summaryrefslogtreecommitdiff
path: root/backend/dvi/mdvi-lib/fontsrch.c
blob: 8ebaa5ca0dd1e2af2aca3c227fd17f1fa9e95b22 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
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;
}