freetype.h source code [include/freetype2/freetype/freetype.h]

1	/****************************************************************************
2	*
3	* freetype.h
4	*
5	* FreeType high-level API and common types (specification only).
6	*
7	* Copyright (C) 1996-2025 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	#ifndef FREETYPE_H_
20	#define FREETYPE_H_
21
22
23	#include <ft2build.h>
24	#include FT_CONFIG_CONFIG_H
25	#include <freetype/fttypes.h>
26	#include <freetype/fterrors.h>
27
28
29	FT_BEGIN_HEADER
30
31
32
33	/**************************************************************************
34	*
35	* @section:
36	* preamble
37	*
38	* @title:
39	* Preamble
40	*
41	* @abstract:
42	* What FreeType is and isn't
43	*
44	* @description:
45	* FreeType is a library that provides access to glyphs in font files. It
46	* scales the glyph images and their metrics to a requested size, and it
47	* rasterizes the glyph images to produce pixel or subpixel alpha coverage
48	* bitmaps.
49	*
50	* Note that FreeType is _not_ a text layout engine. You have to use
51	* higher-level libraries like HarfBuzz, Pango, or ICU for that.
52	*
53	* Note also that FreeType does _not_ perform alpha blending or
54	* compositing the resulting bitmaps or pixmaps by itself. Use your
55	* favourite graphics library (for example, Cairo or Skia) to further
56	* process FreeType's output.
57	*
58	*/
59
60
61	/**************************************************************************
62	*
63	* @section:
64	* header_inclusion
65	*
66	* @title:
67	* FreeType's header inclusion scheme
68	*
69	* @abstract:
70	* How client applications should include FreeType header files.
71	*
72	* @description:
73	* To be as flexible as possible (and for historical reasons), you must
74	* load file `ft2build.h` first before other header files, for example
75	*
76	* ```
77	* #include <ft2build.h>
78	*
79	* #include <freetype/freetype.h>
80	* #include <freetype/ftoutln.h>
81	* ```
82	*/
83
84
85	/**************************************************************************
86	*
87	* @section:
88	* user_allocation
89	*
90	* @title:
91	* User allocation
92	*
93	* @abstract:
94	* How client applications should allocate FreeType data structures.
95	*
96	* @description:
97	* FreeType assumes that structures allocated by the user and passed as
98	* arguments are zeroed out except for the actual data. In other words,
99	* it is recommended to use `calloc` (or variants of it) instead of
100	* `malloc` for allocation.
101	*
102	*/
103
104
105	/**************************************************************************
106	*
107	* @section:
108	* font_testing_macros
109	*
110	* @title:
111	* Font Testing Macros
112	*
113	* @abstract:
114	* Macros to test various properties of fonts.
115	*
116	* @description:
117	* Macros to test the most important font properties.
118	*
119	* It is recommended to use these high-level macros instead of directly
120	* testing the corresponding flags, which are scattered over various
121	* structures.
122	*
123	* @order:
124	* FT_HAS_HORIZONTAL
125	* FT_HAS_VERTICAL
126	* FT_HAS_KERNING
127	* FT_HAS_FIXED_SIZES
128	* FT_HAS_GLYPH_NAMES
129	* FT_HAS_COLOR
130	* FT_HAS_MULTIPLE_MASTERS
131	* FT_HAS_SVG
132	* FT_HAS_SBIX
133	* FT_HAS_SBIX_OVERLAY
134	*
135	* FT_IS_SFNT
136	* FT_IS_SCALABLE
137	* FT_IS_FIXED_WIDTH
138	* FT_IS_CID_KEYED
139	* FT_IS_TRICKY
140	* FT_IS_NAMED_INSTANCE
141	* FT_IS_VARIATION
142	*
143	*/
144
145
146	/**************************************************************************
147	*
148	* @section:
149	* library_setup
150	*
151	* @title:
152	* Library Setup
153	*
154	* @abstract:
155	* Functions to start and end the usage of the FreeType library.
156	*
157	* @description:
158	* Functions to start and end the usage of the FreeType library.
159	*
160	* Note that @FT_Library_Version and @FREETYPE_XXX are of limited use
161	* because even a new release of FreeType with only documentation
162	* changes increases the version number.
163	*
164	* @order:
165	* FT_Library
166	* FT_Init_FreeType
167	* FT_Done_FreeType
168	*
169	* FT_Library_Version
170	* FREETYPE_XXX
171	*
172	*/
173
174
175	/**************************************************************************
176	*
177	* @section:
178	* face_creation
179	*
180	* @title:
181	* Face Creation
182	*
183	* @abstract:
184	* Functions to manage fonts.
185	*
186	* @description:
187	* The functions and structures collected in this section operate on
188	* fonts globally.
189	*
190	* @order:
191	* FT_Face
192	* FT_FaceRec
193	* FT_FACE_FLAG_XXX
194	* FT_STYLE_FLAG_XXX
195	*
196	* FT_New_Face
197	* FT_Done_Face
198	* FT_Reference_Face
199	* FT_New_Memory_Face
200	* FT_Face_Properties
201	* FT_Open_Face
202	* FT_Open_Args
203	* FT_OPEN_XXX
204	* FT_Parameter
205	* FT_Attach_File
206	* FT_Attach_Stream
207	*
208	*/
209
210
211	/**************************************************************************
212	*
213	* @section:
214	* sizing_and_scaling
215	*
216	* @title:
217	* Sizing and Scaling
218	*
219	* @abstract:
220	* Functions to manage font sizes.
221	*
222	* @description:
223	* The functions and structures collected in this section are related to
224	* selecting and manipulating the size of a font globally.
225	*
226	* @order:
227	* FT_Size
228	* FT_SizeRec
229	* FT_Size_Metrics
230	*
231	* FT_Bitmap_Size
232	*
233	* FT_Set_Char_Size
234	* FT_Set_Pixel_Sizes
235	* FT_Request_Size
236	* FT_Select_Size
237	* FT_Size_Request_Type
238	* FT_Size_RequestRec
239	* FT_Size_Request
240	*
241	* FT_Set_Transform
242	* FT_Get_Transform
243	*
244	*/
245
246
247	/**************************************************************************
248	*
249	* @section:
250	* glyph_retrieval
251	*
252	* @title:
253	* Glyph Retrieval
254	*
255	* @abstract:
256	* Functions to manage glyphs.
257	*
258	* @description:
259	* The functions and structures collected in this section operate on
260	* single glyphs, of which @FT_Load_Glyph is most important.
261	*
262	* @order:
263	* FT_GlyphSlot
264	* FT_GlyphSlotRec
265	* FT_Glyph_Metrics
266	*
267	* FT_Load_Glyph
268	* FT_LOAD_XXX
269	* FT_LOAD_TARGET_MODE
270	* FT_LOAD_TARGET_XXX
271	*
272	* FT_Render_Glyph
273	* FT_Render_Mode
274	* FT_Get_Kerning
275	* FT_Kerning_Mode
276	* FT_Get_Track_Kerning
277	*
278	*/
279
280
281	/**************************************************************************
282	*
283	* @section:
284	* character_mapping
285	*
286	* @title:
287	* Character Mapping
288	*
289	* @abstract:
290	* Functions to manage character-to-glyph maps.
291	*
292	* @description:
293	* This section holds functions and structures that are related to
294	* mapping character input codes to glyph indices.
295	*
296	* Note that for many scripts the simplistic approach used by FreeType
297	* of mapping a single character to a single glyph is not valid or
298	* possible! In general, a higher-level library like HarfBuzz or ICU
299	* should be used for handling text strings.
300	*
301	* @order:
302	* FT_CharMap
303	* FT_CharMapRec
304	* FT_Encoding
305	* FT_ENC_TAG
306	*
307	* FT_Select_Charmap
308	* FT_Set_Charmap
309	* FT_Get_Charmap_Index
310	*
311	* FT_Get_Char_Index
312	* FT_Get_First_Char
313	* FT_Get_Next_Char
314	* FT_Load_Char
315	*
316	*/
317
318
319	/**************************************************************************
320	*
321	* @section:
322	* information_retrieval
323	*
324	* @title:
325	* Information Retrieval
326	*
327	* @abstract:
328	* Functions to retrieve font and glyph information.
329	*
330	* @description:
331	* Functions to retrieve font and glyph information. Only some very
332	* basic data is covered; see also the chapter on the format-specific
333	* API for more.
334	*
335	*
336	* @order:
337	* FT_Get_Name_Index
338	* FT_Get_Glyph_Name
339	* FT_Get_Postscript_Name
340	* FT_Get_FSType_Flags
341	* FT_FSTYPE_XXX
342	* FT_Get_SubGlyph_Info
343	* FT_SUBGLYPH_FLAG_XXX
344	*
345	*/
346
347
348	/**************************************************************************
349	*
350	* @section:
351	* other_api_data
352	*
353	* @title:
354	* Other API Data
355	*
356	* @abstract:
357	* Other structures, enumerations, and macros.
358	*
359	* @description:
360	* Other structures, enumerations, and macros. Deprecated functions are
361	* also listed here.
362	*
363	* @order:
364	* FT_Face_Internal
365	* FT_Size_Internal
366	* FT_Slot_Internal
367	*
368	* FT_SubGlyph
369	*
370	* FT_HAS_FAST_GLYPHS
371	* FT_Face_CheckTrueTypePatents
372	* FT_Face_SetUnpatentedHinting
373	*
374	*/
375
376
377	/***********************************************************************/
378	/***********************************************************************/
379	/ /
380	/ B A S I C T Y P E S /
381	/ /
382	/***********************************************************************/
383	/***********************************************************************/
384
385
386	/**************************************************************************
387	*
388	* @section:
389	* glyph_retrieval
390	*
391	*/
392
393	/**************************************************************************
394	*
395	* @struct:
396	* FT_Glyph_Metrics
397	*
398	* @description:
399	* A structure to model the metrics of a single glyph. The values are
400	* expressed in 26.6 fractional pixel format; if the flag
401	* @FT_LOAD_NO_SCALE has been used while loading the glyph, values are
402	* expressed in font units instead.
403	*
404	* @fields:
405	* width ::
406	* The glyph's width.
407	*
408	* height ::
409	* The glyph's height.
410	*
411	* horiBearingX ::
412	* Left side bearing for horizontal layout.
413	*
414	* horiBearingY ::
415	* Top side bearing for horizontal layout.
416	*
417	* horiAdvance ::
418	* Advance width for horizontal layout.
419	*
420	* vertBearingX ::
421	* Left side bearing for vertical layout.
422	*
423	* vertBearingY ::
424	* Top side bearing for vertical layout. Larger positive values mean
425	* further below the vertical glyph origin.
426	*
427	* vertAdvance ::
428	* Advance height for vertical layout. Positive values mean the glyph
429	* has a positive advance downward.
430	*
431	* @note:
432	* If not disabled with @FT_LOAD_NO_HINTING, the values represent
433	* dimensions of the hinted glyph (in case hinting is applicable).
434	*
435	* Stroking a glyph with an outside border does not increase
436	* `horiAdvance` or `vertAdvance`; you have to manually adjust these
437	* values to account for the added width and height.
438	*
439	* FreeType doesn't use the 'VORG' table data for CFF fonts because it
440	* doesn't have an interface to quickly retrieve the glyph height. The
441	* y~coordinate of the vertical origin can be simply computed as
442	* `vertBearingY + height` after loading a glyph.
443	*/
444	typedef struct FT_Glyph_Metrics_
445	{
446	FT_Pos width;
447	FT_Pos height;
448
449	FT_Pos horiBearingX;
450	FT_Pos horiBearingY;
451	FT_Pos horiAdvance;
452
453	FT_Pos vertBearingX;
454	FT_Pos vertBearingY;
455	FT_Pos vertAdvance;
456
457	} FT_Glyph_Metrics;
458
459
460	/**************************************************************************
461	*
462	* @section:
463	* sizing_and_scaling
464	*
465	*/
466
467	/**************************************************************************
468	*
469	* @struct:
470	* FT_Bitmap_Size
471	*
472	* @description:
473	* This structure models the metrics of a bitmap strike (i.e., a set of
474	* glyphs for a given point size and resolution) in a bitmap font. It is
475	* used for the `available_sizes` field of @FT_Face.
476	*
477	* @fields:
478	* height ::
479	* The vertical distance, in pixels, between two consecutive baselines.
480	* It is always positive.
481	*
482	* width ::
483	* The average width, in pixels, of all glyphs in the strike.
484	*
485	* size ::
486	* The nominal size of the strike in 26.6 fractional points. This
487	* field is not very useful.
488	*
489	* x_ppem ::
490	* The horizontal ppem (nominal width) in 26.6 fractional pixels.
491	*
492	* y_ppem ::
493	* The vertical ppem (nominal height) in 26.6 fractional pixels.
494	*
495	* @note:
496	* Windows FNT:
497	* The nominal size given in a FNT font is not reliable. If the driver
498	* finds it incorrect, it sets `size` to some calculated values, and
499	* `x_ppem` and `y_ppem` to the pixel width and height given in the
500	* font, respectively.
501	*
502	* TrueType embedded bitmaps:
503	* `size`, `width`, and `height` values are not contained in the bitmap
504	* strike itself. They are computed from the global font parameters.
505	*/
506	typedef struct FT_Bitmap_Size_
507	{
508	FT_Short height;
509	FT_Short width;
510
511	FT_Pos size;
512
513	FT_Pos x_ppem;
514	FT_Pos y_ppem;
515
516	} FT_Bitmap_Size;
517
518
519	/***********************************************************************/
520	/***********************************************************************/
521	/ /
522	/ O B J E C T C L A S S E S /
523	/ /
524	/***********************************************************************/
525	/***********************************************************************/
526
527	/**************************************************************************
528	*
529	* @section:
530	* library_setup
531	*
532	*/
533
534	/**************************************************************************
535	*
536	* @type:
537	* FT_Library
538	*
539	* @description:
540	* A handle to a FreeType library instance. Each 'library' is completely
541	* independent from the others; it is the 'root' of a set of objects like
542	* fonts, faces, sizes, etc.
543	*
544	* It also embeds a memory manager (see @FT_Memory), as well as a
545	* scan-line converter object (see @FT_Raster).
546	*
547	* [Since 2.5.6] In multi-threaded applications it is easiest to use one
548	* `FT_Library` object per thread. In case this is too cumbersome, a
549	* single `FT_Library` object across threads is possible also, as long as
550	* a mutex lock is used around @FT_New_Face and @FT_Done_Face.
551	*
552	* @note:
553	* Library objects are normally created by @FT_Init_FreeType, and
554	* destroyed with @FT_Done_FreeType. If you need reference-counting
555	* (cf. @FT_Reference_Library), use @FT_New_Library and @FT_Done_Library.
556	*/
557	typedef struct FT_LibraryRec_ *FT_Library;
558
559
560	/**************************************************************************
561	*
562	* @section:
563	* module_management
564	*
565	*/
566
567	/**************************************************************************
568	*
569	* @type:
570	* FT_Module
571	*
572	* @description:
573	* A handle to a given FreeType module object. A module can be a font
574	* driver, a renderer, or anything else that provides services to the
575	* former.
576	*/
577	typedef struct FT_ModuleRec_* FT_Module;
578
579
580	/**************************************************************************
581	*
582	* @type:
583	* FT_Driver
584	*
585	* @description:
586	* A handle to a given FreeType font driver object. A font driver is a
587	* module capable of creating faces from font files.
588	*/
589	typedef struct FT_DriverRec_* FT_Driver;
590
591
592	/**************************************************************************
593	*
594	* @type:
595	* FT_Renderer
596	*
597	* @description:
598	* A handle to a given FreeType renderer. A renderer is a module in
599	* charge of converting a glyph's outline image to a bitmap. It supports
600	* a single glyph image format, and one or more target surface depths.
601	*/
602	typedef struct FT_RendererRec_* FT_Renderer;
603
604
605	/**************************************************************************
606	*
607	* @section:
608	* face_creation
609	*
610	*/
611
612	/**************************************************************************
613	*
614	* @type:
615	* FT_Face
616	*
617	* @description:
618	* A handle to a typographic face object. A face object models a given
619	* typeface, in a given style.
620	*
621	* @note:
622	* A face object also owns a single @FT_GlyphSlot object, as well as one
623	* or more @FT_Size objects.
624	*
625	* Use @FT_New_Face or @FT_Open_Face to create a new face object from a
626	* given filepath or a custom input stream.
627	*
628	* Use @FT_Done_Face to destroy it (along with its slot and sizes).
629	*
630	* An `FT_Face` object can only be safely used from one thread at a time.
631	* Similarly, creation and destruction of `FT_Face` with the same
632	* @FT_Library object can only be done from one thread at a time. On the
633	* other hand, functions like @FT_Load_Glyph and its siblings are
634	* thread-safe and do not need the lock to be held as long as the same
635	* `FT_Face` object is not used from multiple threads at the same time.
636	*
637	* @also:
638	* See @FT_FaceRec for the publicly accessible fields of a given face
639	* object.
640	*/
641	typedef struct FT_FaceRec_* FT_Face;
642
643
644	/**************************************************************************
645	*
646	* @section:
647	* sizing_and_scaling
648	*
649	*/
650
651	/**************************************************************************
652	*
653	* @type:
654	* FT_Size
655	*
656	* @description:
657	* A handle to an object that models a face scaled to a given character
658	* size.
659	*
660	* @note:
661	* An @FT_Face has one _active_ `FT_Size` object that is used by
662	* functions like @FT_Load_Glyph to determine the scaling transformation
663	* that in turn is used to load and hint glyphs and metrics.
664	*
665	* A newly created `FT_Size` object contains only meaningless zero values.
666	* You must use @FT_Set_Char_Size, @FT_Set_Pixel_Sizes, @FT_Request_Size
667	* or even @FT_Select_Size to change the content (i.e., the scaling
668	* values) of the active `FT_Size`. Otherwise, the scaling and hinting
669	* will not be performed.
670	*
671	* You can use @FT_New_Size to create additional size objects for a given
672	* @FT_Face, but they won't be used by other functions until you activate
673	* it through @FT_Activate_Size. Only one size can be activated at any
674	* given time per face.
675	*
676	* @also:
677	* See @FT_SizeRec for the publicly accessible fields of a given size
678	* object.
679	*/
680	typedef struct FT_SizeRec_* FT_Size;
681
682
683	/**************************************************************************
684	*
685	* @section:
686	* glyph_retrieval
687	*
688	*/
689
690	/**************************************************************************
691	*
692	* @type:
693	* FT_GlyphSlot
694	*
695	* @description:
696	* A handle to a given 'glyph slot'. A slot is a container that can hold
697	* any of the glyphs contained in its parent face.
698	*
699	* In other words, each time you call @FT_Load_Glyph or @FT_Load_Char,
700	* the slot's content is erased by the new glyph data, i.e., the glyph's
701	* metrics, its image (bitmap or outline), and other control information.
702	*
703	* @also:
704	* See @FT_GlyphSlotRec for the publicly accessible glyph fields.
705	*/
706	typedef struct FT_GlyphSlotRec_* FT_GlyphSlot;
707
708
709	/**************************************************************************
710	*
711	* @section:
712	* character_mapping
713	*
714	*/
715
716	/**************************************************************************
717	*
718	* @type:
719	* FT_CharMap
720	*
721	* @description:
722	* A handle to a character map (usually abbreviated to 'charmap'). A
723	* charmap is used to translate character codes in a given encoding into
724	* glyph indexes for its parent's face. Some font formats may provide
725	* several charmaps per font.
726	*
727	* Each face object owns zero or more charmaps, but only one of them can
728	* be 'active', providing the data used by @FT_Get_Char_Index or
729	* @FT_Load_Char.
730	*
731	* The list of available charmaps in a face is available through the
732	* `face->num_charmaps` and `face->charmaps` fields of @FT_FaceRec.
733	*
734	* The currently active charmap is available as `face->charmap`. You
735	* should call @FT_Set_Charmap to change it.
736	*
737	* @note:
738	* When a new face is created (either through @FT_New_Face or
739	* @FT_Open_Face), the library looks for a Unicode charmap within the
740	* list and automatically activates it. If there is no Unicode charmap,
741	* FreeType doesn't set an 'active' charmap.
742	*
743	* @also:
744	* See @FT_CharMapRec for the publicly accessible fields of a given
745	* character map.
746	*/
747	typedef struct FT_CharMapRec_* FT_CharMap;
748
749
750	/**************************************************************************
751	*
752	* @macro:
753	* FT_ENC_TAG
754	*
755	* @description:
756	* This macro converts four-letter tags into an unsigned long. It is
757	* used to define 'encoding' identifiers (see @FT_Encoding).
758	*
759	* @note:
760	* Since many 16-bit compilers don't like 32-bit enumerations, you should
761	* redefine this macro in case of problems to something like this:
762	*
763	* ```
764	* #define FT_ENC_TAG( value, a, b, c, d ) value
765	* ```
766	*
767	* to get a simple enumeration without assigning special numbers.
768	*/
769
770	#ifndef FT_ENC_TAG
771
772	#define FT_ENC_TAG( value, a, b, c, d ) \
773	value = ( ( FT_STATIC_BYTE_CAST( FT_UInt32, a ) << 24 ) \| \
774	( FT_STATIC_BYTE_CAST( FT_UInt32, b ) << 16 ) \| \
775	( FT_STATIC_BYTE_CAST( FT_UInt32, c ) << 8 ) \| \
776	FT_STATIC_BYTE_CAST( FT_UInt32, d ) )
777
778	#endif /* FT_ENC_TAG */
779
780
781	/**************************************************************************
782	*
783	* @enum:
784	* FT_Encoding
785	*
786	* @description:
787	* An enumeration to specify character sets supported by charmaps. Used
788	* in the @FT_Select_Charmap API function.
789	*
790	* @note:
791	* Despite the name, this enumeration lists specific character
792	* repertoires (i.e., charsets), and not text encoding methods (e.g.,
793	* UTF-8, UTF-16, etc.).
794	*
795	* Other encodings might be defined in the future.
796	*
797	* @values:
798	* FT_ENCODING_NONE ::
799	* The encoding value~0 is reserved for all formats except BDF, PCF,
800	* and Windows FNT; see below for more information.
801	*
802	* FT_ENCODING_UNICODE ::
803	* The Unicode character set. This value covers all versions of the
804	* Unicode repertoire, including ASCII and Latin-1. Most fonts include
805	* a Unicode charmap, but not all of them.
806	*
807	* For example, if you want to access Unicode value U+1F028 (and the
808	* font contains it), use value 0x1F028 as the input value for
809	* @FT_Get_Char_Index.
810	*
811	* FT_ENCODING_MS_SYMBOL ::
812	* Microsoft Symbol encoding, used to encode mathematical symbols and
813	* wingdings. For more information, see
814	* 'https://learn.microsoft.com/typography/opentype/spec/recom#non-standard-symbol-fonts',
815	* 'http://www.kostis.net/charsets/symbol.htm', and
816	* 'http://www.kostis.net/charsets/wingding.htm'.
817	*
818	* This encoding uses character codes from the PUA (Private Unicode
819	* Area) in the range U+F020-U+F0FF.
820	*
821	* FT_ENCODING_SJIS ::
822	* Shift JIS encoding for Japanese. More info at
823	* 'https://en.wikipedia.org/wiki/Shift_JIS'. See note on multi-byte
824	* encodings below.
825	*
826	* FT_ENCODING_PRC ::
827	* Corresponds to encoding systems mainly for Simplified Chinese as
828	* used in People's Republic of China (PRC). The encoding layout is
829	* based on GB~2312 and its supersets GBK and GB~18030.
830	*
831	* FT_ENCODING_BIG5 ::
832	* Corresponds to an encoding system for Traditional Chinese as used in
833	* Taiwan and Hong Kong.
