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ttmtx.c

Last change on this file was 2, checked in by jglee, 11 years ago
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File size: 15.4 KB

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1	/***************************************************************************/
2	/* */
3	/* ttmtx.c */
4	/* */
5	/* Load the metrics tables common to TTF and OTF fonts (body). */
6	/* */
7	/* Copyright 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_STREAM_H
22	#include FT_TRUETYPE_TAGS_H
23	#include "ttmtx.h"
24
25	#include "sferrors.h"
26
27
28	/*************************************************************************/
29	/* */
30	/* The macro FT_COMPONENT is used in trace mode. It is an implicit */
31	/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
32	/* messages during execution. */
33	/* */
34	#undef FT_COMPONENT
35	#define FT_COMPONENT trace_ttmtx
36
37
38	/*
39	* Unfortunately, we can't enable our memory optimizations if
40	* FT_CONFIG_OPTION_OLD_INTERNALS is defined. This is because at least
41	* one rogue client (libXfont in the X.Org XServer) is directly accessing
42	* the metrics.
43	*/
44
45	/*************************************************************************/
46	/* */
47	/* <Function> */
48	/* tt_face_load_hmtx */
49	/* */
50	/* <Description> */
51	/* Load the `hmtx' or `vmtx' table into a face object. */
52	/* */
53	/* <Input> */
54	/* face :: A handle to the target face object. */
55	/* */
56	/* stream :: The input stream. */
57	/* */
58	/* vertical :: A boolean flag. If set, load `vmtx'. */
59	/* */
60	/* <Return> */
61	/* FreeType error code. 0 means success. */
62	/* */
63	#ifndef FT_CONFIG_OPTION_OLD_INTERNALS
64
65	FT_LOCAL_DEF( FT_Error )
66	tt_face_load_hmtx( TT_Face face,
67	FT_Stream stream,
68	FT_Bool vertical )
69	{
70	FT_Error error;
71	FT_ULong tag, table_size;
72	FT_ULong* ptable_offset;
73	FT_ULong* ptable_size;
74
75
76	if ( vertical )
77	{
78	tag = TTAG_vmtx;
79	ptable_offset = &face->vert_metrics_offset;
80	ptable_size = &face->vert_metrics_size;
81	}
82	else
83	{
84	tag = TTAG_hmtx;
85	ptable_offset = &face->horz_metrics_offset;
86	ptable_size = &face->horz_metrics_size;
87	}
88
89	error = face->goto_table( face, tag, stream, &table_size );
90	if ( error )
91	goto Fail;
92
93	*ptable_size = table_size;
94	*ptable_offset = FT_STREAM_POS();
95
96	Fail:
97	return error;
98	}
99
100	#else /* !FT_CONFIG_OPTION_OLD_INTERNALS */
101
102	FT_LOCAL_DEF( FT_Error )
103	tt_face_load_hmtx( TT_Face face,
104	FT_Stream stream,
105	FT_Bool vertical )
106	{
107	FT_Error error;
108	FT_Memory memory = stream->memory;
109
110	FT_ULong table_len;
111	FT_Long num_shorts, num_longs, num_shorts_checked;
112
113	TT_LongMetrics* longs;
114	TT_ShortMetrics** shorts;
115	FT_Byte* p;
116
117
118	if ( vertical )
119	{
120	void* lm = &face->vertical.long_metrics;
121	void** sm = &face->vertical.short_metrics;
122
123
124	error = face->goto_table( face, TTAG_vmtx, stream, &table_len );
125	if ( error )
126	goto Fail;
127
128	num_longs = face->vertical.number_Of_VMetrics;
129	if ( (FT_ULong)num_longs > table_len / 4 )
130	num_longs = (FT_Long)( table_len / 4 );
131
132	face->vertical.number_Of_VMetrics = 0;
133
134	longs = (TT_LongMetrics*)lm;
135	shorts = (TT_ShortMetrics**)sm;
136	}
137	else
138	{
139	void* lm = &face->horizontal.long_metrics;
140	void** sm = &face->horizontal.short_metrics;
141
142
143	error = face->goto_table( face, TTAG_hmtx, stream, &table_len );
144	if ( error )
145	goto Fail;
146
147	num_longs = face->horizontal.number_Of_HMetrics;
148	if ( (FT_ULong)num_longs > table_len / 4 )
149	num_longs = (FT_Long)( table_len / 4 );
150
151	face->horizontal.number_Of_HMetrics = 0;
152
153	longs = (TT_LongMetrics*)lm;
154	shorts = (TT_ShortMetrics**)sm;
155	}
156
