[PATCH 3/5] drw: fixup font handling

From: Markus Teich <markus.teich_AT_stusta.mhn.de>
Date: Tue, 21 Apr 2015 22:57:52 +0200

- replace static sized fontcache array with dynamic linked list (sent needs
  that).
- remove `drw_` prefix from static helper functions.
- distinguish different error cases in internal xfont_create.
- remove ascent and descent members from struct Fnt since they are seldomly used
  and can still be accessed within the xfont member.
- remove exported function to load a single font, use the drw_fontset_create
  function instead.
- add drw_fontset_getwidth function to calculate width of a string rendered with
  the selected fontset.
- clarify variable name in drw_text (curfont -> usedfont). curfont is only used
  as loop index now.
- fix bug where first font in set was used to calculate truncation width instead
  of currently used fallback font.
---
 drw.c | 147 +++++++++++++++++++++++++++++++++++-------------------------------
 drw.h |  17 ++++----
 2 files changed, 86 insertions(+), 78 deletions(-)
diff --git a/drw.c b/drw.c
index 55dbbb8..a3747a3 100644
--- a/drw.c
+++ b/drw.c
_AT_@ -73,7 +73,6 @@ 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_@ -92,44 +91,39 @@ 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);
 }
 
 /* This function is an implementation detail. Library users should use
- * drw_font_create instead.
+ * drw_fontset_create instead.
  */
 static Fnt *
-drw_font_xcreate(Drw *drw, const char *fontname, FcPattern *fontpattern)
+xfont_create(Drw *drw, const char *fontname, FcPattern *fontpattern)
 {
 	Fnt *font;
 	XftFont *xfont = NULL;
 	FcPattern *pattern = NULL;
 
 	if (fontname) {
-		/* Using the pattern found at font->xfont->pattern does not yield same
-		 * the same substitution results as using the pattern returned by
+		/* Using the pattern found at font->xfont->pattern does not yield 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.
-		 */
+		 * behaviour whereas the former just results in missing-character
+		 * rectangles being drawn, at least with some fonts. */
 		if (!(xfont = XftFontOpenName(drw->dpy, drw->screen, fontname))) {
-			fprintf(stderr, "error, cannot load font: '%s'\n", fontname);
+			fprintf(stderr, "error, cannot load font from name: '%s'\n", fontname);
 			return NULL;
 		}
 		if (!(pattern = FcNameParse((FcChar8 *) fontname))) {
-			fprintf(stderr, "error, cannot load font: '%s'\n", fontname);
+			fprintf(stderr, "error, cannot parse font name to pattern: '%s'\n", fontname);
 			XftFontClose(drw->dpy, xfont);
 			return NULL;
 		}
 	} else if (fontpattern) {
 		if (!(xfont = XftFontOpenPattern(drw->dpy, fontpattern))) {
-			fprintf(stderr, "error, cannot load font pattern.\n");
+			fprintf(stderr, "error, cannot load font from pattern.\n");
 			return NULL;
 		}
 	} else {
_AT_@ -139,37 +133,14 @@ drw_font_xcreate(Drw *drw, const char *fontname, FcPattern *fontpattern)
 	font = ecalloc(1, sizeof(Fnt));
 	font->xfont = xfont;
 	font->pattern = pattern;
-	font->ascent = xfont->ascent;
-	font->descent = xfont->descent;
-	font->h = font->ascent + font->descent;
+	font->h = xfont->ascent + xfont->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(Fnt *font)
+static void
+xfont_free(Fnt *font)
 {
 	if (!font)
 		return;
_AT_@ -179,6 +150,33 @@ drw_font_free(Fnt *font)
 	free(font);
 }
 
