From ba724004c6a368e452114f7dc147a9978fe0f3b4 Mon Sep 17 00:00:00 2001
From: Kirill Bugaev <kirill.bugaev87@gmail.com>
Date: Tue, 16 Apr 2019 04:31:30 +0800
Subject: [PATCH] This patch allows to add spare font besides default. Some
 glyphs can be not present in default font. 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 they will be
 used first for glyphs that absent in default font.

---
 config.def.h |   6 +++
 x.c          | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)

diff --git a/config.def.h b/config.def.h
index 482901e..676719e 100644
--- a/config.def.h
+++ b/config.def.h
@@ -6,6 +6,12 @@
  * 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..d37e59d 100644
--- a/x.c
+++ b/x.c
@@ -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(void);
 static void xunloadfont(Font *);
 static void xunloadfonts(void);
 static void xsetenv(void);
@@ -296,6 +298,7 @@ zoomabs(const Arg *arg)
 {
 	xunloadfonts();
 	xloadfonts(usedfont, arg->f);
+	xloadsparefonts();
 	cresize(0, 0);
 	redraw();
 	xhints();
@@ -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(void)
+{
+	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)
 {
@@ -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