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source: trunk/poppler/freetype2/include/freetype/ftglyph.h @ 262

Last change on this file since 262 was 262, checked in by Eugene Romanenko, 12 years ago
PDF plugin: freetype library updated to version 2.3.8
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1	/***************************************************************************/
2	/* */
3	/* ftglyph.h */
4	/* */
5	/* FreeType convenience functions to handle glyphs (specification). */
6	/* */
7	/* Copyright 1996-2001, 2002, 2003, 2006, 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	/*************************************************************************/
20	/* */
21	/* This file contains the definition of several convenience functions */
22	/* that can be used by client applications to easily retrieve glyph */
23	/* bitmaps and outlines from a given face. */
24	/* */
25	/* These functions should be optional if you are writing a font server */
26	/* or text layout engine on top of FreeType. However, they are pretty */
27	/* handy for many other simple uses of the library. */
28	/* */
29	/*************************************************************************/
30
31
32	#ifndef __FTGLYPH_H__
33	#define __FTGLYPH_H__
34
35
36	#include <ft2build.h>
37	#include FT_FREETYPE_H
38
39	#ifdef FREETYPE_H
40	#error "freetype.h of FreeType 1 has been loaded!"
41	#error "Please fix the directory search order for header files"
42	#error "so that freetype.h of FreeType 2 is found first."
43	#endif
44
45
46	FT_BEGIN_HEADER
47
48
49	/*************************************************************************/
50	/* */
51	/* <Section> */
52	/* glyph_management */
53	/* */
54	/* <Title> */
55	/* Glyph Management */
56	/* */
57	/* <Abstract> */
58	/* Generic interface to manage individual glyph data. */
59	/* */
60	/* <Description> */
61	/* This section contains definitions used to manage glyph data */
62	/* through generic FT_Glyph objects. Each of them can contain a */
63	/* bitmap, a vector outline, or even images in other formats. */
64	/* */
65	/*************************************************************************/
66
67
68	/* forward declaration to a private type */
69	typedef struct FT_Glyph_Class_ FT_Glyph_Class;
70
71
72	/*************************************************************************/
73	/* */
74	/* <Type> */
75	/* FT_Glyph */
76	/* */
77	/* <Description> */
78	/* Handle to an object used to model generic glyph images. It is a */
79	/* pointer to the @FT_GlyphRec structure and can contain a glyph */
80	/* bitmap or pointer. */
81	/* */
82	/* <Note> */
83	/* Glyph objects are not owned by the library. You must thus release */
84	/* them manually (through @FT_Done_Glyph) _before_ calling */
85	/* @FT_Done_FreeType. */
86	/* */
87	typedef struct FT_GlyphRec_* FT_Glyph;
88
89
90	/*************************************************************************/
91	/* */
92	/* <Struct> */
93	/* FT_GlyphRec */
94	/* */
95	/* <Description> */
96	/* The root glyph structure contains a given glyph image plus its */
97	/* advance width in 16.16 fixed float format. */
98	/* */
99	/* <Fields> */
100	/* library :: A handle to the FreeType library object. */
101	/* */
102	/* clazz :: A pointer to the glyph's class. Private. */
103	/* */
104	/* format :: The format of the glyph's image. */
105	/* */
106	/* advance :: A 16.16 vector that gives the glyph's advance width. */
107	/* */
108	typedef struct FT_GlyphRec_
109	{
110	FT_Library library;
111	const FT_Glyph_Class* clazz;
112	FT_Glyph_Format format;
113	FT_Vector advance;
114
115	} FT_GlyphRec;
116
117
118	/*************************************************************************/
119	/* */
120	/* <Type> */
121	/* FT_BitmapGlyph */
122	/* */
123	/* <Description> */
