[PATCH] Add Xft and follback-fonts support to graphics lib

---
 drw.c  |  349 +++++++++++++++++++++++++++++++++++++++++++++++++---------------
 drw.h  |   19 ++--
 util.h |    1 +
 3 files changed, 280 insertions(+), 89 deletions(-)
diff --git a/drw.c b/drw.c
index b130405..eb3b3c3 100644
--- a/drw.c
+++ b/drw.c
_AT_@ -3,10 +3,59 @@
 #include <stdlib.h>
 #include <string.h>
 #include <X11/Xlib.h>
+#include <X11/Xft/Xft.h>
 
 #include "drw.h"
 #include "util.h"
 
+#define UTF_INVALID 0xFFFD
+#define UTF_SIZ 4
+
+static const unsigned char utfbyte[UTF_SIZ + 1] = {0x80,    0, 0xC0, 0xE0, 0xF0};
+static const unsigned char utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
+static const long utfmin[UTF_SIZ + 1] = {       0,    0,  0x80,  0x800,  0x10000};
+static const long utfmax[UTF_SIZ + 1] = {0x10FFFF, 0x7F, 0x7FF, 0xFFFF, 0x10FFFF};
+
+static long
+utf8decodebyte(const char c, size_t *i) {
+	for(*i = 0; *i < (UTF_SIZ + 1); ++(*i))
+		if(((unsigned char)c & utfmask[*i]) == utfbyte[*i])
+			return (unsigned char)c & ~utfmask[*i];
+	return 0;
+}
+
+static size_t
+utf8validate(long *u, size_t i) {
+	if(!BETWEEN(*u, utfmin[i], utfmax[i]) || BETWEEN(*u, 0xD800, 0xDFFF))
+		*u = UTF_INVALID;
+	for(i = 1; *u > utfmax[i]; ++i)
+		;
+	return i;
+}
+
+static size_t
+utf8decode(const char *c, long *u, size_t clen) {
+	size_t i, j, len, type;
+	long udecoded;
+
+	*u = UTF_INVALID;
+	if(!clen)
+		return 0;
+	udecoded = utf8decodebyte(c[0], &len);
+	if(!BETWEEN(len, 1, UTF_SIZ))
+		return 1;
+	for(i = 1, j = 1; i < clen && j < len; ++i, ++j) {
+		udecoded = (udecoded << 6) | utf8decodebyte(c[i], &type);
+		if(type != 0)
+			return j;
+	}
+	if(j < len)
+		return 0;
+	*u = udecoded;
+	utf8validate(u, len);
+	return len;
+}
+
 Drw *
 drw_create(Display *dpy, int screen, Window root, unsigned int w, unsigned int h) {
 	Drw *drw = (Drw *)calloc(1, sizeof(Drw));
_AT_@ -19,6 +68,7 @@ drw_create(Display *dpy, int screen, Window root, unsigned int w, unsigned int h
 	drw->h = h;
 	drw->drawable = XCreatePixmap(dpy, root, w, h, DefaultDepth(dpy, screen));
 	drw->gc = XCreateGC(dpy, root, 0, NULL);
+	drw->fontcount = 0;
 	XSetLineAttributes(dpy, drw->gc, 1, LineSolid, CapButt, JoinMiter);
 	return drw;
 }
_AT_@ -36,56 +86,88 @@ drw_resize(Drw *drw, unsigned int w, unsigned int h) {
 
 void
 drw_free(Drw *drw) {
+	size_t i;
+	for (i = 0; i < drw->fontcount; i++) {
+		drw_font_free(drw->fonts[i]);
+	}
 	XFreePixmap(drw->dpy, drw->drawable);
 	XFreeGC(drw->dpy, drw->gc);
 	free(drw);
 }
 
-Fnt *
-drw_font_create(Display *dpy, const char *fontname) {
+/* This function is an implementation detail. Library users should use
+ * drw_font_create instead.
+ */
+static Fnt *
+drw_font_xcreate(Drw *drw, const char *fontname, FcPattern *fontpattern) {
 	Fnt *font;
-	char *def, **missing;
-	int n;
 