+Fnt*
+drw_fontset_create(Drw* drw, const char *fonts[], size_t fontcount)
+{
+	Fnt *cur, *ret = NULL;
+	size_t i;
+
+	if (!drw || !fonts)
+		return NULL;
+
+	for (i = 1; i <= fontcount; i++) {
+		if ((cur = xfont_create(drw, fonts[fontcount - i], NULL))) {
+			cur->next = ret;
+			ret = cur;
+		}
+	}
+	return (drw->fonts = ret);
+}
+
+void
+drw_fontset_free(Fnt *font)
+{
+	if (font) {
+		drw_fontset_free(font->next);
+		xfont_free(font);
+	}
+}
+
 void
 drw_clr_create(Drw *drw, Clr *dest, const char *clrname)
 {
_AT_@ -209,6 +207,13 @@ drw_scm_create(Drw *drw, const char *clrnames[], size_t clrcount)
 }
 
 void
+drw_setfontset(Drw *drw, Fnt *set)
+{
+	if (drw)
+		drw->fonts = set;
+}
+
+void
 drw_setscheme(Drw *drw, Clr *scm)
 {
 	if (drw)
_AT_@ -234,7 +239,7 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *tex
 	int tx, ty, th;
 	unsigned int ew;
 	XftDraw *d = NULL;
-	Fnt *curfont, *nextfont;
+	Fnt *usedfont, *curfont, *nextfont;
 	size_t i, len;
 	int utf8strlen, utf8charlen, render = x || y || w || h;
 	long utf8codepoint = 0;
_AT_@ -245,7 +250,7 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *tex
 	XftResult result;
 	int charexists = 0;
 
-	if ((render && !drw->scheme) || !drw->fontcount)
+	if (!drw || (render && !drw->scheme) || !text || !drw->fonts)
 		return 0;
 
 	if (!render) {
_AT_@ -259,37 +264,37 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *tex
 		                  DefaultColormap(drw->dpy, drw->screen));
 	}
 
-	curfont = drw->fonts[0];
+	usedfont = drw->fonts;
 	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);
+			for (curfont = drw->fonts; curfont; curfont = curfont->next) {
+				charexists = charexists || XftCharExists(drw->dpy, curfont->xfont, utf8codepoint);
 				if (charexists) {
-					if (drw->fonts[i] == curfont) {
+					if (curfont == usedfont) {
 						utf8strlen += utf8charlen;
 						text += utf8charlen;
 					} else {
-						nextfont = drw->fonts[i];
+						nextfont = curfont;
 					}
 					break;
 				}
 			}
 
-			if (!charexists || (nextfont && nextfont != curfont))
+			if (!charexists || nextfont)
 				break;
 			else
 				charexists = 0;
 		}
 
 		if (utf8strlen) {
-			drw_font_getexts(curfont, utf8str, utf8strlen, &ew, NULL);
+			drw_font_getexts(usedfont, utf8str, utf8strlen, &ew, NULL);
 			/* shorten text if necessary */
-			for (len = MIN(utf8strlen, (sizeof buf) - 1); len && (ew > w - drw->fonts[0]->h || w < drw->fonts[0]->h); len--)
-				drw_font_getexts(curfont, utf8str, len, &ew, NULL);
+			for (len = MIN(utf8strlen, (sizeof buf) - 1); len && (ew > w - usedfont->h || w < usedfont->h); len--)
+				drw_font_getexts(usedfont, utf8str, len, &ew, NULL);
 
 			if (len) {
 				memcpy(buf, utf8str, len);
_AT_@ -298,10 +303,10 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *tex
 					for (i = len; i && i > len - 3; buf[--i] = '.');
 
 				if (render) {
-					th = curfont->ascent + curfont->descent;
-					ty = y + (h / 2) - (th / 2) + curfont->ascent;
+					th = usedfont->h;
+					ty = y + (h - th) / 2 + usedfont->xfont->ascent;
 					tx = x + (h / 2);
-					XftDrawStringUtf8(d, invert ? &drw->scheme[ColBg] : &drw->scheme[ColFg], curfont->xfont, tx, ty, (XftChar8 *)buf, len);
+					XftDrawStringUtf8(d, invert ? &drw->scheme[ColBg] : &drw->scheme[ColFg], usedfont->xfont, tx, ty, (XftChar8 *)buf, len);
 				}
 				x += ew;
 				w -= ew;
_AT_@ -312,26 +317,22 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *tex
 			break;
 		} else if (nextfont) {
 			charexists = 0;
-			curfont = nextfont;
+			usedfont = 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. */
+			if (!drw->fonts->pattern) {
+				/* Refer to the comment in xfont_create for more information. */
 				die("the first font in the cache must be loaded from a font string.\n");
 			}
 