124	/* A handle to an object used to model a bitmap glyph image. This is */
125	/* a sub-class of @FT_Glyph, and a pointer to @FT_BitmapGlyphRec. */
126	/* */
127	typedef struct FT_BitmapGlyphRec_* FT_BitmapGlyph;
128
129
130	/*************************************************************************/
131	/* */
132	/* <Struct> */
133	/* FT_BitmapGlyphRec */
134	/* */
135	/* <Description> */
136	/* A structure used for bitmap glyph images. This really is a */
137	/* `sub-class' of @FT_GlyphRec. */
138	/* */
139	/* <Fields> */
140	/* root :: The root @FT_Glyph fields. */
141	/* */
142	/* left :: The left-side bearing, i.e., the horizontal distance */
143	/* from the current pen position to the left border of the */
144	/* glyph bitmap. */
145	/* */
146	/* top :: The top-side bearing, i.e., the vertical distance from */
147	/* the current pen position to the top border of the glyph */
148	/* bitmap. This distance is positive for upwards~y! */
149	/* */
150	/* bitmap :: A descriptor for the bitmap. */
151	/* */
152	/* <Note> */
153	/* You can typecast an @FT_Glyph to @FT_BitmapGlyph if you have */
154	/* `glyph->format == FT_GLYPH_FORMAT_BITMAP'. This lets you access */
155	/* the bitmap's contents easily. */
156	/* */
157	/* The corresponding pixel buffer is always owned by @FT_BitmapGlyph */
158	/* and is thus created and destroyed with it. */
159	/* */
160	typedef struct FT_BitmapGlyphRec_
161	{
162	FT_GlyphRec root;
163	FT_Int left;
164	FT_Int top;
165	FT_Bitmap bitmap;
166
167	} FT_BitmapGlyphRec;
168
169
170	/*************************************************************************/
171	/* */
172	/* <Type> */
173	/* FT_OutlineGlyph */
174	/* */
175	/* <Description> */
176	/* A handle to an object used to model an outline glyph image. This */
177	/* is a sub-class of @FT_Glyph, and a pointer to @FT_OutlineGlyphRec. */
178	/* */
179	typedef struct FT_OutlineGlyphRec_* FT_OutlineGlyph;
180
181
182	/*************************************************************************/
183	/* */
184	/* <Struct> */
185	/* FT_OutlineGlyphRec */
186	/* */
187	/* <Description> */
188	/* A structure used for outline (vectorial) glyph images. This */
189	/* really is a `sub-class' of @FT_GlyphRec. */
190	/* */
191	/* <Fields> */
192	/* root :: The root @FT_Glyph fields. */
193	/* */
194	/* outline :: A descriptor for the outline. */
195	/* */
196	/* <Note> */
197	/* You can typecast a @FT_Glyph to @FT_OutlineGlyph if you have */
198	/* `glyph->format == FT_GLYPH_FORMAT_OUTLINE'. This lets you access */
199	/* the outline's content easily. */
200	/* */
201	/* As the outline is extracted from a glyph slot, its coordinates are */
202	/* expressed normally in 26.6 pixels, unless the flag */
203	/* @FT_LOAD_NO_SCALE was used in @FT_Load_Glyph() or @FT_Load_Char(). */
204	/* */
205	/* The outline's tables are always owned by the object and are */
206	/* destroyed with it. */
207	/* */
208	typedef struct FT_OutlineGlyphRec_
209	{
210	FT_GlyphRec root;
211	FT_Outline outline;
212
213	} FT_OutlineGlyphRec;
214
215
216	/*************************************************************************/
217	/* */
218	/* <Function> */
219	/* FT_Get_Glyph */
220	/* */
221	/* <Description> */
222	/* A function used to extract a glyph image from a slot. Note that */
223	/* the created @FT_Glyph object must be released with @FT_Done_Glyph. */
224	/* */
225	/* <Input> */
226	/* slot :: A handle to the source glyph slot. */
227	/* */
228	/* <Output> */
229	/* aglyph :: A handle to the glyph object. */
230	/* */
231	/* <Return> */
232	/* FreeType error code. 0~means success. */
233	/* */
234	FT_EXPORT( FT_Error )
235	FT_Get_Glyph( FT_GlyphSlot slot,
236	FT_Glyph *aglyph );
237
238
239	/*************************************************************************/
