1	/****************************************************************************
2	*
3	* freetype.h
4	*
5	* FreeType high-level API and common types (specification only).
6	*
7	* Copyright (C) 1996-2023 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://www.microsoft.com/typography/otspec/recom.htm#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 GX and OpenType variation
1072	* fonts only, holding the named instance index for the current face
1073	* index (starting with value~1; value~0 indicates font access without
1074	* a named instance). For non-variation fonts, bits 16-30 are ignored.
1075	* If we have the third named instance of face~4, say, `face_index` is
1076	* 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 GX or OpenType variation
1096	* (sub)font. Bit 31 is always zero (that is, `style_flags` is always
1097	* a positive value). Note that a variation font has always at least
1098	* 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 variation fonts
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 an OpenType variation font, 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). Note that FreeType
1326	* doesn't handle kerning data from the SFNT 'GPOS' table (as present
1327	* in many OpenType fonts).
1328	*
1329	* FT_FACE_FLAG_FAST_GLYPHS ::
1330	* THIS FLAG IS DEPRECATED. DO NOT USE OR TEST IT.
1331	*
1332	* FT_FACE_FLAG_MULTIPLE_MASTERS ::
1333	* The face contains multiple masters and is capable of interpolating
1334	* between them. Supported formats are Adobe MM, TrueType GX, and
1335	* OpenType variation fonts.
1336	*
1337	* See section @multiple_masters for API details.
1338	*
1339	* FT_FACE_FLAG_GLYPH_NAMES ::
1340	* The face contains glyph names, which can be retrieved using
1341	* @FT_Get_Glyph_Name. Note that some TrueType fonts contain broken
1342	* glyph name tables. Use the function @FT_Has_PS_Glyph_Names when
1343	* needed.
1344	*
1345	* FT_FACE_FLAG_EXTERNAL_STREAM ::
1346	* Used internally by FreeType to indicate that a face's stream was
1347	* provided by the client application and should not be destroyed when
1348	* @FT_Done_Face is called. Don't read or test this flag.
1349	*
1350	* FT_FACE_FLAG_HINTER ::
1351	* The font driver has a hinting machine of its own. For example, with
1352	* TrueType fonts, it makes sense to use data from the SFNT 'gasp'
1353	* table only if the native TrueType hinting engine (with the bytecode
1354	* interpreter) is available and active.
1355	*
1356	* FT_FACE_FLAG_CID_KEYED ::
1357	* The face is CID-keyed. In that case, the face is not accessed by
1358	* glyph indices but by CID values. For subsetted CID-keyed fonts this
1359	* has the consequence that not all index values are a valid argument
1360	* to @FT_Load_Glyph. Only the CID values for which corresponding
1361	* glyphs in the subsetted font exist make `FT_Load_Glyph` return
1362	* successfully; in all other cases you get an
1363	* `FT_Err_Invalid_Argument` error.
1364	*
1365	* Note that CID-keyed fonts that are in an SFNT wrapper (that is, all
1366	* OpenType/CFF fonts) don't have this flag set since the glyphs are
1367	* accessed in the normal way (using contiguous indices); the
1368	* 'CID-ness' isn't visible to the application.
1369	*
1370	* FT_FACE_FLAG_TRICKY ::
1371	* The face is 'tricky', that is, it always needs the font format's
1372	* native hinting engine to get a reasonable result. A typical example
1373	* is the old Chinese font `mingli.ttf` (but not `mingliu.ttc`) that
1374	* uses TrueType bytecode instructions to move and scale all of its
1375	* subglyphs.
1376	*
1377	* It is not possible to auto-hint such fonts using
1378	* @FT_LOAD_FORCE_AUTOHINT; it will also ignore @FT_LOAD_NO_HINTING.
1379	* You have to set both @FT_LOAD_NO_HINTING and @FT_LOAD_NO_AUTOHINT to
1380	* really disable hinting; however, you probably never want this except
1381	* for demonstration purposes.
1382	*
1383	* Currently, there are about a dozen TrueType fonts in the list of
1384	* tricky fonts; they are hard-coded in file `ttobjs.c`.
1385	*
1386	* FT_FACE_FLAG_COLOR ::
1387	* [Since 2.5.1] The face has color glyph tables. See @FT_LOAD_COLOR
1388	* for more information.
1389	*
1390	* FT_FACE_FLAG_VARIATION ::
1391	* [Since 2.9] Set if the current face (or named instance) has been
1392	* altered with @FT_Set_MM_Design_Coordinates,
1393	* @FT_Set_Var_Design_Coordinates, @FT_Set_Var_Blend_Coordinates, or
1394	* @FT_Set_MM_WeightVector to select a non-default instance.
1395	*
1396	* FT_FACE_FLAG_SVG ::
1397	* [Since 2.12] The face has an 'SVG~' OpenType table.
1398	*
1399	* FT_FACE_FLAG_SBIX ::
1400	* [Since 2.12] The face has an 'sbix' OpenType table *and* outlines.
1401	* For such fonts, @FT_FACE_FLAG_SCALABLE is not set by default to
1402	* retain backward compatibility.
1403	*
1404	* FT_FACE_FLAG_SBIX_OVERLAY ::
1405	* [Since 2.12] The face has an 'sbix' OpenType table where outlines
1406	* should be drawn on top of bitmap strikes.
1407	*
1408	*/
1409	#define FT_FACE_FLAG_SCALABLE ( 1L << 0 )
1410	#define FT_FACE_FLAG_FIXED_SIZES ( 1L << 1 )
1411	#define FT_FACE_FLAG_FIXED_WIDTH ( 1L << 2 )
1412	#define FT_FACE_FLAG_SFNT ( 1L << 3 )
1413	#define FT_FACE_FLAG_HORIZONTAL ( 1L << 4 )
1414	#define FT_FACE_FLAG_VERTICAL ( 1L << 5 )
1415	#define FT_FACE_FLAG_KERNING ( 1L << 6 )
1416	#define FT_FACE_FLAG_FAST_GLYPHS ( 1L << 7 )
1417	#define FT_FACE_FLAG_MULTIPLE_MASTERS ( 1L << 8 )
1418	#define FT_FACE_FLAG_GLYPH_NAMES ( 1L << 9 )
1419	#define FT_FACE_FLAG_EXTERNAL_STREAM ( 1L << 10 )
1420	#define FT_FACE_FLAG_HINTER ( 1L << 11 )
1421	#define FT_FACE_FLAG_CID_KEYED ( 1L << 12 )
1422	#define FT_FACE_FLAG_TRICKY ( 1L << 13 )
1423	#define FT_FACE_FLAG_COLOR ( 1L << 14 )
1424	#define FT_FACE_FLAG_VARIATION ( 1L << 15 )
1425	#define FT_FACE_FLAG_SVG ( 1L << 16 )
1426	#define FT_FACE_FLAG_SBIX ( 1L << 17 )
1427	#define FT_FACE_FLAG_SBIX_OVERLAY ( 1L << 18 )
1428
1429
1430	/**************************************************************************
1431	*
1432	* @section:
1433	* font_testing_macros
1434	*
1435	*/
1436
1437	/**************************************************************************
1438	*
1439	* @macro:
1440	* FT_HAS_HORIZONTAL
1441	*
1442	* @description:
1443	* A macro that returns true whenever a face object contains horizontal
1444	* metrics (this is true for all font formats though).
1445	*
1446	* @also:
1447	* @FT_HAS_VERTICAL can be used to check for vertical metrics.
1448	*
1449	*/
1450	#define FT_HAS_HORIZONTAL( face ) \
1451	( !!( (face)->face_flags & FT_FACE_FLAG_HORIZONTAL ) )
1452
1453
1454	/**************************************************************************
1455	*
1456	* @macro:
1457	* FT_HAS_VERTICAL
1458	*
1459	* @description:
1460	* A macro that returns true whenever a face object contains real
1461	* vertical metrics (and not only synthesized ones).
1462	*
1463	*/
1464	#define FT_HAS_VERTICAL( face ) \
1465	( !!( (face)->face_flags & FT_FACE_FLAG_VERTICAL ) )
1466
1467
1468	/**************************************************************************
1469	*
1470	* @macro:
1471	* FT_HAS_KERNING
1472	*
1473	* @description:
1474	* A macro that returns true whenever a face object contains kerning data
1475	* that can be accessed with @FT_Get_Kerning.
1476	*
1477	*/
1478	#define FT_HAS_KERNING( face ) \
1479	( !!( (face)->face_flags & FT_FACE_FLAG_KERNING ) )
1480
1481
1482	/**************************************************************************
1483	*
1484	* @macro:
1485	* FT_IS_SCALABLE
1486	*
1487	* @description:
1488	* A macro that returns true whenever a face object contains a scalable
1489	* font face (true for TrueType, Type~1, Type~42, CID, OpenType/CFF, and
1490	* PFR font formats).
1491	*
1492	*/
1493	#define FT_IS_SCALABLE( face ) \
1494	( !!( (face)->face_flags & FT_FACE_FLAG_SCALABLE ) )
1495
1496
1497	/**************************************************************************
1498	*
1499	* @macro:
1500	* FT_IS_SFNT
1501	*
1502	* @description:
1503	* A macro that returns true whenever a face object contains a font whose
1504	* format is based on the SFNT storage scheme. This usually means:
1505	* TrueType fonts, OpenType fonts, as well as SFNT-based embedded bitmap
1506	* fonts.
1507	*
1508	* If this macro is true, all functions defined in @FT_SFNT_NAMES_H and
1509	* @FT_TRUETYPE_TABLES_H are available.
1510	*
1511	*/
1512	#define FT_IS_SFNT( face ) \
1513	( !!( (face)->face_flags & FT_FACE_FLAG_SFNT ) )
1514
1515
1516	/**************************************************************************
1517	*
1518	* @macro:
1519	* FT_IS_FIXED_WIDTH
1520	*
1521	* @description:
1522	* A macro that returns true whenever a face object contains a font face
1523	* that contains fixed-width (or 'monospace', 'fixed-pitch', etc.)
1524	* glyphs.
1525	*
1526	*/
1527	#define FT_IS_FIXED_WIDTH( face ) \
1528	( !!( (face)->face_flags & FT_FACE_FLAG_FIXED_WIDTH ) )
1529
1530
1531	/**************************************************************************
1532	*
1533	* @macro:
1534	* FT_HAS_FIXED_SIZES
1535	*
1536	* @description:
1537	* A macro that returns true whenever a face object contains some
1538	* embedded bitmaps. See the `available_sizes` field of the @FT_FaceRec
1539	* structure.
