894868175b0ecc86..01fe0aa7f2c8a3a3584f1a1ec08caaef054b16bf 100644 (file)
--- a/st.c
+++ b/st.c
@@ -2591,7 +2591,8 @@ draw(void)
 
        drawregion(0, 0, term.col, term.row);
        xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
-                       term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
+                       term.ocx, term.ocy, term.line[term.ocy][term.ocx],
+                       term.line[term.ocy], term.col);
        term.ocx = cx;
        term.ocy = term.c.y;
        xfinishdraw();

diff --git a/st.h b/st.h
index fa2eddff864f5be9382b2477ddfd630d0f76e4c8..ddc0d2161e7b7713e1c454dd1202d90bf3befbc7 100644 (file)
--- 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 e6e43695fa17e2465756af66f6f883927b044fed..8b5b618101e919b691457e098856baeb18b9bd23 100644 (file)
--- 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 718604067917b7b470a1618cedc72da379ebee37..9c18effcd7ce53dc4937e4eba014c9860a5c7a62 100644 (file)
--- a/x.c
+++ b/x.c
@@ -19,6 +19,7 @@ char *argv0;
 #include "arg.h"
 #include "st.h"
 #include "win.h"
+#include "hb.h"
 
 /* types used in config.h */
 typedef struct {
@@ -1033,6 +1034,9 @@ 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);
@@ -1232,7 +1236,7 @@ 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. */
@@ -1339,6 +1343,9 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
                numspecs++;
        }
 
+       /* Harfbuzz transformation for ligatures. */
+       hbtransform(specs, glyphs, len, x, y);
+
        return numspecs;
 }
 
@@ -1488,14 +1495,17 @@ 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;