834	*
835	* FT_ENCODING_WANSUNG ::
836	* Corresponds to the Korean encoding system known as Extended Wansung
837	* (MS Windows code page 949). For more information see
838	* 'https://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WindowsBestFit/bestfit949.txt'.
839	*
840	* FT_ENCODING_JOHAB ::
841	* The Korean standard character set (KS~C 5601-1992), which
842	* corresponds to MS Windows code page 1361. This character set
843	* includes all possible Hangul character combinations.
844	*
845	* FT_ENCODING_ADOBE_LATIN_1 ::
846	* Corresponds to a Latin-1 encoding as defined in a Type~1 PostScript
847	* font. It is limited to 256 character codes.
848	*
849	* FT_ENCODING_ADOBE_STANDARD ::
850	* Adobe Standard encoding, as found in Type~1, CFF, and OpenType/CFF
851	* fonts. It is limited to 256 character codes.
852	*
853	* FT_ENCODING_ADOBE_EXPERT ::
854	* Adobe Expert encoding, as found in Type~1, CFF, and OpenType/CFF
855	* fonts. It is limited to 256 character codes.
856	*
857	* FT_ENCODING_ADOBE_CUSTOM ::
858	* Corresponds to a custom encoding, as found in Type~1, CFF, and
859	* OpenType/CFF fonts. It is limited to 256 character codes.
860	*
861	* FT_ENCODING_APPLE_ROMAN ::
862	* Apple roman encoding. Many TrueType and OpenType fonts contain a
863	* charmap for this 8-bit encoding, since older versions of Mac OS are
864	* able to use it.
865	*
866	* FT_ENCODING_OLD_LATIN_2 ::
867	* This value is deprecated and was neither used nor reported by
868	* FreeType. Don't use or test for it.
869	*
870	* FT_ENCODING_MS_SJIS ::
871	* Same as FT_ENCODING_SJIS. Deprecated.
872	*
873	* FT_ENCODING_MS_GB2312 ::
874	* Same as FT_ENCODING_PRC. Deprecated.
875	*
876	* FT_ENCODING_MS_BIG5 ::
877	* Same as FT_ENCODING_BIG5. Deprecated.
878	*
879	* FT_ENCODING_MS_WANSUNG ::
880	* Same as FT_ENCODING_WANSUNG. Deprecated.
881	*
882	* FT_ENCODING_MS_JOHAB ::
883	* Same as FT_ENCODING_JOHAB. Deprecated.
884	*
885	* @note:
886	* When loading a font, FreeType makes a Unicode charmap active if
887	* possible (either if the font provides such a charmap, or if FreeType
888	* can synthesize one from PostScript glyph name dictionaries; in either
889	* case, the charmap is tagged with `FT_ENCODING_UNICODE`). If such a
890	* charmap is synthesized, it is placed at the first position of the
891	* charmap array.
892	*
893	* All other encodings are considered legacy and tagged only if
894	* explicitly defined in the font file. Otherwise, `FT_ENCODING_NONE` is
895	* used.
896	*
897	* `FT_ENCODING_NONE` is set by the BDF and PCF drivers if the charmap is
898	* neither Unicode nor ISO-8859-1 (otherwise it is set to
899	* `FT_ENCODING_UNICODE`). Use @FT_Get_BDF_Charset_ID to find out which
900	* encoding is really present. If, for example, the `cs_registry` field
901	* is 'KOI8' and the `cs_encoding` field is 'R', the font is encoded in
902	* KOI8-R.
903	*
904	* `FT_ENCODING_NONE` is always set (with a single exception) by the
905	* winfonts driver. Use @FT_Get_WinFNT_Header and examine the `charset`
906	* field of the @FT_WinFNT_HeaderRec structure to find out which encoding
907	* is really present. For example, @FT_WinFNT_ID_CP1251 (204) means
908	* Windows code page 1251 (for Russian).
909	*
910	* `FT_ENCODING_NONE` is set if `platform_id` is @TT_PLATFORM_MACINTOSH
911	* and `encoding_id` is not `TT_MAC_ID_ROMAN` (otherwise it is set to
912	* `FT_ENCODING_APPLE_ROMAN`).
913	*
914	* If `platform_id` is @TT_PLATFORM_MACINTOSH, use the function
915	* @FT_Get_CMap_Language_ID to query the Mac language ID that may be
916	* needed to be able to distinguish Apple encoding variants. See
917	*
918	* https://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/Readme.txt
919	*
920	* to get an idea how to do that. Basically, if the language ID is~0,
921	* don't use it, otherwise subtract 1 from the language ID. Then examine
922	* `encoding_id`. If, for example, `encoding_id` is `TT_MAC_ID_ROMAN`
923	* and the language ID (minus~1) is `TT_MAC_LANGID_GREEK`, it is the
924	* Greek encoding, not Roman. `TT_MAC_ID_ARABIC` with
925	* `TT_MAC_LANGID_FARSI` means the Farsi variant of the Arabic encoding.
926	*/
927	typedef enum FT_Encoding_
928	{
929	FT_ENC_TAG( FT_ENCODING_NONE, `0`, `0`, `0`, `0` ),
930
931	FT_ENC_TAG( FT_ENCODING_MS_SYMBOL, `'s'`, `'y'`, `'m'`, `'b'` ),
932	FT_ENC_TAG( FT_ENCODING_UNICODE, `'u'`, `'n'`, `'i'`, `'c'` ),
933
934	FT_ENC_TAG( FT_ENCODING_SJIS, `'s'`, `'j'`, `'i'`, `'s'` ),
935	FT_ENC_TAG( FT_ENCODING_PRC, `'g'`, `'b'`, `' '`, `' '` ),
936	FT_ENC_TAG( FT_ENCODING_BIG5, `'b'`, `'i'`, `'g'`, `'5'` ),
937	FT_ENC_TAG( FT_ENCODING_WANSUNG, `'w'`, `'a'`, `'n'`, `'s'` ),
938	FT_ENC_TAG( FT_ENCODING_JOHAB, `'j'`, `'o'`, `'h'`, `'a'` ),
939
940	/ for backward compatibility /
941	FT_ENCODING_GB2312 = FT_ENCODING_PRC,
942	FT_ENCODING_MS_SJIS = FT_ENCODING_SJIS,
943	FT_ENCODING_MS_GB2312 = FT_ENCODING_PRC,
944	FT_ENCODING_MS_BIG5 = FT_ENCODING_BIG5,
945	FT_ENCODING_MS_WANSUNG = FT_ENCODING_WANSUNG,
946	FT_ENCODING_MS_JOHAB = FT_ENCODING_JOHAB,
947
948	FT_ENC_TAG( FT_ENCODING_ADOBE_STANDARD, `'A'`, `'D'`, `'O'`, `'B'` ),
949	FT_ENC_TAG( FT_ENCODING_ADOBE_EXPERT, `'A'`, `'D'`, `'B'`, `'E'` ),
950	FT_ENC_TAG( FT_ENCODING_ADOBE_CUSTOM, `'A'`, `'D'`, `'B'`, `'C'` ),
951	FT_ENC_TAG( FT_ENCODING_ADOBE_LATIN_1, `'l'`, `'a'`, `'t'`, `'1'` ),
952
953	FT_ENC_TAG( FT_ENCODING_OLD_LATIN_2, `'l'`, `'a'`, `'t'`, `'2'` ),
954
955	FT_ENC_TAG( FT_ENCODING_APPLE_ROMAN, `'a'`, `'r'`, `'m'`, `'n'` )
956
957	} FT_Encoding;
958
959
960	/ these constants are deprecated; use the corresponding `FT_Encoding` /
961	/ values instead /
962	#define ft_encoding_none FT_ENCODING_NONE
963	#define ft_encoding_unicode FT_ENCODING_UNICODE
964	#define ft_encoding_symbol FT_ENCODING_MS_SYMBOL
965	#define ft_encoding_latin_1 FT_ENCODING_ADOBE_LATIN_1
966	#define ft_encoding_latin_2 FT_ENCODING_OLD_LATIN_2
967	#define ft_encoding_sjis FT_ENCODING_SJIS
968	#define ft_encoding_gb2312 FT_ENCODING_PRC
969	#define ft_encoding_big5 FT_ENCODING_BIG5
970	#define ft_encoding_wansung FT_ENCODING_WANSUNG
971	#define ft_encoding_johab FT_ENCODING_JOHAB
972
973	#define ft_encoding_adobe_standard FT_ENCODING_ADOBE_STANDARD
974	#define ft_encoding_adobe_expert FT_ENCODING_ADOBE_EXPERT
975	#define ft_encoding_adobe_custom FT_ENCODING_ADOBE_CUSTOM
976	#define ft_encoding_apple_roman FT_ENCODING_APPLE_ROMAN
977
978
979	/**************************************************************************
980	*
981	* @struct:
982	* FT_CharMapRec
983	*
984	* @description:
985	* The base charmap structure.
986	*
987	* @fields:
988	* face ::
989	* A handle to the parent face object.
990	*
991	* encoding ::
992	* An @FT_Encoding tag identifying the charmap. Use this with
993	* @FT_Select_Charmap.
994	*
995	* platform_id ::
996	* An ID number describing the platform for the following encoding ID.
997	* This comes directly from the TrueType specification and gets
998	* emulated for other formats.
999	*
1000	* encoding_id ::
1001	* A platform-specific encoding number. This also comes from the
1002	* TrueType specification and gets emulated similarly.
1003	*/
1004	typedef struct FT_CharMapRec_
1005	{
1006	FT_Face face;
1007	FT_Encoding encoding;
1008	FT_UShort platform_id;
1009	FT_UShort encoding_id;
1010
1011	} FT_CharMapRec;
1012
1013
1014	/***********************************************************************/
1015	/***********************************************************************/
1016	/ /
1017	/ B A S E O B J E C T C L A S S E S /
1018	/ /
1019	/***********************************************************************/
1020	/***********************************************************************/
1021
1022
1023	/**************************************************************************
1024	*
1025	* @section:
1026	* other_api_data
1027	*
1028	*/
1029
1030	/**************************************************************************
1031	*
1032	* @type:
1033	* FT_Face_Internal
1034	*
1035	* @description:
1036	* An opaque handle to an `FT_Face_InternalRec` structure that models the
1037	* private data of a given @FT_Face object.
1038	*
1039	* This structure might change between releases of FreeType~2 and is not
1040	* generally available to client applications.
1041	*/
1042	typedef struct FT_Face_InternalRec_* FT_Face_Internal;
1043
1044
1045	/**************************************************************************
1046	*
1047	* @section:
1048	* face_creation
1049	*
1050	*/
1051
1052	/**************************************************************************
1053	*
1054	* @struct:
1055	* FT_FaceRec
1056	*
1057	* @description:
1058	* FreeType root face class structure. A face object models a typeface
1059	* in a font file.
1060	*
1061	* @fields:
1062	* num_faces ::
1063	* The number of faces in the font file. Some font formats can have
1064	* multiple faces in a single font file.
1065	*
1066	* face_index ::
1067	* This field holds two different values. Bits 0-15 are the index of
1068	* the face in the font file (starting with value~0). They are set
1069	* to~0 if there is only one face in the font file.
1070	*
1071	* [Since 2.6.1] Bits 16-30 are relevant to TrueType GX and OpenType
1072	* Font Variations only, holding the named instance index for the
1073	* current face index (starting with value~1; value~0 indicates font
1074	* access without a named instance). For non-variation fonts, bits
1075	* 16-30 are ignored. If we have the third named instance of face~4,
1076	* say, `face_index` is set to 0x00030004.
1077	*
1078	* Bit 31 is always zero (that is, `face_index` is always a positive
1079	* value).
1080	*
1081	* [Since 2.9] Changing the design coordinates with
1082	* @FT_Set_Var_Design_Coordinates or @FT_Set_Var_Blend_Coordinates does
1083	* not influence the named instance index value (only
1084	* @FT_Set_Named_Instance does that).
1085	*
1086	* face_flags ::
1087	* A set of bit flags that give important information about the face;
1088	* see @FT_FACE_FLAG_XXX for the details.
1089	*
1090	* style_flags ::
1091	* The lower 16~bits contain a set of bit flags indicating the style of
1092	* the face; see @FT_STYLE_FLAG_XXX for the details.
1093	*
1094	* [Since 2.6.1] Bits 16-30 hold the number of named instances
1095	* available for the current face if we have a TrueType GX or OpenType
1096	* Font Variation. Bit 31 is always zero (that is, `style_flags` is
1097	* always a positive value). Note that a variation font has always at
1098	* least one named instance, namely the default instance.
1099	*
1100	* num_glyphs ::
1101	* The number of glyphs in the face. If the face is scalable and has
1102	* sbits (see `num_fixed_sizes`), it is set to the number of outline
1103	* glyphs.
1104	*
1105	* For CID-keyed fonts (not in an SFNT wrapper) this value gives the
1106	* highest CID used in the font.
1107	*
1108	* family_name ::
1109	* The face's family name. This is an ASCII string, usually in
1110	* English, that describes the typeface's family (like 'Times New
1111	* Roman', 'Bodoni', 'Garamond', etc). This is a least common
1112	* denominator used to list fonts. Some formats (TrueType & OpenType)
1113	* provide localized and Unicode versions of this string. Applications
1114	* should use the format-specific interface to access them. Can be
1115	* `NULL` (e.g., in fonts embedded in a PDF file).
1116	*
1117	* In case the font doesn't provide a specific family name entry,
1118	* FreeType tries to synthesize one, deriving it from other name
1119	* entries.
1120	*
1121	* style_name ::
1122	* The face's style name. This is an ASCII string, usually in English,
1123	* that describes the typeface's style (like 'Italic', 'Bold',
1124	* 'Condensed', etc). Not all font formats provide a style name, so
1125	* this field is optional, and can be set to `NULL`. As for
1126	* `family_name`, some formats provide localized and Unicode versions
1127	* of this string. Applications should use the format-specific
1128	* interface to access them.
1129	*
1130	* num_fixed_sizes ::
1131	* The number of bitmap strikes in the face. Even if the face is
1132	* scalable, there might still be bitmap strikes, which are called
1133	* 'sbits' in that case.
1134	*
1135	* available_sizes ::
1136	* An array of @FT_Bitmap_Size for all bitmap strikes in the face. It
1137	* is set to `NULL` if there is no bitmap strike.
1138	*
1139	* Note that FreeType tries to sanitize the strike data since they are
1140	* sometimes sloppy or incorrect, but this can easily fail.
1141	*
1142	* num_charmaps ::
1143	* The number of charmaps in the face.
1144	*
1145	* charmaps ::
1146	* An array of the charmaps of the face.
1147	*
1148	* generic ::
1149	* A field reserved for client uses. See the @FT_Generic type
1150	* description.
1151	*
1152	* bbox ::
1153	* The font bounding box. Coordinates are expressed in font units (see
1154	* `units_per_EM`). The box is large enough to contain any glyph from
1155	* the font. Thus, `bbox.yMax` can be seen as the 'maximum ascender',
1156	* and `bbox.yMin` as the 'minimum descender'. Only relevant for
1157	* scalable formats.
1158	*
1159	* Note that the bounding box might be off by (at least) one pixel for
1160	* hinted fonts. See @FT_Size_Metrics for further discussion.
1161	*
1162	* Note that the bounding box does not vary in OpenType Font Variations
1163	* and should only be used in relation to the default instance.
1164	*
1165	* units_per_EM ::
1166	* The number of font units per EM square for this face. This is
1167	* typically 2048 for TrueType fonts, and 1000 for Type~1 fonts. Only
1168	* relevant for scalable formats.
1169	*
1170	* ascender ::
1171	* The typographic ascender of the face, expressed in font units. For
1172	* font formats not having this information, it is set to `bbox.yMax`.
1173	* Only relevant for scalable formats.
1174	*
1175	* descender ::
1176	* The typographic descender of the face, expressed in font units. For
1177	* font formats not having this information, it is set to `bbox.yMin`.
1178	* Note that this field is negative for values below the baseline.
1179	* Only relevant for scalable formats.
1180	*
1181	* height ::
1182	* This value is the vertical distance between two consecutive
1183	* baselines, expressed in font units. It is always positive. Only
1184	* relevant for scalable formats.
1185	*
1186	* If you want the global glyph height, use `ascender - descender`.
1187	*
1188	* max_advance_width ::
1189	* The maximum advance width, in font units, for all glyphs in this
1190	* face. This can be used to make word wrapping computations faster.
1191	* Only relevant for scalable formats.
1192	*
1193	* max_advance_height ::
1194	* The maximum advance height, in font units, for all glyphs in this
1195	* face. This is only relevant for vertical layouts, and is set to
1196	* `height` for fonts that do not provide vertical metrics. Only
1197	* relevant for scalable formats.
1198	*
1199	* underline_position ::
1200	* The position, in font units, of the underline line for this face.
1201	* It is the center of the underlining stem. Only relevant for
1202	* scalable formats.
1203	*
1204	* underline_thickness ::
1205	* The thickness, in font units, of the underline for this face. Only
1206	* relevant for scalable formats.
1207	*
1208	* glyph ::
1209	* The face's associated glyph slot(s).
1210	*
1211	* size ::
1212	* The current active size for this face.
1213	*
1214	* charmap ::
1215	* The current active charmap for this face.
1216	*
1217	* @note:
1218	* Fields may be changed after a call to @FT_Attach_File or
1219	* @FT_Attach_Stream.
1220	*
1221	* For OpenType Font Variations, the values of the following fields can
1222	* change after a call to @FT_Set_Var_Design_Coordinates (and friends) if
1223	* the font contains an 'MVAR' table: `ascender`, `descender`, `height`,
1224	* `underline_position`, and `underline_thickness`.
1225	*
1226	* Especially for TrueType fonts see also the documentation for
1227	* @FT_Size_Metrics.
1228	*/
1229	typedef struct FT_FaceRec_
1230	{
1231	FT_Long num_faces;
1232	FT_Long face_index;
1233
1234	FT_Long face_flags;
1235	FT_Long style_flags;
1236
1237	FT_Long num_glyphs;
1238
1239	FT_String* family_name;
1240	FT_String* style_name;
1241
1242	FT_Int num_fixed_sizes;
1243	FT_Bitmap_Size* available_sizes;
1244
1245	FT_Int num_charmaps;
1246	FT_CharMap* charmaps;
1247
1248	FT_Generic generic;
1249
1250	/ The following member variables (down to `underline_thickness`) /
1251	/ are only relevant to scalable outlines; cf. @FT_Bitmap_Size /
1252	/ for bitmap fonts. /
1253	FT_BBox bbox;
1254
1255	FT_UShort units_per_EM;
1256	FT_Short ascender;
1257	FT_Short descender;
1258	FT_Short height;
1259
1260	FT_Short max_advance_width;
1261	FT_Short max_advance_height;
1262
1263	FT_Short underline_position;
1264	FT_Short underline_thickness;
1265
1266	FT_GlyphSlot glyph;
1267	FT_Size size;
1268	FT_CharMap charmap;
1269
1270	/ private fields, internal to FreeType /
1271
1272	FT_Driver driver;
1273	FT_Memory memory;
1274	FT_Stream stream;
1275
1276	FT_ListRec sizes_list;
1277
1278	FT_Generic autohint; / face-specific auto-hinter data /
1279	void* extensions; / unused /
1280
1281	FT_Face_Internal internal;
1282
1283	} FT_FaceRec;
1284
1285
1286	/**************************************************************************
1287	*
1288	* @enum:
1289	* FT_FACE_FLAG_XXX
1290	*
1291	* @description:
1292	* A list of bit flags used in the `face_flags` field of the @FT_FaceRec
1293	* structure. They inform client applications of properties of the
1294	* corresponding face.
1295	*
1296	* @values:
1297	* FT_FACE_FLAG_SCALABLE ::
1298	* The face contains outline glyphs. Note that a face can contain
1299	* bitmap strikes also, i.e., a face can have both this flag and
1300	* @FT_FACE_FLAG_FIXED_SIZES set.
1301	*
1302	* FT_FACE_FLAG_FIXED_SIZES ::
1303	* The face contains bitmap strikes. See also the `num_fixed_sizes`
1304	* and `available_sizes` fields of @FT_FaceRec.
1305	*
1306	* FT_FACE_FLAG_FIXED_WIDTH ::
1307	* The face contains fixed-width characters (like Courier, Lucida,
1308	* MonoType, etc.).
1309	*
1310	* FT_FACE_FLAG_SFNT ::
1311	* The face uses the SFNT storage scheme. For now, this means TrueType
1312	* and OpenType.
1313	*
1314	* FT_FACE_FLAG_HORIZONTAL ::
1315	* The face contains horizontal glyph metrics. This should be set for
1316	* all common formats.
1317	*
1318	* FT_FACE_FLAG_VERTICAL ::
1319	* The face contains vertical glyph metrics. This is only available in
1320	* some formats, not all of them.
1321	*
1322	* FT_FACE_FLAG_KERNING ::
1323	* The face contains kerning information. If set, the kerning distance
1324	* can be retrieved using the function @FT_Get_Kerning. Otherwise the
1325	* function always returns the vector (0,0).
1326	*
1327	* Note that for TrueType fonts only, FreeType supports both the 'kern'
1328	* table and the basic, pair-wise kerning feature from the 'GPOS' table
1329	* (with `TT_CONFIG_OPTION_GPOS_KERNING` enabled), though FreeType does
1330	* not support the more advanced GPOS layout features; use a library
1331	* like HarfBuzz for those instead.
1332	*
1333	* FT_FACE_FLAG_FAST_GLYPHS ::
1334	* THIS FLAG IS DEPRECATED. DO NOT USE OR TEST IT.
1335	*
1336	* FT_FACE_FLAG_MULTIPLE_MASTERS ::
1337	* The face contains multiple masters and is capable of interpolating
1338	* between them. Supported formats are Adobe MM, TrueType GX, and
1339	* OpenType Font Variations.
1340	*
1341	* See section @multiple_masters for API details.
1342	*
1343	* FT_FACE_FLAG_GLYPH_NAMES ::
1344	* The face contains glyph names, which can be retrieved using
1345	* @FT_Get_Glyph_Name. Note that some TrueType fonts contain broken
1346	* glyph name tables. Use the function @FT_Has_PS_Glyph_Names when
1347	* needed.
1348	*
1349	* FT_FACE_FLAG_EXTERNAL_STREAM ::
1350	* Used internally by FreeType to indicate that a face's stream was
1351	* provided by the client application and should not be destroyed when
1352	* @FT_Done_Face is called. Don't read or test this flag.
1353	*
1354	* FT_FACE_FLAG_HINTER ::
1355	* The font driver has a hinting machine of its own. For example, with
1356	* TrueType fonts, it makes sense to use data from the SFNT 'gasp'
1357	* table only if the native TrueType hinting engine (with the bytecode
1358	* interpreter) is available and active.
1359	*
1360	* FT_FACE_FLAG_CID_KEYED ::
1361	* The face is CID-keyed. In that case, the face is not accessed by
1362	* glyph indices but by CID values. For subsetted CID-keyed fonts this
1363	* has the consequence that not all index values are a valid argument
1364	* to @FT_Load_Glyph. Only the CID values for which corresponding
1365	* glyphs in the subsetted font exist make `FT_Load_Glyph` return
1366	* successfully; in all other cases you get an
1367	* `FT_Err_Invalid_Argument` error.
1368	*
1369	* Note that CID-keyed fonts that are in an SFNT wrapper (that is, all
1370	* OpenType/CFF fonts) don't have this flag set since the glyphs are
1371	* accessed in the normal way (using contiguous indices); the
1372	* 'CID-ness' isn't visible to the application.