-	font = (Fnt *)calloc(1, sizeof(Fnt));
-	if(!font)
+	if (!(fontname || fontpattern))
+		die("No font specified.\n");
+
+	if (!(font = (Fnt *)calloc(1, sizeof(Fnt))))
 		return NULL;
-	font->set = XCreateFontSet(dpy, fontname, &missing, &n, &def);
-	if(missing) {
-		while(n--)
-			fprintf(stderr, "drw: missing fontset: %s\n", missing[n]);
-		XFreeStringList(missing);
-	}
-	if(font->set) {
-		XFontStruct **xfonts;
-		char **font_names;
-		XExtentsOfFontSet(font->set);
-		n = XFontsOfFontSet(font->set, &xfonts, &font_names);
-		while(n--) {
-			font->ascent = MAX(font->ascent, (*xfonts)->ascent);
-			font->descent = MAX(font->descent,(*xfonts)->descent);
-			xfonts++;
+
+	if (fontname) {
+		/* Using the pattern found at font->xfont->pattern does not yield same
+		 * the same substitution results as using the pattern returned by
+		 * FcNameParse; using the latter results in the desired fallback
+		 * behaviour whereas the former just results in
+		 * missing-character-rectangles being drawn, at least with some fonts.
+		 */
+		if (!(font->xfont = XftFontOpenName(drw->dpy, drw->screen, fontname)) ||
+		    !(font->pattern = FcNameParse((FcChar8 *) fontname))) {
+			if (font->xfont) {
+				XftFontClose(drw->dpy, font->xfont);
+				font->xfont = NULL;
+			}
+			fprintf(stderr, "error, cannot load font: '%s'\n", fontname);
+		}
+	} else if (fontpattern) {
+		if (!(font->xfont = XftFontOpenPattern(drw->dpy, fontpattern))) {
+			fprintf(stderr, "error, cannot load font pattern.\n");
+		} else {
+			font->pattern = NULL;
 		}
 	}
-	else {
-		if(!(font->xfont = XLoadQueryFont(dpy, fontname))
-		&& !(font->xfont = XLoadQueryFont(dpy, "fixed")))
-			die("error, cannot load font: '%s'\n", fontname);
-		font->ascent = font->xfont->ascent;
-		font->descent = font->xfont->descent;
+
+	if (!font->xfont) {
+		free(font);
+		return NULL;
 	}
+
+	font->ascent = font->xfont->ascent;
+	font->descent = font->xfont->descent;
 	font->h = font->ascent + font->descent;
+	font->dpy = drw->dpy;
 	return font;
 }
 
+Fnt*
+drw_font_create(Drw *drw, const char *fontname) {
+	return drw_font_xcreate(drw, fontname, NULL);
+}
+
+void
+drw_load_fonts(Drw* drw, const char *fonts[], size_t fontcount) {
+	size_t i;
+	Fnt *font;
+	for (i = 0; i < fontcount; i++) {
+		if (drw->fontcount >= DRW_FONT_CACHE_SIZE) {
+			die("Font cache exhausted.\n");
+		} else if ((font = drw_font_xcreate(drw, fonts[i], NULL))) {
+			drw->fonts[drw->fontcount++] = font;
+		}
+	}
+}
+
 void
-drw_font_free(Display *dpy, Fnt *font) {
+drw_font_free(Fnt *font) {
 	if(!font)
 		return;
-	if(font->set)
-		XFreeFontSet(dpy, font->set);
-	else
-		XFreeFont(dpy, font->xfont);
+	if(font->pattern)
+		FcPatternDestroy(font->pattern);
+	XftFontClose(font->dpy, font->xfont);
 	free(font);
 }
 
