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ttpload.c

Last change on this file was 2, checked in by jglee, 11 years ago
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File size: 19.1 KB

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1	/***************************************************************************/
2	/* */
3	/* ttpload.c */
4	/* */
5	/* TrueType-specific tables loader (body). */
6	/* */
7	/* Copyright 1996-2001, 2002, 2004, 2005, 2006, 2007, 2008 by */
8	/* David Turner, Robert Wilhelm, and Werner Lemberg. */
9	/* */
10	/* This file is part of the FreeType project, and may only be used, */
11	/* modified, and distributed under the terms of the FreeType project */
12	/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
13	/* this file you indicate that you have read the license and */
14	/* understand and accept it fully. */
15	/* */
16	/***************************************************************************/
17
18
19	#include <ft2build.h>
20	#include FT_INTERNAL_DEBUG_H
21	#include FT_INTERNAL_OBJECTS_H
22	#include FT_INTERNAL_STREAM_H
23	#include FT_TRUETYPE_TAGS_H
24
25	#include "ttpload.h"
26
27	#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
28	#include "ttgxvar.h"
29	#endif
30
31	#include "tterrors.h"
32
33
34	/*************************************************************************/
35	/* */
36	/* The macro FT_COMPONENT is used in trace mode. It is an implicit */
37	/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
38	/* messages during execution. */
39	/* */
40	#undef FT_COMPONENT
41	#define FT_COMPONENT trace_ttpload
42
43
44	/*************************************************************************/
45	/* */
46	/* <Function> */
47	/* tt_face_load_loca */
48	/* */
49	/* <Description> */
50	/* Load the locations table. */
51	/* */
52	/* <InOut> */
53	/* face :: A handle to the target face object. */
54	/* */
55	/* <Input> */
56	/* stream :: The input stream. */
57	/* */
58	/* <Return> */
59	/* FreeType error code. 0 means success. */
60	/* */
61
62	FT_LOCAL_DEF( FT_Error )
63	tt_face_load_loca( TT_Face face,
64	FT_Stream stream )
65	{
66	FT_Error error;
67	FT_ULong table_len;
68	FT_Int shift;
69
70
71	/* we need the size of the `glyf' table for malformed `loca' tables */
72	error = face->goto_table( face, TTAG_glyf, stream, &face->glyf_len );
73
74	/* it is possible that a font doesn't have a glyf table at all */
75	/* or its size is zero */
76	if ( error == TT_Err_Table_Missing )
77	face->glyf_len = 0;
78	else if ( error )
79	goto Exit;
80
81	FT_TRACE2(( "Locations " ));
82	error = face->goto_table( face, TTAG_loca, stream, &table_len );
83	if ( error )
84	{
85	error = TT_Err_Locations_Missing;
86	goto Exit;
87	}
88
89	if ( face->header.Index_To_Loc_Format != 0 )
90	{
91	shift = 2;
92
93	if ( table_len >= 0x40000L )
94	{
95	FT_TRACE2(( "table too large!\n" ));
96	error = TT_Err_Invalid_Table;
97	goto Exit;
98	}
99	face->num_locations = (FT_UInt)( table_len >> shift );
100	}
101	else
102	{
103	shift = 1;
104
105	if ( table_len >= 0x20000L )
106	{
107	FT_TRACE2(( "table too large!\n" ));
108	error = TT_Err_Invalid_Table;
109	goto Exit;
110	}
111	face->num_locations = (FT_UInt)( table_len >> shift );
112	}
113
114	if ( face->num_locations != (FT_UInt)face->root.num_glyphs )
115	{
116	FT_TRACE2(( "glyph count mismatch! loca: %d, maxp: %d\n",
117	face->num_locations, face->root.num_glyphs ));
118
119	/* we only handle the case where `maxp' gives a larger value */
120	if ( face->num_locations < (FT_UInt)face->root.num_glyphs )
121	{
122	FT_Long new_loca_len = (FT_Long)face->root.num_glyphs << shift;
123
124	TT_Table entry = face->dir_tables;
125	TT_Table limit = entry + face->num_tables;
126
127	FT_Long pos = FT_Stream_Pos( stream );
128	FT_Long dist = 0x7FFFFFFFL;
129
130
131	/* compute the distance to next table in font file */
132	for ( ; entry < limit; entry++ )
133	{
134	FT_Long diff = entry->Offset - pos;
135
136
137	if ( diff > 0 && diff < dist )
138	dist = diff;
139	}
140
141	if ( new_loca_len <= dist )
142	{
143	face->num_locations = (FT_Long)face->root.num_glyphs;
144	table_len = new_loca_len;
145
146	FT_TRACE2(( "adjusting num_locations to %d\n",
147	face->num_locations ));
148	}
149	}
150	}
151
152	/*
153	* Extract the frame. We don't need to decompress it since
154	* we are able to parse it directly.