-			fcpattern = FcPatternDuplicate(drw->fonts[0]->pattern);
+			fcpattern = FcPatternDuplicate(drw->fonts->pattern);
 			FcPatternAddCharSet(fcpattern, FC_CHARSET, fccharset);
 			FcPatternAddBool(fcpattern, FC_SCALABLE, FcTrue);
 
_AT_@ -343,12 +344,14 @@ drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, const char *tex
 			FcPatternDestroy(fcpattern);
 
 			if (match) {
-				curfont = drw_font_xcreate(drw, NULL, match);
-				if (curfont && XftCharExists(drw->dpy, curfont->xfont, utf8codepoint)) {
-					drw->fonts[drw->fontcount++] = curfont;
+				usedfont = xfont_create(drw, NULL, match);
+				if (usedfont && XftCharExists(drw->dpy, usedfont->xfont, utf8codepoint)) {
+					for (curfont = drw->fonts; curfont->next; curfont = curfont->next)
+						; /* just find the end of the linked list */
+					curfont->next = usedfont;
 				} else {
-					drw_font_free(curfont);
-					curfont = drw->fonts[0];
+					xfont_free(usedfont);
+					usedfont = drw->fonts;
 				}
 			}
 		}
_AT_@ -366,6 +369,14 @@ drw_map(Drw *drw, Window win, int x, int y, unsigned int w, unsigned int h)
 	XSync(drw->dpy, False);
 }
 
+unsigned int
+drw_fontset_getwidth(Drw *drw, const char *text)
+{
+	if (!drw || !drw->fonts || !text)
+		return 0;
+	return drw_text(drw, 0, 0, 0, 0, text, 0);
+}
+
 void
 drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h)
 {
diff --git a/drw.h b/drw.h
index 55a33e4..cf0e7b4 100644
--- a/drw.h
+++ b/drw.h
_AT_@ -1,17 +1,15 @@
 /* See LICENSE file for copyright and license details. */
-#define DRW_FONT_CACHE_SIZE 32
 
 typedef struct {
 	Cursor cursor;
 } Cur;
 
-typedef struct {
+typedef struct Fnt {
 	Display *dpy;
-	int ascent;
-	int descent;
 	unsigned int h;
 	XftFont *xfont;
 	FcPattern *pattern;
+	struct Fnt *next;
 } Fnt;
 
 enum { ColFg, ColBg }; /* Clr scheme index */
_AT_@ -25,8 +23,7 @@ typedef struct {
 	Drawable drawable;
 	GC gc;
 	Clr *scheme;
-	size_t fontcount;
-	Fnt *fonts[DRW_FONT_CACHE_SIZE];
+	Fnt *fonts;
 } Drw;
 
 /* Drawable abstraction */
_AT_@ -35,9 +32,9 @@ void drw_resize(Drw *drw, unsigned int w, unsigned int h);
 void drw_free(Drw *drw);
 
 /* Fnt abstraction */
-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);
+Fnt *drw_fontset_create(Drw* drw, const char *fonts[], size_t fontcount);
+void drw_fontset_free(Fnt* set);
+unsigned int drw_fontset_getwidth(Drw *drw, const char *text);
 void drw_font_getexts(Fnt *font, const char *text, unsigned int len, unsigned int *w, unsigned int *h);
 
 /* Colorscheme abstraction */
_AT_@ -49,7 +46,7 @@ Cur *drw_cur_create(Drw *drw, int shape);
 void drw_cur_free(Drw *drw, Cur *cursor);
 
 /* Drawing context manipulation */
-void drw_setfont(Drw *drw, Fnt *font);
+void drw_setfontset(Drw *drw, Fnt *set);
 void drw_setscheme(Drw *drw, Clr *scm);
 
 /* Drawing functions */
-- 
2.7.3
--mYCpIKhGyMATD0i+
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Received on Mon Sep 17 2001 - 00:00:00 CEST

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