ligatures patch applied

1 files changed, 164 insertions, 111 deletions

diff --git a/x.c b/x.c
index 821e81e..62bb683 100644
--- a/x.c
+++ b/x.c
@@ -19,6 +19,7 @@ char *argv0;
 #include "arg.h"
 #include "st.h"
 #include "win.h"
+#include "hb.h"
 
 /* types used in config.h */
 typedef struct {
@@ -143,6 +144,7 @@ typedef struct {
 } DC;
 
 static inline ushort sixd_to_16bit(int);
+static void xresetfontsettings(ushort mode, Font **font, int *frcflags);
 static int xmakeglyphfontspecs(XftGlyphFontSpec *, const Glyph *, int, int, int);
 static void xdrawglyphfontspecs(const XftGlyphFontSpec *, Glyph, int, int, int);
 static void xdrawglyph(Glyph, int, int);
@@ -761,7 +763,7 @@ xresize(int col, int row)
 	xclear(0, 0, win.w, win.h);
 
 	/* resize to new width */
-	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec));
+	xw.specbuf = xrealloc(xw.specbuf, col * sizeof(GlyphFontSpec) * 4);
 }
 
 ushort
@@ -1076,6 +1078,9 @@ 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);
@@ -1207,7 +1212,7 @@ xinit(int cols, int rows)
 	XFillRectangle(xw.dpy, xw.buf, dc.gc, 0, 0, win.w, win.h);
 
 	/* font spec buffer */
-	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec));
+	xw.specbuf = xmalloc(cols * sizeof(GlyphFontSpec) * 4);
 
 	/* Xft rendering context */
 	xw.draw = XftDrawCreate(xw.dpy, xw.buf, xw.vis, xw.cmap);
@@ -1261,6 +1266,22 @@ xinit(int cols, int rows)
 		xsel.xtarget = XA_STRING;
 }
 
+void
+xresetfontsettings(ushort mode, Font **font, int *frcflags)
+{
+	*font = &dc.font;
+	if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
+		*font = &dc.ibfont;
+		*frcflags = FRC_ITALICBOLD;
+	} else if (mode & ATTR_ITALIC) {
+		*font = &dc.ifont;
+		*frcflags = FRC_ITALIC;
+	} else if (mode & ATTR_BOLD) {
+		*font = &dc.bfont;
+		*frcflags = FRC_BOLD;
+	}
+}
+
 int
 xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x, int y)
 {
@@ -1275,119 +1296,148 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
 	FcPattern *fcpattern, *fontpattern;
 	FcFontSet *fcsets[] = { NULL };
 	FcCharSet *fccharset;
-	int i, f, numspecs = 0;
+	int i, f, length = 0, start = 0, numspecs = 0;
+  float cluster_xp = xp, cluster_yp = yp;
+	HbTransformData shaped = { 0 };
+
+	/* Initial values. */
+	mode = prevmode = glyphs[0].mode;
+	xresetfontsettings(mode, &font, &frcflags);
 
 	for (i = 0, xp = winx, yp = winy + font->ascent; i < len; ++i) {
-		/* Fetch rune and mode for current glyph. */
-		rune = glyphs[i].u;
 		mode = glyphs[i].mode;
 
 		/* Skip dummy wide-character spacing. */
-		if (mode == ATTR_WDUMMY)
+		if (mode & ATTR_WDUMMY && i < (len - 1))
 			continue;
 
-		/* Determine font for glyph if different from previous glyph. */
-		if (prevmode != mode) {
-			prevmode = mode;
-			font = &dc.font;
-			frcflags = FRC_NORMAL;
-			runewidth = win.cw * ((mode & ATTR_WIDE) ? 2.0f : 1.0f);
-			if ((mode & ATTR_ITALIC) && (mode & ATTR_BOLD)) {
-				font = &dc.ibfont;
-				frcflags = FRC_ITALICBOLD;
-			} else if (mode & ATTR_ITALIC) {
-				font = &dc.ifont;
-				frcflags = FRC_ITALIC;
-			} else if (mode & ATTR_BOLD) {
-				font = &dc.bfont;
-				frcflags = FRC_BOLD;
+		if (
+			prevmode != mode
+			|| ATTRCMP(glyphs[start], glyphs[i])
+			|| selected(x + i, y) != selected(x + start, y)
+			|| i == (len - 1)
+		) {
+			/* Handle 1-character wide segments and end of line */
+			length = i - start;
+			if (i == start) {
+				length = 1;
+			} else if (i == (len - 1)) {
+				length = (i - start + 1);
 			}
-			yp = winy + font->ascent;
-		}
-
-		/* Lookup character index with default font. */
-		glyphidx = XftCharIndex(xw.dpy, font->match, rune);
-		if (glyphidx) {
-			specs[numspecs].font = font->match;
-			specs[numspecs].glyph = glyphidx;
-			specs[numspecs].x = (short)xp;
-			specs[numspecs].y = (short)yp;
-			xp += runewidth;
-			numspecs++;
-			continue;
-		}
 