155	*/
156	if ( FT_FRAME_EXTRACT( table_len, face->glyph_locations ) )
157	goto Exit;
158
159	FT_TRACE2(( "loaded\n" ));
160
161	Exit:
162	return error;
163	}
164
165
166	FT_LOCAL_DEF( FT_ULong )
167	tt_face_get_location( TT_Face face,
168	FT_UInt gindex,
169	FT_UInt *asize )
170	{
171	FT_ULong pos1, pos2;
172	FT_Byte* p;
173	FT_Byte* p_limit;
174
175
176	pos1 = pos2 = 0;
177
178	if ( gindex < face->num_locations )
179	{
180	if ( face->header.Index_To_Loc_Format != 0 )
181	{
182	p = face->glyph_locations + gindex * 4;
183	p_limit = face->glyph_locations + face->num_locations * 4;
184
185	pos1 = FT_NEXT_ULONG( p );
186	pos2 = pos1;
187
188	if ( p + 4 <= p_limit )
189	pos2 = FT_NEXT_ULONG( p );
190	}
191	else
192	{
193	p = face->glyph_locations + gindex * 2;
194	p_limit = face->glyph_locations + face->num_locations * 2;
195
196	pos1 = FT_NEXT_USHORT( p );
197	pos2 = pos1;
198
199	if ( p + 2 <= p_limit )
200	pos2 = FT_NEXT_USHORT( p );
201
202	pos1 <<= 1;
203	pos2 <<= 1;
204	}
205	}
206
207	/* It isn't mentioned explicitly that the `loca' table must be */
208	/* ordered, but implicitly it refers to the length of an entry */
209	/* as the difference between the current and the next position. */
210	/* Anyway, there do exist (malformed) fonts which don't obey */
211	/* this rule, so we are only able to provide an upper bound for */
212	/* the size. */
213	/* */
214	/* We get (intentionally) a wrong, non-zero result in case the */
215	/* `glyf' table is missing. */
216	if ( pos2 >= pos1 )
217	*asize = (FT_UInt)( pos2 - pos1 );
218	else
219	*asize = (FT_UInt)( face->glyf_len - pos1 );
220
221	return pos1;
222	}
223
224
225	FT_LOCAL_DEF( void )
226	tt_face_done_loca( TT_Face face )
227	{
228	FT_Stream stream = face->root.stream;
229
230
231	FT_FRAME_RELEASE( face->glyph_locations );
232	face->num_locations = 0;
233	}
234
235
236
237	/*************************************************************************/
238	/* */
239	/* <Function> */
240	/* tt_face_load_cvt */
241	/* */
242	/* <Description> */
243	/* Load the control value table into a face object. */
244	/* */
245	/* <InOut> */
246	/* face :: A handle to the target face object. */
247	/* */
248	/* <Input> */
249	/* stream :: A handle to the input stream. */
250	/* */
251	/* <Return> */
252	/* FreeType error code. 0 means success. */
253	/* */
254	FT_LOCAL_DEF( FT_Error )
255	tt_face_load_cvt( TT_Face face,
256	FT_Stream stream )
257	{
258	#ifdef TT_USE_BYTECODE_INTERPRETER
259
260	FT_Error error;
261	FT_Memory memory = stream->memory;
262	FT_ULong table_len;
263
264
265	FT_TRACE2(( "CVT " ));
266
267	error = face->goto_table( face, TTAG_cvt, stream, &table_len );
268	if ( error )
269	{
270	FT_TRACE2(( "is missing!\n" ));
271
272	face->cvt_size = 0;
273	face->cvt = NULL;
274	error = TT_Err_Ok;
275
276	goto Exit;
277	}
278
279	face->cvt_size = table_len / 2;
280
281	if ( FT_NEW_ARRAY( face->cvt, face->cvt_size ) )
282	goto Exit;
283
284	if ( FT_FRAME_ENTER( face->cvt_size * 2L ) )
285	goto Exit;
286
287	{
288	FT_Short* cur = face->cvt;
289	FT_Short* limit = cur + face->cvt_size;
290
291
292	for ( ; cur < limit; cur++ )
293	*cur = FT_GET_SHORT();
294	}
295
296	FT_FRAME_EXIT();
297	FT_TRACE2(( "loaded\n" ));
298
299	#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
300	if ( face->doblend )
