inicial

1 files changed, 371 insertions, 0 deletions

diff --git a/backend/dvi/mdvi-lib/fontsrch.c b/backend/dvi/mdvi-lib/fontsrch.c
new file mode 100644
index 00000000..8ebaa5ca
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+++ b/backend/dvi/mdvi-lib/fontsrch.c
@@ -0,0 +1,371 @@
+/* fontsearch.c -- implements the font lookup mechanism in MDVI */
+/*
+ * Copyright (C) 2000, Matias Atria
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/*
+ * How this works:
+ *   Fonts are divided into MAX_CLASS priority classes. The first
+ * MAX_CLASS-1 ones correspond to `real' fonts (pk, gf, vf, type1, truetype,
+ * etc). The last one corresponds to `metric' fonts that are used as a last
+ * resort (tfm, afm, ofm, ...). When a font is looked up, it is tried in a
+ * `high' priority class (0 being the highest priority). The priority is
+ * lowered until it reaches MAX_CLASS-1. Then the whole thing is repeated
+ * for the fallback font. When the search reaches MAX_CLASS-1, we lookup the
+ * original font, and then the fallback font. The search can be done
+ * incrementally, with several calls to mdvi_lookup_font(). If this function
+ * is called again to continue a search, the function assumes the previous
+ * font it returned was not valid, and it goes on to the next step.
+ *
+ * Reason for this:
+ *   Some font types are quite expensive to load (e.g. Type1),  so loading
+ * them is deferred until the last possible moment. This means that a font that
+ * was supposed to exist may have to be discarded. Until now, MDVI had no ability to
+ * "resume" a search, so in this case it would have produced an error, regardless
+ * of whether the offending font existed in other formats.
+ *   Also, given the large number of font types supported by MDVI, some mechanism
+ * was necessary to bring some order into the chaos.
+ *
+ * This mechanism fixes these two problems. For the first one, a search can
+ * be "resumed" and all the font formats tried for the missing font, and
+ * again for the fallback font (see above). As for the second, the
+ * hierarchical division in classes gives a lot of flexibility in how the
+ * fonts are configured.
+ */
+
+#include <config.h>
+#include "mdvi.h"
+
+#define HAVE_PROTOTYPES 1
+#include <kpathsea/tex-file.h>
+#include <kpathsea/tex-glyph.h>
+
+struct _DviFontClass {
+	DviFontClass *next;
+	DviFontClass *prev;
+	DviFontInfo  info;
+	int	links;
+	int	id;
+};
+
+char *_mdvi_fallback_font = MDVI_FALLBACK_FONT;
+
+/* this leaves classes 0 and 1 for `real' fonts */
+#define MAX_CLASS	3
+static ListHead font_classes[MAX_CLASS];
+static int initialized = 0;
+
+static void init_font_classes(void)
+{
+	int	i;
+	
+	for(i = 0; i < MAX_CLASS; i++)
+		listh_init(&font_classes[i]);
+	initialized = 1;
+}
+
+int	mdvi_get_font_classes(void)
+{
+	return (MAX_CLASS - 2);
+}
+
+char	**mdvi_list_font_class(int klass)
+{
+	char	**list;
+	int	i, n;
+	DviFontClass *fc;
+	
+	if(klass == -1)
+		klass = MAX_CLASS-1;
+	if(klass < 0 || klass >= MAX_CLASS)
+		return NULL;
+	n = font_classes[klass].count;
+	list = xnalloc(char *, n + 1);
+	fc = (DviFontClass *)font_classes[klass].head;
+	for(i = 0; i < n; fc = fc->next, i++) {
+		list[i] = mdvi_strdup(fc->info.name);
+	}
+	list[i] = NULL;
+	return list;
+}
+