-		/* Fallback on font cache, search the font cache for match. */
-		for (f = 0; f < frclen; f++) {
-			glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
-			/* Everything correct. */
-			if (glyphidx && frc[f].flags == frcflags)
-				break;
-			/* We got a default font for a not found glyph. */
-			if (!glyphidx && frc[f].flags == frcflags
-					&& frc[f].unicodep == rune) {
-				break;
+			/* Shape the segment. */
+			hbtransform(&shaped, font->match, glyphs, start, length);
+			runewidth = win.cw * ((glyphs[start].mode & ATTR_WIDE) ? 2.0f : 1.0f);
+			cluster_xp = xp; cluster_yp = yp;
+			for (int code_idx = 0; code_idx < shaped.count; code_idx++) {
+				int idx = shaped.glyphs[code_idx].cluster;
+
+				if (glyphs[start + idx].mode & ATTR_WDUMMY)
+					continue;
+
+				/* Advance the drawing cursor if we've moved to a new cluster */
+				if (code_idx > 0 && idx != shaped.glyphs[code_idx - 1].cluster) {
+					xp += runewidth;
+					cluster_xp = xp;
+					cluster_yp = yp;
+					runewidth = win.cw * ((glyphs[start + idx].mode & ATTR_WIDE) ? 2.0f : 1.0f);
+				}
+
+				if (shaped.glyphs[code_idx].codepoint != 0) {
+					/* If symbol is found, put it into the specs. */
+					specs[numspecs].font = font->match;
+					specs[numspecs].glyph = shaped.glyphs[code_idx].codepoint;
+					specs[numspecs].x = cluster_xp + (short)(shaped.positions[code_idx].x_offset / 64.);
+					specs[numspecs].y = cluster_yp - (short)(shaped.positions[code_idx].y_offset / 64.);
+					cluster_xp += shaped.positions[code_idx].x_advance / 64.;
+					cluster_yp += shaped.positions[code_idx].y_advance / 64.;
+					numspecs++;
+				} else {
+					/* If it's not found, try to fetch it through the font cache. */
+					rune = glyphs[start + idx].u;
+					for (f = 0; f < frclen; f++) {
+						glyphidx = XftCharIndex(xw.dpy, frc[f].font, rune);
+						/* Everything correct. */
+						if (glyphidx && frc[f].flags == frcflags)
+							break;
+						/* We got a default font for a not found glyph. */
+						if (!glyphidx && frc[f].flags == frcflags
+								&& frc[f].unicodep == rune) {
+							break;
+						}
+					}
+
+					/* Nothing was found. Use fontconfig to find matching font. */
+					if (f >= frclen) {
+						if (!font->set)
+							font->set = FcFontSort(0, font->pattern,
+																		 1, 0, &fcres);
+						fcsets[0] = font->set;
+
+						/*
+						 * Nothing was found in the cache. Now use
+						 * some dozen of Fontconfig calls to get the
+						 * font for one single character.
+						 *
+						 * Xft and fontconfig are design failures.
+						 */
+						fcpattern = FcPatternDuplicate(font->pattern);
+						fccharset = FcCharSetCreate();
+
+						FcCharSetAddChar(fccharset, rune);
+						FcPatternAddCharSet(fcpattern, FC_CHARSET,
+								fccharset);
+						FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
+
+						FcConfigSubstitute(0, fcpattern,
+								FcMatchPattern);
+						FcDefaultSubstitute(fcpattern);
+
+						fontpattern = FcFontSetMatch(0, fcsets, 1,
+								fcpattern, &fcres);
+
+						/* Allocate memory for the new cache entry. */
+						if (frclen >= frccap) {
+							frccap += 16;
+							frc = xrealloc(frc, frccap * sizeof(Fontcache));
+						}
+
+						frc[frclen].font = XftFontOpenPattern(xw.dpy,
+								fontpattern);
+						if (!frc[frclen].font)
+							die("XftFontOpenPattern failed seeking fallback font: %s\n",
+								strerror(errno));
+						frc[frclen].flags = frcflags;
+						frc[frclen].unicodep = rune;
+
+						glyphidx = XftCharIndex(xw.dpy, frc[frclen].font, rune);
+
+						f = frclen;
+						frclen++;
+
+						FcPatternDestroy(fcpattern);
+						FcCharSetDestroy(fccharset);
+					}
+
+					specs[numspecs].font = frc[f].font;
+					specs[numspecs].glyph = glyphidx;
+					specs[numspecs].x = (short)xp;
+					specs[numspecs].y = (short)yp;
+					numspecs++;
+				}
 			}
-		}
-
-		/* Nothing was found. Use fontconfig to find matching font. */
-		if (f >= frclen) {
-			if (!font->set)
-				font->set = FcFontSort(0, font->pattern,
-				                       1, 0, &fcres);
-			fcsets[0] = font->set;
 