1540	*
1541	*/
1542	#define FT_HAS_FIXED_SIZES( face ) \
1543	( !!( (face)->face_flags & FT_FACE_FLAG_FIXED_SIZES ) )
1544
1545
1546	/**************************************************************************
1547	*
1548	* @section:
1549	* other_api_data
1550	*
1551	*/
1552
1553	/**************************************************************************
1554	*
1555	* @macro:
1556	* FT_HAS_FAST_GLYPHS
1557	*
1558	* @description:
1559	* Deprecated.
1560	*
1561	*/
1562	#define FT_HAS_FAST_GLYPHS( face ) 0
1563
1564
1565	/**************************************************************************
1566	*
1567	* @section:
1568	* font_testing_macros
1569	*
1570	*/
1571
1572	/**************************************************************************
1573	*
1574	* @macro:
1575	* FT_HAS_GLYPH_NAMES
1576	*
1577	* @description:
1578	* A macro that returns true whenever a face object contains some glyph
1579	* names that can be accessed through @FT_Get_Glyph_Name.
1580	*
1581	*/
1582	#define FT_HAS_GLYPH_NAMES( face ) \
1583	( !!( (face)->face_flags & FT_FACE_FLAG_GLYPH_NAMES ) )
1584
1585
1586	/**************************************************************************
1587	*
1588	* @macro:
1589	* FT_HAS_MULTIPLE_MASTERS
1590	*
1591	* @description:
1592	* A macro that returns true whenever a face object contains some
1593	* multiple masters. The functions provided by @FT_MULTIPLE_MASTERS_H
1594	* are then available to choose the exact design you want.
1595	*
1596	*/
1597	#define FT_HAS_MULTIPLE_MASTERS( face ) \
1598	( !!( (face)->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS ) )
1599
1600
1601	/**************************************************************************
1602	*
1603	* @macro:
1604	* FT_IS_NAMED_INSTANCE
1605	*
1606	* @description:
1607	* A macro that returns true whenever a face object is a named instance
1608	* of a GX or OpenType variation font.
1609	*
1610	* [Since 2.9] Changing the design coordinates with
1611	* @FT_Set_Var_Design_Coordinates or @FT_Set_Var_Blend_Coordinates does
1612	* not influence the return value of this macro (only
1613	* @FT_Set_Named_Instance does that).
1614	*
1615	* @since:
1616	* 2.7
1617	*
1618	*/
1619	#define FT_IS_NAMED_INSTANCE( face ) \
1620	( !!( (face)->face_index & 0x7FFF0000L ) )
1621
1622
1623	/**************************************************************************
1624	*
1625	* @macro:
1626	* FT_IS_VARIATION
1627	*
1628	* @description:
1629	* A macro that returns true whenever a face object has been altered by
1630	* @FT_Set_MM_Design_Coordinates, @FT_Set_Var_Design_Coordinates,
1631	* @FT_Set_Var_Blend_Coordinates, or @FT_Set_MM_WeightVector.
1632	*
1633	* @since:
1634	* 2.9
1635	*
1636	*/
1637	#define FT_IS_VARIATION( face ) \
1638	( !!( (face)->face_flags & FT_FACE_FLAG_VARIATION ) )
1639
1640
1641	/**************************************************************************
1642	*
1643	* @macro:
1644	* FT_IS_CID_KEYED
1645	*
1646	* @description:
1647	* A macro that returns true whenever a face object contains a CID-keyed
1648	* font. See the discussion of @FT_FACE_FLAG_CID_KEYED for more details.
1649	*
1650	* If this macro is true, all functions defined in @FT_CID_H are
1651	* available.
1652	*
1653	*/
1654	#define FT_IS_CID_KEYED( face ) \
1655	( !!( (face)->face_flags & FT_FACE_FLAG_CID_KEYED ) )
1656
1657
1658	/**************************************************************************
1659	*
1660	* @macro:
1661	* FT_IS_TRICKY
1662	*
1663	* @description:
1664	* A macro that returns true whenever a face represents a 'tricky' font.
1665	* See the discussion of @FT_FACE_FLAG_TRICKY for more details.
1666	*
1667	*/
1668	#define FT_IS_TRICKY( face ) \
1669	( !!( (face)->face_flags & FT_FACE_FLAG_TRICKY ) )
1670
1671
1672	/**************************************************************************
1673	*
1674	* @macro:
1675	* FT_HAS_COLOR
1676	*
1677	* @description:
1678	* A macro that returns true whenever a face object contains tables for
1679	* color glyphs.
1680	*
1681	* @since:
1682	* 2.5.1
1683	*
1684	*/
1685	#define FT_HAS_COLOR( face ) \
1686	( !!( (face)->face_flags & FT_FACE_FLAG_COLOR ) )
1687
1688
1689	/**************************************************************************
1690	*
1691	* @macro:
1692	* FT_HAS_SVG
1693	*
1694	* @description:
1695	* A macro that returns true whenever a face object contains an 'SVG~'
1696	* OpenType table.
1697	*
1698	* @since:
1699	* 2.12
1700	*/
1701	#define FT_HAS_SVG( face ) \
1702	( !!( (face)->face_flags & FT_FACE_FLAG_SVG ) )
1703
1704
1705	/**************************************************************************
1706	*
1707	* @macro:
1708	* FT_HAS_SBIX
1709	*
1710	* @description:
1711	* A macro that returns true whenever a face object contains an 'sbix'
1712	* OpenType table *and* outline glyphs.
1713	*
1714	* Currently, FreeType only supports bitmap glyphs in PNG format for this
1715	* table (i.e., JPEG and TIFF formats are unsupported, as are
1716	* Apple-specific formats not part of the OpenType specification).
1717	*
1718	* @note:
1719	* For backward compatibility, a font with an 'sbix' table is treated as
1720	* a bitmap-only face. Using @FT_Open_Face with
1721	* @FT_PARAM_TAG_IGNORE_SBIX, an application can switch off 'sbix'
1722	* handling so that the face is treated as an ordinary outline font with
1723	* scalable outlines.
1724	*
1725	* Here is some pseudo code that roughly illustrates how to implement
1726	* 'sbix' handling according to the OpenType specification.
1727	*
1728	* ```
1729	* if ( FT_HAS_SBIX( face ) )
1730	* {
1731	* // open font as a scalable one without sbix handling
1732	* FT_Face face2;
1733	* FT_Parameter param = { FT_PARAM_TAG_IGNORE_SBIX, NULL };
1734	* FT_Open_Args args = { FT_OPEN_PARAMS | ...,
1735	* ...,
1736	* 1, &param };
1737	*
1738	*
1739	* FT_Open_Face( library, &args, 0, &face2 );
1740	*
1741	* <sort `face->available_size` as necessary into
1742	* `preferred_sizes`[*]>
1743	*
1744	* for ( i = 0; i < face->num_fixed_sizes; i++ )
1745	* {
1746	* size = preferred_sizes[i].size;
1747	*
1748	* error = FT_Set_Pixel_Sizes( face, size, size );
1749	* <error handling omitted>
1750	*
1751	* // check whether we have a glyph in a bitmap strike
1752	* error = FT_Load_Glyph( face,
1753	* glyph_index,
1754	* FT_LOAD_SBITS_ONLY |
1755	* FT_LOAD_BITMAP_METRICS_ONLY );
1756	* if ( error == FT_Err_Invalid_Argument )
1757	* continue;
1758	* else if ( error )
1759	* <other error handling omitted>
1760	* else
1761	* break;
1762	* }
1763	*
1764	* if ( i != face->num_fixed_sizes )
1765	* <load embedded bitmap with `FT_Load_Glyph`,
1766	* scale it, display it, etc.>
1767	*
1768	* if ( i == face->num_fixed_sizes ||
1769	* FT_HAS_SBIX_OVERLAY( face ) )
1770	* <use `face2` to load outline glyph with `FT_Load_Glyph`,
1771	* scale it, display it on top of the bitmap, etc.>
1772	* }
1773	* ```
1774	*
1775	* [*] Assuming a target value of 400dpi and available strike sizes 100,
1776	* 200, 300, and 400dpi, a possible order might be [400, 200, 300, 100]:
1777	* scaling 200dpi to 400dpi usually gives better results than scaling
1778	* 300dpi to 400dpi; it is also much faster. However, scaling 100dpi to
1779	* 400dpi can yield a too pixelated result, thus the preference might be
1780	* 300dpi over 100dpi.
1781	*
1782	* @since:
1783	* 2.12
1784	*/
1785	#define FT_HAS_SBIX( face ) \
1786	( !!( (face)->face_flags & FT_FACE_FLAG_SBIX ) )
1787
1788
1789	/**************************************************************************
1790	*
1791	* @macro:
1792	* FT_HAS_SBIX_OVERLAY
1793	*
1794	* @description:
1795	* A macro that returns true whenever a face object contains an 'sbix'
1796	* OpenType table with bit~1 in its `flags` field set, instructing the
1797	* application to overlay the bitmap strike with the corresponding
1798	* outline glyph. See @FT_HAS_SBIX for pseudo code how to use it.
1799	*
1800	* @since:
1801	* 2.12
1802	*/
1803	#define FT_HAS_SBIX_OVERLAY( face ) \
1804	( !!( (face)->face_flags & FT_FACE_FLAG_SBIX_OVERLAY ) )
1805
1806
1807	/**************************************************************************
1808	*
1809	* @section:
1810	* face_creation
1811	*
1812	*/
1813
1814	/**************************************************************************
1815	*
1816	* @enum:
1817	* FT_STYLE_FLAG_XXX
1818	*
1819	* @description:
1820	* A list of bit flags to indicate the style of a given face. These are
1821	* used in the `style_flags` field of @FT_FaceRec.
1822	*
1823	* @values:
1824	* FT_STYLE_FLAG_ITALIC ::
1825	* The face style is italic or oblique.
1826	*
1827	* FT_STYLE_FLAG_BOLD ::
1828	* The face is bold.
1829	*
1830	* @note:
1831	* The style information as provided by FreeType is very basic. More
1832	* details are beyond the scope and should be done on a higher level (for
1833	* example, by analyzing various fields of the 'OS/2' table in SFNT based
1834	* fonts).
1835	*/
1836	#define FT_STYLE_FLAG_ITALIC ( 1 << 0 )
1837	#define FT_STYLE_FLAG_BOLD ( 1 << 1 )
1838
1839
1840	/**************************************************************************
1841	*
1842	* @section:
1843	* other_api_data
1844	*
1845	*/
1846
1847	/**************************************************************************
1848	*
1849	* @type:
1850	* FT_Size_Internal
1851	*
1852	* @description:
1853	* An opaque handle to an `FT_Size_InternalRec` structure, used to model
1854	* private data of a given @FT_Size object.