1373	*
1374	* FT_FACE_FLAG_TRICKY ::
1375	* The face is 'tricky', that is, it always needs the font format's
1376	* native hinting engine to get a reasonable result. A typical example
1377	* is the old Chinese font `mingli.ttf` (but not `mingliu.ttc`) that
1378	* uses TrueType bytecode instructions to move and scale all of its
1379	* subglyphs.
1380	*
1381	* It is not possible to auto-hint such fonts using
1382	* @FT_LOAD_FORCE_AUTOHINT; it will also ignore @FT_LOAD_NO_HINTING.
1383	* You have to set both @FT_LOAD_NO_HINTING and @FT_LOAD_NO_AUTOHINT to
1384	* really disable hinting; however, you probably never want this except
1385	* for demonstration purposes.
1386	*
1387	* Currently, there are about a dozen TrueType fonts in the list of
1388	* tricky fonts; they are hard-coded in file `ttobjs.c`.
1389	*
1390	* FT_FACE_FLAG_COLOR ::
1391	* [Since 2.5.1] The face has color glyph tables. See @FT_LOAD_COLOR
1392	* for more information.
1393	*
1394	* FT_FACE_FLAG_VARIATION ::
1395	* [Since 2.9] Set if the current face (or named instance) has been
1396	* altered with @FT_Set_MM_Design_Coordinates,
1397	* @FT_Set_Var_Design_Coordinates, @FT_Set_Var_Blend_Coordinates, or
1398	* @FT_Set_MM_WeightVector to select a non-default instance.
1399	*
1400	* FT_FACE_FLAG_SVG ::
1401	* [Since 2.12] The face has an 'SVG~' OpenType table.
1402	*
1403	* FT_FACE_FLAG_SBIX ::
1404	* [Since 2.12] The face has an 'sbix' OpenType table and outlines.
1405	* For such fonts, @FT_FACE_FLAG_SCALABLE is not set by default to
1406	* retain backward compatibility.
1407	*
1408	* FT_FACE_FLAG_SBIX_OVERLAY ::
1409	* [Since 2.12] The face has an 'sbix' OpenType table where outlines
1410	* should be drawn on top of bitmap strikes.
1411	*
1412	*/
1413	#define FT_FACE_FLAG_SCALABLE ( 1L << 0 )
1414	#define FT_FACE_FLAG_FIXED_SIZES ( 1L << 1 )
1415	#define FT_FACE_FLAG_FIXED_WIDTH ( 1L << 2 )
1416	#define FT_FACE_FLAG_SFNT ( 1L << 3 )
1417	#define FT_FACE_FLAG_HORIZONTAL ( 1L << 4 )
1418	#define FT_FACE_FLAG_VERTICAL ( 1L << 5 )
1419	#define FT_FACE_FLAG_KERNING ( 1L << 6 )
1420	#define FT_FACE_FLAG_FAST_GLYPHS ( 1L << 7 )
1421	#define FT_FACE_FLAG_MULTIPLE_MASTERS ( 1L << 8 )
1422	#define FT_FACE_FLAG_GLYPH_NAMES ( 1L << 9 )
1423	#define FT_FACE_FLAG_EXTERNAL_STREAM ( 1L << 10 )
1424	#define FT_FACE_FLAG_HINTER ( 1L << 11 )
1425	#define FT_FACE_FLAG_CID_KEYED ( 1L << 12 )
1426	#define FT_FACE_FLAG_TRICKY ( 1L << 13 )
1427	#define FT_FACE_FLAG_COLOR ( 1L << 14 )
1428	#define FT_FACE_FLAG_VARIATION ( 1L << 15 )
1429	#define FT_FACE_FLAG_SVG ( 1L << 16 )
1430	#define FT_FACE_FLAG_SBIX ( 1L << 17 )
1431	#define FT_FACE_FLAG_SBIX_OVERLAY ( 1L << 18 )
1432
1433
1434	/**************************************************************************
1435	*
1436	* @section:
1437	* font_testing_macros
1438	*
1439	*/
1440
1441	/**************************************************************************
1442	*
1443	* @macro:
1444	* FT_HAS_HORIZONTAL
1445	*
1446	* @description:
1447	* A macro that returns true whenever a face object contains horizontal
1448	* metrics (this is true for all font formats though).
1449	*
1450	* @also:
1451	* @FT_HAS_VERTICAL can be used to check for vertical metrics.
1452	*
1453	*/
1454	#define FT_HAS_HORIZONTAL( face ) \
1455	( !!( (face)->face_flags & FT_FACE_FLAG_HORIZONTAL ) )
1456
1457
1458	/**************************************************************************
1459	*
1460	* @macro:
1461	* FT_HAS_VERTICAL
1462	*
1463	* @description:
1464	* A macro that returns true whenever a face object contains real
1465	* vertical metrics (and not only synthesized ones).
1466	*
1467	*/
1468	#define FT_HAS_VERTICAL( face ) \
1469	( !!( (face)->face_flags & FT_FACE_FLAG_VERTICAL ) )
1470
1471
1472	/**************************************************************************
1473	*
1474	* @macro:
1475	* FT_HAS_KERNING
1476	*
1477	* @description:
1478	* A macro that returns true whenever a face object contains kerning data
1479	* that can be accessed with @FT_Get_Kerning.
1480	*
1481	*/
1482	#define FT_HAS_KERNING( face ) \
1483	( !!( (face)->face_flags & FT_FACE_FLAG_KERNING ) )
1484
1485
1486	/**************************************************************************
1487	*
1488	* @macro:
1489	* FT_IS_SCALABLE
1490	*
1491	* @description:
1492	* A macro that returns true whenever a face object contains a scalable
1493	* font face (true for TrueType, Type~1, Type~42, CID, OpenType/CFF, and
1494	* PFR font formats).
1495	*
1496	*/
1497	#define FT_IS_SCALABLE( face ) \
1498	( !!( (face)->face_flags & FT_FACE_FLAG_SCALABLE ) )
1499
1500
1501	/**************************************************************************
1502	*
1503	* @macro:
1504	* FT_IS_SFNT
1505	*
1506	* @description:
1507	* A macro that returns true whenever a face object contains a font whose
1508	* format is based on the SFNT storage scheme. This usually means:
1509	* TrueType fonts, OpenType fonts, as well as SFNT-based embedded bitmap
1510	* fonts.
1511	*
1512	* If this macro is true, all functions defined in @FT_SFNT_NAMES_H and
1513	* @FT_TRUETYPE_TABLES_H are available.
1514	*
1515	*/
1516	#define FT_IS_SFNT( face ) \
1517	( !!( (face)->face_flags & FT_FACE_FLAG_SFNT ) )
1518
1519
1520	/**************************************************************************
1521	*
1522	* @macro:
1523	* FT_IS_FIXED_WIDTH
1524	*
1525	* @description:
1526	* A macro that returns true whenever a face object contains a font face
1527	* that contains fixed-width (or 'monospace', 'fixed-pitch', etc.)
1528	* glyphs.
1529	*
1530	*/
1531	#define FT_IS_FIXED_WIDTH( face ) \
1532	( !!( (face)->face_flags & FT_FACE_FLAG_FIXED_WIDTH ) )
1533
1534
1535	/**************************************************************************
1536	*
1537	* @macro:
1538	* FT_HAS_FIXED_SIZES
1539	*
1540	* @description:
1541	* A macro that returns true whenever a face object contains some
1542	* embedded bitmaps. See the `available_sizes` field of the @FT_FaceRec
1543	* structure.
1544	*
1545	*/
1546	#define FT_HAS_FIXED_SIZES( face ) \
1547	( !!( (face)->face_flags & FT_FACE_FLAG_FIXED_SIZES ) )
1548
1549
1550	/**************************************************************************
1551	*
1552	* @section:
1553	* other_api_data
1554	*
1555	*/
1556
1557	/**************************************************************************
1558	*
1559	* @macro:
1560	* FT_HAS_FAST_GLYPHS
1561	*
1562	* @description:
1563	* Deprecated.
1564	*
1565	*/
1566	#define FT_HAS_FAST_GLYPHS( face ) 0
1567
1568
1569	/**************************************************************************
1570	*
1571	* @section:
1572	* font_testing_macros
1573	*
1574	*/
1575
1576	/**************************************************************************
1577	*
1578	* @macro:
1579	* FT_HAS_GLYPH_NAMES
1580	*
1581	* @description:
1582	* A macro that returns true whenever a face object contains some glyph
1583	* names that can be accessed through @FT_Get_Glyph_Name.
1584	*
1585	*/
1586	#define FT_HAS_GLYPH_NAMES( face ) \
1587	( !!( (face)->face_flags & FT_FACE_FLAG_GLYPH_NAMES ) )
1588
1589
1590	/**************************************************************************
1591	*
1592	* @macro:
1593	* FT_HAS_MULTIPLE_MASTERS
1594	*
1595	* @description:
1596	* A macro that returns true whenever a face object contains some
1597	* multiple masters. The functions provided by @FT_MULTIPLE_MASTERS_H
1598	* are then available to choose the exact design you want.
1599	*
1600	*/
1601	#define FT_HAS_MULTIPLE_MASTERS( face ) \
1602	( !!( (face)->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS ) )
1603
1604
1605	/**************************************************************************
1606	*
1607	* @macro:
1608	* FT_IS_NAMED_INSTANCE
1609	*
1610	* @description:
1611	* A macro that returns true whenever a face object is a named instance
1612	* of a TrueType GX or OpenType Font Variations.
1613	*
1614	* [Since 2.9] Changing the design coordinates with
1615	* @FT_Set_Var_Design_Coordinates or @FT_Set_Var_Blend_Coordinates does
1616	* not influence the return value of this macro (only
1617	* @FT_Set_Named_Instance does that).
1618	*
1619	* @since:
1620	* 2.7
1621	*
1622	*/
1623	#define FT_IS_NAMED_INSTANCE( face ) \
1624	( !!( (face)->face_index & 0x7FFF0000L ) )
1625
1626
1627	/**************************************************************************
1628	*
1629	* @macro:
1630	* FT_IS_VARIATION
1631	*
1632	* @description:
1633	* A macro that returns true whenever a face object has been altered by
1634	* @FT_Set_MM_Design_Coordinates, @FT_Set_Var_Design_Coordinates,
1635	* @FT_Set_Var_Blend_Coordinates, or @FT_Set_MM_WeightVector.
1636	*
1637	* @since:
1638	* 2.9
1639	*
1640	*/
1641	#define FT_IS_VARIATION( face ) \
1642	( !!( (face)->face_flags & FT_FACE_FLAG_VARIATION ) )
1643
1644
1645	/**************************************************************************
1646	*
1647	* @macro:
1648	* FT_IS_CID_KEYED
1649	*
1650	* @description:
1651	* A macro that returns true whenever a face object contains a CID-keyed
1652	* font. See the discussion of @FT_FACE_FLAG_CID_KEYED for more details.
1653	*
1654	* If this macro is true, all functions defined in @FT_CID_H are
1655	* available.
1656	*
1657	*/
1658	#define FT_IS_CID_KEYED( face ) \
1659	( !!( (face)->face_flags & FT_FACE_FLAG_CID_KEYED ) )
1660
1661
1662	/**************************************************************************
1663	*
1664	* @macro:
1665	* FT_IS_TRICKY
1666	*
1667	* @description:
1668	* A macro that returns true whenever a face represents a 'tricky' font.
1669	* See the discussion of @FT_FACE_FLAG_TRICKY for more details.
1670	*
1671	*/
1672	#define FT_IS_TRICKY( face ) \
1673	( !!( (face)->face_flags & FT_FACE_FLAG_TRICKY ) )
1674
1675
1676	/**************************************************************************
1677	*
1678	* @macro:
1679	* FT_HAS_COLOR
1680	*
1681	* @description:
1682	* A macro that returns true whenever a face object contains tables for
1683	* color glyphs.
1684	*
1685	* @since:
1686	* 2.5.1
1687	*
1688	*/
1689	#define FT_HAS_COLOR( face ) \
1690	( !!( (face)->face_flags & FT_FACE_FLAG_COLOR ) )
1691
1692
1693	/**************************************************************************
1694	*
1695	* @macro:
1696	* FT_HAS_SVG
1697	*
1698	* @description:
1699	* A macro that returns true whenever a face object contains an 'SVG~'
1700	* OpenType table.
1701	*
1702	* @since:
1703	* 2.12
1704	*/
1705	#define FT_HAS_SVG( face ) \
1706	( !!( (face)->face_flags & FT_FACE_FLAG_SVG ) )
1707
1708
1709	/**************************************************************************
1710	*
1711	* @macro:
1712	* FT_HAS_SBIX
1713	*
1714	* @description:
1715	* A macro that returns true whenever a face object contains an 'sbix'
1716	* OpenType table and outline glyphs.
1717	*
1718	* Currently, FreeType only supports bitmap glyphs in PNG format for this
1719	* table (i.e., JPEG and TIFF formats are unsupported, as are
1720	* Apple-specific formats not part of the OpenType specification).
1721	*
1722	* @note:
1723	* For backward compatibility, a font with an 'sbix' table is treated as
1724	* a bitmap-only face. Using @FT_Open_Face with
1725	* @FT_PARAM_TAG_IGNORE_SBIX, an application can switch off 'sbix'
1726	* handling so that the face is treated as an ordinary outline font with
1727	* scalable outlines.
1728	*
1729	* Here is some pseudo code that roughly illustrates how to implement
1730	* 'sbix' handling according to the OpenType specification.
1731	*
1732	* ```
1733	* if ( FT_HAS_SBIX( face ) )
1734	* {
1735	* // open font as a scalable one without sbix handling
1736	* FT_Face face2;
1737	* FT_Parameter param = { FT_PARAM_TAG_IGNORE_SBIX, NULL };
1738	* FT_Open_Args args = { FT_OPEN_PARAMS \| ...,
1739	* ...,
1740	* 1, &param };
1741	*
1742	*
1743	* FT_Open_Face( library, &args, 0, &face2 );
1744	*
1745	* <sort `face->available_size` as necessary into
1746	* `preferred_sizes`[*]>
1747	*
1748	* for ( i = 0; i < face->num_fixed_sizes; i++ )
1749	* {
1750	* size = preferred_sizes[i].size;
1751	*
1752	* error = FT_Set_Pixel_Sizes( face, size, size );
1753	* <error handling omitted>
1754	*
1755	* // check whether we have a glyph in a bitmap strike
1756	* error = FT_Load_Glyph( face,
1757	* glyph_index,
1758	* FT_LOAD_SBITS_ONLY \|
1759	* FT_LOAD_BITMAP_METRICS_ONLY );
1760	* if ( error == FT_Err_Invalid_Argument )
1761	* continue;
1762	* else if ( error )
1763	* <other error handling omitted>
1764	* else
1765	* break;
1766	* }
1767	*
1768	* if ( i != face->num_fixed_sizes )
1769	* <load embedded bitmap with `FT_Load_Glyph`,
1770	* scale it, display it, etc.>
1771	*
1772	* if ( i == face->num_fixed_sizes \|\|
1773	* FT_HAS_SBIX_OVERLAY( face ) )
1774	* <use `face2` to load outline glyph with `FT_Load_Glyph`,
1775	* scale it, display it on top of the bitmap, etc.>
1776	* }
1777	* ```
1778	*
1779	* [*] Assuming a target value of 400dpi and available strike sizes 100,
1780	* 200, 300, and 400dpi, a possible order might be [400, 200, 300, 100]:
1781	* scaling 200dpi to 400dpi usually gives better results than scaling
1782	* 300dpi to 400dpi; it is also much faster. However, scaling 100dpi to
1783	* 400dpi can yield a too pixelated result, thus the preference might be
1784	* 300dpi over 100dpi.
1785	*
1786	* @since:
1787	* 2.12
1788	*/
1789	#define FT_HAS_SBIX( face ) \
1790	( !!( (face)->face_flags & FT_FACE_FLAG_SBIX ) )
1791
1792
1793	/**************************************************************************
1794	*
1795	* @macro:
1796	* FT_HAS_SBIX_OVERLAY
1797	*
1798	* @description:
1799	* A macro that returns true whenever a face object contains an 'sbix'
1800	* OpenType table with bit~1 in its `flags` field set, instructing the
1801	* application to overlay the bitmap strike with the corresponding
1802	* outline glyph. See @FT_HAS_SBIX for pseudo code how to use it.
1803	*
1804	* @since:
1805	* 2.12
1806	*/
1807	#define FT_HAS_SBIX_OVERLAY( face ) \
1808	( !!( (face)->face_flags & FT_FACE_FLAG_SBIX_OVERLAY ) )
1809
1810
1811	/**************************************************************************
1812	*
1813	* @section:
1814	* face_creation
1815	*
1816	*/
1817
1818	/**************************************************************************
1819	*
1820	* @enum:
1821	* FT_STYLE_FLAG_XXX
1822	*
1823	* @description:
1824	* A list of bit flags to indicate the style of a given face. These are
1825	* used in the `style_flags` field of @FT_FaceRec.
1826	*
1827	* @values:
1828	* FT_STYLE_FLAG_ITALIC ::
1829	* The face style is italic or oblique.
1830	*
1831	* FT_STYLE_FLAG_BOLD ::
1832	* The face is bold.
1833	*
1834	* @note:
1835	* The style information as provided by FreeType is very basic. More
1836	* details are beyond the scope and should be done on a higher level (for
1837	* example, by analyzing various fields of the 'OS/2' table in SFNT based
1838	* fonts).
1839	*/
1840	#define FT_STYLE_FLAG_ITALIC ( 1 << 0 )
1841	#define FT_STYLE_FLAG_BOLD ( 1 << 1 )
1842
1843
1844	/**************************************************************************
1845	*
1846	* @section:
1847	* other_api_data
1848	*
1849	*/
1850
1851	/**************************************************************************
1852	*
1853	* @type:
1854	* FT_Size_Internal
1855	*
1856	* @description:
1857	* An opaque handle to an `FT_Size_InternalRec` structure, used to model
1858	* private data of a given @FT_Size object.
1859	*/
1860	typedef struct FT_Size_InternalRec_* FT_Size_Internal;
1861
1862
1863	/**************************************************************************
1864	*
1865	* @section:
1866	* sizing_and_scaling
1867	*
1868	*/
1869
1870	/**************************************************************************
1871	*
1872	* @struct:
1873	* FT_Size_Metrics
1874	*
1875	* @description:
1876	* The size metrics structure gives the metrics of a size object.
1877	*
1878	* @fields:
1879	* x_ppem ::
1880	* The width of the scaled EM square in pixels, hence the term 'ppem'
1881	* (pixels per EM). It is also referred to as 'nominal width'.
1882	*
1883	* y_ppem ::
1884	* The height of the scaled EM square in pixels, hence the term 'ppem'
1885	* (pixels per EM). It is also referred to as 'nominal height'.
1886	*
1887	* x_scale ::
1888	* A 16.16 fractional scaling value to convert horizontal metrics from
1889	* font units to 26.6 fractional pixels. Only relevant for scalable
1890	* font formats.
1891	*
1892	* y_scale ::
1893	* A 16.16 fractional scaling value to convert vertical metrics from
1894	* font units to 26.6 fractional pixels. Only relevant for scalable
1895	* font formats.
1896	*
1897	* ascender ::
1898	* The ascender in 26.6 fractional pixels, rounded up to an integer
1899	* value. See @FT_FaceRec for the details.
1900	*
1901	* descender ::
1902	* The descender in 26.6 fractional pixels, rounded down to an integer
1903	* value. See @FT_FaceRec for the details.
1904	*
1905	* height ::
1906	* The height in 26.6 fractional pixels, rounded to an integer value.
1907	* See @FT_FaceRec for the details.
1908	*
1909	* max_advance ::
1910	* The maximum advance width in 26.6 fractional pixels, rounded to an
1911	* integer value. See @FT_FaceRec for the details.
1912	*
1913	* @note:
1914	* The scaling values, if relevant, are determined first during a size
1915	* changing operation. The remaining fields are then set by the driver.
1916	* For scalable formats, they are usually set to scaled values of the
1917	* corresponding fields in @FT_FaceRec. Some values like ascender or
1918	* descender are rounded for historical reasons; more precise values (for
1919	* outline fonts) can be derived by scaling the corresponding @FT_FaceRec
1920	* values manually, with code similar to the following.
1921	*
1922	* ```
1923	* scaled_ascender = FT_MulFix( face->ascender,
1924	* size_metrics->y_scale );
1925	* ```
1926	*
1927	* Note that due to glyph hinting and the selected rendering mode these
1928	* values are usually not exact; consequently, they must be treated as
1929	* unreliable with an error margin of at least one pixel!
1930	*
1931	* Indeed, the only way to get the exact metrics is to render _all_
1932	* glyphs. As this would be a definite performance hit, it is up to
1933	* client applications to perform such computations.
1934	*
1935	* The `FT_Size_Metrics` structure is valid for bitmap fonts also.
1936	*
1937	*
1938	* TrueType fonts with native bytecode hinting
1939	*
1940	* All applications that handle TrueType fonts with native hinting must
1941	* be aware that TTFs expect different rounding of vertical font
1942	* dimensions. The application has to cater for this, especially if it
1943	* wants to rely on a TTF's vertical data (for example, to properly align
1944	* box characters vertically).
1945	*
1946	* Only the application knows _in advance_ that it is going to use native
1947	* hinting for TTFs! FreeType, on the other hand, selects the hinting
1948	* mode not at the time of creating an @FT_Size object but much later,
1949	* namely while calling @FT_Load_Glyph.
1950	*
1951	* Here is some pseudo code that illustrates a possible solution.
1952	*
1953	* ```
1954	* font_format = FT_Get_Font_Format( face );
1955	*
1956	* if ( !strcmp( font_format, "TrueType" ) &&
1957	* do_native_bytecode_hinting )
1958	* {
1959	* ascender = ROUND( FT_MulFix( face->ascender,
1960	* size_metrics->y_scale ) );
1961	* descender = ROUND( FT_MulFix( face->descender,
1962	* size_metrics->y_scale ) );
1963	* }
1964	* else
1965	* {
1966	* ascender = size_metrics->ascender;
1967	* descender = size_metrics->descender;
1968	* }
1969	*
1970	* height = size_metrics->height;
1971	* max_advance = size_metrics->max_advance;
1972	* ```
1973	*/
1974	typedef struct FT_Size_Metrics_
1975	{
1976	FT_UShort x_ppem; / horizontal pixels per EM /
1977	FT_UShort y_ppem; / vertical pixels per EM /
1978
1979	FT_Fixed x_scale; / scaling values used to convert font /
1980	FT_Fixed y_scale; / units to 26.6 fractional pixels /
1981
1982	FT_Pos ascender; / ascender in 26.6 frac. pixels /
1983	FT_Pos descender; / descender in 26.6 frac. pixels /
1984	FT_Pos height; / text height in 26.6 frac. pixels /
1985	FT_Pos max_advance; / max horizontal advance, in 26.6 pixels /
1986
1987	} FT_Size_Metrics;
1988
1989
1990	/**************************************************************************
1991	*
1992	* @struct:
1993	* FT_SizeRec
1994	*
1995	* @description:
1996	* FreeType root size class structure. A size object models a face
1997	* object at a given size.
1998	*
1999	* @fields:
2000	* face ::
2001	* Handle to the parent face object.
2002	*
2003	* generic ::
2004	* A typeless pointer, unused by the FreeType library or any of its
2005	* drivers. It can be used by client applications to link their own
2006	* data to each size object.
2007	*
2008	* metrics ::
2009	* Metrics for this size object. This field is read-only.