+int	mdvi_register_font_type(DviFontInfo *info, int klass)
+{
+	DviFontClass *fc;
+
+	if(klass == -1)
+		klass = MAX_CLASS-1;
+	if(klass < 0 || klass >= MAX_CLASS)
+		return -1;
+	if(!initialized)
+		init_font_classes();
+	fc = xalloc(struct _DviFontClass);
+	fc->links = 0;
+	fc->id = klass;
+	fc->info.name = mdvi_strdup(info->name);
+	fc->info.scalable = info->scalable;
+	fc->info.load = info->load;
+	fc->info.getglyph = info->getglyph;
+	fc->info.shrink0 = info->shrink0;
+	fc->info.shrink1 = info->shrink1;
+	fc->info.freedata = info->freedata;
+	fc->info.reset = info->reset;
+	fc->info.lookup = info->lookup;
+	fc->info.kpse_type = info->kpse_type;
+	listh_append(&font_classes[klass], LIST(fc));
+	return 0;
+}
+
+int	mdvi_unregister_font_type(const char *name, int klass)
+{
+	DviFontClass *fc;
+	int	k;
+
+	if(klass == -1)
+		klass = MAX_CLASS - 1;
+	
+	if(klass >= 0 && klass < MAX_CLASS) {
+		k = klass;
+		LIST_FOREACH(fc, DviFontClass, &font_classes[k]) {
+			if(STREQ(fc->info.name, name))
+				break;
+		}
+	} else if(klass < 0) {
+		for(k = 0; k < MAX_CLASS; k++) {
+			LIST_FOREACH(fc, DviFontClass, &font_classes[k]) {
+				if(STREQ(fc->info.name, name))
+					break;
+			}
+			if(fc) break;
+		}
+	} else
+		return -1;
+	
+	if(fc == NULL || fc->links)
+		return -1;
+	/* remove it */
+	listh_remove(&font_classes[k], LIST(fc));
+	
+	/* and destroy it */
+	mdvi_free(fc->info.name);
+	mdvi_free(fc);
+	return 0;
+}
+
+static char *lookup_font(DviFontClass *ptr, const char *name, Ushort *h, Ushort *v)
+{
+	char	*filename;
+
+	/*
+	 * If the font type registered a function to do the lookup, use that. 
+	 * Otherwise we use kpathsea.
+	 */	
+	if(ptr->info.lookup)
+		filename = ptr->info.lookup(name, h, v);
+	else if(ptr->info.kpse_type <= kpse_any_glyph_format) {
+		kpse_glyph_file_type type;
+
+		filename = kpse_find_glyph(name, Max(*h, *v),
+			ptr->info.kpse_type, &type);
+		/* if kpathsea returned a fallback font, reject it */
+		if(filename && type.source == kpse_glyph_source_fallback) {
+			mdvi_free(filename);
+			filename = NULL;
+		} else if(filename)
+			*h = *v = type.dpi;
+	} else
+		filename = kpse_find_file(name, ptr->info.kpse_type, 1);
+	return filename;
+}
+
+/*
+ * Class MAX_CLASS-1 is special: it consists of `metric' fonts that should
+ * be tried as a last resort
+ */
+char	*mdvi_lookup_font(DviFontSearch *search)
+{
+	int kid;
+	int k;
+	DviFontClass *ptr;
+	DviFontClass *last;
+	char	*filename = NULL;
+	const char *name;
+	Ushort	hdpi, vdpi;
+
+	if(search->id < 0)
+		return NULL;
+	
+	if(search->curr == NULL) {
+		/* this is the initial search */
+		name = search->wanted_name;
+		hdpi = search->hdpi;
+		vdpi = search->vdpi;
+		kid = 0;
+		last = NULL;
+	} else {
+		name = search->actual_name;
+		hdpi = search->actual_hdpi;
+		vdpi = search->actual_vdpi;
+		kid = search->id;
+		last = search->curr;
+	}
+
+	ptr = NULL;
+again:
+	/* try all classes except MAX_CLASS-1 */
+	for(k = kid; !filename && k < MAX_CLASS-1; k++) {
+		if(last == NULL)
+			ptr = (DviFontClass *)font_classes[k].head;
+		else
+			ptr = last->next;
+		while(ptr) {
+			DEBUG((DBG_FONTS, "%d: trying `%s' at (%d,%d)dpi as `%s'\n",
+				k, name, hdpi, vdpi, ptr->info.name));
+			/* lookup the font in this class */
+			filename = lookup_font(ptr, name, &hdpi, &vdpi);