240	/* */
241	/* <Function> */
242	/* FT_Glyph_Copy */
243	/* */
244	/* <Description> */
245	/* A function used to copy a glyph image. Note that the created */
246	/* @FT_Glyph object must be released with @FT_Done_Glyph. */
247	/* */
248	/* <Input> */
249	/* source :: A handle to the source glyph object. */
250	/* */
251	/* <Output> */
252	/* target :: A handle to the target glyph object. 0~in case of */
253	/* error. */
254	/* */
255	/* <Return> */
256	/* FreeType error code. 0~means success. */
257	/* */
258	FT_EXPORT( FT_Error )
259	FT_Glyph_Copy( FT_Glyph source,
260	FT_Glyph *target );
261
262
263	/*************************************************************************/
264	/* */
265	/* <Function> */
266	/* FT_Glyph_Transform */
267	/* */
268	/* <Description> */
269	/* Transform a glyph image if its format is scalable. */
270	/* */
271	/* <InOut> */
272	/* glyph :: A handle to the target glyph object. */
273	/* */
274	/* <Input> */
275	/* matrix :: A pointer to a 2x2 matrix to apply. */
276	/* */
277	/* delta :: A pointer to a 2d vector to apply. Coordinates are */
278	/* expressed in 1/64th of a pixel. */
279	/* */
280	/* <Return> */
281	/* FreeType error code (if not 0, the glyph format is not scalable). */
282	/* */
283	/* <Note> */
284	/* The 2x2 transformation matrix is also applied to the glyph's */
285	/* advance vector. */
286	/* */
287	FT_EXPORT( FT_Error )
288	FT_Glyph_Transform( FT_Glyph glyph,
289	FT_Matrix* matrix,
290	FT_Vector* delta );
291
292
293	/*************************************************************************/
294	/* */
295	/* <Enum> */
296	/* FT_Glyph_BBox_Mode */
297	/* */
298	/* <Description> */
299	/* The mode how the values of @FT_Glyph_Get_CBox are returned. */
300	/* */
301	/* <Values> */
302	/* FT_GLYPH_BBOX_UNSCALED :: */
303	/* Return unscaled font units. */
304	/* */
305	/* FT_GLYPH_BBOX_SUBPIXELS :: */
306	/* Return unfitted 26.6 coordinates. */
307	/* */
308	/* FT_GLYPH_BBOX_GRIDFIT :: */
309	/* Return grid-fitted 26.6 coordinates. */
310	/* */
311	/* FT_GLYPH_BBOX_TRUNCATE :: */
312	/* Return coordinates in integer pixels. */
313	/* */
314	/* FT_GLYPH_BBOX_PIXELS :: */
315	/* Return grid-fitted pixel coordinates. */
316	/* */
317	typedef enum FT_Glyph_BBox_Mode_
318	{
319	FT_GLYPH_BBOX_UNSCALED = 0,
320	FT_GLYPH_BBOX_SUBPIXELS = 0,
321	FT_GLYPH_BBOX_GRIDFIT = 1,
322	FT_GLYPH_BBOX_TRUNCATE = 2,
323	FT_GLYPH_BBOX_PIXELS = 3
324
325	} FT_Glyph_BBox_Mode;
326
327
328	/*************************************************************************/
329	/* */
330	/* <Enum> */
331	/* ft_glyph_bbox_xxx */
332	/* */
333	/* <Description> */
334	/* These constants are deprecated. Use the corresponding */
335	/* @FT_Glyph_BBox_Mode values instead. */
336	/* */
337	/* <Values> */
338	/* ft_glyph_bbox_unscaled :: See @FT_GLYPH_BBOX_UNSCALED. */
339	/* ft_glyph_bbox_subpixels :: See @FT_GLYPH_BBOX_SUBPIXELS. */
340	/* ft_glyph_bbox_gridfit :: See @FT_GLYPH_BBOX_GRIDFIT. */
341	/* ft_glyph_bbox_truncate :: See @FT_GLYPH_BBOX_TRUNCATE. */
342	/* ft_glyph_bbox_pixels :: See @FT_GLYPH_BBOX_PIXELS. */
343	/* */
344	#define ft_glyph_bbox_unscaled FT_GLYPH_BBOX_UNSCALED
345	#define ft_glyph_bbox_subpixels FT_GLYPH_BBOX_SUBPIXELS
346	#define ft_glyph_bbox_gridfit FT_GLYPH_BBOX_GRIDFIT
347	#define ft_glyph_bbox_truncate FT_GLYPH_BBOX_TRUNCATE
348	#define ft_glyph_bbox_pixels FT_GLYPH_BBOX_PIXELS
349
350
351	/*************************************************************************/
352	/* */
353	/* <Function> */
354	/* FT_Glyph_Get_CBox */
355	/* */
356	/* <Description> */
357	/* Return a glyph's `control box'. The control box encloses all the */
358	/* outline's points, including BÃ©zier control points. Though it */
359	/* coincides with the exact bounding box for most glyphs, it can be */