2010	*/
2011	typedef struct FT_SizeRec_
2012	{
2013	FT_Face face; / parent face object /
2014	FT_Generic generic; / generic pointer for client uses /
2015	FT_Size_Metrics metrics; / size metrics /
2016	FT_Size_Internal internal;
2017
2018	} FT_SizeRec;
2019
2020
2021	/**************************************************************************
2022	*
2023	* @section:
2024	* other_api_data
2025	*
2026	*/
2027
2028	/**************************************************************************
2029	*
2030	* @struct:
2031	* FT_SubGlyph
2032	*
2033	* @description:
2034	* The subglyph structure is an internal object used to describe
2035	* subglyphs (for example, in the case of composites).
2036	*
2037	* @note:
2038	* The subglyph implementation is not part of the high-level API, hence
2039	* the forward structure declaration.
2040	*
2041	* You can however retrieve subglyph information with
2042	* @FT_Get_SubGlyph_Info.
2043	*/
2044	typedef struct FT_SubGlyphRec_* FT_SubGlyph;
2045
2046
2047	/**************************************************************************
2048	*
2049	* @type:
2050	* FT_Slot_Internal
2051	*
2052	* @description:
2053	* An opaque handle to an `FT_Slot_InternalRec` structure, used to model
2054	* private data of a given @FT_GlyphSlot object.
2055	*/
2056	typedef struct FT_Slot_InternalRec_* FT_Slot_Internal;
2057
2058
2059	/**************************************************************************
2060	*
2061	* @section:
2062	* glyph_retrieval
2063	*
2064	*/
2065
2066	/**************************************************************************
2067	*
2068	* @struct:
2069	* FT_GlyphSlotRec
2070	*
2071	* @description:
2072	* FreeType root glyph slot class structure. A glyph slot is a container
2073	* where individual glyphs can be loaded, be they in outline or bitmap
2074	* format.
2075	*
2076	* @fields:
2077	* library ::
2078	* A handle to the FreeType library instance this slot belongs to.
2079	*
2080	* face ::
2081	* A handle to the parent face object.
2082	*
2083	* next ::
2084	* In some cases (like some font tools), several glyph slots per face
2085	* object can be a good thing. As this is rare, the glyph slots are
2086	* listed through a direct, single-linked list using its `next` field.
2087	*
2088	* glyph_index ::
2089	* [Since 2.10] The glyph index passed as an argument to @FT_Load_Glyph
2090	* while initializing the glyph slot.
2091	*
2092	* generic ::
2093	* A typeless pointer unused by the FreeType library or any of its
2094	* drivers. It can be used by client applications to link their own
2095	* data to each glyph slot object.
2096	*
2097	* metrics ::
2098	* The metrics of the last loaded glyph in the slot. The returned
2099	* values depend on the last load flags (see the @FT_Load_Glyph API
2100	* function) and can be expressed either in 26.6 fractional pixels or
2101	* font units.
2102	*
2103	* Note that even when the glyph image is transformed, the metrics are
2104	* not.
2105	*
2106	* linearHoriAdvance ::
2107	* The advance width of the unhinted glyph. Its value is expressed in
2108	* 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when
2109	* loading the glyph. This field can be important to perform correct
2110	* WYSIWYG layout. Only relevant for scalable glyphs.
2111	*
2112	* linearVertAdvance ::
2113	* The advance height of the unhinted glyph. Its value is expressed in
2114	* 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when
2115	* loading the glyph. This field can be important to perform correct
2116	* WYSIWYG layout. Only relevant for scalable glyphs.
2117	*
2118	* advance ::
2119	* This shorthand is, depending on @FT_LOAD_IGNORE_TRANSFORM, the
2120	* transformed (hinted) advance width for the glyph, in 26.6 fractional
2121	* pixel format. As specified with @FT_LOAD_VERTICAL_LAYOUT, it uses
2122	* either the `horiAdvance` or the `vertAdvance` value of `metrics`
2123	* field.
2124	*
2125	* format ::
2126	* This field indicates the format of the image contained in the glyph
2127	* slot. Typically @FT_GLYPH_FORMAT_BITMAP, @FT_GLYPH_FORMAT_OUTLINE,
2128	* or @FT_GLYPH_FORMAT_COMPOSITE, but other values are possible.
2129	*
2130	* bitmap ::
2131	* This field is used as a bitmap descriptor. Note that the address
2132	* and content of the bitmap buffer can change between calls of
2133	* @FT_Load_Glyph and a few other functions.
2134	*
2135	* bitmap_left ::
2136	* The bitmap's left bearing expressed in integer pixels.
2137	*
2138	* bitmap_top ::
2139	* The bitmap's top bearing expressed in integer pixels. This is the
2140	* distance from the baseline to the top-most glyph scanline, upwards
2141	* y~coordinates being positive.
2142	*
2143	* outline ::
2144	* The outline descriptor for the current glyph image if its format is
2145	* @FT_GLYPH_FORMAT_OUTLINE. Once a glyph is loaded, `outline` can be
2146	* transformed, distorted, emboldened, etc. However, it must not be
2147	* freed.
2148	*
2149	* [Since 2.10.1] If @FT_LOAD_NO_SCALE is set, outline coordinates of
2150	* OpenType Font Variations for a selected instance are internally
2151	* handled as 26.6 fractional font units but returned as (rounded)
2152	* integers, as expected. To get unrounded font units, don't use
2153	* @FT_LOAD_NO_SCALE but load the glyph with @FT_LOAD_NO_HINTING and
2154	* scale it, using the font's `units_per_EM` value as the ppem.
2155	*
2156	* num_subglyphs ::
2157	* The number of subglyphs in a composite glyph. This field is only
2158	* valid for the composite glyph format that should normally only be
2159	* loaded with the @FT_LOAD_NO_RECURSE flag.
2160	*
2161	* subglyphs ::
2162	* An array of subglyph descriptors for composite glyphs. There are
2163	* `num_subglyphs` elements in there. Currently internal to FreeType.
2164	*
2165	* control_data ::
2166	* Certain font drivers can also return the control data for a given
2167	* glyph image (e.g. TrueType bytecode, Type~1 charstrings, etc.).
2168	* This field is a pointer to such data; it is currently internal to
2169	* FreeType.
2170	*
2171	* control_len ::
2172	* This is the length in bytes of the control data. Currently internal
2173	* to FreeType.
2174	*
2175	* other ::
2176	* Reserved.
2177	*
2178	* lsb_delta ::
2179	* The difference between hinted and unhinted left side bearing while
2180	* auto-hinting is active. Zero otherwise.
2181	*
2182	* rsb_delta ::
2183	* The difference between hinted and unhinted right side bearing while
2184	* auto-hinting is active. Zero otherwise.
2185	*
2186	* @note:
2187	* If @FT_Load_Glyph is called with default flags (see @FT_LOAD_DEFAULT)
2188	* the glyph image is loaded in the glyph slot in its native format
2189	* (e.g., an outline glyph for TrueType and Type~1 formats). [Since 2.9]
2190	* The prospective bitmap metrics are calculated according to
2191	* @FT_LOAD_TARGET_XXX and other flags even for the outline glyph, even
2192	* if @FT_LOAD_RENDER is not set.
2193	*
2194	* This image can later be converted into a bitmap by calling
2195	* @FT_Render_Glyph. This function searches the current renderer for the
2196	* native image's format, then invokes it.
2197	*
2198	* The renderer is in charge of transforming the native image through the
2199	* slot's face transformation fields, then converting it into a bitmap
2200	* that is returned in `slot->bitmap`.
2201	*
2202	* Note that `slot->bitmap_left` and `slot->bitmap_top` are also used to
2203	* specify the position of the bitmap relative to the current pen
2204	* position (e.g., coordinates (0,0) on the baseline). Of course,
2205	* `slot->format` is also changed to @FT_GLYPH_FORMAT_BITMAP.
2206	*
2207	* Here is a small pseudo code fragment that shows how to use `lsb_delta`
2208	* and `rsb_delta` to do fractional positioning of glyphs:
2209	*
2210	* ```
2211	* FT_GlyphSlot slot = face->glyph;
2212	* FT_Pos origin_x = 0;
2213	*
2214	*
2215	* for all glyphs do
2216	* <load glyph with `FT_Load_Glyph'>
2217	*
2218	* FT_Outline_Translate( slot->outline, origin_x & 63, 0 );
2219	*
2220	* <save glyph image, or render glyph, or ...>
2221	*
2222	* <compute kern between current and next glyph
2223	* and add it to `origin_x'>
2224	*
2225	* origin_x += slot->advance.x;
2226	* origin_x += slot->lsb_delta - slot->rsb_delta;
2227	* endfor
2228	* ```
2229	*
2230	* Here is another small pseudo code fragment that shows how to use
2231	* `lsb_delta` and `rsb_delta` to improve integer positioning of glyphs:
2232	*
2233	* ```
2234	* FT_GlyphSlot slot = face->glyph;
2235	* FT_Pos origin_x = 0;
2236	* FT_Pos prev_rsb_delta = 0;
2237	*
2238	*
2239	* for all glyphs do
2240	* <compute kern between current and previous glyph
2241	* and add it to `origin_x'>
2242	*
2243	* <load glyph with `FT_Load_Glyph'>
2244	*
2245	* if ( prev_rsb_delta - slot->lsb_delta > 32 )
2246	* origin_x -= 64;
2247	* else if ( prev_rsb_delta - slot->lsb_delta < -31 )
2248	* origin_x += 64;
2249	*
2250	* prev_rsb_delta = slot->rsb_delta;
2251	*
2252	* <save glyph image, or render glyph, or ...>
2253	*
2254	* origin_x += slot->advance.x;
2255	* endfor
2256	* ```
2257	*
2258	* If you use strong auto-hinting, you must apply these delta values!
2259	* Otherwise you will experience far too large inter-glyph spacing at
2260	* small rendering sizes in most cases. Note that it doesn't harm to use
2261	* the above code for other hinting modes also, since the delta values
2262	* are zero then.
2263	*/
2264	typedef struct FT_GlyphSlotRec_
2265	{
2266	FT_Library library;
2267	FT_Face face;
2268	FT_GlyphSlot next;
2269	FT_UInt glyph_index; / new in 2.10; was reserved previously /
2270	FT_Generic generic;
2271
2272	FT_Glyph_Metrics metrics;
2273	FT_Fixed linearHoriAdvance;
2274	FT_Fixed linearVertAdvance;
2275	FT_Vector advance;
2276
2277	FT_Glyph_Format format;
2278
2279	FT_Bitmap bitmap;
2280	FT_Int bitmap_left;
2281	FT_Int bitmap_top;
2282
2283	FT_Outline outline;
2284
2285	FT_UInt num_subglyphs;
2286	FT_SubGlyph subglyphs;
2287
2288	void* control_data;
2289	long control_len;
2290
2291	FT_Pos lsb_delta;
2292	FT_Pos rsb_delta;
2293
2294	void* other;
2295
2296	FT_Slot_Internal internal;
2297
2298	} FT_GlyphSlotRec;
2299
2300
2301	/***********************************************************************/
2302	/***********************************************************************/
2303	/ /
2304	/ F U N C T I O N S /
2305	/ /
2306	/***********************************************************************/
2307	/***********************************************************************/
2308
2309
2310	/**************************************************************************
2311	*
2312	* @section:
2313	* library_setup
2314	*
2315	*/
2316
2317	/**************************************************************************
2318	*
2319	* @function:
2320	* FT_Init_FreeType
2321	*
2322	* @description:
2323	* Initialize a new FreeType library object. The set of modules that are
2324	* registered by this function is determined at build time.
2325	*
2326	* @output:
2327	* alibrary ::
2328	* A handle to a new library object.
2329	*
2330	* @return:
2331	* FreeType error code. 0~means success.
2332	*
2333	* @note:
2334	* In case you want to provide your own memory allocating routines, use
2335	* @FT_New_Library instead, followed by a call to @FT_Add_Default_Modules
2336	* (or a series of calls to @FT_Add_Module) and
2337	* @FT_Set_Default_Properties.
2338	*
2339	* See the documentation of @FT_Library and @FT_Face for multi-threading
2340	* issues.
2341	*
2342	* If you need reference-counting (cf. @FT_Reference_Library), use
2343	* @FT_New_Library and @FT_Done_Library.
2344	*
2345	* If compilation option `FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES` is
2346	* set, this function reads the `FREETYPE_PROPERTIES` environment
2347	* variable to control driver properties. See section @properties for
2348	* more.
2349	*/
2350	FT_EXPORT( FT_Error )
2351	FT_Init_FreeType( FT_Library *alibrary );
2352
2353
2354	/**************************************************************************
2355	*
2356	* @function:
2357	* FT_Done_FreeType
2358	*
2359	* @description:
2360	* Destroy a given FreeType library object and all of its children,
2361	* including resources, drivers, faces, sizes, etc.
2362	*
2363	* @input:
2364	* library ::
2365	* A handle to the target library object.
2366	*
2367	* @return:
2368	* FreeType error code. 0~means success.
2369	*/
2370	FT_EXPORT( FT_Error )
2371	FT_Done_FreeType( FT_Library library );
2372
2373
2374	/**************************************************************************
2375	*
2376	* @section:
2377	* face_creation
2378	*
2379	*/
2380
2381	/**************************************************************************
2382	*
2383	* @enum:
2384	* FT_OPEN_XXX
2385	*
2386	* @description:
2387	* A list of bit field constants used within the `flags` field of the
2388	* @FT_Open_Args structure.
2389	*
2390	* @values:
2391	* FT_OPEN_MEMORY ::
2392	* This is a memory-based stream.
2393	*
2394	* FT_OPEN_STREAM ::
2395	* Copy the stream from the `stream` field.
2396	*
2397	* FT_OPEN_PATHNAME ::
2398	* Create a new input stream from a C~path name.
2399	*
2400	* FT_OPEN_DRIVER ::
2401	* Use the `driver` field.
2402	*
2403	* FT_OPEN_PARAMS ::
2404	* Use the `num_params` and `params` fields.
2405	*
2406	* @note:
2407	* The `FT_OPEN_MEMORY`, `FT_OPEN_STREAM`, and `FT_OPEN_PATHNAME` flags
2408	* are mutually exclusive.
2409	*/
2410	#define FT_OPEN_MEMORY 0x1
2411	#define FT_OPEN_STREAM 0x2
2412	#define FT_OPEN_PATHNAME 0x4
2413	#define FT_OPEN_DRIVER 0x8
2414	#define FT_OPEN_PARAMS 0x10
2415
2416
2417	/ these constants are deprecated; use the corresponding `FT_OPEN_XXX` /
2418	/ values instead /
2419	#define ft_open_memory FT_OPEN_MEMORY
2420	#define ft_open_stream FT_OPEN_STREAM
2421	#define ft_open_pathname FT_OPEN_PATHNAME
2422	#define ft_open_driver FT_OPEN_DRIVER
2423	#define ft_open_params FT_OPEN_PARAMS
2424
2425
2426	/**************************************************************************
2427	*
2428	* @struct:
2429	* FT_Parameter
2430	*
2431	* @description:
2432	* A simple structure to pass more or less generic parameters to
2433	* @FT_Open_Face and @FT_Face_Properties.
2434	*
2435	* @fields:
2436	* tag ::
2437	* A four-byte identification tag.
2438	*
2439	* data ::
2440	* A pointer to the parameter data.
2441	*
2442	* @note:
2443	* The ID and function of parameters are driver-specific. See section
2444	* @parameter_tags for more information.
2445	*/
2446	typedef struct FT_Parameter_
2447	{
2448	FT_ULong tag;
2449	FT_Pointer data;
2450
2451	} FT_Parameter;
2452
2453
2454	/**************************************************************************
2455	*
2456	* @struct:
2457	* FT_Open_Args
2458	*
2459	* @description:
2460	* A structure to indicate how to open a new font file or stream. A
2461	* pointer to such a structure can be used as a parameter for the
2462	* functions @FT_Open_Face and @FT_Attach_Stream.
2463	*
2464	* @fields:
2465	* flags ::
2466	* A set of bit flags indicating how to use the structure.
2467	*
2468	* memory_base ::
2469	* The first byte of the file in memory.
2470	*
2471	* memory_size ::
2472	* The size in bytes of the file in memory.
2473	*
2474	* pathname ::
2475	* A pointer to an 8-bit file pathname, which must be a C~string (i.e.,
2476	* no null bytes except at the very end). The pointer is not owned by
2477	* FreeType.
2478	*
2479	* stream ::
2480	* A handle to a source stream object.
2481	*
2482	* driver ::
2483	* This field is exclusively used by @FT_Open_Face; it simply specifies
2484	* the font driver to use for opening the face. If set to `NULL`,
2485	* FreeType tries to load the face with each one of the drivers in its
2486	* list.
2487	*
2488	* num_params ::
2489	* The number of extra parameters.
2490	*
2491	* params ::
2492	* Extra parameters passed to the font driver when opening a new face.
2493	*
2494	* @note:
2495	* The stream type is determined by the contents of `flags`:
2496	*
2497	* If the @FT_OPEN_MEMORY bit is set, assume that this is a memory file
2498	* of `memory_size` bytes, located at `memory_address`. The data are not
2499	* copied, and the client is responsible for releasing and destroying
2500	* them _after_ the corresponding call to @FT_Done_Face.
2501	*
2502	* Otherwise, if the @FT_OPEN_STREAM bit is set, assume that a custom
2503	* input stream `stream` is used.
2504	*
2505	* Otherwise, if the @FT_OPEN_PATHNAME bit is set, assume that this is a
2506	* normal file and use `pathname` to open it.
2507	*
2508	* If none of the above bits are set or if multiple are set at the same
2509	* time, the flags are invalid and @FT_Open_Face fails.
2510	*
2511	* If the @FT_OPEN_DRIVER bit is set, @FT_Open_Face only tries to open
2512	* the file with the driver whose handler is in `driver`.
2513	*
2514	* If the @FT_OPEN_PARAMS bit is set, the parameters given by
2515	* `num_params` and `params` is used. They are ignored otherwise.
2516	*
2517	* Ideally, both the `pathname` and `params` fields should be tagged as
2518	* 'const'; this is missing for API backward compatibility. In other
2519	* words, applications should treat them as read-only.
2520	*/
2521	typedef struct FT_Open_Args_
2522	{
2523	FT_UInt flags;
2524	const FT_Byte* memory_base;
2525	FT_Long memory_size;
2526	FT_String* pathname;
2527	FT_Stream stream;
2528	FT_Module driver;
2529	FT_Int num_params;
2530	FT_Parameter* params;
2531
2532	} FT_Open_Args;
2533
2534
2535	/**************************************************************************
2536	*
2537	* @function:
2538	* FT_New_Face
2539	*
2540	* @description:
2541	* Call @FT_Open_Face to open a font by its pathname.
2542	*
2543	* @inout:
2544	* library ::
2545	* A handle to the library resource.
2546	*
2547	* @input:
2548	* pathname ::
2549	* A path to the font file.
2550	*
2551	* face_index ::
2552	* See @FT_Open_Face for a detailed description of this parameter.
2553	*
2554	* @output:
2555	* aface ::
2556	* A handle to a new face object. If `face_index` is greater than or
2557	* equal to zero, it must be non-`NULL`.
2558	*
2559	* @return:
2560	* FreeType error code. 0~means success.
2561	*
2562	* @note:
2563	* The `pathname` string should be recognizable as such by a standard
2564	* `fopen` call on your system; in particular, this means that `pathname`
2565	* must not contain null bytes. If that is not sufficient to address all
2566	* file name possibilities (for example, to handle wide character file
2567	* names on Windows in UTF-16 encoding) you might use @FT_Open_Face to
2568	* pass a memory array or a stream object instead.
2569	*
2570	* Use @FT_Done_Face to destroy the created @FT_Face object (along with
2571	* its slot and sizes).
2572	*/
2573	FT_EXPORT( FT_Error )
2574	FT_New_Face( FT_Library library,
2575	const char* filepathname,
2576	FT_Long face_index,
2577	FT_Face *aface );
2578
2579
2580	/**************************************************************************
2581	*
2582	* @function:
2583	* FT_New_Memory_Face
2584	*
2585	* @description:
2586	* Call @FT_Open_Face to open a font that has been loaded into memory.
2587	*
2588	* @inout:
2589	* library ::
2590	* A handle to the library resource.
2591	*
2592	* @input:
2593	* file_base ::
2594	* A pointer to the beginning of the font data.
2595	*
2596	* file_size ::
2597	* The size of the memory chunk used by the font data.
2598	*
2599	* face_index ::
2600	* See @FT_Open_Face for a detailed description of this parameter.
2601	*
2602	* @output:
2603	* aface ::
2604	* A handle to a new face object. If `face_index` is greater than or
2605	* equal to zero, it must be non-`NULL`.
2606	*
2607	* @return:
2608	* FreeType error code. 0~means success.
2609	*
2610	* @note:
2611	* You must not deallocate the memory before calling @FT_Done_Face.
2612	*/
2613	FT_EXPORT( FT_Error )
2614	FT_New_Memory_Face( FT_Library library,
2615	const FT_Byte* file_base,
2616	FT_Long file_size,
2617	FT_Long face_index,
2618	FT_Face *aface );
2619
2620
2621	/**************************************************************************
2622	*
2623	* @function:
2624	* FT_Open_Face
2625	*
2626	* @description:
2627	* Create a face object from a given resource described by @FT_Open_Args.
2628	*
2629	* @inout:
2630	* library ::
2631	* A handle to the library resource.
2632	*
2633	* @input:
2634	* args ::
2635	* A pointer to an `FT_Open_Args` structure that must be filled by the
2636	* caller.
2637	*
2638	* face_index ::
2639	* This field holds two different values. Bits 0-15 are the index of
2640	* the face in the font file (starting with value~0). Set it to~0 if
2641	* there is only one face in the font file.
2642	*
2643	* [Since 2.6.1] Bits 16-30 are relevant to TrueType GX and OpenType
2644	* Font Variations only, specifying the named instance index for the
2645	* current face index (starting with value~1; value~0 makes FreeType
2646	* ignore named instances). For non-variation fonts, bits 16-30 are
2647	* ignored. Assuming that you want to access the third named instance
2648	* in face~4, `face_index` should be set to 0x00030004. If you want
2649	* to access face~4 without variation handling, simply set
2650	* `face_index` to value~4.
2651	*
2652	* `FT_Open_Face` and its siblings can be used to quickly check whether
2653	* the font format of a given font resource is supported by FreeType.
2654	* In general, if the `face_index` argument is negative, the function's
2655	* return value is~0 if the font format is recognized, or non-zero
2656	* otherwise. The function allocates a more or less empty face handle
2657	* in `*aface` (if `aface` isn't `NULL`); the only two useful fields in
2658	* this special case are `face->num_faces` and `face->style_flags`.
2659	* For any negative value of `face_index`, `face->num_faces` gives the
2660	* number of faces within the font file. For the negative value
2661	* '-(N+1)' (with 'N' a non-negative 16-bit value), bits 16-30 in
2662	* `face->style_flags` give the number of named instances in face 'N'
2663	* if we have a variation font (or zero otherwise). After examination,
2664	* the returned @FT_Face structure should be deallocated with a call to
2665	* @FT_Done_Face.
2666	*
2667	* @output:
2668	* aface ::
2669	* A handle to a new face object. If `face_index` is greater than or
2670	* equal to zero, it must be non-`NULL`.
2671	*
2672	* @return:
2673	* FreeType error code. 0~means success.
2674	*
2675	* @note:
2676	* Unlike FreeType 1.x, this function automatically creates a glyph slot
2677	* for the face object that can be accessed directly through
2678	* `face->glyph`.
2679	*
2680	* Each new face object created with this function also owns a default
2681	* @FT_Size object, accessible as `face->size`.
2682	*
2683	* One @FT_Library instance can have multiple face objects, that is,
2684	* @FT_Open_Face and its siblings can be called multiple times using the
2685	* same `library` argument.