1855	*/
1856	typedef struct FT_Size_InternalRec_* FT_Size_Internal;
1857
1858
1859	/**************************************************************************
1860	*
1861	* @section:
1862	* sizing_and_scaling
1863	*
1864	*/
1865
1866	/**************************************************************************
1867	*
1868	* @struct:
1869	* FT_Size_Metrics
1870	*
1871	* @description:
1872	* The size metrics structure gives the metrics of a size object.
1873	*
1874	* @fields:
1875	* x_ppem ::
1876	* The width of the scaled EM square in pixels, hence the term 'ppem'
1877	* (pixels per EM). It is also referred to as 'nominal width'.
1878	*
1879	* y_ppem ::
1880	* The height of the scaled EM square in pixels, hence the term 'ppem'
1881	* (pixels per EM). It is also referred to as 'nominal height'.
1882	*
1883	* x_scale ::
1884	* A 16.16 fractional scaling value to convert horizontal metrics from
1885	* font units to 26.6 fractional pixels. Only relevant for scalable
1886	* font formats.
1887	*
1888	* y_scale ::
1889	* A 16.16 fractional scaling value to convert vertical metrics from
1890	* font units to 26.6 fractional pixels. Only relevant for scalable
1891	* font formats.
1892	*
1893	* ascender ::
1894	* The ascender in 26.6 fractional pixels, rounded up to an integer
1895	* value. See @FT_FaceRec for the details.
1896	*
1897	* descender ::
1898	* The descender in 26.6 fractional pixels, rounded down to an integer
1899	* value. See @FT_FaceRec for the details.
1900	*
1901	* height ::
1902	* The height in 26.6 fractional pixels, rounded to an integer value.
1903	* See @FT_FaceRec for the details.
1904	*
1905	* max_advance ::
1906	* The maximum advance width in 26.6 fractional pixels, rounded to an
1907	* integer value. See @FT_FaceRec for the details.
1908	*
1909	* @note:
1910	* The scaling values, if relevant, are determined first during a size
1911	* changing operation. The remaining fields are then set by the driver.
1912	* For scalable formats, they are usually set to scaled values of the
1913	* corresponding fields in @FT_FaceRec. Some values like ascender or
1914	* descender are rounded for historical reasons; more precise values (for
1915	* outline fonts) can be derived by scaling the corresponding @FT_FaceRec
1916	* values manually, with code similar to the following.
1917	*
1918	* ```
1919	* scaled_ascender = FT_MulFix( face->ascender,
1920	* size_metrics->y_scale );
1921	* ```
1922	*
1923	* Note that due to glyph hinting and the selected rendering mode these
1924	* values are usually not exact; consequently, they must be treated as
1925	* unreliable with an error margin of at least one pixel!
1926	*
1927	* Indeed, the only way to get the exact metrics is to render _all_
1928	* glyphs. As this would be a definite performance hit, it is up to
1929	* client applications to perform such computations.
1930	*
1931	* The `FT_Size_Metrics` structure is valid for bitmap fonts also.
1932	*
1933	*
1934	* **TrueType fonts with native bytecode hinting**
1935	*
1936	* All applications that handle TrueType fonts with native hinting must
1937	* be aware that TTFs expect different rounding of vertical font
1938	* dimensions. The application has to cater for this, especially if it
1939	* wants to rely on a TTF's vertical data (for example, to properly align
1940	* box characters vertically).
1941	*
1942	* Only the application knows _in advance_ that it is going to use native
1943	* hinting for TTFs! FreeType, on the other hand, selects the hinting
1944	* mode not at the time of creating an @FT_Size object but much later,
1945	* namely while calling @FT_Load_Glyph.
1946	*
1947	* Here is some pseudo code that illustrates a possible solution.
1948	*
1949	* ```
1950	* font_format = FT_Get_Font_Format( face );
1951	*
1952	* if ( !strcmp( font_format, "TrueType" ) &&
1953	* do_native_bytecode_hinting )
1954	* {
1955	* ascender = ROUND( FT_MulFix( face->ascender,
1956	* size_metrics->y_scale ) );
1957	* descender = ROUND( FT_MulFix( face->descender,
1958	* size_metrics->y_scale ) );
1959	* }
1960	* else
1961	* {
1962	* ascender = size_metrics->ascender;
1963	* descender = size_metrics->descender;
1964	* }
1965	*
1966	* height = size_metrics->height;
1967	* max_advance = size_metrics->max_advance;
1968	* ```
1969	*/
1970	typedef struct FT_Size_Metrics_
1971	{
1972	FT_UShort x_ppem; /* horizontal pixels per EM */
1973	FT_UShort y_ppem; /* vertical pixels per EM */
1974
1975	FT_Fixed x_scale; /* scaling values used to convert font */
1976	FT_Fixed y_scale; /* units to 26.6 fractional pixels */
1977
1978	FT_Pos ascender; /* ascender in 26.6 frac. pixels */
1979	FT_Pos descender; /* descender in 26.6 frac. pixels */
1980	FT_Pos height; /* text height in 26.6 frac. pixels */
1981	FT_Pos max_advance; /* max horizontal advance, in 26.6 pixels */
1982
1983	} FT_Size_Metrics;
1984
1985
1986	/**************************************************************************
1987	*
1988	* @struct:
1989	* FT_SizeRec
1990	*
1991	* @description:
1992	* FreeType root size class structure. A size object models a face
1993	* object at a given size.
1994	*
1995	* @fields:
1996	* face ::
1997	* Handle to the parent face object.
1998	*
1999	* generic ::
2000	* A typeless pointer, unused by the FreeType library or any of its
2001	* drivers. It can be used by client applications to link their own
2002	* data to each size object.
2003	*
2004	* metrics ::
2005	* Metrics for this size object. This field is read-only.
2006	*/
2007	typedef struct FT_SizeRec_
2008	{
2009	FT_Face face; /* parent face object */
2010	FT_Generic generic; /* generic pointer for client uses */
2011	FT_Size_Metrics metrics; /* size metrics */
2012	FT_Size_Internal internal;
2013
2014	} FT_SizeRec;
2015
2016
2017	/**************************************************************************
2018	*
2019	* @section:
2020	* other_api_data
2021	*
2022	*/
2023
2024	/**************************************************************************
2025	*
2026	* @struct:
2027	* FT_SubGlyph
2028	*
2029	* @description:
2030	* The subglyph structure is an internal object used to describe
2031	* subglyphs (for example, in the case of composites).
2032	*
2033	* @note:
2034	* The subglyph implementation is not part of the high-level API, hence
2035	* the forward structure declaration.
2036	*
2037	* You can however retrieve subglyph information with
2038	* @FT_Get_SubGlyph_Info.
2039	*/
2040	typedef struct FT_SubGlyphRec_* FT_SubGlyph;
2041
2042
2043	/**************************************************************************
2044	*
2045	* @type:
2046	* FT_Slot_Internal
2047	*
2048	* @description:
2049	* An opaque handle to an `FT_Slot_InternalRec` structure, used to model
2050	* private data of a given @FT_GlyphSlot object.
2051	*/
2052	typedef struct FT_Slot_InternalRec_* FT_Slot_Internal;
2053
2054
2055	/**************************************************************************
2056	*
2057	* @section:
2058	* glyph_retrieval
2059	*
2060	*/
2061
2062	/**************************************************************************
2063	*
2064	* @struct:
2065	* FT_GlyphSlotRec
2066	*
2067	* @description:
2068	* FreeType root glyph slot class structure. A glyph slot is a container
2069	* where individual glyphs can be loaded, be they in outline or bitmap
2070	* format.
2071	*
2072	* @fields:
2073	* library ::
2074	* A handle to the FreeType library instance this slot belongs to.
2075	*
2076	* face ::
2077	* A handle to the parent face object.
2078	*
2079	* next ::
2080	* In some cases (like some font tools), several glyph slots per face
2081	* object can be a good thing. As this is rare, the glyph slots are
2082	* listed through a direct, single-linked list using its `next` field.
2083	*
2084	* glyph_index ::
2085	* [Since 2.10] The glyph index passed as an argument to @FT_Load_Glyph
2086	* while initializing the glyph slot.
2087	*
2088	* generic ::
2089	* A typeless pointer unused by the FreeType library or any of its
2090	* drivers. It can be used by client applications to link their own
2091	* data to each glyph slot object.
2092	*
2093	* metrics ::
2094	* The metrics of the last loaded glyph in the slot. The returned
2095	* values depend on the last load flags (see the @FT_Load_Glyph API
2096	* function) and can be expressed either in 26.6 fractional pixels or
2097	* font units.
2098	*
2099	* Note that even when the glyph image is transformed, the metrics are
2100	* not.
2101	*
2102	* linearHoriAdvance ::
2103	* The advance width of the unhinted glyph. Its value is expressed in
2104	* 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when
2105	* loading the glyph. This field can be important to perform correct
2106	* WYSIWYG layout. Only relevant for scalable glyphs.
2107	*
2108	* linearVertAdvance ::
2109	* The advance height of the unhinted glyph. Its value is expressed in
2110	* 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when
2111	* loading the glyph. This field can be important to perform correct
2112	* WYSIWYG layout. Only relevant for scalable glyphs.
2113	*
2114	* advance ::
2115	* This shorthand is, depending on @FT_LOAD_IGNORE_TRANSFORM, the
2116	* transformed (hinted) advance width for the glyph, in 26.6 fractional
2117	* pixel format. As specified with @FT_LOAD_VERTICAL_LAYOUT, it uses
2118	* either the `horiAdvance` or the `vertAdvance` value of `metrics`
2119	* field.
2120	*
2121	* format ::
2122	* This field indicates the format of the image contained in the glyph
2123	* slot. Typically @FT_GLYPH_FORMAT_BITMAP, @FT_GLYPH_FORMAT_OUTLINE,
2124	* or @FT_GLYPH_FORMAT_COMPOSITE, but other values are possible.
2125	*
2126	* bitmap ::
2127	* This field is used as a bitmap descriptor. Note that the address
2128	* and content of the bitmap buffer can change between calls of
2129	* @FT_Load_Glyph and a few other functions.
2130	*
2131	* bitmap_left ::
2132	* The bitmap's left bearing expressed in integer pixels.
2133	*
2134	* bitmap_top ::
2135	* The bitmap's top bearing expressed in integer pixels. This is the
2136	* distance from the baseline to the top-most glyph scanline, upwards
2137	* y~coordinates being **positive**.