_AT_@ -93,7 +175,7 @@ Clr *
 drw_clr_create(Drw *drw, const char *clrname) {
 	Clr *clr;
 	Colormap cmap;
-	XColor color;
+	Visual *vis;
 
 	if(!drw)
 		return NULL;
_AT_@ -101,9 +183,10 @@ drw_clr_create(Drw *drw, const char *clrname) {
 	if(!clr)
 		return NULL;
 	cmap = DefaultColormap(drw->dpy, drw->screen);
-	if(!XAllocNamedColor(drw->dpy, cmap, clrname, &color, &color))
+	vis = DefaultVisual(drw->dpy, drw->screen);
+	if(!XftColorAllocName(drw->dpy, vis, cmap, clrname, &clr->rgb))
 		die("error, cannot allocate color '%s'\n", clrname);
-	clr->rgb = color.pixel;
+	clr->pix = clr->rgb.pixel;
 	return clr;
 }
 
_AT_@ -114,14 +197,8 @@ drw_clr_free(Clr *clr) {
 }
 
 void
-drw_setfont(Drw *drw, Fnt *font) {
-	if(drw)
-		drw->font = font;
-}
-
-void
 drw_setscheme(Drw *drw, ClrScheme *scheme) {
-	if(drw && scheme) 
+	if(drw && scheme)
 		drw->scheme = scheme;
 }
 
_AT_@ -129,46 +206,160 @@ void
 drw_rect(Drw *drw, int x, int y, unsigned int w, unsigned int h, int filled, int empty, int invert) {
 	int dx;
 
-	if(!drw || !drw->font || !drw->scheme)
+	if(!drw || !drw->fontcount || !drw->scheme)
 		return;
-	XSetForeground(drw->dpy, drw->gc, invert ? drw->scheme->bg->rgb : drw->scheme->fg->rgb);
-	dx = (drw->font->ascent + drw->font->descent + 2) / 4;
+	XSetForeground(drw->dpy, drw->gc, invert ? drw->scheme->bg->pix : drw->scheme->fg->pix);
+	dx = (drw->fonts[0]->ascent + drw->fonts[0]->descent + 2) / 4;
 	if(filled)
 		XFillRectangle(drw->dpy, drw->drawable, drw->gc, x+1, y+1, dx+1, dx+1);
 	else if(empty)
 		XDrawRectangle(drw->dpy, drw->drawable, drw->gc, x+1, y+1, dx, dx);
 }
 
-void
+int
 drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *text, int invert) {
-	char buf[256];
-	int i, tx, ty, th, len, olen;
+	char buf[1024];
+	int tx, ty, th;
 	Extnts tex;
+	Colormap cmap;
+	Visual *vis;
+	XftDraw *d;
+	Fnt *curfont, *nextfont;
+	size_t i, len;
+	int utf8strlen, utf8charlen, render;
+	long utf8codepoint = 0;
+	const char *utf8str;
+	FcCharSet *fccharset;
+	FcPattern *fcpattern;
+	FcPattern *match;
+	XftResult result;
+	int charexists = 0;
 