360	/* slightly larger in some situations (like when rotating an outline */
361	/* which contains BÃ©zier outside arcs). */
362	/* */
363	/* Computing the control box is very fast, while getting the bounding */
364	/* box can take much more time as it needs to walk over all segments */
365	/* and arcs in the outline. To get the latter, you can use the */
366	/* `ftbbox' component which is dedicated to this single task. */
367	/* */
368	/* <Input> */
369	/* glyph :: A handle to the source glyph object. */
370	/* */
371	/* mode :: The mode which indicates how to interpret the returned */
372	/* bounding box values. */
373	/* */
374	/* <Output> */
375	/* acbox :: The glyph coordinate bounding box. Coordinates are */
376	/* expressed in 1/64th of pixels if it is grid-fitted. */
377	/* */
378	/* <Note> */
379	/* Coordinates are relative to the glyph origin, using the y~upwards */
380	/* convention. */
381	/* */
382	/* If the glyph has been loaded with @FT_LOAD_NO_SCALE, `bbox_mode' */
383	/* must be set to @FT_GLYPH_BBOX_UNSCALED to get unscaled font */
384	/* units in 26.6 pixel format. The value @FT_GLYPH_BBOX_SUBPIXELS */
385	/* is another name for this constant. */
386	/* */
387	/* Note that the maximum coordinates are exclusive, which means that */
388	/* one can compute the width and height of the glyph image (be it in */
389	/* integer or 26.6 pixels) as: */
390	/* */
391	/* { */
392	/* width = bbox.xMax - bbox.xMin; */
393	/* height = bbox.yMax - bbox.yMin; */
394	/* } */
395	/* */
396	/* Note also that for 26.6 coordinates, if `bbox_mode' is set to */
397	/* @FT_GLYPH_BBOX_GRIDFIT, the coordinates will also be grid-fitted, */
398	/* which corresponds to: */
399	/* */
400	/* { */
401	/* bbox.xMin = FLOOR(bbox.xMin); */
402	/* bbox.yMin = FLOOR(bbox.yMin); */
403	/* bbox.xMax = CEILING(bbox.xMax); */
404	/* bbox.yMax = CEILING(bbox.yMax); */
405	/* } */
406	/* */
407	/* To get the bbox in pixel coordinates, set `bbox_mode' to */
408	/* @FT_GLYPH_BBOX_TRUNCATE. */
409	/* */
410	/* To get the bbox in grid-fitted pixel coordinates, set `bbox_mode' */
411	/* to @FT_GLYPH_BBOX_PIXELS. */
412	/* */
413	FT_EXPORT( void )
414	FT_Glyph_Get_CBox( FT_Glyph glyph,
415	FT_UInt bbox_mode,
416	FT_BBox *acbox );
417
418
419	/*************************************************************************/
420	/* */
421	/* <Function> */
422	/* FT_Glyph_To_Bitmap */
423	/* */
424	/* <Description> */
425	/* Convert a given glyph object to a bitmap glyph object. */
426	/* */
427	/* <InOut> */
428	/* the_glyph :: A pointer to a handle to the target glyph. */
429	/* */
430	/* <Input> */
431	/* render_mode :: An enumeration that describes how the data is */
432	/* rendered. */
433	/* */
434	/* origin :: A pointer to a vector used to translate the glyph */
435	/* image before rendering. Can be~0 (if no */
436	/* translation). The origin is expressed in */
437	/* 26.6 pixels. */
438	/* */
439	/* destroy :: A boolean that indicates that the original glyph */
440	/* image should be destroyed by this function. It is */
441	/* never destroyed in case of error. */
442	/* */
443	/* <Return> */
444	/* FreeType error code. 0~means success. */
445	/* */
446	/* <Note> */
447	/* This function does nothing if the glyph format isn't scalable. */
448	/* */
449	/* The glyph image is translated with the `origin' vector before */
450	/* rendering. */
451	/* */
452	/* The first parameter is a pointer to an @FT_Glyph handle, that will */
453	/* be _replaced_ by this function (with newly allocated data). */
454	/* Typically, you would use (omitting error handling): */
455	/* */
456	/* */
457	/* { */
458	/* FT_Glyph glyph; */
459	/* FT_BitmapGlyph glyph_bitmap; */
460	/* */
461	/* */
462	/* // load glyph */
463	/* error = FT_Load_Char( face, glyph_index, FT_LOAD_DEFAUT ); */