157	/* never trust derived values */
158
159	num_shorts = face->max_profile.numGlyphs - num_longs;
160	num_shorts_checked = ( table_len - num_longs * 4L ) / 2;
161
162	if ( num_shorts < 0 )
163	{
164	FT_ERROR(( "%cmtx has more metrics than glyphs.\n" ));
165
166	/* Adobe simply ignores this problem. So we shall do the same. */
167	#if 0
168	error = vertical ? SFNT_Err_Invalid_Vert_Metrics
169	: SFNT_Err_Invalid_Horiz_Metrics;
170	goto Exit;
171	#else
172	num_shorts = 0;
173	#endif
174	}
175
176	if ( FT_QNEW_ARRAY( *longs, num_longs ) \|\|
177	FT_QNEW_ARRAY( *shorts, num_shorts ) )
178	goto Fail;
179
180	if ( FT_FRAME_ENTER( table_len ) )
181	goto Fail;
182
183	p = stream->cursor;
184
185	{
186	TT_LongMetrics cur = *longs;
187	TT_LongMetrics limit = cur + num_longs;
188
189
190	for ( ; cur < limit; cur++ )
191	{
192	cur->advance = FT_NEXT_USHORT( p );
193	cur->bearing = FT_NEXT_SHORT( p );
194	}
195	}
196
197	/* do we have an inconsistent number of metric values? */
198	{
199	TT_ShortMetrics* cur = *shorts;
200	TT_ShortMetrics* limit = cur +
201	FT_MIN( num_shorts, num_shorts_checked );
202
203
204	for ( ; cur < limit; cur++ )
205	*cur = FT_NEXT_SHORT( p );
206
207	/* We fill up the missing left side bearings with the */
208	/* last valid value. Since this will occur for buggy CJK */
209	/* fonts usually only, nothing serious will happen. */
210	if ( num_shorts > num_shorts_checked && num_shorts_checked > 0 )
211	{
212	FT_Short val = (*shorts)[num_shorts_checked - 1];
213
214
215	limit = *shorts + num_shorts;
216	for ( ; cur < limit; cur++ )
217	*cur = val;
218	}
219	}
220
221	FT_FRAME_EXIT();
222
223	if ( vertical )
224	face->vertical.number_Of_VMetrics = (FT_UShort)num_longs;
225	else
226	face->horizontal.number_Of_HMetrics = (FT_UShort)num_longs;
227
228	Fail:
229	return error;
230	}
231
232	#endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */
233
234
235	/*************************************************************************/
236	/* */
237	/* <Function> */
238	/* tt_face_load_hhea */
239	/* */
240	/* <Description> */
241	/* Load the `hhea' or 'vhea' table into a face object. */
242	/* */
243	/* <Input> */
244	/* face :: A handle to the target face object. */
245	/* */
246	/* stream :: The input stream. */
247	/* */
248	/* vertical :: A boolean flag. If set, load `vhea'. */
249	/* */
250	/* <Return> */
251	/* FreeType error code. 0 means success. */
252	/* */
253	FT_LOCAL_DEF( FT_Error )
254	tt_face_load_hhea( TT_Face face,
255	FT_Stream stream,
256	FT_Bool vertical )
257	{
258	FT_Error error;
259	TT_HoriHeader* header;
260
261	const FT_Frame_Field metrics_header_fields[] =
262	{
263	#undef FT_STRUCTURE
264	#define FT_STRUCTURE TT_HoriHeader
265
266	FT_FRAME_START( 36 ),
267	FT_FRAME_ULONG ( Version ),
268	FT_FRAME_SHORT ( Ascender ),
269	FT_FRAME_SHORT ( Descender ),
270	FT_FRAME_SHORT ( Line_Gap ),
271	FT_FRAME_USHORT( advance_Width_Max ),
272	FT_FRAME_SHORT ( min_Left_Side_Bearing ),
273	FT_FRAME_SHORT ( min_Right_Side_Bearing ),
274	FT_FRAME_SHORT ( xMax_Extent ),
275	FT_FRAME_SHORT ( caret_Slope_Rise ),
276	FT_FRAME_SHORT ( caret_Slope_Run ),
277	FT_FRAME_SHORT ( caret_Offset ),
278	FT_FRAME_SHORT ( Reserved[0] ),
279	FT_FRAME_SHORT ( Reserved[1] ),
280	FT_FRAME_SHORT ( Reserved[2] ),
281	FT_FRAME_SHORT ( Reserved[3] ),
282	FT_FRAME_SHORT ( metric_Data_Format ),
283	FT_FRAME_USHORT( number_Of_HMetrics ),
284	FT_FRAME_END
285	};
286
287
288	if ( vertical )
289	{
290	void *v = &face->vertical;
291
292
293	error = face->goto_table( face, TTAG_vhea, stream, 0 );
294	if ( error )
295	goto Fail;
296
297	header = (TT_HoriHeader*)v;
298	}
299	else
300	{
301	error = face->goto_table( face, TTAG_hhea, stream, 0 );
302	if ( error )
303	goto Fail;
304
305	header = &face->horizontal;
306	}
307
308	if ( FT_STREAM_READ_FIELDS( metrics_header_fields, header ) )