2686	*
2687	* See the discussion of reference counters in the description of
2688	* @FT_Reference_Face.
2689	*
2690	* If `FT_OPEN_STREAM` is set in `args->flags`, the stream in
2691	* `args->stream` is automatically closed before this function returns
2692	* any error (including `FT_Err_Invalid_Argument`).
2693	*
2694	* @example:
2695	* To loop over all faces, use code similar to the following snippet
2696	* (omitting the error handling).
2697	*
2698	* ```
2699	* ...
2700	* FT_Face face;
2701	* FT_Long i, num_faces;
2702	*
2703	*
2704	* error = FT_Open_Face( library, args, -1, &face );
2705	* if ( error ) { ... }
2706	*
2707	* num_faces = face->num_faces;
2708	* FT_Done_Face( face );
2709	*
2710	* for ( i = 0; i < num_faces; i++ )
2711	* {
2712	* ...
2713	* error = FT_Open_Face( library, args, i, &face );
2714	* ...
2715	* FT_Done_Face( face );
2716	* ...
2717	* }
2718	* ```
2719	*
2720	* To loop over all valid values for `face_index`, use something similar
2721	* to the following snippet, again without error handling. The code
2722	* accesses all faces immediately (thus only a single call of
2723	* `FT_Open_Face` within the do-loop), with and without named instances.
2724	*
2725	* ```
2726	* ...
2727	* FT_Face face;
2728	*
2729	* FT_Long num_faces = 0;
2730	* FT_Long num_instances = 0;
2731	*
2732	* FT_Long face_idx = 0;
2733	* FT_Long instance_idx = 0;
2734	*
2735	*
2736	* do
2737	* {
2738	* FT_Long id = ( instance_idx << 16 ) + face_idx;
2739	*
2740	*
2741	* error = FT_Open_Face( library, args, id, &face );
2742	* if ( error ) { ... }
2743	*
2744	* num_faces = face->num_faces;
2745	* num_instances = face->style_flags >> 16;
2746	*
2747	* ...
2748	*
2749	* FT_Done_Face( face );
2750	*
2751	* if ( instance_idx < num_instances )
2752	* instance_idx++;
2753	* else
2754	* {
2755	* face_idx++;
2756	* instance_idx = 0;
2757	* }
2758	*
2759	* } while ( face_idx < num_faces )
2760	* ```
2761	*/
2762	FT_EXPORT( FT_Error )
2763	FT_Open_Face( FT_Library library,
2764	const FT_Open_Args* args,
2765	FT_Long face_index,
2766	FT_Face *aface );
2767
2768
2769	/**************************************************************************
2770	*
2771	* @function:
2772	* FT_Attach_File
2773	*
2774	* @description:
2775	* Call @FT_Attach_Stream to attach a file.
2776	*
2777	* @inout:
2778	* face ::
2779	* The target face object.
2780	*
2781	* @input:
2782	* filepathname ::
2783	* The pathname.
2784	*
2785	* @return:
2786	* FreeType error code. 0~means success.
2787	*/
2788	FT_EXPORT( FT_Error )
2789	FT_Attach_File( FT_Face face,
2790	const char* filepathname );
2791
2792
2793	/**************************************************************************
2794	*
2795	* @function:
2796	* FT_Attach_Stream
2797	*
2798	* @description:
2799	* 'Attach' data to a face object. Normally, this is used to read
2800	* additional information for the face object. For example, you can
2801	* attach an AFM file that comes with a Type~1 font to get the kerning
2802	* values and other metrics.
2803	*
2804	* @inout:
2805	* face ::
2806	* The target face object.
2807	*
2808	* @input:
2809	* parameters ::
2810	* A pointer to @FT_Open_Args that must be filled by the caller.
2811	*
2812	* @return:
2813	* FreeType error code. 0~means success.
2814	*
2815	* @note:
2816	* The meaning of the 'attach' (i.e., what really happens when the new
2817	* file is read) is not fixed by FreeType itself. It really depends on
2818	* the font format (and thus the font driver).
2819	*
2820	* Client applications are expected to know what they are doing when
2821	* invoking this function. Most drivers simply do not implement file or
2822	* stream attachments.
2823	*/
2824	FT_EXPORT( FT_Error )
2825	FT_Attach_Stream( FT_Face face,
2826	const FT_Open_Args* parameters );
2827
2828
2829	/**************************************************************************
2830	*
2831	* @function:
2832	* FT_Reference_Face
2833	*
2834	* @description:
2835	* A counter gets initialized to~1 at the time an @FT_Face structure is
2836	* created. This function increments the counter. @FT_Done_Face then
2837	* only destroys a face if the counter is~1, otherwise it simply
2838	* decrements the counter.
2839	*
2840	* This function helps in managing life-cycles of structures that
2841	* reference @FT_Face objects.
2842	*
2843	* @input:
2844	* face ::
2845	* A handle to a target face object.
2846	*
2847	* @return:
2848	* FreeType error code. 0~means success.
2849	*
2850	* @since:
2851	* 2.4.2
2852	*
2853	*/
2854	FT_EXPORT( FT_Error )
2855	FT_Reference_Face( FT_Face face );
2856
2857
2858	/**************************************************************************
2859	*
2860	* @function:
2861	* FT_Done_Face
2862	*
2863	* @description:
2864	* Discard a given face object, as well as all of its child slots and
2865	* sizes.
2866	*
2867	* @input:
2868	* face ::
2869	* A handle to a target face object.
2870	*
2871	* @return:
2872	* FreeType error code. 0~means success.
2873	*
2874	* @note:
2875	* See the discussion of reference counters in the description of
2876	* @FT_Reference_Face.
2877	*/
2878	FT_EXPORT( FT_Error )
2879	FT_Done_Face( FT_Face face );
2880
2881
2882	/**************************************************************************
2883	*
2884	* @section:
2885	* sizing_and_scaling
2886	*
2887	*/
2888
2889	/**************************************************************************
2890	*
2891	* @function:
2892	* FT_Select_Size
2893	*
2894	* @description:
2895	* Select a bitmap strike. To be more precise, this function sets the
2896	* scaling factors of the active @FT_Size object in a face so that
2897	* bitmaps from this particular strike are taken by @FT_Load_Glyph and
2898	* friends.
2899	*
2900	* @inout:
2901	* face ::
2902	* A handle to a target face object.
2903	*
2904	* @input:
2905	* strike_index ::
2906	* The index of the bitmap strike in the `available_sizes` field of
2907	* @FT_FaceRec structure.
2908	*
2909	* @return:
2910	* FreeType error code. 0~means success.
2911	*
2912	* @note:
2913	* For bitmaps embedded in outline fonts it is common that only a subset
2914	* of the available glyphs at a given ppem value is available. FreeType
2915	* silently uses outlines if there is no bitmap for a given glyph index.
2916	*
2917	* For TrueType GX and OpenType Font Variations, a bitmap strike makes
2918	* sense only if the default instance is active (that is, no glyph
2919	* variation takes place); otherwise, FreeType simply ignores bitmap
2920	* strikes. The same is true for all named instances that are different
2921	* from the default instance.
2922	*
2923	* Don't use this function if you are using the FreeType cache API.
2924	*/
2925	FT_EXPORT( FT_Error )
2926	FT_Select_Size( FT_Face face,
2927	FT_Int strike_index );
2928
2929
2930	/**************************************************************************
2931	*
2932	* @enum:
2933	* FT_Size_Request_Type
2934	*
2935	* @description:
2936	* An enumeration type that lists the supported size request types, i.e.,
2937	* what input size (in font units) maps to the requested output size (in
2938	* pixels, as computed from the arguments of @FT_Size_Request).
2939	*
2940	* @values:
2941	* FT_SIZE_REQUEST_TYPE_NOMINAL ::
2942	* The nominal size. The `units_per_EM` field of @FT_FaceRec is used
2943	* to determine both scaling values.
2944	*
2945	* This is the standard scaling found in most applications. In
2946	* particular, use this size request type for TrueType fonts if they
2947	* provide optical scaling or something similar. Note, however, that
2948	* `units_per_EM` is a rather abstract value which bears no relation to
2949	* the actual size of the glyphs in a font.
2950	*
2951	* FT_SIZE_REQUEST_TYPE_REAL_DIM ::
2952	* The real dimension. The sum of the `ascender` and (minus of) the
2953	* `descender` fields of @FT_FaceRec is used to determine both scaling
2954	* values.
2955	*
2956	* FT_SIZE_REQUEST_TYPE_BBOX ::
2957	* The font bounding box. The width and height of the `bbox` field of
2958	* @FT_FaceRec are used to determine the horizontal and vertical
2959	* scaling value, respectively.
2960	*
2961	* FT_SIZE_REQUEST_TYPE_CELL ::
2962	* The `max_advance_width` field of @FT_FaceRec is used to determine
2963	* the horizontal scaling value; the vertical scaling value is
2964	* determined the same way as @FT_SIZE_REQUEST_TYPE_REAL_DIM does.
2965	* Finally, both scaling values are set to the smaller one. This type
2966	* is useful if you want to specify the font size for, say, a window of
2967	* a given dimension and 80x24 cells.
2968	*
2969	* FT_SIZE_REQUEST_TYPE_SCALES ::
2970	* Specify the scaling values directly.
2971	*
2972	* @note:
2973	* The above descriptions only apply to scalable formats. For bitmap
2974	* formats, the behaviour is up to the driver.
2975	*
2976	* See the note section of @FT_Size_Metrics if you wonder how size
2977	* requesting relates to scaling values.
2978	*/
2979	typedef enum FT_Size_Request_Type_
2980	{
2981	FT_SIZE_REQUEST_TYPE_NOMINAL,
2982	FT_SIZE_REQUEST_TYPE_REAL_DIM,
2983	FT_SIZE_REQUEST_TYPE_BBOX,
2984	FT_SIZE_REQUEST_TYPE_CELL,
2985	FT_SIZE_REQUEST_TYPE_SCALES,
2986
2987	FT_SIZE_REQUEST_TYPE_MAX
2988
2989	} FT_Size_Request_Type;
2990
2991
2992	/**************************************************************************
2993	*
2994	* @struct:
2995	* FT_Size_RequestRec
2996	*
2997	* @description:
2998	* A structure to model a size request.
2999	*
3000	* @fields:
3001	* type ::
3002	* See @FT_Size_Request_Type.
3003	*
3004	* width ::
3005	* The desired width, given as a 26.6 fractional point value (with 72pt
3006	* = 1in).
3007	*
3008	* height ::
3009	* The desired height, given as a 26.6 fractional point value (with
3010	* 72pt = 1in).
3011	*
3012	* horiResolution ::
3013	* The horizontal resolution (dpi, i.e., pixels per inch). If set to
3014	* zero, `width` is treated as a 26.6 fractional pixel value, which
3015	* gets internally rounded to an integer.
3016	*
3017	* vertResolution ::
3018	* The vertical resolution (dpi, i.e., pixels per inch). If set to
3019	* zero, `height` is treated as a 26.6 fractional pixel value,
3020	* which gets internally rounded to an integer.
3021	*
3022	* @note:
3023	* If `width` is zero, the horizontal scaling value is set equal to the
3024	* vertical scaling value, and vice versa.
3025	*
3026	* If `type` is `FT_SIZE_REQUEST_TYPE_SCALES`, `width` and `height` are
3027	* interpreted directly as 16.16 fractional scaling values, without any
3028	* further modification, and both `horiResolution` and `vertResolution`
3029	* are ignored.
3030	*/
3031	typedef struct FT_Size_RequestRec_
3032	{
3033	FT_Size_Request_Type type;
3034	FT_Long width;
3035	FT_Long height;
3036	FT_UInt horiResolution;
3037	FT_UInt vertResolution;
3038
3039	} FT_Size_RequestRec;
3040
3041
3042	/**************************************************************************
3043	*
3044	* @struct:
3045	* FT_Size_Request
3046	*
3047	* @description:
3048	* A handle to a size request structure.
3049	*/
3050	typedef struct FT_Size_RequestRec_ *FT_Size_Request;
3051
3052
3053	/**************************************************************************
3054	*
3055	* @function:
3056	* FT_Request_Size
3057	*
3058	* @description:
3059	* Resize the scale of the active @FT_Size object in a face.
3060	*
3061	* @inout:
3062	* face ::
3063	* A handle to a target face object.
3064	*
3065	* @input:
3066	* req ::
3067	* A pointer to a @FT_Size_RequestRec.
3068	*
3069	* @return:
3070	* FreeType error code. 0~means success.
3071	*
3072	* @note:
3073	* Although drivers may select the bitmap strike matching the request,
3074	* you should not rely on this if you intend to select a particular
3075	* bitmap strike. Use @FT_Select_Size instead in that case.
3076	*
3077	* The relation between the requested size and the resulting glyph size
3078	* is dependent entirely on how the size is defined in the source face.
3079	* The font designer chooses the final size of each glyph relative to
3080	* this size. For more information refer to
3081	* 'https://freetype.org/freetype2/docs/glyphs/glyphs-2.html'.
3082	*
3083	* Contrary to @FT_Set_Char_Size, this function doesn't have special code
3084	* to normalize zero-valued widths, heights, or resolutions, which are
3085	* treated as @FT_LOAD_NO_SCALE.
3086	*
3087	* Don't use this function if you are using the FreeType cache API.
3088	*/
3089	FT_EXPORT( FT_Error )
3090	FT_Request_Size( FT_Face face,
3091	FT_Size_Request req );
3092
3093
3094	/**************************************************************************
3095	*
3096	* @function:
3097	* FT_Set_Char_Size
3098	*
3099	* @description:
3100	* Call @FT_Request_Size to request the nominal size (in points).
3101	*
3102	* @inout:
3103	* face ::
3104	* A handle to a target face object.
3105	*
3106	* @input:
3107	* char_width ::
3108	* The nominal width, in 26.6 fractional points.
3109	*
3110	* char_height ::
3111	* The nominal height, in 26.6 fractional points.
3112	*
3113	* horz_resolution ::
3114	* The horizontal resolution in dpi.
3115	*
3116	* vert_resolution ::
3117	* The vertical resolution in dpi.
3118	*
3119	* @return:
3120	* FreeType error code. 0~means success.
3121	*
3122	* @note:
3123	* While this function allows fractional points as input values, the
3124	* resulting ppem value for the given resolution is always rounded to the
3125	* nearest integer.
3126	*
3127	* If either the character width or height is zero, it is set equal to
3128	* the other value.
3129	*
3130	* If either the horizontal or vertical resolution is zero, it is set
3131	* equal to the other value.
3132	*
3133	* A character width or height smaller than 1pt is set to 1pt; if both
3134	* resolution values are zero, they are set to 72dpi.
3135	*
3136	* Don't use this function if you are using the FreeType cache API.
3137	*/
3138	FT_EXPORT( FT_Error )
3139	FT_Set_Char_Size( FT_Face face,
3140	FT_F26Dot6 char_width,
3141	FT_F26Dot6 char_height,
3142	FT_UInt horz_resolution,
3143	FT_UInt vert_resolution );
3144
3145
3146	/**************************************************************************
3147	*
3148	* @function:
3149	* FT_Set_Pixel_Sizes
3150	*
3151	* @description:
3152	* Call @FT_Request_Size to request the nominal size (in pixels).
3153	*
3154	* @inout:
3155	* face ::
3156	* A handle to the target face object.
3157	*
3158	* @input:
3159	* pixel_width ::
3160	* The nominal width, in pixels.
3161	*
3162	* pixel_height ::
3163	* The nominal height, in pixels.
3164	*
3165	* @return:
3166	* FreeType error code. 0~means success.
3167	*
3168	* @note:
3169	* You should not rely on the resulting glyphs matching or being
3170	* constrained to this pixel size. Refer to @FT_Request_Size to
3171	* understand how requested sizes relate to actual sizes.
3172	*
3173	* Don't use this function if you are using the FreeType cache API.
3174	*/
3175	FT_EXPORT( FT_Error )
3176	FT_Set_Pixel_Sizes( FT_Face face,
3177	FT_UInt pixel_width,
3178	FT_UInt pixel_height );
3179
3180
3181	/**************************************************************************
3182	*
3183	* @section:
3184	* glyph_retrieval
3185	*
3186	*/
3187
3188	/**************************************************************************
3189	*
3190	* @function:
3191	* FT_Load_Glyph
3192	*
3193	* @description:
3194	* Load a glyph into the glyph slot of a face object.
3195	*
3196	* @inout:
3197	* face ::
3198	* A handle to the target face object where the glyph is loaded.
3199	*
3200	* @input:
3201	* glyph_index ::
3202	* The index of the glyph in the font file. For CID-keyed fonts
3203	* (either in PS or in CFF format) this argument specifies the CID
3204	* value.
3205	*
3206	* load_flags ::
3207	* A flag indicating what to load for this glyph. The @FT_LOAD_XXX
3208	* flags can be used to control the glyph loading process (e.g.,
3209	* whether the outline should be scaled, whether to load bitmaps or
3210	* not, whether to hint the outline, etc).
3211	*
3212	* @return:
3213	* FreeType error code. 0~means success.
3214	*
3215	* @note:
3216	* For proper scaling and hinting, the active @FT_Size object owned by
3217	* the face has to be meaningfully initialized by calling
3218	* @FT_Set_Char_Size before this function, for example. The loaded
3219	* glyph may be transformed. See @FT_Set_Transform for the details.
3220	*
3221	* For subsetted CID-keyed fonts, `FT_Err_Invalid_Argument` is returned
3222	* for invalid CID values (that is, for CID values that don't have a
3223	* corresponding glyph in the font). See the discussion of the
3224	* @FT_FACE_FLAG_CID_KEYED flag for more details.
3225	*
3226	* If you receive `FT_Err_Glyph_Too_Big`, try getting the glyph outline
3227	* at EM size, then scale it manually and fill it as a graphics
3228	* operation.
3229	*/
3230	FT_EXPORT( FT_Error )
3231	FT_Load_Glyph( FT_Face face,
3232	FT_UInt glyph_index,
3233	FT_Int32 load_flags );
3234
3235
3236	/**************************************************************************
3237	*
3238	* @section:
3239	* character_mapping
3240	*
3241	*/
3242
3243	/**************************************************************************
3244	*
3245	* @function:
3246	* FT_Load_Char
3247	*
3248	* @description:
3249	* Load a glyph into the glyph slot of a face object, accessed by its
3250	* character code.
3251	*
3252	* @inout:
3253	* face ::
3254	* A handle to a target face object where the glyph is loaded.
3255	*
3256	* @input:
3257	* char_code ::
3258	* The glyph's character code, according to the current charmap used in
3259	* the face.
3260	*
3261	* load_flags ::
3262	* A flag indicating what to load for this glyph. The @FT_LOAD_XXX
3263	* constants can be used to control the glyph loading process (e.g.,
3264	* whether the outline should be scaled, whether to load bitmaps or
3265	* not, whether to hint the outline, etc).
3266	*
3267	* @return:
3268	* FreeType error code. 0~means success.
3269	*
3270	* @note:
3271	* This function simply calls @FT_Get_Char_Index and @FT_Load_Glyph.
3272	*
3273	* Many fonts contain glyphs that can't be loaded by this function since
3274	* its glyph indices are not listed in any of the font's charmaps.
3275	*
3276	* If no active cmap is set up (i.e., `face->charmap` is zero), the call
3277	* to @FT_Get_Char_Index is omitted, and the function behaves identically
3278	* to @FT_Load_Glyph.
3279	*/
3280	FT_EXPORT( FT_Error )
3281	FT_Load_Char( FT_Face face,
3282	FT_ULong char_code,
3283	FT_Int32 load_flags );
3284
3285
3286	/**************************************************************************
3287	*
3288	* @section:
3289	* glyph_retrieval
3290	*
3291	*/
3292
3293	/**************************************************************************
3294	*
3295	* @enum:
3296	* FT_LOAD_XXX
3297	*
3298	* @description:
3299	* A list of bit field constants for @FT_Load_Glyph to indicate what kind
3300	* of operations to perform during glyph loading.
3301	*
3302	* @values:
3303	* FT_LOAD_DEFAULT ::
3304	* Corresponding to~0, this value is used as the default glyph load
3305	* operation. In this case, the following happens:
3306	*
3307	* 1. FreeType looks for a bitmap for the glyph corresponding to the
3308	* face's current size. If one is found, the function returns. The
3309	* bitmap data can be accessed from the glyph slot (see note below).
3310	*
3311	* 2. If no embedded bitmap is searched for or found, FreeType looks
3312	* for a scalable outline. If one is found, it is loaded from the font
3313	* file, scaled to device pixels, then 'hinted' to the pixel grid in
3314	* order to optimize it. The outline data can be accessed from the
3315	* glyph slot (see note below).
3316	*
3317	* Note that by default the glyph loader doesn't render outlines into
3318	* bitmaps. The following flags are used to modify this default
3319	* behaviour to more specific and useful cases.
3320	*
3321	* FT_LOAD_NO_SCALE ::
3322	* Don't scale the loaded outline glyph but keep it in font units.
3323	* This flag is also assumed if @FT_Size owned by the face was not
3324	* properly initialized.
3325	*
3326	* This flag implies @FT_LOAD_NO_HINTING and @FT_LOAD_NO_BITMAP, and
3327	* unsets @FT_LOAD_RENDER.
3328	*
3329	* If the font is 'tricky' (see @FT_FACE_FLAG_TRICKY for more), using
3330	* `FT_LOAD_NO_SCALE` usually yields meaningless outlines because the
3331	* subglyphs must be scaled and positioned with hinting instructions.
3332	* This can be solved by loading the font without `FT_LOAD_NO_SCALE`
3333	* and setting the character size to `font->units_per_EM`.
3334	*
3335	* FT_LOAD_NO_HINTING ::
3336	* Disable hinting. This generally generates 'blurrier' bitmap glyphs
3337	* when the glyphs are rendered in any of the anti-aliased modes. See
3338	* also the note below.
3339	*
3340	* This flag is implied by @FT_LOAD_NO_SCALE.
3341	*
3342	* FT_LOAD_RENDER ::
3343	* Call @FT_Render_Glyph after the glyph is loaded. By default, the
3344	* glyph is rendered in @FT_RENDER_MODE_NORMAL mode. This can be
3345	* overridden by @FT_LOAD_TARGET_XXX or @FT_LOAD_MONOCHROME.
3346	*
3347	* This flag is unset by @FT_LOAD_NO_SCALE.
3348	*
3349	* FT_LOAD_NO_BITMAP ::
3350	* Ignore bitmap strikes when loading. Bitmap-only fonts ignore this
3351	* flag.
3352	*
3353	* @FT_LOAD_NO_SCALE always sets this flag.
3354	*
3355	* FT_LOAD_SBITS_ONLY ::
3356	* [Since 2.12] This is the opposite of @FT_LOAD_NO_BITMAP, more or
3357	* less: @FT_Load_Glyph returns `FT_Err_Invalid_Argument` if the face
3358	* contains a bitmap strike for the given size (or the strike selected
3359	* by @FT_Select_Size) but there is no glyph in the strike.
3360	*
3361	* Note that this load flag was part of FreeType since version 2.0.6
3362	* but previously tagged as internal.
3363	*
3364	* FT_LOAD_VERTICAL_LAYOUT ::
3365	* Load the glyph for vertical text layout. In particular, the
3366	* `advance` value in the @FT_GlyphSlotRec structure is set to the
3367	* `vertAdvance` value of the `metrics` field.
3368	*
3369	* In case @FT_HAS_VERTICAL doesn't return true, you shouldn't use this
3370	* flag currently. Reason is that in this case vertical metrics get
3371	* synthesized, and those values are not always consistent across
3372	* various font formats.
3373	*
3374	* FT_LOAD_FORCE_AUTOHINT ::
3375	* Prefer the auto-hinter over the font's native hinter. See also the
3376	* note below.