2138	*
2139	* outline ::
2140	* The outline descriptor for the current glyph image if its format is
2141	* @FT_GLYPH_FORMAT_OUTLINE. Once a glyph is loaded, `outline` can be
2142	* transformed, distorted, emboldened, etc. However, it must not be
2143	* freed.
2144	*
2145	* [Since 2.10.1] If @FT_LOAD_NO_SCALE is set, outline coordinates of
2146	* OpenType variation fonts for a selected instance are internally
2147	* handled as 26.6 fractional font units but returned as (rounded)
2148	* integers, as expected. To get unrounded font units, don't use
2149	* @FT_LOAD_NO_SCALE but load the glyph with @FT_LOAD_NO_HINTING and
2150	* scale it, using the font's `units_per_EM` value as the ppem.
2151	*
2152	* num_subglyphs ::
2153	* The number of subglyphs in a composite glyph. This field is only
2154	* valid for the composite glyph format that should normally only be
2155	* loaded with the @FT_LOAD_NO_RECURSE flag.
2156	*
2157	* subglyphs ::
2158	* An array of subglyph descriptors for composite glyphs. There are
2159	* `num_subglyphs` elements in there. Currently internal to FreeType.
2160	*
2161	* control_data ::
2162	* Certain font drivers can also return the control data for a given
2163	* glyph image (e.g. TrueType bytecode, Type~1 charstrings, etc.).
2164	* This field is a pointer to such data; it is currently internal to
2165	* FreeType.
2166	*
2167	* control_len ::
2168	* This is the length in bytes of the control data. Currently internal
2169	* to FreeType.
2170	*
2171	* other ::
2172	* Reserved.
2173	*
2174	* lsb_delta ::
2175	* The difference between hinted and unhinted left side bearing while
2176	* auto-hinting is active. Zero otherwise.
2177	*
2178	* rsb_delta ::
2179	* The difference between hinted and unhinted right side bearing while
2180	* auto-hinting is active. Zero otherwise.
2181	*
2182	* @note:
2183	* If @FT_Load_Glyph is called with default flags (see @FT_LOAD_DEFAULT)
2184	* the glyph image is loaded in the glyph slot in its native format
2185	* (e.g., an outline glyph for TrueType and Type~1 formats). [Since 2.9]
2186	* The prospective bitmap metrics are calculated according to
2187	* @FT_LOAD_TARGET_XXX and other flags even for the outline glyph, even
2188	* if @FT_LOAD_RENDER is not set.
2189	*
2190	* This image can later be converted into a bitmap by calling
2191	* @FT_Render_Glyph. This function searches the current renderer for the
2192	* native image's format, then invokes it.
2193	*
2194	* The renderer is in charge of transforming the native image through the
2195	* slot's face transformation fields, then converting it into a bitmap
2196	* that is returned in `slot->bitmap`.
2197	*
2198	* Note that `slot->bitmap_left` and `slot->bitmap_top` are also used to
2199	* specify the position of the bitmap relative to the current pen
2200	* position (e.g., coordinates (0,0) on the baseline). Of course,
2201	* `slot->format` is also changed to @FT_GLYPH_FORMAT_BITMAP.
2202	*
2203	* Here is a small pseudo code fragment that shows how to use `lsb_delta`
2204	* and `rsb_delta` to do fractional positioning of glyphs:
2205	*
2206	* ```
2207	* FT_GlyphSlot slot = face->glyph;
2208	* FT_Pos origin_x = 0;
2209	*
2210	*
2211	* for all glyphs do
2212	* <load glyph with `FT_Load_Glyph'>
2213	*
2214	* FT_Outline_Translate( slot->outline, origin_x & 63, 0 );
2215	*
2216	* <save glyph image, or render glyph, or ...>
2217	*
2218	* <compute kern between current and next glyph
2219	* and add it to `origin_x'>
2220	*
2221	* origin_x += slot->advance.x;
2222	* origin_x += slot->lsb_delta - slot->rsb_delta;
2223	* endfor
2224	* ```
2225	*
2226	* Here is another small pseudo code fragment that shows how to use
2227	* `lsb_delta` and `rsb_delta` to improve integer positioning of glyphs:
2228	*
2229	* ```
2230	* FT_GlyphSlot slot = face->glyph;
2231	* FT_Pos origin_x = 0;
2232	* FT_Pos prev_rsb_delta = 0;
2233	*
2234	*
2235	* for all glyphs do
2236	* <compute kern between current and previous glyph
2237	* and add it to `origin_x'>
2238	*
2239	* <load glyph with `FT_Load_Glyph'>
2240	*
2241	* if ( prev_rsb_delta - slot->lsb_delta > 32 )
2242	* origin_x -= 64;
2243	* else if ( prev_rsb_delta - slot->lsb_delta < -31 )
2244	* origin_x += 64;
2245	*
2246	* prev_rsb_delta = slot->rsb_delta;
2247	*
2248	* <save glyph image, or render glyph, or ...>
2249	*
2250	* origin_x += slot->advance.x;
2251	* endfor
2252	* ```
2253	*
2254	* If you use strong auto-hinting, you **must** apply these delta values!
2255	* Otherwise you will experience far too large inter-glyph spacing at
2256	* small rendering sizes in most cases. Note that it doesn't harm to use
2257	* the above code for other hinting modes also, since the delta values
2258	* are zero then.
2259	*/
2260	typedef struct FT_GlyphSlotRec_
2261	{
2262	FT_Library library;
2263	FT_Face face;
2264	FT_GlyphSlot next;
2265	FT_UInt glyph_index; /* new in 2.10; was reserved previously */
2266	FT_Generic generic;
2267
2268	FT_Glyph_Metrics metrics;
2269	FT_Fixed linearHoriAdvance;
2270	FT_Fixed linearVertAdvance;
2271	FT_Vector advance;
2272
2273	FT_Glyph_Format format;
2274
2275	FT_Bitmap bitmap;
2276	FT_Int bitmap_left;
2277	FT_Int bitmap_top;
2278
2279	FT_Outline outline;
2280
2281	FT_UInt num_subglyphs;
2282	FT_SubGlyph subglyphs;
2283
2284	void* control_data;
2285	long control_len;
2286
2287	FT_Pos lsb_delta;
2288	FT_Pos rsb_delta;
2289
2290	void* other;
2291
2292	FT_Slot_Internal internal;
2293
2294	} FT_GlyphSlotRec;
2295
2296
2297	/*************************************************************************/
2298	/*************************************************************************/
2299	/* */
2300	/* F U N C T I O N S */
2301	/* */
2302	/*************************************************************************/
2303	/*************************************************************************/
2304
2305
2306	/**************************************************************************
2307	*
2308	* @section:
2309	* library_setup
2310	*
2311	*/
2312
2313	/**************************************************************************
2314	*
2315	* @function:
2316	* FT_Init_FreeType
2317	*
2318	* @description:
2319	* Initialize a new FreeType library object. The set of modules that are
2320	* registered by this function is determined at build time.
2321	*
2322	* @output:
2323	* alibrary ::
2324	* A handle to a new library object.
2325	*
2326	* @return:
2327	* FreeType error code. 0~means success.
2328	*
2329	* @note:
2330	* In case you want to provide your own memory allocating routines, use
2331	* @FT_New_Library instead, followed by a call to @FT_Add_Default_Modules
2332	* (or a series of calls to @FT_Add_Module) and
2333	* @FT_Set_Default_Properties.
2334	*
2335	* See the documentation of @FT_Library and @FT_Face for multi-threading
2336	* issues.
2337	*
2338	* If you need reference-counting (cf. @FT_Reference_Library), use
2339	* @FT_New_Library and @FT_Done_Library.
2340	*
2341	* If compilation option `FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES` is
2342	* set, this function reads the `FREETYPE_PROPERTIES` environment
2343	* variable to control driver properties. See section @properties for
2344	* more.
2345	*/
2346	FT_EXPORT( FT_Error )
2347	FT_Init_FreeType( FT_Library *alibrary );
2348
2349
2350	/**************************************************************************
2351	*
2352	* @function:
2353	* FT_Done_FreeType
2354	*
2355	* @description:
2356	* Destroy a given FreeType library object and all of its children,
2357	* including resources, drivers, faces, sizes, etc.
2358	*
2359	* @input:
2360	* library ::
2361	* A handle to the target library object.
2362	*
2363	* @return:
2364	* FreeType error code. 0~means success.
2365	*/
2366	FT_EXPORT( FT_Error )
2367	FT_Done_FreeType( FT_Library library );
2368
2369
2370	/**************************************************************************
2371	*
2372	* @section:
2373	* face_creation
2374	*
2375	*/
2376
2377	/**************************************************************************
2378	*
2379	* @enum:
2380	* FT_OPEN_XXX
2381	*
2382	* @description:
2383	* A list of bit field constants used within the `flags` field of the
2384	* @FT_Open_Args structure.
2385	*
2386	* @values:
2387	* FT_OPEN_MEMORY ::
2388	* This is a memory-based stream.
2389	*
2390	* FT_OPEN_STREAM ::
2391	* Copy the stream from the `stream` field.
2392	*
2393	* FT_OPEN_PATHNAME ::
2394	* Create a new input stream from a C~path name.
2395	*
2396	* FT_OPEN_DRIVER ::
2397	* Use the `driver` field.
2398	*
2399	* FT_OPEN_PARAMS ::
2400	* Use the `num_params` and `params` fields.
2401	*
2402	* @note:
2403	* The `FT_OPEN_MEMORY`, `FT_OPEN_STREAM`, and `FT_OPEN_PATHNAME` flags
2404	* are mutually exclusive.
2405	*/
2406	#define FT_OPEN_MEMORY 0x1
2407	#define FT_OPEN_STREAM 0x2
2408	#define FT_OPEN_PATHNAME 0x4
2409	#define FT_OPEN_DRIVER 0x8
2410	#define FT_OPEN_PARAMS 0x10
2411
2412
2413	/* these constants are deprecated; use the corresponding `FT_OPEN_XXX` */
2414	/* values instead */
2415	#define ft_open_memory FT_OPEN_MEMORY
2416	#define ft_open_stream FT_OPEN_STREAM
2417	#define ft_open_pathname FT_OPEN_PATHNAME
2418	#define ft_open_driver FT_OPEN_DRIVER
2419	#define ft_open_params FT_OPEN_PARAMS
2420
2421
2422	/**************************************************************************
2423	*
2424	* @struct:
2425	* FT_Parameter
2426	*
2427	* @description:
2428	* A simple structure to pass more or less generic parameters to
2429	* @FT_Open_Face and @FT_Face_Properties.