309	goto Fail;
310
311	FT_TRACE3(( "Ascender: %5d\n", header->Ascender ));
312	FT_TRACE3(( "Descender: %5d\n", header->Descender ));
313	FT_TRACE3(( "number_Of_Metrics: %5u\n", header->number_Of_HMetrics ));
314
315	header->long_metrics = NULL;
316	header->short_metrics = NULL;
317
318	Fail:
319	return error;
320	}
321
322
323	/*************************************************************************/
324	/* */
325	/* <Function> */
326	/* tt_face_get_metrics */
327	/* */
328	/* <Description> */
329	/* Returns the horizontal or vertical metrics in font units for a */
330	/* given glyph. The metrics are the left side bearing (resp. top */
331	/* side bearing) and advance width (resp. advance height). */
332	/* */
333	/* <Input> */
334	/* header :: A pointer to either the horizontal or vertical metrics */
335	/* structure. */
336	/* */
337	/* idx :: The glyph index. */
338	/* */
339	/* <Output> */
340	/* bearing :: The bearing, either left side or top side. */
341	/* */
342	/* advance :: The advance width resp. advance height. */
343	/* */
344	#ifndef FT_CONFIG_OPTION_OLD_INTERNALS
345
346	FT_LOCAL_DEF( FT_Error )
347	tt_face_get_metrics( TT_Face face,
348	FT_Bool vertical,
349	FT_UInt gindex,
350	FT_Short *abearing,
351	FT_UShort *aadvance )
352	{
353	FT_Error error;
354	FT_Stream stream = face->root.stream;
355	TT_HoriHeader* header;
356	FT_ULong table_pos, table_size, table_end;
357	FT_UShort k;
358
359
360	if ( vertical )
361	{
362	void* v = &face->vertical;
363
364
365	header = (TT_HoriHeader*)v;
366	table_pos = face->vert_metrics_offset;
367	table_size = face->vert_metrics_size;
368	}
369	else
370	{
371	header = &face->horizontal;
372	table_pos = face->horz_metrics_offset;
373	table_size = face->horz_metrics_size;
374	}
375
376	table_end = table_pos + table_size;
377
378	k = header->number_Of_HMetrics;
379
380	if ( k > 0 )
381	{
382	if ( gindex < (FT_UInt)k )
383	{
384	table_pos += 4 * gindex;
385	if ( table_pos + 4 > table_end )
386	goto NoData;
387
388	if ( FT_STREAM_SEEK( table_pos ) \|\|
389	FT_READ_USHORT( *aadvance ) \|\|
390	FT_READ_SHORT( *abearing ) )
391	goto NoData;
392	}
393	else
394	{
395	table_pos += 4 * ( k - 1 );
396	if ( table_pos + 4 > table_end )
397	goto NoData;
398
399	if ( FT_STREAM_SEEK( table_pos ) \|\|
400	FT_READ_USHORT( *aadvance ) )
401	goto NoData;
402
403	table_pos += 4 + 2 * ( gindex - k );
404	if ( table_pos + 2 > table_end )
405	*abearing = 0;
406	else
407	{
408	if ( !FT_STREAM_SEEK( table_pos ) )
409	(void)FT_READ_SHORT( *abearing );
410	}
411	}
412	}
413	else
414	{
415	NoData:
416	*abearing = 0;
417	*aadvance = 0;
418	}
419
420	return SFNT_Err_Ok;
421	}
422
423	#else /* !FT_CONFIG_OPTION_OLD_INTERNALS */
424
425	FT_LOCAL_DEF( FT_Error )
426	tt_face_get_metrics( TT_Face face,
427	FT_Bool vertical,
428	FT_UInt gindex,
429	FT_Short* abearing,
430	FT_UShort* aadvance )
431	{
432	void* v = &face->vertical;
433	void* h = &face->horizontal;
434	TT_HoriHeader* header = vertical ? (TT_HoriHeader*)v
435	: (TT_HoriHeader*)h;
436	TT_LongMetrics longs_m;
437	FT_UShort k = header->number_Of_HMetrics;
438
439
440	if ( k == 0 \|\|
441	!header->long_metrics \|\|
442	gindex >= (FT_UInt)face->max_profile.numGlyphs )
443	{
444	abearing = aadvance = 0;
445	return SFNT_Err_Ok;
446	}
447
448	if ( gindex < (FT_UInt)k )
449	{
450	longs_m = (TT_LongMetrics)header->long_metrics + gindex;
451	*abearing = longs_m->bearing;
452	*aadvance = longs_m->advance;
453	}
454	else
455	{
456	abearing = ((TT_ShortMetrics)header->short_metrics)[gindex - k];
457	*aadvance = ((TT_LongMetrics)header->long_metrics)[k - 1].advance;
458	}
459
460	return SFNT_Err_Ok;
461	}
462
463	#endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */
464
465
466	/* END */

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

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