301	error = tt_face_vary_cvt( face, stream );
302	#endif
303
304	Exit:
305	return error;
306
307	#else /* !TT_USE_BYTECODE_INTERPRETER */
308
309	FT_UNUSED( face );
310	FT_UNUSED( stream );
311
312	return TT_Err_Ok;
313
314	#endif
315	}
316
317
318	/*************************************************************************/
319	/* */
320	/* <Function> */
321	/* tt_face_load_fpgm */
322	/* */
323	/* <Description> */
324	/* Load the font program. */
325	/* */
326	/* <InOut> */
327	/* face :: A handle to the target face object. */
328	/* */
329	/* <Input> */
330	/* stream :: A handle to the input stream. */
331	/* */
332	/* <Return> */
333	/* FreeType error code. 0 means success. */
334	/* */
335	FT_LOCAL_DEF( FT_Error )
336	tt_face_load_fpgm( TT_Face face,
337	FT_Stream stream )
338	{
339	#ifdef TT_USE_BYTECODE_INTERPRETER
340
341	FT_Error error;
342	FT_ULong table_len;
343
344
345	FT_TRACE2(( "Font program " ));
346
347	/* The font program is optional */
348	error = face->goto_table( face, TTAG_fpgm, stream, &table_len );
349	if ( error )
350	{
351	face->font_program = NULL;
352	face->font_program_size = 0;
353	error = TT_Err_Ok;
354
355	FT_TRACE2(( "is missing!\n" ));
356	}
357	else
358	{
359	face->font_program_size = table_len;
360	if ( FT_FRAME_EXTRACT( table_len, face->font_program ) )
361	goto Exit;
362
363	FT_TRACE2(( "loaded, %12d bytes\n", face->font_program_size ));
364	}
365
366	Exit:
367	return error;
368
369	#else /* !TT_USE_BYTECODE_INTERPRETER */
370
371	FT_UNUSED( face );
372	FT_UNUSED( stream );
373
374	return TT_Err_Ok;
375
376	#endif
377	}
378
379
380	/*************************************************************************/
381	/* */
382	/* <Function> */
383	/* tt_face_load_prep */
384	/* */
385	/* <Description> */
386	/* Load the cvt program. */
387	/* */
388	/* <InOut> */
389	/* face :: A handle to the target face object. */
390	/* */
391	/* <Input> */
392	/* stream :: A handle to the input stream. */
393	/* */
394	/* <Return> */
395	/* FreeType error code. 0 means success. */
396	/* */
397	FT_LOCAL_DEF( FT_Error )
398	tt_face_load_prep( TT_Face face,
399	FT_Stream stream )
400	{
401	#ifdef TT_USE_BYTECODE_INTERPRETER
402
403	FT_Error error;
404	FT_ULong table_len;
405
406
407	FT_TRACE2(( "Prep program " ));
408
409	error = face->goto_table( face, TTAG_prep, stream, &table_len );
410	if ( error )
411	{
412	face->cvt_program = NULL;
413	face->cvt_program_size = 0;
414	error = TT_Err_Ok;
415
416	FT_TRACE2(( "is missing!\n" ));
417	}
418	else
419	{
420	face->cvt_program_size = table_len;
421	if ( FT_FRAME_EXTRACT( table_len, face->cvt_program ) )
422	goto Exit;
423
424	FT_TRACE2(( "loaded, %12d bytes\n", face->cvt_program_size ));
425	}
426
427	Exit:
428	return error;
429
430	#else /* !TT_USE_BYTECODE_INTERPRETER */
431
432	FT_UNUSED( face );
433	FT_UNUSED( stream );
434
435	return TT_Err_Ok;
436
437	#endif
438	}
439
440
441	/*************************************************************************/
442	/* */
443	/* <Function> */
444	/* tt_face_load_hdmx */
445	/* */
446	/* <Description> */
447	/* Load the `hdmx' table into the face object. */
448	/* */
449	/* <Input> */
450	/* face :: A handle to the target face object. */
451	/* */
452	/* stream :: A handle to the input stream. */
453	/* */
454	/* <Return> */