-	if(!drw || !drw->scheme)
-		return;
-	XSetForeground(drw->dpy, drw->gc, invert ? drw->scheme->fg->rgb : drw->scheme->bg->rgb);
-	XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h);
-	if(!text || !drw->font)
-		return;
-	olen = strlen(text);
-	drw_font_getexts(drw->font, text, olen, &tex);
-	th = drw->font->ascent + drw->font->descent;
-	ty = y + (h / 2) - (th / 2) + drw->font->ascent;
-	tx = x + (h / 2);
-	/* shorten text if necessary */
-	for(len = MIN(olen, sizeof buf); len && (tex.w > w - tex.h || w < tex.h); len--)
-		drw_font_getexts(drw->font, text, len, &tex);
-	if(!len)
-		return;
-	memcpy(buf, text, len);
-	if(len < olen)
-		for(i = len; i && i > len - 3; buf[--i] = '.');
-	XSetForeground(drw->dpy, drw->gc, invert ? drw->scheme->bg->rgb : drw->scheme->fg->rgb);
-	if(drw->font->set)
-		XmbDrawString(drw->dpy, drw->drawable, drw->font->set, drw->gc, tx, ty, buf, len);
-	else
-		XDrawString(drw->dpy, drw->drawable, drw->gc, tx, ty, buf, len);
+	if (!(render = x || y || w || h)) {
+		w = ~w;
+	}
+
+	if (!drw || !drw->scheme) {
+		return 0;
+	} else if (render) {
+		XSetForeground(drw->dpy, drw->gc, invert ? drw->scheme->fg->pix : drw->scheme->bg->pix);
+		XFillRectangle(drw->dpy, drw->drawable, drw->gc, x, y, w, h);
+	}
+
+	if (!text || !drw->fontcount) {
+		return 0;
+	} else if (render) {
+		cmap = DefaultColormap(drw->dpy, drw->screen);
+		vis = DefaultVisual(drw->dpy, drw->screen);
+		d = XftDrawCreate(drw->dpy, drw->drawable, vis, cmap);
+	}
+
+	curfont = drw->fonts[0];
+	while (1) {
+		utf8strlen = 0;
+		utf8str = text;
+		nextfont = NULL;
+		while (*text) {
+			utf8charlen = utf8decode(text, &utf8codepoint, UTF_SIZ);
+			for (i = 0; i < drw->fontcount; i++) {
+				charexists = charexists || XftCharExists(drw->dpy, drw->fonts[i]->xfont, utf8codepoint);
+				if (charexists) {
+					if (drw->fonts[i] == curfont) {
+						utf8strlen += utf8charlen;
+						text += utf8charlen;
+					} else {
+						nextfont = drw->fonts[i];
+					}
+					break;
+				}
+			}
+
+			if (!charexists || (nextfont && nextfont != curfont)) {
+				break;
+			} else {
+				charexists = 0;
+			}
+		}
+
+		if (utf8strlen) {
+			drw_font_getexts(curfont, utf8str, utf8strlen, &tex);
+			/* shorten text if necessary */
+			for(len = MIN(utf8strlen, (sizeof buf) - 1); len && (tex.w > w - drw->fonts[0]->h || w < drw->fonts[0]->h); len--)
+				drw_font_getexts(curfont, utf8str, len, &tex);
+
+			if (len) {
+				memcpy(buf, utf8str, len);
+				buf[len] = '\0';
+				if(len < utf8strlen)
+					for(i = len; i && i > len - 3; buf[--i] = '.');
+
+				if (render) {
+					th = curfont->ascent + curfont->descent;
+					ty = y + (h / 2) - (th / 2) + curfont->ascent;
+					tx = x + (h / 2);
+					XftDrawStringUtf8(d, invert ? &drw->scheme->bg->rgb : &drw->scheme->fg->rgb, curfont->xfont, tx, ty, (XftChar8 *)buf, len);
+				}
+
+				x += tex.w;
+				w -= tex.w;
+			}
+		}
+
+		if (!*text) {
+			break;
+		} else if (nextfont) {
+			charexists = 0;
+			curfont = nextfont;
+		} else {
+			/* Regardless of whether or not a fallback font is found, the
+			 * character must be drawn.
+			 */
+			charexists = 1;
+
+			if (drw->fontcount >= DRW_FONT_CACHE_SIZE) {
+				continue;
+			}
+
+			fccharset = FcCharSetCreate();
+			FcCharSetAddChar(fccharset, utf8codepoint);
+
+			if (!drw->fonts[0]->pattern) {
+				/* Refer to the comment in drw_font_xcreate for more
+				 * information.
+				 */
+				die("The first font in the cache must be loaded from a font string.\n");
+			}
+
+			fcpattern = FcPatternDuplicate(drw->fonts[0]->pattern);
+			FcPatternAddCharSet(fcpattern, FC_CHARSET, fccharset);
+			FcPatternAddBool(fcpattern, FC_SCALABLE, FcTrue);
+
+			FcConfigSubstitute(NULL, fcpattern, FcMatchPattern);
+			FcDefaultSubstitute(fcpattern);
+			match = XftFontMatch(drw->dpy, drw->screen, fcpattern, &result);
+
+			FcCharSetDestroy(fccharset);
+			FcPatternDestroy(fcpattern);
+
+			if (match) {
+				curfont = drw_font_xcreate(drw, NULL, match);
+				if (curfont && XftCharExists(drw->dpy, curfont->xfont, utf8codepoint)) {
+					drw->fonts[drw->fontcount++] = curfont;
+				} else {
+					if (curfont) {
+						drw_font_free(curfont);
+					}
+					curfont = drw->fonts[0];
+				}
+			}
+		}
+	}
+
+	if (render) {
+		XftDrawDestroy(d);
+	}
+
+	return x;
 }
 