2430	*
2431	* @fields:
2432	* tag ::
2433	* A four-byte identification tag.
2434	*
2435	* data ::
2436	* A pointer to the parameter data.
2437	*
2438	* @note:
2439	* The ID and function of parameters are driver-specific. See section
2440	* @parameter_tags for more information.
2441	*/
2442	typedef struct FT_Parameter_
2443	{
2444	FT_ULong tag;
2445	FT_Pointer data;
2446
2447	} FT_Parameter;
2448
2449
2450	/**************************************************************************
2451	*
2452	* @struct:
2453	* FT_Open_Args
2454	*
2455	* @description:
2456	* A structure to indicate how to open a new font file or stream. A
2457	* pointer to such a structure can be used as a parameter for the
2458	* functions @FT_Open_Face and @FT_Attach_Stream.
2459	*
2460	* @fields:
2461	* flags ::
2462	* A set of bit flags indicating how to use the structure.
2463	*
2464	* memory_base ::
2465	* The first byte of the file in memory.
2466	*
2467	* memory_size ::
2468	* The size in bytes of the file in memory.
2469	*
2470	* pathname ::
2471	* A pointer to an 8-bit file pathname, which must be a C~string (i.e.,
2472	* no null bytes except at the very end). The pointer is not owned by
2473	* FreeType.
2474	*
2475	* stream ::
2476	* A handle to a source stream object.
2477	*
2478	* driver ::
2479	* This field is exclusively used by @FT_Open_Face; it simply specifies
2480	* the font driver to use for opening the face. If set to `NULL`,
2481	* FreeType tries to load the face with each one of the drivers in its
2482	* list.
2483	*
2484	* num_params ::
2485	* The number of extra parameters.
2486	*
2487	* params ::
2488	* Extra parameters passed to the font driver when opening a new face.
2489	*
2490	* @note:
2491	* The stream type is determined by the contents of `flags`:
2492	*
2493	* If the @FT_OPEN_MEMORY bit is set, assume that this is a memory file
2494	* of `memory_size` bytes, located at `memory_address`. The data are not
2495	* copied, and the client is responsible for releasing and destroying
2496	* them _after_ the corresponding call to @FT_Done_Face.
2497	*
2498	* Otherwise, if the @FT_OPEN_STREAM bit is set, assume that a custom
2499	* input stream `stream` is used.
2500	*
2501	* Otherwise, if the @FT_OPEN_PATHNAME bit is set, assume that this is a
2502	* normal file and use `pathname` to open it.
2503	*
2504	* If none of the above bits are set or if multiple are set at the same
2505	* time, the flags are invalid and @FT_Open_Face fails.
2506	*
2507	* If the @FT_OPEN_DRIVER bit is set, @FT_Open_Face only tries to open
2508	* the file with the driver whose handler is in `driver`.
2509	*
2510	* If the @FT_OPEN_PARAMS bit is set, the parameters given by
2511	* `num_params` and `params` is used. They are ignored otherwise.
2512	*
2513	* Ideally, both the `pathname` and `params` fields should be tagged as
2514	* 'const'; this is missing for API backward compatibility. In other
2515	* words, applications should treat them as read-only.
2516	*/
2517	typedef struct FT_Open_Args_
2518	{
2519	FT_UInt flags;
2520	const FT_Byte* memory_base;
2521	FT_Long memory_size;
2522	FT_String* pathname;
2523	FT_Stream stream;
2524	FT_Module driver;
2525	FT_Int num_params;
2526	FT_Parameter* params;
2527
2528	} FT_Open_Args;
2529
2530
2531	/**************************************************************************
2532	*
2533	* @function:
2534	* FT_New_Face
2535	*
2536	* @description:
2537	* Call @FT_Open_Face to open a font by its pathname.
2538	*
2539	* @inout:
2540	* library ::
2541	* A handle to the library resource.
2542	*
2543	* @input:
2544	* pathname ::
2545	* A path to the font file.
2546	*
2547	* face_index ::
2548	* See @FT_Open_Face for a detailed description of this parameter.
2549	*
2550	* @output:
2551	* aface ::
2552	* A handle to a new face object. If `face_index` is greater than or
2553	* equal to zero, it must be non-`NULL`.
2554	*
2555	* @return:
2556	* FreeType error code. 0~means success.
2557	*
2558	* @note:
2559	* The `pathname` string should be recognizable as such by a standard
2560	* `fopen` call on your system; in particular, this means that `pathname`
2561	* must not contain null bytes. If that is not sufficient to address all
2562	* file name possibilities (for example, to handle wide character file
2563	* names on Windows in UTF-16 encoding) you might use @FT_Open_Face to
2564	* pass a memory array or a stream object instead.
2565	*
2566	* Use @FT_Done_Face to destroy the created @FT_Face object (along with
2567	* its slot and sizes).
2568	*/
2569	FT_EXPORT( FT_Error )
2570	FT_New_Face( FT_Library library,
2571	const char* filepathname,
2572	FT_Long face_index,
2573	FT_Face *aface );
2574
2575
2576	/**************************************************************************
2577	*
2578	* @function:
2579	* FT_New_Memory_Face
2580	*
2581	* @description:
2582	* Call @FT_Open_Face to open a font that has been loaded into memory.
2583	*
2584	* @inout:
2585	* library ::
2586	* A handle to the library resource.
2587	*
2588	* @input:
2589	* file_base ::
2590	* A pointer to the beginning of the font data.
2591	*
2592	* file_size ::
2593	* The size of the memory chunk used by the font data.
2594	*
2595	* face_index ::
2596	* See @FT_Open_Face for a detailed description of this parameter.
2597	*
2598	* @output:
2599	* aface ::
2600	* A handle to a new face object. If `face_index` is greater than or
2601	* equal to zero, it must be non-`NULL`.
2602	*
2603	* @return:
2604	* FreeType error code. 0~means success.
2605	*
2606	* @note:
2607	* You must not deallocate the memory before calling @FT_Done_Face.
2608	*/
2609	FT_EXPORT( FT_Error )
2610	FT_New_Memory_Face( FT_Library library,
2611	const FT_Byte* file_base,
2612	FT_Long file_size,
2613	FT_Long face_index,
2614	FT_Face *aface );
2615
2616
2617	/**************************************************************************
2618	*
2619	* @function:
2620	* FT_Open_Face
2621	*
2622	* @description:
2623	* Create a face object from a given resource described by @FT_Open_Args.
2624	*
2625	* @inout:
2626	* library ::
2627	* A handle to the library resource.
2628	*
2629	* @input:
2630	* args ::
2631	* A pointer to an `FT_Open_Args` structure that must be filled by the
2632	* caller.
2633	*
2634	* face_index ::
2635	* This field holds two different values. Bits 0-15 are the index of
2636	* the face in the font file (starting with value~0). Set it to~0 if
2637	* there is only one face in the font file.
2638	*
2639	* [Since 2.6.1] Bits 16-30 are relevant to GX and OpenType variation
2640	* fonts only, specifying the named instance index for the current face
2641	* index (starting with value~1; value~0 makes FreeType ignore named
2642	* instances). For non-variation fonts, bits 16-30 are ignored.
2643	* Assuming that you want to access the third named instance in face~4,
2644	* `face_index` should be set to 0x00030004. If you want to access
2645	* face~4 without variation handling, simply set `face_index` to
2646	* value~4.
2647	*
2648	* `FT_Open_Face` and its siblings can be used to quickly check whether
2649	* the font format of a given font resource is supported by FreeType.
2650	* In general, if the `face_index` argument is negative, the function's
2651	* return value is~0 if the font format is recognized, or non-zero
2652	* otherwise. The function allocates a more or less empty face handle
2653	* in `*aface` (if `aface` isn't `NULL`); the only two useful fields in
2654	* this special case are `face->num_faces` and `face->style_flags`.
2655	* For any negative value of `face_index`, `face->num_faces` gives the
2656	* number of faces within the font file. For the negative value
2657	* '-(N+1)' (with 'N' a non-negative 16-bit value), bits 16-30 in
2658	* `face->style_flags` give the number of named instances in face 'N'
2659	* if we have a variation font (or zero otherwise). After examination,
2660	* the returned @FT_Face structure should be deallocated with a call to
2661	* @FT_Done_Face.
2662	*
2663	* @output:
2664	* aface ::
2665	* A handle to a new face object. If `face_index` is greater than or
2666	* equal to zero, it must be non-`NULL`.
2667	*
2668	* @return:
2669	* FreeType error code. 0~means success.
2670	*
2671	* @note:
2672	* Unlike FreeType 1.x, this function automatically creates a glyph slot
2673	* for the face object that can be accessed directly through
2674	* `face->glyph`.
2675	*
2676	* Each new face object created with this function also owns a default
2677	* @FT_Size object, accessible as `face->size`.
2678	*
2679	* One @FT_Library instance can have multiple face objects, that is,
2680	* @FT_Open_Face and its siblings can be called multiple times using the
2681	* same `library` argument.
2682	*
2683	* See the discussion of reference counters in the description of
2684	* @FT_Reference_Face.
2685	*
2686	* If `FT_OPEN_STREAM` is set in `args->flags`, the stream in
2687	* `args->stream` is automatically closed before this function returns
2688	* any error (including `FT_Err_Invalid_Argument`).
2689	*
2690	* @example:
2691	* To loop over all faces, use code similar to the following snippet
2692	* (omitting the error handling).
2693	*
2694	* ```
2695	* ...
2696	* FT_Face face;
2697	* FT_Long i, num_faces;
2698	*
2699	*
2700	* error = FT_Open_Face( library, args, -1, &face );
2701	* if ( error ) { ... }
2702	*
2703	* num_faces = face->num_faces;
2704	* FT_Done_Face( face );
2705	*
2706	* for ( i = 0; i < num_faces; i++ )
2707	* {
2708	* ...
2709	* error = FT_Open_Face( library, args, i, &face );
2710	* ...
2711	* FT_Done_Face( face );
2712	* ...
2713	* }
2714	* ```
2715	*
2716	* To loop over all valid values for `face_index`, use something similar
2717	* to the following snippet, again without error handling. The code
2718	* accesses all faces immediately (thus only a single call of
2719	* `FT_Open_Face` within the do-loop), with and without named instances.
2720	*
2721	* ```
2722	* ...