3377	*
3378	* FT_LOAD_PEDANTIC ::
3379	* Make the font driver perform pedantic verifications during glyph
3380	* loading and hinting. This is mostly used to detect broken glyphs in
3381	* fonts. By default, FreeType tries to handle broken fonts also.
3382	*
3383	* In particular, errors from the TrueType bytecode engine are not
3384	* passed to the application if this flag is not set; this might result
3385	* in partially hinted or distorted glyphs in case a glyph's bytecode
3386	* is buggy.
3387	*
3388	* FT_LOAD_NO_RECURSE ::
3389	* Don't load composite glyphs recursively. Instead, the font driver
3390	* fills the `num_subglyph` and `subglyphs` values of the glyph slot;
3391	* it also sets `glyph->format` to @FT_GLYPH_FORMAT_COMPOSITE. The
3392	* description of subglyphs can then be accessed with
3393	* @FT_Get_SubGlyph_Info.
3394	*
3395	* Don't use this flag for retrieving metrics information since some
3396	* font drivers only return rudimentary data.
3397	*
3398	* This flag implies @FT_LOAD_NO_SCALE and @FT_LOAD_IGNORE_TRANSFORM.
3399	*
3400	* FT_LOAD_IGNORE_TRANSFORM ::
3401	* Ignore the transform matrix set by @FT_Set_Transform.
3402	*
3403	* FT_LOAD_MONOCHROME ::
3404	* This flag is used with @FT_LOAD_RENDER to indicate that you want to
3405	* render an outline glyph to a 1-bit monochrome bitmap glyph, with
3406	* 8~pixels packed into each byte of the bitmap data.
3407	*
3408	* Note that this has no effect on the hinting algorithm used. You
3409	* should rather use @FT_LOAD_TARGET_MONO so that the
3410	* monochrome-optimized hinting algorithm is used.
3411	*
3412	* FT_LOAD_LINEAR_DESIGN ::
3413	* Keep `linearHoriAdvance` and `linearVertAdvance` fields of
3414	* @FT_GlyphSlotRec in font units. See @FT_GlyphSlotRec for details.
3415	*
3416	* FT_LOAD_NO_AUTOHINT ::
3417	* Disable the auto-hinter. See also the note below.
3418	*
3419	* FT_LOAD_COLOR ::
3420	* Load colored glyphs. FreeType searches in the following order;
3421	* there are slight differences depending on the font format.
3422	*
3423	* [Since 2.5] Load embedded color bitmap images (provided
3424	* @FT_LOAD_NO_BITMAP is not set). The resulting color bitmaps, if
3425	* available, have the @FT_PIXEL_MODE_BGRA format, with pre-multiplied
3426	* color channels. If the flag is not set and color bitmaps are found,
3427	* they are converted to 256-level gray bitmaps, using the
3428	* @FT_PIXEL_MODE_GRAY format.
3429	*
3430	* [Since 2.12] If the glyph index maps to an entry in the face's
3431	* 'SVG~' table, load the associated SVG document from this table and
3432	* set the `format` field of @FT_GlyphSlotRec to @FT_GLYPH_FORMAT_SVG
3433	* ([since 2.13.1] provided @FT_LOAD_NO_SVG is not set). Note that
3434	* FreeType itself can't render SVG documents; however, the library
3435	* provides hooks to seamlessly integrate an external renderer. See
3436	* sections @ot_svg_driver and @svg_fonts for more.
3437	*
3438	* [Since 2.10, experimental] If the glyph index maps to an entry in
3439	* the face's 'COLR' table with a 'CPAL' palette table (as defined in
3440	* the OpenType specification), make @FT_Render_Glyph provide a default
3441	* blending of the color glyph layers associated with the glyph index,
3442	* using the same bitmap format as embedded color bitmap images. This
3443	* is mainly for convenience and works only for glyphs in 'COLR' v0
3444	* tables. There is no rendering support for 'COLR' v1 (with the
3445	* exception of v1 tables that exclusively use v0 features)! You need
3446	* a graphics library like Skia or Cairo to interpret the graphics
3447	* commands stored in v1 tables. For full control of color layers use
3448	* @FT_Get_Color_Glyph_Layer and FreeType's color functions like
3449	* @FT_Palette_Select instead of setting @FT_LOAD_COLOR for rendering
3450	* so that the client application can handle blending by itself.
3451	*
3452	* FT_LOAD_NO_SVG ::
3453	* [Since 2.13.1] Ignore SVG glyph data when loading.
3454	*
3455	* FT_LOAD_COMPUTE_METRICS ::
3456	* [Since 2.6.1] Compute glyph metrics from the glyph data, without the
3457	* use of bundled metrics tables (for example, the 'hdmx' table in
3458	* TrueType fonts). This flag is mainly used by font validating or
3459	* font editing applications, which need to ignore, verify, or edit
3460	* those tables.
3461	*
3462	* Currently, this flag is only implemented for TrueType fonts.
3463	*
3464	* FT_LOAD_BITMAP_METRICS_ONLY ::
3465	* [Since 2.7.1] Request loading of the metrics and bitmap image
3466	* information of a (possibly embedded) bitmap glyph without allocating
3467	* or copying the bitmap image data itself. No effect if the target
3468	* glyph is not a bitmap image.
3469	*
3470	* This flag unsets @FT_LOAD_RENDER.
3471	*
3472	* FT_LOAD_CROP_BITMAP ::
3473	* Ignored. Deprecated.
3474	*
3475	* FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ::
3476	* Ignored. Deprecated.
3477	*
3478	* @note:
3479	* By default, hinting is enabled and the font's native hinter (see
3480	* @FT_FACE_FLAG_HINTER) is preferred over the auto-hinter. You can
3481	* disable hinting by setting @FT_LOAD_NO_HINTING or change the
3482	* precedence by setting @FT_LOAD_FORCE_AUTOHINT. You can also set
3483	* @FT_LOAD_NO_AUTOHINT in case you don't want the auto-hinter to be used
3484	* at all.
3485	*
3486	* See the description of @FT_FACE_FLAG_TRICKY for a special exception
3487	* (affecting only a handful of Asian fonts).
3488	*
3489	* Besides deciding which hinter to use, you can also decide which
3490	* hinting algorithm to use. See @FT_LOAD_TARGET_XXX for details.
3491	*
3492	* Note that the auto-hinter needs a valid Unicode cmap (either a native
3493	* one or synthesized by FreeType) for producing correct results. If a
3494	* font provides an incorrect mapping (for example, assigning the
3495	* character code U+005A, LATIN CAPITAL LETTER~Z, to a glyph depicting a
3496	* mathematical integral sign), the auto-hinter might produce useless
3497	* results.
3498	*
3499	*/
3500	#define FT_LOAD_DEFAULT 0x0
3501	#define FT_LOAD_NO_SCALE ( 1L << 0 )
3502	#define FT_LOAD_NO_HINTING ( 1L << 1 )
3503	#define FT_LOAD_RENDER ( 1L << 2 )
3504	#define FT_LOAD_NO_BITMAP ( 1L << 3 )
3505	#define FT_LOAD_VERTICAL_LAYOUT ( 1L << 4 )
3506	#define FT_LOAD_FORCE_AUTOHINT ( 1L << 5 )
3507	#define FT_LOAD_CROP_BITMAP ( 1L << 6 )
3508	#define FT_LOAD_PEDANTIC ( 1L << 7 )
3509	#define FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ( 1L << 9 )
3510	#define FT_LOAD_NO_RECURSE ( 1L << 10 )
3511	#define FT_LOAD_IGNORE_TRANSFORM ( 1L << 11 )
3512	#define FT_LOAD_MONOCHROME ( 1L << 12 )
3513	#define FT_LOAD_LINEAR_DESIGN ( 1L << 13 )
3514	#define FT_LOAD_SBITS_ONLY ( 1L << 14 )
3515	#define FT_LOAD_NO_AUTOHINT ( 1L << 15 )
3516	/ Bits 16-19 are used by `FT_LOAD_TARGET_` /
3517	#define FT_LOAD_COLOR ( 1L << 20 )
3518	#define FT_LOAD_COMPUTE_METRICS ( 1L << 21 )
3519	#define FT_LOAD_BITMAP_METRICS_ONLY ( 1L << 22 )
3520	#define FT_LOAD_NO_SVG ( 1L << 24 )
3521
3522	/ /
3523
3524	/ used internally only by certain font drivers /
3525	#define FT_LOAD_ADVANCE_ONLY ( 1L << 8 )
3526	#define FT_LOAD_SVG_ONLY ( 1L << 23 )
3527
3528
3529	/**************************************************************************
3530	*
3531	* @enum:
3532	* FT_LOAD_TARGET_XXX
3533	*
3534	* @description:
3535	* A list of values to select a specific hinting algorithm for the
3536	* hinter. You should OR one of these values to your `load_flags` when
3537	* calling @FT_Load_Glyph.
3538	*
3539	* Note that a font's native hinters may ignore the hinting algorithm you
3540	* have specified (e.g., the TrueType bytecode interpreter). You can set
3541	* @FT_LOAD_FORCE_AUTOHINT to ensure that the auto-hinter is used.
3542	*
3543	* @values:
3544	* FT_LOAD_TARGET_NORMAL ::
3545	* The default hinting algorithm, optimized for standard gray-level
3546	* rendering. For monochrome output, use @FT_LOAD_TARGET_MONO instead.
3547	*
3548	* FT_LOAD_TARGET_LIGHT ::
3549	* A lighter hinting algorithm for gray-level modes. Many generated
3550	* glyphs are fuzzier but better resemble their original shape. This
3551	* is achieved by snapping glyphs to the pixel grid only vertically
3552	* (Y-axis), as is done by FreeType's new CFF engine or Microsoft's
3553	* ClearType font renderer. This preserves inter-glyph spacing in
3554	* horizontal text. The snapping is done either by the native font
3555	* driver, if the driver itself and the font support it, or by the
3556	* auto-hinter.
3557	*
3558	* Advance widths are rounded to integer values; however, using the
3559	* `lsb_delta` and `rsb_delta` fields of @FT_GlyphSlotRec, it is
3560	* possible to get fractional advance widths for subpixel positioning
3561	* (which is recommended to use).
3562	*
3563	* If configuration option `AF_CONFIG_OPTION_TT_SIZE_METRICS` is
3564	* active, TrueType-like metrics are used to make this mode behave
3565	* similarly as in unpatched FreeType versions between 2.4.6 and 2.7.1
3566	* (inclusive).
3567	*
3568	* FT_LOAD_TARGET_MONO ::
3569	* Strong hinting algorithm that should only be used for monochrome
3570	* output. The result is probably unpleasant if the glyph is rendered
3571	* in non-monochrome modes.
3572	*
3573	* Note that for outline fonts only the TrueType font driver has proper
3574	* monochrome hinting support, provided the TTFs contain hints for B/W
3575	* rendering (which most fonts no longer provide). If these conditions
3576	* are not met it is very likely that you get ugly results at smaller
3577	* sizes.
3578	*
3579	* FT_LOAD_TARGET_LCD ::
3580	* A variant of @FT_LOAD_TARGET_LIGHT optimized for horizontally
3581	* decimated LCD displays.
3582	*
3583	* FT_LOAD_TARGET_LCD_V ::
3584	* A variant of @FT_LOAD_TARGET_NORMAL optimized for vertically
3585	* decimated LCD displays.
3586	*
3587	* @note:
3588	* You should use only _one_ of the `FT_LOAD_TARGET_XXX` values in your
3589	* `load_flags`. They can't be ORed.
3590	*
3591	* If @FT_LOAD_RENDER is also set, the glyph is rendered in the
3592	* corresponding mode (i.e., the mode that matches the used algorithm
3593	* best). An exception is `FT_LOAD_TARGET_MONO` since it implies
3594	* @FT_LOAD_MONOCHROME.
3595	*
3596	* You can use a hinting algorithm that doesn't correspond to the same
3597	* rendering mode. As an example, it is possible to use the 'light'
3598	* hinting algorithm and have the results rendered in horizontal LCD
3599	* pixel mode, with code like
3600	*
3601	* ```
3602	* FT_Load_Glyph( face, glyph_index,
3603	* load_flags \| FT_LOAD_TARGET_LIGHT );
3604	*
3605	* FT_Render_Glyph( face->glyph, FT_RENDER_MODE_LCD );
3606	* ```
3607	*
3608	* In general, you should stick with one rendering mode. For example,
3609	* switching between @FT_LOAD_TARGET_NORMAL and @FT_LOAD_TARGET_MONO
3610	* enforces a lot of recomputation for TrueType fonts, which is slow.
3611	* Another reason is caching: Selecting a different mode usually causes
3612	* changes in both the outlines and the rasterized bitmaps; it is thus
3613	* necessary to empty the cache after a mode switch to avoid false hits.
3614	*
3615	*/
3616	#define FT_LOAD_TARGET_( x ) ( FT_STATIC_CAST( FT_Int32, (x) & 15 ) << 16 )
3617
3618	#define FT_LOAD_TARGET_NORMAL FT_LOAD_TARGET_( FT_RENDER_MODE_NORMAL )
3619	#define FT_LOAD_TARGET_LIGHT FT_LOAD_TARGET_( FT_RENDER_MODE_LIGHT )
3620	#define FT_LOAD_TARGET_MONO FT_LOAD_TARGET_( FT_RENDER_MODE_MONO )
3621	#define FT_LOAD_TARGET_LCD FT_LOAD_TARGET_( FT_RENDER_MODE_LCD )
3622	#define FT_LOAD_TARGET_LCD_V FT_LOAD_TARGET_( FT_RENDER_MODE_LCD_V )
3623
3624
3625	/**************************************************************************
3626	*
3627	* @macro:
3628	* FT_LOAD_TARGET_MODE
3629	*
3630	* @description:
3631	* Return the @FT_Render_Mode corresponding to a given
3632	* @FT_LOAD_TARGET_XXX value.
3633	*
3634	*/
3635	#define FT_LOAD_TARGET_MODE( x ) \
3636	FT_STATIC_CAST( FT_Render_Mode, ( (x) >> 16 ) & 15 )
3637
3638
3639	/**************************************************************************
3640	*
3641	* @section:
3642	* sizing_and_scaling
3643	*
3644	*/
3645
3646	/**************************************************************************
3647	*
3648	* @function:
3649	* FT_Set_Transform
3650	*
3651	* @description:
3652	* Set the transformation that is applied to glyph images when they are
3653	* loaded into a glyph slot through @FT_Load_Glyph.
3654	*
3655	* @inout:
3656	* face ::
3657	* A handle to the source face object.
3658	*
3659	* @input:
3660	* matrix ::
3661	* A pointer to the transformation's 2x2 matrix. Use `NULL` for the
3662	* identity matrix.
3663	* delta ::
3664	* A pointer to the translation vector. Use `NULL` for the null
3665	* vector.
3666	*
3667	* @note:
3668	* This function is provided as a convenience, but keep in mind that
3669	* @FT_Matrix coefficients are only 16.16 fixed-point values, which can
3670	* limit the accuracy of the results. Using floating-point computations
3671	* to perform the transform directly in client code instead will always
3672	* yield better numbers.
3673	*
3674	* The transformation is only applied to scalable image formats after the
3675	* glyph has been loaded. It means that hinting is unaltered by the
3676	* transformation and is performed on the character size given in the
3677	* last call to @FT_Set_Char_Size or @FT_Set_Pixel_Sizes.
3678	*
3679	* Note that this also transforms the `face.glyph.advance` field, but
3680	* not the values in `face.glyph.metrics`.
3681	*/
3682	FT_EXPORT( void )
3683	FT_Set_Transform( FT_Face face,
3684	FT_Matrix* matrix,
3685	FT_Vector* delta );
3686
3687
3688	/**************************************************************************
3689	*
3690	* @function:
3691	* FT_Get_Transform
3692	*
3693	* @description:
3694	* Return the transformation that is applied to glyph images when they
3695	* are loaded into a glyph slot through @FT_Load_Glyph. See
3696	* @FT_Set_Transform for more details.
3697	*
3698	* @input:
3699	* face ::
3700	* A handle to the source face object.
3701	*
3702	* @output:
3703	* matrix ::
3704	* A pointer to a transformation's 2x2 matrix. Set this to NULL if you
3705	* are not interested in the value.
3706	*
3707	* delta ::
3708	* A pointer to a translation vector. Set this to NULL if you are not
3709	* interested in the value.
3710	*
3711	* @since:
3712	* 2.11
3713	*
3714	*/
3715	FT_EXPORT( void )
3716	FT_Get_Transform( FT_Face face,
3717	FT_Matrix* matrix,
3718	FT_Vector* delta );
3719
3720
3721	/**************************************************************************
3722	*
3723	* @section:
3724	* glyph_retrieval
3725	*
3726	*/
3727
3728	/**************************************************************************
3729	*
3730	* @enum:
3731	* FT_Render_Mode
3732	*
3733	* @description:
3734	* Render modes supported by FreeType~2. Each mode corresponds to a
3735	* specific type of scanline conversion performed on the outline.
3736	*
3737	* For bitmap fonts and embedded bitmaps the `bitmap->pixel_mode` field
3738	* in the @FT_GlyphSlotRec structure gives the format of the returned
3739	* bitmap.
3740	*
3741	* All modes except @FT_RENDER_MODE_MONO use 256 levels of opacity,
3742	* indicating pixel coverage. Use linear alpha blending and gamma
3743	* correction to correctly render non-monochrome glyph bitmaps onto a
3744	* surface; see @FT_Render_Glyph.
3745	*
3746	* The @FT_RENDER_MODE_SDF is a special render mode that uses up to 256
3747	* distance values, indicating the signed distance from the grid position
3748	* to the nearest outline.
3749	*
3750	* @values:
3751	* FT_RENDER_MODE_NORMAL ::
3752	* Default render mode; it corresponds to 8-bit anti-aliased bitmaps.
3753	*
3754	* FT_RENDER_MODE_LIGHT ::
3755	* This is equivalent to @FT_RENDER_MODE_NORMAL. It is only defined as
3756	* a separate value because render modes are also used indirectly to
3757	* define hinting algorithm selectors. See @FT_LOAD_TARGET_XXX for
3758	* details.
3759	*
3760	* FT_RENDER_MODE_MONO ::
3761	* This mode corresponds to 1-bit bitmaps (with 2~levels of opacity).
3762	*
3763	* FT_RENDER_MODE_LCD ::
3764	* This mode corresponds to horizontal RGB and BGR subpixel displays
3765	* like LCD screens. It produces 8-bit bitmaps that are 3~times the
3766	* width of the original glyph outline in pixels, and which use the
3767	* @FT_PIXEL_MODE_LCD mode.
3768	*
3769	* FT_RENDER_MODE_LCD_V ::
3770	* This mode corresponds to vertical RGB and BGR subpixel displays
3771	* (like PDA screens, rotated LCD displays, etc.). It produces 8-bit
3772	* bitmaps that are 3~times the height of the original glyph outline in
3773	* pixels and use the @FT_PIXEL_MODE_LCD_V mode.
3774	*
3775	* FT_RENDER_MODE_SDF ::
3776	* The positive (unsigned) 8-bit bitmap values can be converted to the
3777	* single-channel signed distance field (SDF) by subtracting 128, with
3778	* the positive and negative results corresponding to the inside and
3779	* the outside of a glyph contour, respectively. The distance units are
3780	* arbitrarily determined by an adjustable @spread property.
3781	*
3782	* @note:
3783	* The selected render mode only affects scalable vector glyphs of a font.
3784	* Embedded bitmaps often have a different pixel mode like
3785	* @FT_PIXEL_MODE_MONO. You can use @FT_Bitmap_Convert to transform them
3786	* into 8-bit pixmaps.
3787	*
3788	*/
3789	typedef enum FT_Render_Mode_
3790	{
3791	FT_RENDER_MODE_NORMAL = `0`,
3792	FT_RENDER_MODE_LIGHT,
3793	FT_RENDER_MODE_MONO,
3794	FT_RENDER_MODE_LCD,
3795	FT_RENDER_MODE_LCD_V,
3796	FT_RENDER_MODE_SDF,
3797
3798	FT_RENDER_MODE_MAX
3799
3800	} FT_Render_Mode;
3801
3802
3803	/ these constants are deprecated; use the corresponding /
3804	/ `FT_Render_Mode` values instead /
3805	#define ft_render_mode_normal FT_RENDER_MODE_NORMAL
3806	#define ft_render_mode_mono FT_RENDER_MODE_MONO
3807
3808
3809	/**************************************************************************
3810	*
3811	* @function:
3812	* FT_Render_Glyph
3813	*
3814	* @description:
3815	* Convert a given glyph image to a bitmap. It does so by inspecting the
3816	* glyph image format, finding the relevant renderer, and invoking it.
3817	*
3818	* @inout:
3819	* slot ::
3820	* A handle to the glyph slot containing the image to convert.
3821	*
3822	* @input:
3823	* render_mode ::
3824	* The render mode used to render the glyph image into a bitmap. See
3825	* @FT_Render_Mode for a list of possible values.
3826	*
3827	* If @FT_RENDER_MODE_NORMAL is used, a previous call of @FT_Load_Glyph
3828	* with flag @FT_LOAD_COLOR makes `FT_Render_Glyph` provide a default
3829	* blending of colored glyph layers associated with the current glyph
3830	* slot (provided the font contains such layers) instead of rendering
3831	* the glyph slot's outline. This is an experimental feature; see
3832	* @FT_LOAD_COLOR for more information.
3833	*
3834	* @return:
3835	* FreeType error code. 0~means success.
3836	*
3837	* @note:
3838	* When FreeType outputs a bitmap of a glyph, it really outputs an alpha
3839	* coverage map. If a pixel is completely covered by a filled-in
3840	* outline, the bitmap contains 0xFF at that pixel, meaning that
3841	* 0xFF/0xFF fraction of that pixel is covered, meaning the pixel is 100%
3842	* black (or 0% bright). If a pixel is only 50% covered (value 0x80),
3843	* the pixel is made 50% black (50% bright or a middle shade of grey).
3844	* 0% covered means 0% black (100% bright or white).
3845	*
3846	* On high-DPI screens like on smartphones and tablets, the pixels are so
3847	* small that their chance of being completely covered and therefore
3848	* completely black are fairly good. On the low-DPI screens, however,
3849	* the situation is different. The pixels are too large for most of the
3850	* details of a glyph and shades of gray are the norm rather than the
3851	* exception.
3852	*
3853	* This is relevant because all our screens have a second problem: they
3854	* are not linear. 1~+~1 is not~2. Twice the value does not result in
3855	* twice the brightness. When a pixel is only 50% covered, the coverage
3856	* map says 50% black, and this translates to a pixel value of 128 when
3857	* you use 8~bits per channel (0-255). However, this does not translate
3858	* to 50% brightness for that pixel on our sRGB and gamma~2.2 screens.
3859	* Due to their non-linearity, they dwell longer in the darks and only a
3860	* pixel value of about 186 results in 50% brightness -- 128 ends up too
3861	* dark on both bright and dark backgrounds. The net result is that dark
3862	* text looks burnt-out, pixely and blotchy on bright background, bright
3863	* text too frail on dark backgrounds, and colored text on colored
3864	* background (for example, red on green) seems to have dark halos or
3865	* 'dirt' around it. The situation is especially ugly for diagonal stems
3866	* like in 'w' glyph shapes where the quality of FreeType's anti-aliasing
3867	* depends on the correct display of grays. On high-DPI screens where
3868	* smaller, fully black pixels reign supreme, this doesn't matter, but on
3869	* our low-DPI screens with all the gray shades, it does. 0% and 100%
3870	* brightness are the same things in linear and non-linear space, just
3871	* all the shades in-between aren't.