+			if(filename)
+				break;
+			ptr = ptr->next;
+		}
+		last = NULL;
+	}
+	if(filename != NULL) {
+		search->id = k-1;
+		search->curr = ptr;
+		search->actual_name = name;
+		search->actual_hdpi = hdpi;
+		search->actual_vdpi = vdpi;
+		search->info = &ptr->info;
+		ptr->links++;
+		return filename;
+	}
+
+	if(kid < MAX_CLASS - 1 && !STREQ(name, _mdvi_fallback_font)) {
+		mdvi_warning("font `%s' at %dx%d not found, trying `%s' instead\n",
+			     name, hdpi, vdpi, _mdvi_fallback_font);
+		name = _mdvi_fallback_font;
+		kid = 0;
+		goto again;
+	}
+
+	/* we tried the fallback font, and all the `real' classes. Let's
+	 * try the `metric' class now */
+	name = search->wanted_name;
+	hdpi = search->hdpi;
+	vdpi = search->vdpi;
+	if(kid == MAX_CLASS-1) {
+		/* we were looking into this class from the beginning */
+		if(last == NULL) {
+			/* no more fonts to try */
+			return NULL;
+		}
+		ptr = last->next;
+	} else {
+		mdvi_warning("font `%s' not found, trying metric files instead\n",
+			     name);
+		ptr = (DviFontClass *)font_classes[MAX_CLASS-1].head;
+	}
+
+metrics:
+	while(ptr) {
+		DEBUG((DBG_FONTS, "metric: trying `%s' at (%d,%d)dpi as `%s'\n",
+			name, hdpi, vdpi, ptr->info.name));
+		filename = lookup_font(ptr, name, &hdpi, &vdpi);
+		if(filename)
+			break;
+		ptr = ptr->next;
+	}
+	if(filename != NULL) {
+		if(STREQ(name, _mdvi_fallback_font))
+			search->id = MAX_CLASS;
+		else
+			search->id = MAX_CLASS - 1;
+		search->curr = ptr;
+		search->actual_name = name;
+		search->actual_hdpi = hdpi;
+		search->actual_vdpi = vdpi;
+		search->info = &ptr->info;
+		ptr->links++;
+		return filename;
+	}
+	if(!STREQ(name, _mdvi_fallback_font)) {
+		mdvi_warning("metric file for `%s' not found, trying `%s' instead\n",
+			     name, _mdvi_fallback_font);
+		name = _mdvi_fallback_font;
+		ptr = (DviFontClass *)font_classes[MAX_CLASS-1].head;
+		goto metrics;
+	}
+
+	search->id = -1;
+	search->actual_name = NULL;
+	
+	/* tough luck, nothing found */
+	return NULL;
+}
+
+/* called by `font_reference' to do the initial lookup */
+DviFont	*mdvi_add_font(const char *name, Int32 sum,
+	int hdpi, int vdpi, Int32 scale)
+{
+	DviFont	*font;
+	
+	font = xalloc(DviFont);
+	font->fontname = mdvi_strdup(name);
+	SEARCH_INIT(font->search, font->fontname, hdpi, vdpi);
+	font->filename = mdvi_lookup_font(&font->search);
+	if(font->filename == NULL) {
+		/* this answer is final */
+		mdvi_free(font->fontname);
+		mdvi_free(font);
+		return NULL;
+	}
+	font->hdpi = font->search.actual_hdpi;
+	font->vdpi = font->search.actual_vdpi;
+	font->scale = scale;
+	font->design = 0;
+	font->checksum = sum;
+	font->type = 0;
+	font->links = 0;
+	font->loc = 0;
+	font->hic = 0;
+	font->in = NULL;
+	font->chars = NULL;
+	font->subfonts = NULL;
+
+	return font;
+}
+
+int	mdvi_font_retry(DviParams *params, DviFont *font)
+{
+	/* try the search again */
+	char	*filename;
+
+	ASSERT(font->search.curr != NULL);	
+	/* we won't be using this class anymore */
+	font->search.curr->links--;
+
+	filename = mdvi_lookup_font(&font->search);
+	if(filename == NULL)
+		return -1;
+	mdvi_free(font->filename);
+	font->filename = filename;
+	/* copy the new information */
+	font->hdpi = font->search.actual_hdpi;
+	font->vdpi = font->search.actual_vdpi;
+
+	return 0;
+}