2723	* FT_Face face;
2724	*
2725	* FT_Long num_faces = 0;
2726	* FT_Long num_instances = 0;
2727	*
2728	* FT_Long face_idx = 0;
2729	* FT_Long instance_idx = 0;
2730	*
2731	*
2732	* do
2733	* {
2734	* FT_Long id = ( instance_idx << 16 ) + face_idx;
2735	*
2736	*
2737	* error = FT_Open_Face( library, args, id, &face );
2738	* if ( error ) { ... }
2739	*
2740	* num_faces = face->num_faces;
2741	* num_instances = face->style_flags >> 16;
2742	*
2743	* ...
2744	*
2745	* FT_Done_Face( face );
2746	*
2747	* if ( instance_idx < num_instances )
2748	* instance_idx++;
2749	* else
2750	* {
2751	* face_idx++;
2752	* instance_idx = 0;
2753	* }
2754	*
2755	* } while ( face_idx < num_faces )
2756	* ```
2757	*/
2758	FT_EXPORT( FT_Error )
2759	FT_Open_Face( FT_Library library,
2760	const FT_Open_Args* args,
2761	FT_Long face_index,
2762	FT_Face *aface );
2763
2764
2765	/**************************************************************************
2766	*
2767	* @function:
2768	* FT_Attach_File
2769	*
2770	* @description:
2771	* Call @FT_Attach_Stream to attach a file.
2772	*
2773	* @inout:
2774	* face ::
2775	* The target face object.
2776	*
2777	* @input:
2778	* filepathname ::
2779	* The pathname.
2780	*
2781	* @return:
2782	* FreeType error code. 0~means success.
2783	*/
2784	FT_EXPORT( FT_Error )
2785	FT_Attach_File( FT_Face face,
2786	const char* filepathname );
2787
2788
2789	/**************************************************************************
2790	*
2791	* @function:
2792	* FT_Attach_Stream
2793	*
2794	* @description:
2795	* 'Attach' data to a face object. Normally, this is used to read
2796	* additional information for the face object. For example, you can
2797	* attach an AFM file that comes with a Type~1 font to get the kerning
2798	* values and other metrics.
2799	*
2800	* @inout:
2801	* face ::
2802	* The target face object.
2803	*
2804	* @input:
2805	* parameters ::
2806	* A pointer to @FT_Open_Args that must be filled by the caller.
2807	*
2808	* @return:
2809	* FreeType error code. 0~means success.
2810	*
2811	* @note:
2812	* The meaning of the 'attach' (i.e., what really happens when the new
2813	* file is read) is not fixed by FreeType itself. It really depends on
2814	* the font format (and thus the font driver).
2815	*
2816	* Client applications are expected to know what they are doing when
2817	* invoking this function. Most drivers simply do not implement file or
2818	* stream attachments.
2819	*/
2820	FT_EXPORT( FT_Error )
2821	FT_Attach_Stream( FT_Face face,
2822	const FT_Open_Args* parameters );
2823
2824
2825	/**************************************************************************
2826	*
2827	* @function:
2828	* FT_Reference_Face
2829	*
2830	* @description:
2831	* A counter gets initialized to~1 at the time an @FT_Face structure is
2832	* created. This function increments the counter. @FT_Done_Face then
2833	* only destroys a face if the counter is~1, otherwise it simply
2834	* decrements the counter.
2835	*
2836	* This function helps in managing life-cycles of structures that
2837	* reference @FT_Face objects.
2838	*
2839	* @input:
2840	* face ::
2841	* A handle to a target face object.
2842	*
2843	* @return:
2844	* FreeType error code. 0~means success.
2845	*
2846	* @since:
2847	* 2.4.2
2848	*
2849	*/
2850	FT_EXPORT( FT_Error )
2851	FT_Reference_Face( FT_Face face );
2852
2853
2854	/**************************************************************************
2855	*
2856	* @function:
2857	* FT_Done_Face
2858	*
2859	* @description:
2860	* Discard a given face object, as well as all of its child slots and
2861	* sizes.
2862	*
2863	* @input:
2864	* face ::
2865	* A handle to a target face object.
2866	*
2867	* @return:
2868	* FreeType error code. 0~means success.
2869	*
2870	* @note:
2871	* See the discussion of reference counters in the description of
2872	* @FT_Reference_Face.
2873	*/
2874	FT_EXPORT( FT_Error )
2875	FT_Done_Face( FT_Face face );
2876
2877
2878	/**************************************************************************
2879	*
2880	* @section:
2881	* sizing_and_scaling
2882	*
2883	*/
2884
2885	/**************************************************************************
2886	*
2887	* @function:
2888	* FT_Select_Size
2889	*
2890	* @description:
2891	* Select a bitmap strike. To be more precise, this function sets the
2892	* scaling factors of the active @FT_Size object in a face so that
2893	* bitmaps from this particular strike are taken by @FT_Load_Glyph and
2894	* friends.
2895	*
2896	* @inout:
2897	* face ::
2898	* A handle to a target face object.
2899	*
2900	* @input:
2901	* strike_index ::
2902	* The index of the bitmap strike in the `available_sizes` field of
2903	* @FT_FaceRec structure.
2904	*
2905	* @return:
2906	* FreeType error code. 0~means success.
2907	*
2908	* @note:
2909	* For bitmaps embedded in outline fonts it is common that only a subset
2910	* of the available glyphs at a given ppem value is available. FreeType
2911	* silently uses outlines if there is no bitmap for a given glyph index.
2912	*
2913	* For GX and OpenType variation fonts, a bitmap strike makes sense only
2914	* if the default instance is active (that is, no glyph variation takes
2915	* place); otherwise, FreeType simply ignores bitmap strikes. The same
2916	* is true for all named instances that are different from the default
2917	* instance.
2918	*
2919	* Don't use this function if you are using the FreeType cache API.
2920	*/
2921	FT_EXPORT( FT_Error )
2922	FT_Select_Size( FT_Face face,
2923	FT_Int strike_index );
2924
2925
2926	/**************************************************************************
2927	*
2928	* @enum:
2929	* FT_Size_Request_Type
2930	*
2931	* @description:
2932	* An enumeration type that lists the supported size request types, i.e.,
2933	* what input size (in font units) maps to the requested output size (in
2934	* pixels, as computed from the arguments of @FT_Size_Request).
2935	*
2936	* @values:
2937	* FT_SIZE_REQUEST_TYPE_NOMINAL ::
2938	* The nominal size. The `units_per_EM` field of @FT_FaceRec is used
2939	* to determine both scaling values.
2940	*
2941	* This is the standard scaling found in most applications. In
2942	* particular, use this size request type for TrueType fonts if they
2943	* provide optical scaling or something similar. Note, however, that
2944	* `units_per_EM` is a rather abstract value which bears no relation to
2945	* the actual size of the glyphs in a font.
2946	*
2947	* FT_SIZE_REQUEST_TYPE_REAL_DIM ::
2948	* The real dimension. The sum of the `ascender` and (minus of) the
2949	* `descender` fields of @FT_FaceRec is used to determine both scaling
2950	* values.
2951	*
2952	* FT_SIZE_REQUEST_TYPE_BBOX ::
2953	* The font bounding box. The width and height of the `bbox` field of
2954	* @FT_FaceRec are used to determine the horizontal and vertical
2955	* scaling value, respectively.
2956	*
2957	* FT_SIZE_REQUEST_TYPE_CELL ::
2958	* The `max_advance_width` field of @FT_FaceRec is used to determine
2959	* the horizontal scaling value; the vertical scaling value is
2960	* determined the same way as @FT_SIZE_REQUEST_TYPE_REAL_DIM does.
2961	* Finally, both scaling values are set to the smaller one. This type
2962	* is useful if you want to specify the font size for, say, a window of
2963	* a given dimension and 80x24 cells.
2964	*
2965	* FT_SIZE_REQUEST_TYPE_SCALES ::
2966	* Specify the scaling values directly.
2967	*
2968	* @note:
2969	* The above descriptions only apply to scalable formats. For bitmap
2970	* formats, the behaviour is up to the driver.
2971	*
2972	* See the note section of @FT_Size_Metrics if you wonder how size
2973	* requesting relates to scaling values.
2974	*/
2975	typedef enum FT_Size_Request_Type_
2976	{
2977	FT_SIZE_REQUEST_TYPE_NOMINAL,
2978	FT_SIZE_REQUEST_TYPE_REAL_DIM,
2979	FT_SIZE_REQUEST_TYPE_BBOX,
2980	FT_SIZE_REQUEST_TYPE_CELL,
2981	FT_SIZE_REQUEST_TYPE_SCALES,
2982
2983	FT_SIZE_REQUEST_TYPE_MAX
2984
2985	} FT_Size_Request_Type;
2986
2987
2988	/**************************************************************************
2989	*
2990	* @struct:
2991	* FT_Size_RequestRec
2992	*
2993	* @description:
2994	* A structure to model a size request.
2995	*
2996	* @fields:
2997	* type ::
2998	* See @FT_Size_Request_Type.
2999	*
3000	* width ::
3001	* The desired width, given as a 26.6 fractional point value (with 72pt
3002	* = 1in).
3003	*
3004	* height ::
3005	* The desired height, given as a 26.6 fractional point value (with
3006	* 72pt = 1in).
3007	*
3008	* horiResolution ::
3009	* The horizontal resolution (dpi, i.e., pixels per inch). If set to
3010	* zero, `width` is treated as a 26.6 fractional **pixel** value, which
3011	* gets internally rounded to an integer.
3012	*
3013	* vertResolution ::
3014	* The vertical resolution (dpi, i.e., pixels per inch). If set to
3015	* zero, `height` is treated as a 26.6 fractional **pixel** value,
3016	* which gets internally rounded to an integer.
3017	*
3018	* @note:
3019	* If `width` is zero, the horizontal scaling value is set equal to the
3020	* vertical scaling value, and vice versa.
3021	*
3022	* If `type` is `FT_SIZE_REQUEST_TYPE_SCALES`, `width` and `height` are
3023	* interpreted directly as 16.16 fractional scaling values, without any
3024	* further modification, and both `horiResolution` and `vertResolution`
3025	* are ignored.
3026	*/
3027	typedef struct FT_Size_RequestRec_
3028	{
3029	FT_Size_Request_Type type;
3030	FT_Long width;
3031	FT_Long height;
3032	FT_UInt horiResolution;
3033	FT_UInt vertResolution;
3034
3035	} FT_Size_RequestRec;
3036
3037
3038	/**************************************************************************
3039	*
3040	* @struct:
3041	* FT_Size_Request
3042	*
3043	* @description:
3044	* A handle to a size request structure.