3872	*
3873	* The blending function for placing text over a background is
3874	*
3875	* ```
3876	* dst = alpha * src + (1 - alpha) * dst ,
3877	* ```
3878	*
3879	* which is known as the OVER operator.
3880	*
3881	* To correctly composite an anti-aliased pixel of a glyph onto a
3882	* surface,
3883	*
3884	* 1. take the foreground and background colors (e.g., in sRGB space)
3885	* and apply gamma to get them in a linear space,
3886	*
3887	* 2. use OVER to blend the two linear colors using the glyph pixel
3888	* as the alpha value (remember, the glyph bitmap is an alpha coverage
3889	* bitmap), and
3890	*
3891	* 3. apply inverse gamma to the blended pixel and write it back to
3892	* the image.
3893	*
3894	* Internal testing at Adobe found that a target inverse gamma of~1.8 for
3895	* step~3 gives good results across a wide range of displays with an sRGB
3896	* gamma curve or a similar one.
3897	*
3898	* This process can cost performance. There is an approximation that
3899	* does not need to know about the background color; see
3900	* https://web.archive.org/web/20211019204945/https://bel.fi/alankila/lcd/
3901	* and
3902	* https://web.archive.org/web/20210211002939/https://bel.fi/alankila/lcd/alpcor.html
3903	* for details.
3904	*
3905	* ATTENTION: Linear blending is even more important when dealing
3906	* with subpixel-rendered glyphs to prevent color-fringing! A
3907	* subpixel-rendered glyph must first be filtered with a filter that
3908	* gives equal weight to the three color primaries and does not exceed a
3909	* sum of 0x100, see section @lcd_rendering. Then the only difference to
3910	* gray linear blending is that subpixel-rendered linear blending is done
3911	* 3~times per pixel: red foreground subpixel to red background subpixel
3912	* and so on for green and blue.
3913	*/
3914	FT_EXPORT( FT_Error )
3915	FT_Render_Glyph( FT_GlyphSlot slot,
3916	FT_Render_Mode render_mode );
3917
3918
3919	/**************************************************************************
3920	*
3921	* @enum:
3922	* FT_Kerning_Mode
3923	*
3924	* @description:
3925	* An enumeration to specify the format of kerning values returned by
3926	* @FT_Get_Kerning.
3927	*
3928	* @values:
3929	* FT_KERNING_DEFAULT ::
3930	* Return grid-fitted kerning distances in 26.6 fractional pixels.
3931	*
3932	* FT_KERNING_UNFITTED ::
3933	* Return un-grid-fitted kerning distances in 26.6 fractional pixels.
3934	*
3935	* FT_KERNING_UNSCALED ::
3936	* Return the kerning vector in original font units.
3937	*
3938	* @note:
3939	* `FT_KERNING_DEFAULT` returns full pixel values; it also makes FreeType
3940	* heuristically scale down kerning distances at small ppem values so
3941	* that they don't become too big.
3942	*
3943	* Both `FT_KERNING_DEFAULT` and `FT_KERNING_UNFITTED` use the current
3944	* horizontal scaling factor (as set e.g. with @FT_Set_Char_Size) to
3945	* convert font units to pixels.
3946	*/
3947	typedef enum FT_Kerning_Mode_
3948	{
3949	FT_KERNING_DEFAULT = `0`,
3950	FT_KERNING_UNFITTED,
3951	FT_KERNING_UNSCALED
3952
3953	} FT_Kerning_Mode;
3954
3955
3956	/ these constants are deprecated; use the corresponding /
3957	/ `FT_Kerning_Mode` values instead /
3958	#define ft_kerning_default FT_KERNING_DEFAULT
3959	#define ft_kerning_unfitted FT_KERNING_UNFITTED
3960	#define ft_kerning_unscaled FT_KERNING_UNSCALED
3961
3962
3963	/**************************************************************************
3964	*
3965	* @function:
3966	* FT_Get_Kerning
3967	*
3968	* @description:
3969	* Return the kerning vector between two glyphs of the same face.
3970	*
3971	* @input:
3972	* face ::
3973	* A handle to a source face object.
3974	*
3975	* left_glyph ::
3976	* The index of the left glyph in the kern pair.
3977	*
3978	* right_glyph ::
3979	* The index of the right glyph in the kern pair.
3980	*
3981	* kern_mode ::
3982	* See @FT_Kerning_Mode for more information. Determines the scale and
3983	* dimension of the returned kerning vector.
3984	*
3985	* @output:
3986	* akerning ::
3987	* The kerning vector. This is either in font units, fractional pixels
3988	* (26.6 format), or pixels for scalable formats, and in pixels for
3989	* fixed-sizes formats.
3990	*
3991	* @return:
3992	* FreeType error code. 0~means success.
3993	*
3994	* @note:
3995	* Only horizontal layouts (left-to-right & right-to-left) are supported
3996	* by this method. Other layouts, or more sophisticated kernings, are
3997	* out of the scope of this API function -- they can be implemented
3998	* through format-specific interfaces.
3999	*
4000	* Note that, for TrueType and OpenType fonts only, this can extract data
4001	* from both the 'kern' table and the basic, pair-wise kerning feature
4002	* from the GPOS table (with `TT_CONFIG_OPTION_GPOS_KERNING` enabled),
4003	* though FreeType does not support the more advanced GPOS layout
4004	* features; use a library like HarfBuzz for those instead. If a font
4005	* has both a 'kern' table and kern features of a GPOS table, the 'kern'
4006	* table will be used.
4007	*
4008	* Also note for right-to-left scripts, the functionality may differ for
4009	* fonts with GPOS tables vs. 'kern' tables. For GPOS, right-to-left
4010	* fonts typically use both a placement offset and an advance for pair
4011	* positioning, which this API does not support, so it would output
4012	* kerning values of zero; though if the right-to-left font used only
4013	* advances in GPOS pair positioning, then this API could output kerning
4014	* values for it, but it would use `left_glyph` to mean the first glyph
4015	* for that case. Whereas 'kern' tables are always advance-only and
4016	* always store the left glyph first.
4017	*
4018	* Use @FT_HAS_KERNING to find out whether a font has data that can be
4019	* extracted with `FT_Get_Kerning`.
4020	*/
4021	FT_EXPORT( FT_Error )
4022	FT_Get_Kerning( FT_Face face,
4023	FT_UInt left_glyph,
4024	FT_UInt right_glyph,
4025	FT_UInt kern_mode,
4026	FT_Vector *akerning );
4027
4028
4029	/**************************************************************************
4030	*
4031	* @function:
4032	* FT_Get_Track_Kerning
4033	*
4034	* @description:
4035	* Return the track kerning for a given face object at a given size.
4036	*
4037	* @input:
4038	* face ::
4039	* A handle to a source face object.
4040	*
4041	* point_size ::
4042	* The point size in 16.16 fractional points.
4043	*
4044	* degree ::
4045	* The degree of tightness. Increasingly negative values represent
4046	* tighter track kerning, while increasingly positive values represent
4047	* looser track kerning. Value zero means no track kerning.
4048	*
4049	* @output:
4050	* akerning ::
4051	* The kerning in 16.16 fractional points, to be uniformly applied
4052	* between all glyphs.
4053	*
4054	* @return:
4055	* FreeType error code. 0~means success.
4056	*
4057	* @note:
4058	* Currently, only the Type~1 font driver supports track kerning, using
4059	* data from AFM files (if attached with @FT_Attach_File or
4060	* @FT_Attach_Stream).
4061	*
4062	* Only very few AFM files come with track kerning data; please refer to
4063	* Adobe's AFM specification for more details.
4064	*/
4065	FT_EXPORT( FT_Error )
4066	FT_Get_Track_Kerning( FT_Face face,
4067	FT_Fixed point_size,
4068	FT_Int degree,
4069	FT_Fixed* akerning );
4070
4071
4072	/**************************************************************************
4073	*
4074	* @section:
4075	* character_mapping
4076	*
4077	*/
4078
4079	/**************************************************************************
4080	*
4081	* @function:
4082	* FT_Select_Charmap
4083	*
4084	* @description:
4085	* Select a given charmap by its encoding tag (as listed in
4086	* `freetype.h`).
4087	*
4088	* @inout:
4089	* face ::
4090	* A handle to the source face object.
4091	*
4092	* @input:
4093	* encoding ::
4094	* A handle to the selected encoding.
4095	*
4096	* @return:
4097	* FreeType error code. 0~means success.
4098	*
4099	* @note:
4100	* This function returns an error if no charmap in the face corresponds
4101	* to the encoding queried here.
4102	*
4103	* Because many fonts contain more than a single cmap for Unicode
4104	* encoding, this function has some special code to select the one that
4105	* covers Unicode best ('best' in the sense that a UCS-4 cmap is
4106	* preferred to a UCS-2 cmap). It is thus preferable to @FT_Set_Charmap
4107	* in this case.
4108	*/
4109	FT_EXPORT( FT_Error )
4110	FT_Select_Charmap( FT_Face face,
4111	FT_Encoding encoding );
4112
4113
4114	/**************************************************************************
4115	*
4116	* @function:
4117	* FT_Set_Charmap
4118	*
4119	* @description:
4120	* Select a given charmap for character code to glyph index mapping.
4121	*
4122	* @inout:
4123	* face ::
4124	* A handle to the source face object.
4125	*
4126	* @input:
4127	* charmap ::
4128	* A handle to the selected charmap.
4129	*
4130	* @return:
4131	* FreeType error code. 0~means success.
4132	*
4133	* @note:
4134	* This function returns an error if the charmap is not part of the face
4135	* (i.e., if it is not listed in the `face->charmaps` table).
4136	*
4137	* It also fails if an OpenType type~14 charmap is selected (which
4138	* doesn't map character codes to glyph indices at all).
4139	*/
4140	FT_EXPORT( FT_Error )
4141	FT_Set_Charmap( FT_Face face,
4142	FT_CharMap charmap );
4143
4144
4145	/**************************************************************************
4146	*
4147	* @function:
4148	* FT_Get_Charmap_Index
4149	*
4150	* @description:
4151	* Retrieve index of a given charmap.
4152	*
4153	* @input:
4154	* charmap ::
4155	* A handle to a charmap.
4156	*
4157	* @return:
4158	* The index into the array of character maps within the face to which
4159	* `charmap` belongs. If an error occurs, -1 is returned.
4160	*
4161	*/
4162	FT_EXPORT( FT_Int )
4163	FT_Get_Charmap_Index( FT_CharMap charmap );
4164
4165
4166	/**************************************************************************
4167	*
4168	* @function:
4169	* FT_Get_Char_Index
4170	*
4171	* @description:
4172	* Return the glyph index of a given character code. This function uses
4173	* the currently selected charmap to do the mapping.
4174	*
4175	* @input:
4176	* face ::
4177	* A handle to the source face object.
4178	*
4179	* charcode ::
4180	* The character code.
4181	*
4182	* @return:
4183	* The glyph index. 0~means 'undefined character code'.
4184	*
4185	* @note:
4186	* If you use FreeType to manipulate the contents of font files directly,
4187	* be aware that the glyph index returned by this function doesn't always
4188	* correspond to the internal indices used within the file. This is done
4189	* to ensure that value~0 always corresponds to the 'missing glyph'. If
4190	* the first glyph is not named '.notdef', then for Type~1 and Type~42
4191	* fonts, '.notdef' will be moved into the glyph ID~0 position, and
4192	* whatever was there will be moved to the position '.notdef' had. For
4193	* Type~1 fonts, if there is no '.notdef' glyph at all, then one will be
4194	* created at index~0 and whatever was there will be moved to the last
4195	* index -- Type~42 fonts are considered invalid under this condition.
4196	*/
4197	FT_EXPORT( FT_UInt )
4198	FT_Get_Char_Index( FT_Face face,
4199	FT_ULong charcode );
4200
4201
4202	/**************************************************************************
4203	*
4204	* @function:
4205	* FT_Get_First_Char
4206	*
4207	* @description:
4208	* Return the first character code in the current charmap of a given
4209	* face, together with its corresponding glyph index.
4210	*
4211	* @input:
4212	* face ::
4213	* A handle to the source face object.
4214	*
4215	* @output:
4216	* agindex ::
4217	* Glyph index of first character code. 0~if charmap is empty.
4218	*
4219	* @return:
4220	* The charmap's first character code.
4221	*
4222	* @note:
4223	* You should use this function together with @FT_Get_Next_Char to parse
4224	* all character codes available in a given charmap. The code should
4225	* look like this:
4226	*
4227	* ```
4228	* FT_ULong charcode;
4229	* FT_UInt gindex;
4230	*
4231	*
4232	* charcode = FT_Get_First_Char( face, &gindex );
4233	* while ( gindex != 0 )
4234	* {
4235	* ... do something with (charcode,gindex) pair ...
4236	*
4237	* charcode = FT_Get_Next_Char( face, charcode, &gindex );
4238	* }
4239	* ```
4240	*
4241	* Be aware that character codes can have values up to 0xFFFFFFFF; this
4242	* might happen for non-Unicode or malformed cmaps. However, even with
4243	* regular Unicode encoding, so-called 'last resort fonts' (using SFNT
4244	* cmap format 13, see function @FT_Get_CMap_Format) normally have
4245	* entries for all Unicode characters up to 0x1FFFFF, which can cause *a
4246	* lot* of iterations.
4247	*
4248	* Note that `*agindex` is set to~0 if the charmap is empty. The result
4249	* itself can be~0 in two cases: if the charmap is empty or if the
4250	* value~0 is the first valid character code.
4251	*/
4252	FT_EXPORT( FT_ULong )
4253	FT_Get_First_Char( FT_Face face,
4254	FT_UInt *agindex );
4255
4256
4257	/**************************************************************************
4258	*
4259	* @function:
4260	* FT_Get_Next_Char
4261	*
4262	* @description:
4263	* Return the next character code in the current charmap of a given face
4264	* following the value `char_code`, as well as the corresponding glyph
4265	* index.
4266	*
4267	* @input:
4268	* face ::
4269	* A handle to the source face object.
4270	*
4271	* char_code ::
4272	* The starting character code.
4273	*
4274	* @output:
4275	* agindex ::
4276	* Glyph index of next character code. 0~if charmap is empty.
4277	*
4278	* @return:
4279	* The charmap's next character code.
4280	*
4281	* @note:
4282	* You should use this function with @FT_Get_First_Char to walk over all
4283	* character codes available in a given charmap. See the note for that
4284	* function for a simple code example.
4285	*
4286	* Note that `*agindex` is set to~0 when there are no more codes in the
4287	* charmap.
4288	*/
4289	FT_EXPORT( FT_ULong )
4290	FT_Get_Next_Char( FT_Face face,
4291	FT_ULong char_code,
4292	FT_UInt *agindex );
4293
4294
4295	/**************************************************************************
4296	*
4297	* @section:
4298	* face_creation
4299	*
4300	*/
4301
4302	/**************************************************************************
4303	*
4304	* @function:
4305	* FT_Face_Properties
4306	*
4307	* @description:
4308	* Set or override certain (library or module-wide) properties on a
4309	* face-by-face basis. Useful for finer-grained control and avoiding
4310	* locks on shared structures (threads can modify their own faces as they
4311	* see fit).
4312	*
4313	* Contrary to @FT_Property_Set, this function uses @FT_Parameter so that
4314	* you can pass multiple properties to the target face in one call. Note
4315	* that only a subset of the available properties can be controlled.
4316	*
4317	* * @FT_PARAM_TAG_STEM_DARKENING (stem darkening, corresponding to the
4318	* property `no-stem-darkening` provided by the 'autofit', 'cff',
4319	* 'type1', and 't1cid' modules; see @no-stem-darkening).
4320	*
4321	* * @FT_PARAM_TAG_LCD_FILTER_WEIGHTS (LCD filter weights, corresponding
4322	* to function @FT_Library_SetLcdFilterWeights).
4323	*
4324	* * @FT_PARAM_TAG_RANDOM_SEED (seed value for the CFF, Type~1, and CID
4325	* 'random' operator, corresponding to the `random-seed` property
4326	* provided by the 'cff', 'type1', and 't1cid' modules; see
4327	* @random-seed).
4328	*
4329	* Pass `NULL` as `data` in @FT_Parameter for a given tag to reset the
4330	* option and use the library or module default again.
4331	*
4332	* @input:
4333	* face ::
4334	* A handle to the source face object.
4335	*
4336	* num_properties ::
4337	* The number of properties that follow.
4338	*
4339	* properties ::
4340	* A handle to an @FT_Parameter array with `num_properties` elements.
4341	*
4342	* @return:
4343	* FreeType error code. 0~means success.
4344	*
4345	* @example:
4346	* Here is an example that sets three properties. You must define
4347	* `FT_CONFIG_OPTION_SUBPIXEL_RENDERING` to make the LCD filter examples
4348	* work.
4349	*
4350	* ```
4351	* FT_Parameter property1;
4352	* FT_Bool darken_stems = 1;
4353	*
4354	* FT_Parameter property2;
4355	* FT_LcdFiveTapFilter custom_weight =
4356	* { 0x11, 0x44, 0x56, 0x44, 0x11 };
4357	*
4358	* FT_Parameter property3;
4359	* FT_Int32 random_seed = 314159265;
4360	*
4361	* FT_Parameter properties[3] = { property1,
4362	* property2,
4363	* property3 };
4364	*
4365	*
4366	* property1.tag = FT_PARAM_TAG_STEM_DARKENING;
4367	* property1.data = &darken_stems;
4368	*
4369	* property2.tag = FT_PARAM_TAG_LCD_FILTER_WEIGHTS;
4370	* property2.data = custom_weight;
4371	*
4372	* property3.tag = FT_PARAM_TAG_RANDOM_SEED;
4373	* property3.data = &random_seed;
4374	*
4375	* FT_Face_Properties( face, 3, properties );
4376	* ```
4377	*
4378	* The next example resets a single property to its default value.
4379	*
4380	* ```
4381	* FT_Parameter property;
4382	*
4383	*
4384	* property.tag = FT_PARAM_TAG_LCD_FILTER_WEIGHTS;
4385	* property.data = NULL;
4386	*
4387	* FT_Face_Properties( face, 1, &property );
4388	* ```
4389	*
4390	* @since:
4391	* 2.8
4392	*
4393	*/
4394	FT_EXPORT( FT_Error )
4395	FT_Face_Properties( FT_Face face,
4396	FT_UInt num_properties,
4397	FT_Parameter* properties );
4398
4399
4400	/**************************************************************************
4401	*
4402	* @section:
4403	* information_retrieval
4404	*
4405	*/
4406
4407	/**************************************************************************
4408	*
4409	* @function:
4410	* FT_Get_Name_Index
4411	*
4412	* @description:
4413	* Return the glyph index of a given glyph name. This only works
4414	* for those faces where @FT_HAS_GLYPH_NAMES returns true.
4415	*
4416	* @input:
4417	* face ::
4418	* A handle to the source face object.
4419	*
4420	* glyph_name ::
4421	* The glyph name.
4422	*
4423	* @return:
4424	* The glyph index. 0~means 'undefined character code'.
4425	*
4426	* @note:
4427	* Acceptable glyph names might come from the [Adobe Glyph
4428	* List](https://github.com/adobe-type-tools/agl-aglfn). See
4429	* @FT_Get_Glyph_Name for the inverse functionality.
4430	*
4431	* This function has limited capabilities if the config macro
4432	* `FT_CONFIG_OPTION_POSTSCRIPT_NAMES` is not defined in `ftoption.h`:
4433	* It then works only for fonts that actually embed glyph names (which
4434	* many recent OpenType fonts do not).
4435	*/
4436	FT_EXPORT( FT_UInt )
4437	FT_Get_Name_Index( FT_Face face,
4438	const FT_String* glyph_name );
4439
4440
4441	/**************************************************************************
4442	*
4443	* @function:
4444	* FT_Get_Glyph_Name
4445	*
4446	* @description:
4447	* Retrieve the ASCII name of a given glyph in a face. This only works
4448	* for those faces where @FT_HAS_GLYPH_NAMES returns true.
4449	*
4450	* @input:
4451	* face ::
4452	* A handle to a source face object.
4453	*
4454	* glyph_index ::
4455	* The glyph index.
4456	*
4457	* buffer_max ::
4458	* The maximum number of bytes available in the buffer.
4459	*
4460	* @output:
4461	* buffer ::
4462	* A pointer to a target buffer where the name is copied to.
4463	*
4464	* @return:
4465	* FreeType error code. 0~means success.
4466	*
4467	* @note:
4468	* An error is returned if the face doesn't provide glyph names or if the
4469	* glyph index is invalid. In all cases of failure, the first byte of
4470	* `buffer` is set to~0 to indicate an empty name.
4471	*
4472	* The glyph name is truncated to fit within the buffer if it is too
4473	* long. The returned string is always zero-terminated.
4474	*
4475	* Be aware that FreeType reorders glyph indices internally so that glyph
4476	* index~0 always corresponds to the 'missing glyph' (called '.notdef').
4477	*
4478	* This function has limited capabilities if the config macro
4479	* `FT_CONFIG_OPTION_POSTSCRIPT_NAMES` is not defined in `ftoption.h`:
4480	* It then works only for fonts that actually embed glyph names (which
4481	* many recent OpenType fonts do not).
4482	*/
4483	FT_EXPORT( FT_Error )
4484	FT_Get_Glyph_Name( FT_Face face,
4485	FT_UInt glyph_index,
4486	FT_Pointer buffer,
4487	FT_UInt buffer_max );
4488
4489
4490	/**************************************************************************
4491	*
4492	* @function:
4493	* FT_Get_Postscript_Name
4494	*
4495	* @description:
4496	* Retrieve the ASCII PostScript name of a given face, if available.
4497	* This only works with PostScript, TrueType, and OpenType fonts.
4498	*
4499	* @input:
4500	* face ::
4501	* A handle to the source face object.
4502	*
4503	* @return:
4504	* A pointer to the face's PostScript name. `NULL` if unavailable.
4505	*
4506	* @note:
4507	* The returned pointer is owned by the face and is destroyed with it.
4508	*
4509	* For variation fonts, this string changes if you select a different
4510	* instance, and you have to call `FT_Get_PostScript_Name` again to
4511	* retrieve it. FreeType follows Adobe TechNote #5902, 'Generating
4512	* PostScript Names for Fonts Using OpenType Font Variations'.
4513	*
4514	* https://download.macromedia.com/pub/developer/opentype/tech-notes/5902.AdobePSNameGeneration.html
4515	*
4516	* [Since 2.9] Special PostScript names for named instances are only
4517	* returned if the named instance is set with @FT_Set_Named_Instance (and
4518	* the font has corresponding entries in its 'fvar' table or is the
4519	* default named instance). If @FT_IS_VARIATION returns true, the
4520	* algorithmically derived PostScript name is provided, not looking up
4521	* special entries for named instances.
4522	*/
4523	FT_EXPORT( const char* )
4524	FT_Get_Postscript_Name( FT_Face face );
4525
4526
4527	/**************************************************************************
4528	*
4529	* @enum:
4530	* FT_SUBGLYPH_FLAG_XXX
4531	*
4532	* @description:
4533	* A list of constants describing subglyphs. Please refer to the 'glyf'
4534	* table description in the OpenType specification for the meaning of the
4535	* various flags (which get synthesized for non-OpenType subglyphs).
