[hackers] [font2][PATCH] Some glyphs can be not present in font defined by default. For this glyphs st uses font-config and try to find them in font cache first. This patch append fonts defined in `font2` variable to the beginning of font cache. So it will be used as spare fonts.

---
 config.def.h |   5 +++
 x.c          | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 106 insertions(+)
diff --git a/config.def.h b/config.def.h
index 482901e..5defc0f 100644
--- a/config.def.h
+++ b/config.def.h
_AT_@ -6,6 +6,11 @@
  * font: see http://freedesktop.org/software/fontconfig/fontconfig-user.html
  */
 static char *font = "Liberation Mono:pixelsize=12:antialias=true:autohint=true";
+/* Spare fonts */
+static char *font2[] = {
+	"Inconsolata for Powerline:pixelsize=12:antialias=true:autohint=true",
+	"Hack Nerd Font Mono:pixelsize=11:antialias=true:autohint=true",
+};
 static int borderpx = 2;
 
 /*
diff --git a/x.c b/x.c
index 5828a3b..90e083c 100644
--- a/x.c
+++ b/x.c
_AT_@ -149,6 +149,8 @@ static void xhints(void);
 static int xloadcolor(int, const char *, Color *);
 static int xloadfont(Font *, FcPattern *);
 static void xloadfonts(char *, double);
+static int xloadsparefont(FcPattern *, int);
+static void xloadsparefonts();
 static void xunloadfont(Font *);
 static void xunloadfonts(void);
 static void xsetenv(void);
_AT_@ -296,6 +298,7 @@ zoomabs(const Arg *arg)
 {
 	xunloadfonts();
 	xloadfonts(usedfont, arg->f);
+	xloadsparefonts();
 	cresize(0, 0);
 	redraw();
 	xhints();
_AT_@ -977,6 +980,101 @@ xloadfonts(char *fontstr, double fontsize)
 	FcPatternDestroy(pattern);
 }
 
+int
+xloadsparefont(FcPattern *pattern, int flags)
+{
+	FcPattern *match;
+	FcResult result;
+	
+	match = FcFontMatch(NULL, pattern, &result);
+	if (!match) {
+		return 1;
+	}
+
+	if (!(frc[frclen].font = XftFontOpenPattern(xw.dpy, match))) {
+		FcPatternDestroy(match);
+		return 1;
+	}
+
+	frc[frclen].flags = flags;
+	/* Believe U+0000 glyph will present in each default font */
+	frc[frclen].unicodep = 0;
+	frclen++;
+
+	return 0;
+}
+
+void
+xloadsparefonts()
+{
+	FcPattern *pattern;
+	double sizeshift, fontval;
+	int fc;
+	char **fp;
+
+	if (frclen != 0)
+		die("can't embed spare fonts. cache isn't empty");
+
+	/* Calculate count of spare fonts */
+	fc = sizeof(font2) / sizeof(*font2);
+	if (fc == 0)
+		return;
+
+	/* Allocate memory for cache entries. */
+	if (frccap < 4 * fc) {
+		frccap += 4 * fc - frccap;
+		frc = xrealloc(frc, frccap * sizeof(Fontcache));
+	}
+
+	for (fp = font2; fp - font2 < fc; ++fp) {
+	
+		if (**fp == '-')
+			pattern = XftXlfdParse(*fp, False, False);
+		else
+			pattern = FcNameParse((FcChar8 *)*fp);
+	
+		if (!pattern)
+			die("can't open spare font %s\n", *fp);
+	   		
+		if (defaultfontsize > 0) {
+			sizeshift = usedfontsize - defaultfontsize;
+			if (sizeshift != 0 &&
+					FcPatternGetDouble(pattern, FC_PIXEL_SIZE, 0, &fontval) ==
+					FcResultMatch) {	
+				fontval += sizeshift;
+				FcPatternDel(pattern, FC_PIXEL_SIZE);
+				FcPatternDel(pattern, FC_SIZE);
+				FcPatternAddDouble(pattern, FC_PIXEL_SIZE, fontval);
+			}
+		}
+	
+		FcPatternAddBool(pattern, FC_SCALABLE, 1);
+	
+		FcConfigSubstitute(NULL, pattern, FcMatchPattern);
+		XftDefaultSubstitute(xw.dpy, xw.scr, pattern);
+	
+		if (xloadsparefont(pattern, FRC_NORMAL))
+			die("can't open spare font %s\n", *fp);
+	
+		FcPatternDel(pattern, FC_SLANT);
+		FcPatternAddInteger(pattern, FC_SLANT, FC_SLANT_ITALIC);
+		if (xloadsparefont(pattern, FRC_ITALIC))
+			die("can't open spare font %s\n", *fp);
+			
+		FcPatternDel(pattern, FC_WEIGHT);
+		FcPatternAddInteger(pattern, FC_WEIGHT, FC_WEIGHT_BOLD);
+		if (xloadsparefont(pattern, FRC_ITALICBOLD))
+			die("can't open spare font %s\n", *fp);
+	
+		FcPatternDel(pattern, FC_SLANT);
+		FcPatternAddInteger(pattern, FC_SLANT, FC_SLANT_ROMAN);
+		if (xloadsparefont(pattern, FRC_BOLD))
+			die("can't open spare font %s\n", *fp);
+	
+		FcPatternDestroy(pattern);
+	}
+}
+
 void
 xunloadfont(Font *f)
 {
_AT_@ -1057,6 +1155,9 @@ xinit(int cols, int rows)
 	usedfont = (opt_font == NULL)? font : opt_font;
 	xloadfonts(usedfont, 0);
 
+	/* spare fonts */
+	xloadsparefonts();
+
 	/* colors */
 	xw.cmap = XDefaultColormap(xw.dpy, xw.scr);
 	xloadcols();
-- 
2.21.0