455	/* FreeType error code. 0 means success. */
456	/* */
457
458	FT_LOCAL_DEF( FT_Error )
459	tt_face_load_hdmx( TT_Face face,
460	FT_Stream stream )
461	{
462	FT_Error error;
463	FT_Memory memory = stream->memory;
464	FT_UInt version, nn, num_records;
465	FT_ULong table_size, record_size;
466	FT_Byte* p;
467	FT_Byte* limit;
468
469
470	/* this table is optional */
471	error = face->goto_table( face, TTAG_hdmx, stream, &table_size );
472	if ( error \|\| table_size < 8 )
473	return TT_Err_Ok;
474
475	if ( FT_FRAME_EXTRACT( table_size, face->hdmx_table ) )
476	goto Exit;
477
478	p = face->hdmx_table;
479	limit = p + table_size;
480
481	version = FT_NEXT_USHORT( p );
482	num_records = FT_NEXT_USHORT( p );
483	record_size = FT_NEXT_ULONG( p );
484
485	/* The maximum number of bytes in an hdmx device record is the */
486	/* maximum number of glyphs + 2; this is 0xFFFF + 2; this is */
487	/* the reason why `record_size' is a long (which we read as */
488	/* unsigned long for convenience). In practice, two bytes */
489	/* sufficient to hold the size value. */
490	/* */
491	/* There are at least two fonts, HANNOM-A and HANNOM-B version */
492	/* 2.0 (2005), which get this wrong: The upper two bytes of */
493	/* the size value are set to 0xFF instead of 0x00. We catch */
494	/* and fix this. */
495
496	if ( record_size >= 0xFFFF0000UL )
497	record_size &= 0xFFFFU;
498
499	/* The limit for `num_records' is a heuristic value. */
500
501	if ( version != 0 \|\| num_records > 255 \|\| record_size > 0x10001L )
502	{
503	error = TT_Err_Invalid_File_Format;
504	goto Fail;
505	}
506
507	if ( FT_NEW_ARRAY( face->hdmx_record_sizes, num_records ) )
508	goto Fail;
509
510	for ( nn = 0; nn < num_records; nn++ )
511	{
512	if ( p + record_size > limit )
513	break;
514
515	face->hdmx_record_sizes[nn] = p[0];
516	p += record_size;
517	}
518
519	face->hdmx_record_count = nn;
520	face->hdmx_table_size = table_size;
521	face->hdmx_record_size = record_size;
522
523	Exit:
524	return error;
525
526	Fail:
527	FT_FRAME_RELEASE( face->hdmx_table );
528	face->hdmx_table_size = 0;
529	goto Exit;
530	}
531
532
533	FT_LOCAL_DEF( void )
534	tt_face_free_hdmx( TT_Face face )
535	{
536	FT_Stream stream = face->root.stream;
537	FT_Memory memory = stream->memory;
538
539
540	FT_FREE( face->hdmx_record_sizes );
541	FT_FRAME_RELEASE( face->hdmx_table );
542	}
543
544
545	/*************************************************************************/
546	/* */
547	/* Return the advance width table for a given pixel size if it is found */
548	/* in the font's `hdmx' table (if any). */
549	/* */
550	FT_LOCAL_DEF( FT_Byte* )
551	tt_face_get_device_metrics( TT_Face face,
552	FT_UInt ppem,
553	FT_UInt gindex )
554	{
555	FT_UInt nn;
556	FT_Byte* result = NULL;
557	FT_ULong record_size = face->hdmx_record_size;
558	FT_Byte* record = face->hdmx_table + 8;
559
560
561	for ( nn = 0; nn < face->hdmx_record_count; nn++ )
562	if ( face->hdmx_record_sizes[nn] == ppem )
563	{
564	gindex += 2;
565	if ( gindex < record_size )
566	result = record + nn * record_size + gindex;
567	break;
568	}
569
570	return result;
571	}
572
573
574	/* END */

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source: svn/trunk/zasc/freetype-2.3.9/ttpload.c

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