464	/* */
465	/* // extract glyph image */
466	/* error = FT_Get_Glyph( face->glyph, &glyph ); */
467	/* */
468	/* // convert to a bitmap (default render mode + destroying old) */
469	/* if ( glyph->format != FT_GLYPH_FORMAT_BITMAP ) */
470	/* { */
471	/* error = FT_Glyph_To_Bitmap( &glyph, FT_RENDER_MODE_DEFAULT, */
472	/* 0, 1 ); */
473	/* if ( error ) // `glyph' unchanged */
474	/* ... */
475	/* } */
476	/* */
477	/* // access bitmap content by typecasting */
478	/* glyph_bitmap = (FT_BitmapGlyph)glyph; */
479	/* */
480	/* // do funny stuff with it, like blitting/drawing */
481	/* ... */
482	/* */
483	/* // discard glyph image (bitmap or not) */
484	/* FT_Done_Glyph( glyph ); */
485	/* } */
486	/* */
487	/* */
488	/* Here another example, again without error handling: */
489	/* */
490	/* */
491	/* { */
492	/* FT_Glyph glyphs[MAX_GLYPHS] */
493	/* */
494	/* */
495	/* ... */
496	/* */
497	/* for ( idx = 0; i < MAX_GLYPHS; i++ ) */
498	/* error = FT_Load_Glyph( face, idx, FT_LOAD_DEFAULT ) \|\| */
499	/* FT_Get_Glyph ( face->glyph, &glyph[idx] ); */
500	/* */
501	/* ... */
502	/* */
503	/* for ( idx = 0; i < MAX_GLYPHS; i++ ) */
504	/* { */
505	/* FT_Glyph bitmap = glyphs[idx]; */
506	/* */
507	/* */
508	/* ... */
509	/* */
510	/* // after this call, `bitmap' no longer points into */
511	/* // the `glyphs' array (and the old value isn't destroyed) */
512	/* FT_Glyph_To_Bitmap( &bitmap, FT_RENDER_MODE_MONO, 0, 0 ); */
513	/* */
514	/* ... */
515	/* */
516	/* FT_Done_Glyph( bitmap ); */
517	/* } */
518	/* */
519	/* ... */
520	/* */
521	/* for ( idx = 0; i < MAX_GLYPHS; i++ ) */
522	/* FT_Done_Glyph( glyphs[idx] ); */
523	/* } */
524	/* */
525	FT_EXPORT( FT_Error )
526	FT_Glyph_To_Bitmap( FT_Glyph* the_glyph,
527	FT_Render_Mode render_mode,
528	FT_Vector* origin,
529	FT_Bool destroy );
530
531
532	/*************************************************************************/
533	/* */
534	/* <Function> */
535	/* FT_Done_Glyph */
536	/* */
537	/* <Description> */
538	/* Destroy a given glyph. */
539	/* */
540	/* <Input> */
541	/* glyph :: A handle to the target glyph object. */
542	/* */
543	FT_EXPORT( void )
544	FT_Done_Glyph( FT_Glyph glyph );
545
546	/* */
547
548
549	/* other helpful functions */
550
551	/*************************************************************************/
552	/* */
553	/* <Section> */
554	/* computations */
555	/* */
556	/*************************************************************************/
557
558
559	/*************************************************************************/
560	/* */
561	/* <Function> */
562	/* FT_Matrix_Multiply */
563	/* */
564	/* <Description> */
565	/* Perform the matrix operation `b = ab'. /
566	/* */
567	/* <Input> */
568	/* a :: A pointer to matrix `a'. */
569	/* */
570	/* <InOut> */
571	/* b :: A pointer to matrix `b'. */
572	/* */
573	/* <Note> */
574	/* The result is undefined if either `a' or `b' is zero. */
575	/* */
576	FT_EXPORT( void )
577	FT_Matrix_Multiply( const FT_Matrix* a,
578	FT_Matrix* b );
579
580
581	/*************************************************************************/
582	/* */
583	/* <Function> */
584	/* FT_Matrix_Invert */
585	/* */
586	/* <Description> */
587	/* Invert a 2x2 matrix. Return an error if it can't be inverted. */
588	/* */
589	/* <InOut> */
590	/* matrix :: A pointer to the target matrix. Remains untouched in */
591	/* case of error. */
592	/* */
593	/* <Return> */
594	/* FreeType error code. 0~means success. */
595	/* */
596	FT_EXPORT( FT_Error )
597	FT_Matrix_Invert( FT_Matrix* matrix );
598
599
600	/* */
601
602
603	FT_END_HEADER
604
605	#endif /* __FTGLYPH_H__ */
606
607
608	/* END */
609
610
611	/* Local Variables: */
612	/* coding: utf-8 */
613	/* End: */

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