3045	*/
3046	typedef struct FT_Size_RequestRec_ *FT_Size_Request;
3047
3048
3049	/**************************************************************************
3050	*
3051	* @function:
3052	* FT_Request_Size
3053	*
3054	* @description:
3055	* Resize the scale of the active @FT_Size object in a face.
3056	*
3057	* @inout:
3058	* face ::
3059	* A handle to a target face object.
3060	*
3061	* @input:
3062	* req ::
3063	* A pointer to a @FT_Size_RequestRec.
3064	*
3065	* @return:
3066	* FreeType error code. 0~means success.
3067	*
3068	* @note:
3069	* Although drivers may select the bitmap strike matching the request,
3070	* you should not rely on this if you intend to select a particular
3071	* bitmap strike. Use @FT_Select_Size instead in that case.
3072	*
3073	* The relation between the requested size and the resulting glyph size
3074	* is dependent entirely on how the size is defined in the source face.
3075	* The font designer chooses the final size of each glyph relative to
3076	* this size. For more information refer to
3077	* 'https://www.freetype.org/freetype2/docs/glyphs/glyphs-2.html'.
3078	*
3079	* Contrary to @FT_Set_Char_Size, this function doesn't have special code
3080	* to normalize zero-valued widths, heights, or resolutions, which are
3081	* treated as @FT_LOAD_NO_SCALE.
3082	*
3083	* Don't use this function if you are using the FreeType cache API.
3084	*/
3085	FT_EXPORT( FT_Error )
3086	FT_Request_Size( FT_Face face,
3087	FT_Size_Request req );
3088
3089
3090	/**************************************************************************
3091	*
3092	* @function:
3093	* FT_Set_Char_Size
3094	*
3095	* @description:
3096	* Call @FT_Request_Size to request the nominal size (in points).
3097	*
3098	* @inout:
3099	* face ::
3100	* A handle to a target face object.
3101	*
3102	* @input:
3103	* char_width ::
3104	* The nominal width, in 26.6 fractional points.
3105	*
3106	* char_height ::
3107	* The nominal height, in 26.6 fractional points.
3108	*
3109	* horz_resolution ::
3110	* The horizontal resolution in dpi.
3111	*
3112	* vert_resolution ::
3113	* The vertical resolution in dpi.
3114	*
3115	* @return:
3116	* FreeType error code. 0~means success.
3117	*
3118	* @note:
3119	* While this function allows fractional points as input values, the
3120	* resulting ppem value for the given resolution is always rounded to the
3121	* nearest integer.
3122	*
3123	* If either the character width or height is zero, it is set equal to
3124	* the other value.
3125	*
3126	* If either the horizontal or vertical resolution is zero, it is set
3127	* equal to the other value.
3128	*
3129	* A character width or height smaller than 1pt is set to 1pt; if both
3130	* resolution values are zero, they are set to 72dpi.
3131	*
3132	* Don't use this function if you are using the FreeType cache API.
3133	*/
3134	FT_EXPORT( FT_Error )
3135	FT_Set_Char_Size( FT_Face face,
3136	FT_F26Dot6 char_width,
3137	FT_F26Dot6 char_height,
3138	FT_UInt horz_resolution,
3139	FT_UInt vert_resolution );
3140
3141
3142	/**************************************************************************
3143	*
3144	* @function:
3145	* FT_Set_Pixel_Sizes
3146	*
3147	* @description:
3148	* Call @FT_Request_Size to request the nominal size (in pixels).
3149	*
3150	* @inout:
3151	* face ::
3152	* A handle to the target face object.
3153	*
3154	* @input:
3155	* pixel_width ::
3156	* The nominal width, in pixels.
3157	*
3158	* pixel_height ::
3159	* The nominal height, in pixels.
3160	*
3161	* @return:
3162	* FreeType error code. 0~means success.
3163	*
3164	* @note:
3165	* You should not rely on the resulting glyphs matching or being
3166	* constrained to this pixel size. Refer to @FT_Request_Size to
3167	* understand how requested sizes relate to actual sizes.
3168	*
3169	* Don't use this function if you are using the FreeType cache API.
3170	*/
3171	FT_EXPORT( FT_Error )
3172	FT_Set_Pixel_Sizes( FT_Face face,
3173	FT_UInt pixel_width,
3174	FT_UInt pixel_height );
3175
3176
3177	/**************************************************************************
3178	*
3179	* @section:
3180	* glyph_retrieval
3181	*
3182	*/
3183
3184	/**************************************************************************
3185	*
3186	* @function:
3187	* FT_Load_Glyph
3188	*
3189	* @description:
3190	* Load a glyph into the glyph slot of a face object.
3191	*
3192	* @inout:
3193	* face ::
3194	* A handle to the target face object where the glyph is loaded.
3195	*
3196	* @input:
3197	* glyph_index ::
3198	* The index of the glyph in the font file. For CID-keyed fonts
3199	* (either in PS or in CFF format) this argument specifies the CID
3200	* value.
3201	*
3202	* load_flags ::
3203	* A flag indicating what to load for this glyph. The @FT_LOAD_XXX
3204	* flags can be used to control the glyph loading process (e.g.,
3205	* whether the outline should be scaled, whether to load bitmaps or
3206	* not, whether to hint the outline, etc).
3207	*
3208	* @return:
3209	* FreeType error code. 0~means success.
3210	*
3211	* @note:
3212	* For proper scaling and hinting, the active @FT_Size object owned by
3213	* the face has to be meaningfully initialized by calling
3214	* @FT_Set_Char_Size before this function, for example. The loaded
3215	* glyph may be transformed. See @FT_Set_Transform for the details.
3216	*
3217	* For subsetted CID-keyed fonts, `FT_Err_Invalid_Argument` is returned
3218	* for invalid CID values (that is, for CID values that don't have a
3219	* corresponding glyph in the font). See the discussion of the
3220	* @FT_FACE_FLAG_CID_KEYED flag for more details.
3221	*
3222	* If you receive `FT_Err_Glyph_Too_Big`, try getting the glyph outline
3223	* at EM size, then scale it manually and fill it as a graphics
3224	* operation.
3225	*/
3226	FT_EXPORT( FT_Error )
3227	FT_Load_Glyph( FT_Face face,
3228	FT_UInt glyph_index,
3229	FT_Int32 load_flags );
3230
3231
3232	/**************************************************************************
3233	*
3234	* @section:
3235	* character_mapping
3236	*
3237	*/
3238
3239	/**************************************************************************
3240	*
3241	* @function:
3242	* FT_Load_Char
3243	*
3244	* @description:
3245	* Load a glyph into the glyph slot of a face object, accessed by its
3246	* character code.
3247	*
3248	* @inout:
3249	* face ::
3250	* A handle to a target face object where the glyph is loaded.
3251	*
3252	* @input:
3253	* char_code ::
3254	* The glyph's character code, according to the current charmap used in
3255	* the face.
3256	*
3257	* load_flags ::
3258	* A flag indicating what to load for this glyph. The @FT_LOAD_XXX
3259	* constants can be used to control the glyph loading process (e.g.,
3260	* whether the outline should be scaled, whether to load bitmaps or
3261	* not, whether to hint the outline, etc).
3262	*
3263	* @return:
3264	* FreeType error code. 0~means success.
3265	*
3266	* @note:
3267	* This function simply calls @FT_Get_Char_Index and @FT_Load_Glyph.
3268	*
3269	* Many fonts contain glyphs that can't be loaded by this function since
3270	* its glyph indices are not listed in any of the font's charmaps.
3271	*
3272	* If no active cmap is set up (i.e., `face->charmap` is zero), the call
3273	* to @FT_Get_Char_Index is omitted, and the function behaves identically
3274	* to @FT_Load_Glyph.
3275	*/
3276	FT_EXPORT( FT_Error )
3277	FT_Load_Char( FT_Face face,
3278	FT_ULong char_code,
3279	FT_Int32 load_flags );
3280
3281
3282	/**************************************************************************
3283	*
3284	* @section:
3285	* glyph_retrieval
3286	*
3287	*/
3288
3289	/**************************************************************************
3290	*
3291	* @enum:
3292	* FT_LOAD_XXX
3293	*
3294	* @description:
3295	* A list of bit field constants for @FT_Load_Glyph to indicate what kind
3296	* of operations to perform during glyph loading.
3297	*
3298	* @values:
3299	* FT_LOAD_DEFAULT ::
3300	* Corresponding to~0, this value is used as the default glyph load
3301	* operation. In this case, the following happens:
3302	*
3303	* 1. FreeType looks for a bitmap for the glyph corresponding to the
3304	* face's current size. If one is found, the function returns. The
3305	* bitmap data can be accessed from the glyph slot (see note below).
3306	*
3307	* 2. If no embedded bitmap is searched for or found, FreeType looks
3308	* for a scalable outline. If one is found, it is loaded from the font
3309	* file, scaled to device pixels, then 'hinted' to the pixel grid in
3310	* order to optimize it. The outline data can be accessed from the
3311	* glyph slot (see note below).
3312	*
3313	* Note that by default the glyph loader doesn't render outlines into
3314	* bitmaps. The following flags are used to modify this default
3315	* behaviour to more specific and useful cases.
3316	*
3317	* FT_LOAD_NO_SCALE ::
3318	* Don't scale the loaded outline glyph but keep it in font units.
3319	* This flag is also assumed if @FT_Size owned by the face was not
3320	* properly initialized.
3321	*
3322	* This flag implies @FT_LOAD_NO_HINTING and @FT_LOAD_NO_BITMAP, and
3323	* unsets @FT_LOAD_RENDER.
3324	*
3325	* If the font is 'tricky' (see @FT_FACE_FLAG_TRICKY for more), using
3326	* `FT_LOAD_NO_SCALE` usually yields meaningless outlines because the
3327	* subglyphs must be scaled and positioned with hinting instructions.
3328	* This can be solved by loading the font without `FT_LOAD_NO_SCALE`
3329	* and setting the character size to `font->units_per_EM`.
3330	*
3331	* FT_LOAD_NO_HINTING ::
3332	* Disable hinting. This generally generates 'blurrier' bitmap glyphs
3333	* when the glyphs are rendered in any of the anti-aliased modes. See
3334	* also the note below.
3335	*
3336	* This flag is implied by @FT_LOAD_NO_SCALE.
3337	*
3338	* FT_LOAD_RENDER ::
3339	* Call @FT_Render_Glyph after the glyph is loaded. By default, the
3340	* glyph is rendered in @FT_RENDER_MODE_NORMAL mode. This can be
3341	* overridden by @FT_LOAD_TARGET_XXX or @FT_LOAD_MONOCHROME.
3342	*
3343	* This flag is unset by @FT_LOAD_NO_SCALE.