 void
_AT_@ -182,19 +373,13 @@ drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h) {
 
 void
 drw_font_getexts(Fnt *font, const char *text, unsigned int len, Extnts *tex) {
-	XRectangle r;
+	XGlyphInfo ext;
 
 	if(!font || !text)
 		return;
-	if(font->set) {
-		XmbTextExtents(font->set, text, len, NULL, &r);
-		tex->w = r.width;
-		tex->h = r.height;
-	}
-	else {
-		tex->h = font->ascent + font->descent;
-		tex->w = XTextWidth(font->xfont, text, len);
-	}
+	XftTextExtentsUtf8(font->dpy, font->xfont, (XftChar8 *)text, len, &ext);
+	tex->h = font->h;
+	tex->w = ext.xOff;
 }
 
 unsigned int
diff --git a/drw.h b/drw.h
index a5f34e0..536171b 100644
--- a/drw.h
+++ b/drw.h
_AT_@ -1,7 +1,9 @@
 /* See LICENSE file for copyright and license details. */
+#define DRW_FONT_CACHE_SIZE 32
 
 typedef struct {
-	unsigned long rgb;
+	unsigned long pix;
+	XftColor rgb;
 } Clr;
 
 typedef struct {
_AT_@ -9,11 +11,12 @@ typedef struct {
 } Cur;
 
 typedef struct {
+	Display *dpy;
 	int ascent;
 	int descent;
 	unsigned int h;
-	XFontSet set;
-	XFontStruct *xfont;
+	XftFont *xfont;
+	FcPattern *pattern;
 } Fnt;
 
 typedef struct {
_AT_@ -30,7 +33,8 @@ typedef struct {
 	Drawable drawable;
 	GC gc;
 	ClrScheme *scheme;
-	Fnt *font;
+	size_t fontcount;
+	Fnt *fonts[DRW_FONT_CACHE_SIZE];
 } Drw;
 
 typedef struct {
_AT_@ -44,8 +48,9 @@ void drw_resize(Drw *drw, unsigned int w, unsigned int h);
 void drw_free(Drw *drw);
 
 /* Fnt abstraction */
-Fnt *drw_font_create(Display *dpy, const char *fontname);
-void drw_font_free(Display *dpy, Fnt *font);
+Fnt *drw_font_create(Drw *drw, const char *fontname);
+void drw_load_fonts(Drw* drw, const char *fonts[], size_t fontcount);
+void drw_font_free(Fnt *font);
 void drw_font_getexts(Fnt *font, const char *text, unsigned int len, Extnts *extnts);
 unsigned int drw_font_getexts_width(Fnt *font, const char *text, unsigned int len);
 
_AT_@ -63,7 +68,7 @@ void drw_setscheme(Drw *drw, ClrScheme *scheme);
 
 /* Drawing functions */
 void drw_rect(Drw *drw, int x, int y, unsigned int w, unsigned int h, int filled, int empty, int invert);
-void drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *text, int invert);
+int drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *text, int invert);
 
 /* Map functions */
 void drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h);
diff --git a/util.h b/util.h
index 033700c..f7ce721 100644
--- a/util.h
+++ b/util.h
_AT_@ -2,5 +2,6 @@
 
 #define MAX(A, B)               ((A) > (B) ? (A) : (B))
 #define MIN(A, B)               ((A) < (B) ? (A) : (B))
+#define BETWEEN(X, A, B)        ((A) <= (X) && (X) <= (B))
 
 void die(const char *errstr, ...);
-- 
1.7.10.4
--OgqxwSJOaUobr8KG--