4536	*
4537	* https://learn.microsoft.com/typography/opentype/spec/glyf#composite-glyph-description
4538	*
4539	* @values:
4540	* FT_SUBGLYPH_FLAG_ARGS_ARE_WORDS ::
4541	* FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES ::
4542	* FT_SUBGLYPH_FLAG_ROUND_XY_TO_GRID ::
4543	* FT_SUBGLYPH_FLAG_SCALE ::
4544	* FT_SUBGLYPH_FLAG_XY_SCALE ::
4545	* FT_SUBGLYPH_FLAG_2X2 ::
4546	* FT_SUBGLYPH_FLAG_USE_MY_METRICS ::
4547	*
4548	*/
4549	#define FT_SUBGLYPH_FLAG_ARGS_ARE_WORDS 1
4550	#define FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES 2
4551	#define FT_SUBGLYPH_FLAG_ROUND_XY_TO_GRID 4
4552	#define FT_SUBGLYPH_FLAG_SCALE 8
4553	#define FT_SUBGLYPH_FLAG_XY_SCALE 0x40
4554	#define FT_SUBGLYPH_FLAG_2X2 0x80
4555	#define FT_SUBGLYPH_FLAG_USE_MY_METRICS 0x200
4556
4557
4558	/**************************************************************************
4559	*
4560	* @function:
4561	* FT_Get_SubGlyph_Info
4562	*
4563	* @description:
4564	* Retrieve a description of a given subglyph. Only use it if
4565	* `glyph->format` is @FT_GLYPH_FORMAT_COMPOSITE; an error is returned
4566	* otherwise.
4567	*
4568	* @input:
4569	* glyph ::
4570	* The source glyph slot.
4571	*
4572	* sub_index ::
4573	* The index of the subglyph. Must be less than
4574	* `glyph->num_subglyphs`.
4575	*
4576	* @output:
4577	* p_index ::
4578	* The glyph index of the subglyph.
4579	*
4580	* p_flags ::
4581	* The subglyph flags, see @FT_SUBGLYPH_FLAG_XXX.
4582	*
4583	* p_arg1 ::
4584	* The subglyph's first argument (if any).
4585	*
4586	* p_arg2 ::
4587	* The subglyph's second argument (if any).
4588	*
4589	* p_transform ::
4590	* The subglyph transformation (if any).
4591	*
4592	* @return:
4593	* FreeType error code. 0~means success.
4594	*
4595	* @note:
4596	* The values of `p_arg1`, `p_arg2`, and `*p_transform` must be
4597	* interpreted depending on the flags returned in `*p_flags`. See the
4598	* OpenType specification for details.
4599	*
4600	* https://learn.microsoft.com/typography/opentype/spec/glyf#composite-glyph-description
4601	*
4602	*/
4603	FT_EXPORT( FT_Error )
4604	FT_Get_SubGlyph_Info( FT_GlyphSlot glyph,
4605	FT_UInt sub_index,
4606	FT_Int *p_index,
4607	FT_UInt *p_flags,
4608	FT_Int *p_arg1,
4609	FT_Int *p_arg2,
4610	FT_Matrix *p_transform );
4611
4612
4613	/**************************************************************************
4614	*
4615	* @enum:
4616	* FT_FSTYPE_XXX
4617	*
4618	* @description:
4619	* A list of bit flags used in the `fsType` field of the OS/2 table in a
4620	* TrueType or OpenType font and the `FSType` entry in a PostScript font.
4621	* These bit flags are returned by @FT_Get_FSType_Flags; they inform
4622	* client applications of embedding and subsetting restrictions
4623	* associated with a font.
4624	*
4625	* See
4626	* https://adobe-type-tools.github.io/font-tech-notes/pdfs/AcrobatDC_FontPolicies.pdf
4627	* for more details.
4628	*
4629	* @values:
4630	* FT_FSTYPE_INSTALLABLE_EMBEDDING ::
4631	* Fonts with no fsType bit set may be embedded and permanently
4632	* installed on the remote system by an application.
4633	*
4634	* FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING ::
4635	* Fonts that have only this bit set must not be modified, embedded or
4636	* exchanged in any manner without first obtaining permission of the
4637	* font software copyright owner.
4638	*
4639	* FT_FSTYPE_PREVIEW_AND_PRINT_EMBEDDING ::
4640	* The font may be embedded and temporarily loaded on the remote
4641	* system. Documents containing Preview & Print fonts must be opened
4642	* 'read-only'; no edits can be applied to the document.
4643	*
4644	* FT_FSTYPE_EDITABLE_EMBEDDING ::
4645	* The font may be embedded but must only be installed temporarily on
4646	* other systems. In contrast to Preview & Print fonts, documents
4647	* containing editable fonts may be opened for reading, editing is
4648	* permitted, and changes may be saved.
4649	*
4650	* FT_FSTYPE_NO_SUBSETTING ::
4651	* The font may not be subsetted prior to embedding.
4652	*
4653	* FT_FSTYPE_BITMAP_EMBEDDING_ONLY ::
4654	* Only bitmaps contained in the font may be embedded; no outline data
4655	* may be embedded. If there are no bitmaps available in the font,
4656	* then the font is unembeddable.
4657	*
4658	* @note:
4659	* The flags are ORed together, thus more than a single value can be
4660	* returned.
4661	*
4662	* While the `fsType` flags can indicate that a font may be embedded, a
4663	* license with the font vendor may be separately required to use the
4664	* font in this way.
4665	*/
4666	#define FT_FSTYPE_INSTALLABLE_EMBEDDING 0x0000
4667	#define FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING 0x0002
4668	#define FT_FSTYPE_PREVIEW_AND_PRINT_EMBEDDING 0x0004
4669	#define FT_FSTYPE_EDITABLE_EMBEDDING 0x0008
4670	#define FT_FSTYPE_NO_SUBSETTING 0x0100
4671	#define FT_FSTYPE_BITMAP_EMBEDDING_ONLY 0x0200
4672
4673
4674	/**************************************************************************
4675	*
4676	* @function:
4677	* FT_Get_FSType_Flags
4678	*
4679	* @description:
4680	* Return the `fsType` flags for a font.
4681	*
4682	* @input:
4683	* face ::
4684	* A handle to the source face object.
4685	*
4686	* @return:
4687	* The `fsType` flags, see @FT_FSTYPE_XXX.
4688	*
4689	* @note:
4690	* Use this function rather than directly reading the `fs_type` field in
4691	* the @PS_FontInfoRec structure, which is only guaranteed to return the
4692	* correct results for Type~1 fonts.
4693	*
4694	* @since:
4695	* 2.3.8
4696	*
4697	*/
4698	FT_EXPORT( FT_UShort )
4699	FT_Get_FSType_Flags( FT_Face face );
4700
4701
4702	/**************************************************************************
4703	*
4704	* @section:
4705	* glyph_variants
4706	*
4707	* @title:
4708	* Unicode Variation Sequences
4709	*
4710	* @abstract:
4711	* The FreeType~2 interface to Unicode Variation Sequences (UVS), using
4712	* the SFNT cmap format~14.
4713	*
4714	* @description:
4715	* Many characters, especially for CJK scripts, have variant forms. They
4716	* are a sort of grey area somewhere between being totally irrelevant and
4717	* semantically distinct; for this reason, the Unicode consortium decided
4718	* to introduce Variation Sequences (VS), consisting of a Unicode base
4719	* character and a variation selector instead of further extending the
4720	* already huge number of characters.
4721	*
4722	* Unicode maintains two different sets, namely 'Standardized Variation
4723	* Sequences' and registered 'Ideographic Variation Sequences' (IVS),
4724	* collected in the 'Ideographic Variation Database' (IVD).
4725	*
4726	* https://unicode.org/Public/UCD/latest/ucd/StandardizedVariants.txt
4727	* https://unicode.org/reports/tr37/ https://unicode.org/ivd/
4728	*
4729	* To date (January 2017), the character with the most ideographic
4730	* variations is U+9089, having 32 such IVS.
4731	*
4732	* Three Mongolian Variation Selectors have the values U+180B-U+180D; 256
4733	* generic Variation Selectors are encoded in the ranges U+FE00-U+FE0F
4734	* and U+E0100-U+E01EF. IVS currently use Variation Selectors from the
4735	* range U+E0100-U+E01EF only.
4736	*
4737	* A VS consists of the base character value followed by a single
4738	* Variation Selector. For example, to get the first variation of
4739	* U+9089, you have to write the character sequence `U+9089 U+E0100`.
4740	*
4741	* Adobe and MS decided to support both standardized and ideographic VS
4742	* with a new cmap subtable (format~14). It is an odd subtable because
4743	* it is not a mapping of input code points to glyphs, but contains lists
4744	* of all variations supported by the font.
4745	*
4746	* A variation may be either 'default' or 'non-default' for a given font.
4747	* A default variation is the one you will get for that code point if you
4748	* look it up in the standard Unicode cmap. A non-default variation is a
4749	* different glyph.
4750	*
4751	*/
4752
4753
4754	/**************************************************************************
4755	*
4756	* @function:
4757	* FT_Face_GetCharVariantIndex
4758	*
4759	* @description:
4760	* Return the glyph index of a given character code as modified by the
4761	* variation selector.
4762	*
4763	* @input:
4764	* face ::
4765	* A handle to the source face object.
4766	*
4767	* charcode ::
4768	* The character code point in Unicode.
4769	*
4770	* variantSelector ::
4771	* The Unicode code point of the variation selector.
4772	*
4773	* @return:
4774	* The glyph index. 0~means either 'undefined character code', or
4775	* 'undefined selector code', or 'no variation selector cmap subtable',
4776	* or 'current CharMap is not Unicode'.
4777	*
4778	* @note:
4779	* If you use FreeType to manipulate the contents of font files directly,
4780	* be aware that the glyph index returned by this function doesn't always
4781	* correspond to the internal indices used within the file. This is done
4782	* to ensure that value~0 always corresponds to the 'missing glyph'.
4783	*
4784	* This function is only meaningful if
4785	* a) the font has a variation selector cmap sub table, and
4786	* b) the current charmap has a Unicode encoding.
4787	*
4788	* @since:
4789	* 2.3.6
4790	*
4791	*/
4792	FT_EXPORT( FT_UInt )
4793	FT_Face_GetCharVariantIndex( FT_Face face,
4794	FT_ULong charcode,
4795	FT_ULong variantSelector );
4796
4797
4798	/**************************************************************************
4799	*
4800	* @function:
4801	* FT_Face_GetCharVariantIsDefault
4802	*
4803	* @description:
4804	* Check whether this variation of this Unicode character is the one to
4805	* be found in the charmap.
4806	*
4807	* @input:
4808	* face ::
4809	* A handle to the source face object.
4810	*
4811	* charcode ::
4812	* The character codepoint in Unicode.
4813	*
4814	* variantSelector ::
4815	* The Unicode codepoint of the variation selector.
4816	*
4817	* @return:
4818	* 1~if found in the standard (Unicode) cmap, 0~if found in the variation
4819	* selector cmap, or -1 if it is not a variation.
4820	*
4821	* @note:
4822	* This function is only meaningful if the font has a variation selector
4823	* cmap subtable.
4824	*
4825	* @since:
4826	* 2.3.6
4827	*
4828	*/
4829	FT_EXPORT( FT_Int )
4830	FT_Face_GetCharVariantIsDefault( FT_Face face,
4831	FT_ULong charcode,
4832	FT_ULong variantSelector );
4833
4834
4835	/**************************************************************************
4836	*
4837	* @function:
4838	* FT_Face_GetVariantSelectors
4839	*
4840	* @description:
4841	* Return a zero-terminated list of Unicode variation selectors found in
4842	* the font.
4843	*
4844	* @input:
4845	* face ::
4846	* A handle to the source face object.
4847	*
4848	* @return:
4849	* A pointer to an array of selector code points, or `NULL` if there is
4850	* no valid variation selector cmap subtable.
4851	*
4852	* @note:
4853	* The last item in the array is~0; the array is owned by the @FT_Face
4854	* object but can be overwritten or released on the next call to a
4855	* FreeType function.
4856	*
4857	* @since:
4858	* 2.3.6
4859	*
4860	*/
4861	FT_EXPORT( FT_UInt32* )
4862	FT_Face_GetVariantSelectors( FT_Face face );
4863
4864
4865	/**************************************************************************
4866	*
4867	* @function:
4868	* FT_Face_GetVariantsOfChar
4869	*
4870	* @description:
4871	* Return a zero-terminated list of Unicode variation selectors found for
4872	* the specified character code.
4873	*
4874	* @input:
4875	* face ::
4876	* A handle to the source face object.
4877	*
4878	* charcode ::
4879	* The character codepoint in Unicode.
4880	*
4881	* @return:
4882	* A pointer to an array of variation selector code points that are
4883	* active for the given character, or `NULL` if the corresponding list is
4884	* empty.
4885	*
4886	* @note:
4887	* The last item in the array is~0; the array is owned by the @FT_Face
4888	* object but can be overwritten or released on the next call to a
4889	* FreeType function.
4890	*
4891	* @since:
4892	* 2.3.6
4893	*
4894	*/
4895	FT_EXPORT( FT_UInt32* )
4896	FT_Face_GetVariantsOfChar( FT_Face face,
4897	FT_ULong charcode );
4898
4899
4900	/**************************************************************************
4901	*
4902	* @function:
4903	* FT_Face_GetCharsOfVariant
4904	*
4905	* @description:
4906	* Return a zero-terminated list of Unicode character codes found for the
4907	* specified variation selector.
4908	*
4909	* @input:
4910	* face ::
4911	* A handle to the source face object.
4912	*
4913	* variantSelector ::
4914	* The variation selector code point in Unicode.
4915	*
4916	* @return:
4917	* A list of all the code points that are specified by this selector
4918	* (both default and non-default codes are returned) or `NULL` if there
4919	* is no valid cmap or the variation selector is invalid.
4920	*
4921	* @note:
4922	* The last item in the array is~0; the array is owned by the @FT_Face
4923	* object but can be overwritten or released on the next call to a
4924	* FreeType function.
4925	*
4926	* @since:
4927	* 2.3.6
4928	*
4929	*/
4930	FT_EXPORT( FT_UInt32* )
4931	FT_Face_GetCharsOfVariant( FT_Face face,
4932	FT_ULong variantSelector );
4933
4934
4935	/**************************************************************************
4936	*
4937	* @section:
4938	* computations
4939	*
4940	* @title:
4941	* Computations
4942	*
4943	* @abstract:
4944	* Crunching fixed numbers and vectors.
4945	*
4946	* @description:
4947	* This section contains various functions used to perform computations
4948	* on 16.16 fixed-point numbers or 2D vectors. FreeType does not use
4949	* floating-point data types.
4950	*
4951	* Attention: Most arithmetic functions take `FT_Long` as arguments.
4952	* For historical reasons, FreeType was designed under the assumption
4953	* that `FT_Long` is a 32-bit integer; results can thus be undefined if
4954	* the arguments don't fit into 32 bits.
4955	*
4956	* @order:
4957	* FT_MulDiv
4958	* FT_MulFix
4959	* FT_DivFix
4960	* FT_RoundFix
4961	* FT_CeilFix
4962	* FT_FloorFix
4963	* FT_Vector_Transform
4964	* FT_Matrix_Multiply
4965	* FT_Matrix_Invert
4966	*
4967	*/
4968
4969
4970	/**************************************************************************
4971	*
4972	* @function:
4973	* FT_MulDiv
4974	*
4975	* @description:
4976	* Compute `(a*b)/c` with maximum accuracy, using a 64-bit intermediate
4977	* integer whenever necessary.
4978	*
4979	* This function isn't necessarily as fast as some processor-specific
4980	* operations, but is at least completely portable.
4981	*
4982	* @input:
4983	* a ::
4984	* The first multiplier.
4985	*
4986	* b ::
4987	* The second multiplier.
4988	*
4989	* c ::
4990	* The divisor.
4991	*
4992	* @return:
4993	* The result of `(a*b)/c`. This function never traps when trying to
4994	* divide by zero; it simply returns 'MaxInt' or 'MinInt' depending on
4995	* the signs of `a` and `b`.
4996	*/
4997	FT_EXPORT( FT_Long )
4998	FT_MulDiv( FT_Long a,
4999	FT_Long b,
5000	FT_Long c );
5001
5002
5003	/**************************************************************************
5004	*
5005	* @function:
5006	* FT_MulFix
5007	*
5008	* @description:
5009	* Compute `(a*b)/0x10000` with maximum accuracy. Its main use is to
5010	* multiply a given value by a 16.16 fixed-point factor.
5011	*
5012	* @input:
5013	* a ::
5014	* The first multiplier.
5015	*
5016	* b ::
5017	* The second multiplier. Use a 16.16 factor here whenever possible
5018	* (see note below).
5019	*
5020	* @return:
5021	* The result of `(a*b)/0x10000`.
5022	*
5023	* @note:
5024	* This function has been optimized for the case where the absolute value
5025	* of `a` is less than 2048, and `b` is a 16.16 scaling factor. As this
5026	* happens mainly when scaling from notional units to fractional pixels
5027	* in FreeType, it resulted in noticeable speed improvements between
5028	* versions 2.x and 1.x.
5029	*
5030	* As a conclusion, always try to place a 16.16 factor as the _second_
5031	* argument of this function; this can make a great difference.
5032	*/
5033	FT_EXPORT( FT_Long )
5034	FT_MulFix( FT_Long a,
5035	FT_Long b );
5036
5037
5038	/**************************************************************************
5039	*
5040	* @function:
5041	* FT_DivFix
5042	*
5043	* @description:
5044	* Compute `(a*0x10000)/b` with maximum accuracy. Its main use is to
5045	* divide a given value by a 16.16 fixed-point factor.
5046	*
5047	* @input:
5048	* a ::
5049	* The numerator.
5050	*
5051	* b ::
5052	* The denominator. Use a 16.16 factor here.
5053	*
5054	* @return:
5055	* The result of `(a*0x10000)/b`.
5056	*/
5057	FT_EXPORT( FT_Long )
5058	FT_DivFix( FT_Long a,
5059	FT_Long b );
5060
5061
5062	/**************************************************************************
5063	*
5064	* @function:
5065	* FT_RoundFix
5066	*
5067	* @description:
5068	* Round a 16.16 fixed number.
5069	*
5070	* @input:
5071	* a ::
5072	* The number to be rounded.
5073	*
5074	* @return:
5075	* `a` rounded to the nearest 16.16 fixed integer, halfway cases away
5076	* from zero.
5077	*
5078	* @note:
5079	* The function uses wrap-around arithmetic.
5080	*/
5081	FT_EXPORT( FT_Fixed )
5082	FT_RoundFix( FT_Fixed a );
5083
5084
5085	/**************************************************************************
5086	*
5087	* @function:
5088	* FT_CeilFix
5089	*
5090	* @description:
5091	* Compute the smallest following integer of a 16.16 fixed number.
5092	*
5093	* @input:
5094	* a ::
5095	* The number for which the ceiling function is to be computed.
5096	*
5097	* @return:
5098	* `a` rounded towards plus infinity.
5099	*
5100	* @note:
5101	* The function uses wrap-around arithmetic.
5102	*/
5103	FT_EXPORT( FT_Fixed )
5104	FT_CeilFix( FT_Fixed a );
5105
5106
5107	/**************************************************************************
5108	*
5109	* @function:
5110	* FT_FloorFix
5111	*
5112	* @description:
5113	* Compute the largest previous integer of a 16.16 fixed number.
5114	*
5115	* @input:
5116	* a ::
5117	* The number for which the floor function is to be computed.
5118	*
5119	* @return:
5120	* `a` rounded towards minus infinity.
5121	*/
5122	FT_EXPORT( FT_Fixed )
5123	FT_FloorFix( FT_Fixed a );
5124
5125
5126	/**************************************************************************
5127	*
5128	* @function:
5129	* FT_Vector_Transform
5130	*
5131	* @description:
5132	* Transform a single vector through a 2x2 matrix.
5133	*
5134	* @inout:
5135	* vector ::
5136	* The target vector to transform.
5137	*
5138	* @input:
5139	* matrix ::
5140	* A pointer to the source 2x2 matrix.
5141	*
5142	* @note:
5143	* The result is undefined if either `vector` or `matrix` is invalid.
5144	*/
5145	FT_EXPORT( void )
5146	FT_Vector_Transform( FT_Vector* vector,
5147	const FT_Matrix* matrix );
5148
5149
5150	/**************************************************************************
5151	*
5152	* @section:
5153	* library_setup
5154	*
5155	*/
5156
5157	/**************************************************************************
5158	*
5159	* @enum:
5160	* FREETYPE_XXX
5161	*
5162	* @description:
5163	* These three macros identify the FreeType source code version. Use
5164	* @FT_Library_Version to access them at runtime.
5165	*
5166	* @values:
5167	* FREETYPE_MAJOR ::
5168	* The major version number.
5169	* FREETYPE_MINOR ::
5170	* The minor version number.
5171	* FREETYPE_PATCH ::
5172	* The patch level.
5173	*
5174	* @note:
5175	* The version number of FreeType if built as a dynamic link library with
5176	* the 'libtool' package is _not_ controlled by these three macros.
5177	*
5178	*/
5179	#define FREETYPE_MAJOR 2
5180	#define FREETYPE_MINOR 14
5181	#define FREETYPE_PATCH 1
5182
5183
5184	/**************************************************************************
5185	*
5186	* @function:
5187	* FT_Library_Version
5188	*
5189	* @description:
5190	* Return the version of the FreeType library being used. This is useful
5191	* when dynamically linking to the library, since one cannot use the
5192	* macros @FREETYPE_MAJOR, @FREETYPE_MINOR, and @FREETYPE_PATCH.
5193	*
5194	* @input:
5195	* library ::
5196	* A source library handle.
5197	*
5198	* @output:
5199	* amajor ::
5200	* The major version number.
5201	*
5202	* aminor ::
5203	* The minor version number.
5204	*
5205	* apatch ::
5206	* The patch version number.
5207	*
5208	* @note:
5209	* The reason why this function takes a `library` argument is because
5210	* certain programs implement library initialization in a custom way that
5211	* doesn't use @FT_Init_FreeType.
5212	*
5213	* In such cases, the library version might not be available before the
5214	* library object has been created.
5215	*/
5216	FT_EXPORT( void )
5217	FT_Library_Version( FT_Library library,
5218	FT_Int *amajor,
5219	FT_Int *aminor,
5220	FT_Int *apatch );
5221
5222
5223	/**************************************************************************
5224	*
5225	* @section:
5226	* other_api_data
5227	*
5228	*/
5229
5230	/**************************************************************************
5231	*
5232	* @function:
5233	* FT_Face_CheckTrueTypePatents
5234	*
5235	* @description:
5236	* Deprecated, does nothing.
5237	*
5238	* @input:
5239	* face ::
5240	* A face handle.
5241	*
5242	* @return:
5243	* Always returns false.
5244	*
5245	* @note:
5246	* Since May 2010, TrueType hinting is no longer patented.
5247	*
5248	* @since:
5249	* 2.3.5
5250	*
5251	*/
5252	FT_EXPORT( FT_Bool )
5253	FT_Face_CheckTrueTypePatents( FT_Face face );
5254
5255
5256	/**************************************************************************
5257	*
5258	* @function:
5259	* FT_Face_SetUnpatentedHinting
5260	*
5261	* @description:
5262	* Deprecated, does nothing.
5263	*
5264	* @input:
5265	* face ::
5266	* A face handle.
5267	*
5268	* value ::
5269	* New boolean setting.
5270	*
5271	* @return:
5272	* Always returns false.
5273	*
5274	* @note:
5275	* Since May 2010, TrueType hinting is no longer patented.
5276	*
5277	* @since:
5278	* 2.3.5
5279	*
5280	*/
5281	FT_EXPORT( FT_Bool )
5282	FT_Face_SetUnpatentedHinting( FT_Face face,
5283	FT_Bool value );
5284
5285	/ /
5286
5287
5288	FT_END_HEADER
5289
5290	#endif /* FREETYPE_H_ */
5291
5292
5293	/ END /
5294

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