-			/*
-			 * Nothing was found in the cache. Now use
-			 * some dozen of Fontconfig calls to get the
-			 * font for one single character.
-			 *
-			 * Xft and fontconfig are design failures.
-			 */
-			fcpattern = FcPatternDuplicate(font->pattern);
-			fccharset = FcCharSetCreate();
-
-			FcCharSetAddChar(fccharset, rune);
-			FcPatternAddCharSet(fcpattern, FC_CHARSET,
-					fccharset);
-			FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
+			/* Cleanup and get ready for next segment. */
+			hbcleanup(&shaped);
+			start = i;
 
-			FcConfigSubstitute(0, fcpattern,
-					FcMatchPattern);
-			FcDefaultSubstitute(fcpattern);
-
-			fontpattern = FcFontSetMatch(0, fcsets, 1,
-					fcpattern, &fcres);
-
-			/* Allocate memory for the new cache entry. */
-			if (frclen >= frccap) {
-				frccap += 16;
-				frc = xrealloc(frc, frccap * sizeof(Fontcache));
+			/* Determine font for glyph if different from previous glyph. */
+			if (prevmode != mode) {
+				prevmode = mode;
+				xresetfontsettings(mode, &font, &frcflags);
+				yp = winy + font->ascent;
 			}
-
-			frc[frclen].font = XftFontOpenPattern(xw.dpy,
-					fontpattern);
-			if (!frc[frclen].font)
-				die("XftFontOpenPattern failed seeking fallback font: %s\n",
-					strerror(errno));
-			frc[frclen].flags = frcflags;
-			frc[frclen].unicodep = rune;
-
-			glyphidx = XftCharIndex(xw.dpy, frc[frclen].font, rune);
-
-			f = frclen;
-			frclen++;
-
-			FcPatternDestroy(fcpattern);
-			FcCharSetDestroy(fccharset);
 		}
-
-		specs[numspecs].font = frc[f].font;
-		specs[numspecs].glyph = glyphidx;
-		specs[numspecs].x = (short)xp;
-		specs[numspecs].y = (short)yp;
-		xp += runewidth;
-		numspecs++;
 	}
 
 	return numspecs;
@@ -1539,14 +1589,17 @@ 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;
@@ -1674,18 +1727,16 @@ xdrawline(Line line, int x1, int y1, int x2)
 	Glyph base, new;
 	XftGlyphFontSpec *specs = xw.specbuf;
 
-	numspecs = xmakeglyphfontspecs(specs, &line[x1], x2 - x1, x1, y1);
 	i = ox = 0;
-	for (x = x1; x < x2 && i < numspecs; x++) {
+	for (x = x1; x < x2; x++) {
 		new = line[x];
 		if (new.mode == ATTR_WDUMMY)
 			continue;
 		if (selected(x, y1))
 			new.mode ^= ATTR_REVERSE;
-		if (i > 0 && ATTRCMP(base, new)) {
-			xdrawglyphfontspecs(specs, base, i, ox, y1);
-			specs += i;
-			numspecs -= i;
+		if ((i > 0) && ATTRCMP(base, new)) {
+			numspecs = xmakeglyphfontspecs(specs, &line[ox], x - ox, ox, y1);
+			xdrawglyphfontspecs(specs, base, numspecs, ox, y1);
 			i = 0;
 		}
 		if (i == 0) {
@@ -1694,8 +1745,10 @@ xdrawline(Line line, int x1, int y1, int x2)
 		}
 		i++;
 	}
-	if (i > 0)
-		xdrawglyphfontspecs(specs, base, i, ox, y1);
+	if (i > 0) {
+		numspecs = xmakeglyphfontspecs(specs, &line[ox], x2 - ox, ox, y1);
+		xdrawglyphfontspecs(specs, base, numspecs, ox, y1);
+	}
 }
 
 void