3344	*
3345	* FT_LOAD_NO_BITMAP ::
3346	* Ignore bitmap strikes when loading. Bitmap-only fonts ignore this
3347	* flag.
3348	*
3349	* @FT_LOAD_NO_SCALE always sets this flag.
3350	*
3351	* FT_LOAD_SBITS_ONLY ::
3352	* [Since 2.12] This is the opposite of @FT_LOAD_NO_BITMAP, more or
3353	* less: @FT_Load_Glyph returns `FT_Err_Invalid_Argument` if the face
3354	* contains a bitmap strike for the given size (or the strike selected
3355	* by @FT_Select_Size) but there is no glyph in the strike.
3356	*
3357	* Note that this load flag was part of FreeType since version 2.0.6
3358	* but previously tagged as internal.
3359	*
3360	* FT_LOAD_VERTICAL_LAYOUT ::
3361	* Load the glyph for vertical text layout. In particular, the
3362	* `advance` value in the @FT_GlyphSlotRec structure is set to the
3363	* `vertAdvance` value of the `metrics` field.
3364	*
3365	* In case @FT_HAS_VERTICAL doesn't return true, you shouldn't use this
3366	* flag currently. Reason is that in this case vertical metrics get
3367	* synthesized, and those values are not always consistent across
3368	* various font formats.
3369	*
3370	* FT_LOAD_FORCE_AUTOHINT ::
3371	* Prefer the auto-hinter over the font's native hinter. See also the
3372	* note below.
3373	*
3374	* FT_LOAD_PEDANTIC ::
3375	* Make the font driver perform pedantic verifications during glyph
3376	* loading and hinting. This is mostly used to detect broken glyphs in
3377	* fonts. By default, FreeType tries to handle broken fonts also.
3378	*
3379	* In particular, errors from the TrueType bytecode engine are not
3380	* passed to the application if this flag is not set; this might result
3381	* in partially hinted or distorted glyphs in case a glyph's bytecode
3382	* is buggy.
3383	*
3384	* FT_LOAD_NO_RECURSE ::
3385	* Don't load composite glyphs recursively. Instead, the font driver
3386	* fills the `num_subglyph` and `subglyphs` values of the glyph slot;
3387	* it also sets `glyph->format` to @FT_GLYPH_FORMAT_COMPOSITE. The
3388	* description of subglyphs can then be accessed with
3389	* @FT_Get_SubGlyph_Info.
3390	*
3391	* Don't use this flag for retrieving metrics information since some
3392	* font drivers only return rudimentary data.
3393	*
3394	* This flag implies @FT_LOAD_NO_SCALE and @FT_LOAD_IGNORE_TRANSFORM.
3395	*
3396	* FT_LOAD_IGNORE_TRANSFORM ::
3397	* Ignore the transform matrix set by @FT_Set_Transform.
3398	*
3399	* FT_LOAD_MONOCHROME ::
3400	* This flag is used with @FT_LOAD_RENDER to indicate that you want to
3401	* render an outline glyph to a 1-bit monochrome bitmap glyph, with
3402	* 8~pixels packed into each byte of the bitmap data.
3403	*
3404	* Note that this has no effect on the hinting algorithm used. You
3405	* should rather use @FT_LOAD_TARGET_MONO so that the
3406	* monochrome-optimized hinting algorithm is used.
3407	*
3408	* FT_LOAD_LINEAR_DESIGN ::
3409	* Keep `linearHoriAdvance` and `linearVertAdvance` fields of
3410	* @FT_GlyphSlotRec in font units. See @FT_GlyphSlotRec for details.
3411	*
3412	* FT_LOAD_NO_AUTOHINT ::
3413	* Disable the auto-hinter. See also the note below.
3414	*
3415	* FT_LOAD_COLOR ::
3416	* Load colored glyphs. FreeType searches in the following order;
3417	* there are slight differences depending on the font format.
3418	*
3419	* [Since 2.5] Load embedded color bitmap images (provided
3420	* @FT_LOAD_NO_BITMAP is not set). The resulting color bitmaps, if
3421	* available, have the @FT_PIXEL_MODE_BGRA format, with pre-multiplied
3422	* color channels. If the flag is not set and color bitmaps are found,
3423	* they are converted to 256-level gray bitmaps, using the
3424	* @FT_PIXEL_MODE_GRAY format.
3425	*
3426	* [Since 2.12] If the glyph index maps to an entry in the face's
3427	* 'SVG~' table, load the associated SVG document from this table and
3428	* set the `format` field of @FT_GlyphSlotRec to @FT_GLYPH_FORMAT_SVG
3429	* ([since 2.13.1] provided @FT_LOAD_NO_SVG is not set). Note that
3430	* FreeType itself can't render SVG documents; however, the library
3431	* provides hooks to seamlessly integrate an external renderer. See
3432	* sections @ot_svg_driver and @svg_fonts for more.
3433	*
3434	* [Since 2.10, experimental] If the glyph index maps to an entry in
3435	* the face's 'COLR' table with a 'CPAL' palette table (as defined in
3436	* the OpenType specification), make @FT_Render_Glyph provide a default
3437	* blending of the color glyph layers associated with the glyph index,
3438	* using the same bitmap format as embedded color bitmap images. This
3439	* is mainly for convenience and works only for glyphs in 'COLR' v0
3440	* tables (or glyphs in 'COLR' v1 tables that exclusively use v0
3441	* features). For full control of color layers use
3442	* @FT_Get_Color_Glyph_Layer and FreeType's color functions like
3443	* @FT_Palette_Select instead of setting @FT_LOAD_COLOR for rendering
3444	* so that the client application can handle blending by itself.
3445	*
3446	* FT_LOAD_NO_SVG ::
3447	* [Since 2.13.1] Ignore SVG glyph data when loading.
3448	*
3449	* FT_LOAD_COMPUTE_METRICS ::
3450	* [Since 2.6.1] Compute glyph metrics from the glyph data, without the
3451	* use of bundled metrics tables (for example, the 'hdmx' table in
3452	* TrueType fonts). This flag is mainly used by font validating or
3453	* font editing applications, which need to ignore, verify, or edit
3454	* those tables.
3455	*
3456	* Currently, this flag is only implemented for TrueType fonts.
3457	*
3458	* FT_LOAD_BITMAP_METRICS_ONLY ::
3459	* [Since 2.7.1] Request loading of the metrics and bitmap image
3460	* information of a (possibly embedded) bitmap glyph without allocating
3461	* or copying the bitmap image data itself. No effect if the target
3462	* glyph is not a bitmap image.
3463	*
3464	* This flag unsets @FT_LOAD_RENDER.
3465	*
3466	* FT_LOAD_CROP_BITMAP ::
3467	* Ignored. Deprecated.
3468	*
3469	* FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ::
3470	* Ignored. Deprecated.
3471	*
3472	* @note:
3473	* By default, hinting is enabled and the font's native hinter (see
3474	* @FT_FACE_FLAG_HINTER) is preferred over the auto-hinter. You can
3475	* disable hinting by setting @FT_LOAD_NO_HINTING or change the
3476	* precedence by setting @FT_LOAD_FORCE_AUTOHINT. You can also set
3477	* @FT_LOAD_NO_AUTOHINT in case you don't want the auto-hinter to be used
3478	* at all.
3479	*
3480	* See the description of @FT_FACE_FLAG_TRICKY for a special exception
3481	* (affecting only a handful of Asian fonts).
3482	*
3483	* Besides deciding which hinter to use, you can also decide which
3484	* hinting algorithm to use. See @FT_LOAD_TARGET_XXX for details.
3485	*
3486	* Note that the auto-hinter needs a valid Unicode cmap (either a native
3487	* one or synthesized by FreeType) for producing correct results. If a
3488	* font provides an incorrect mapping (for example, assigning the
3489	* character code U+005A, LATIN CAPITAL LETTER~Z, to a glyph depicting a
3490	* mathematical integral sign), the auto-hinter might produce useless
3491	* results.
3492	*
3493	*/
3494	#define FT_LOAD_DEFAULT 0x0
3495	#define FT_LOAD_NO_SCALE ( 1L << 0 )
3496	#define FT_LOAD_NO_HINTING ( 1L << 1 )
3497	#define FT_LOAD_RENDER ( 1L << 2 )
3498	#define FT_LOAD_NO_BITMAP ( 1L << 3 )
3499	#define FT_LOAD_VERTICAL_LAYOUT ( 1L << 4 )
3500	#define FT_LOAD_FORCE_AUTOHINT ( 1L << 5 )
3501	#define FT_LOAD_CROP_BITMAP ( 1L << 6 )
3502	#define FT_LOAD_PEDANTIC ( 1L << 7 )
3503	#define FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ( 1L << 9 )
3504	#define FT_LOAD_NO_RECURSE ( 1L << 10 )
3505	#define FT_LOAD_IGNORE_TRANSFORM ( 1L << 11 )
3506	#define FT_LOAD_MONOCHROME ( 1L << 12 )
3507	#define FT_LOAD_LINEAR_DESIGN ( 1L << 13 )
3508	#define FT_LOAD_SBITS_ONLY ( 1L << 14 )
3509	#define FT_LOAD_NO_AUTOHINT ( 1L << 15 )
3510	/* Bits 16-19 are used by `FT_LOAD_TARGET_` */
3511	#define FT_LOAD_COLOR ( 1L << 20 )
3512	#define FT_LOAD_COMPUTE_METRICS ( 1L << 21 )
3513	#define FT_LOAD_BITMAP_METRICS_ONLY ( 1L << 22 )
3514	#define FT_LOAD_NO_SVG ( 1L << 24 )
3515
3516	/* */
3517
3518	/* used internally only by certain font drivers */
3519	#define FT_LOAD_ADVANCE_ONLY ( 1L << 8 )
3520	#define FT_LOAD_SVG_ONLY ( 1L << 23 )
3521
3522
3523	/**************************************************************************
3524	*
3525	* @enum:
3526	* FT_LOAD_TARGET_XXX
3527	*
3528	* @description:
3529	* A list of values to select a specific hinting algorithm for the
3530	* hinter. You should OR one of these values to your `load_flags` when
3531	* calling @FT_Load_Glyph.
3532	*
3533	* Note that a font's native hinters may ignore the hinting algorithm you
3534	* have specified (e.g., the TrueType bytecode interpreter). You can set
3535	* @FT_LOAD_FORCE_AUTOHINT to ensure that the auto-hinter is used.
3536	*
3537	* @values:
3538	* FT_LOAD_TARGET_NORMAL ::
3539	* The default hinting algorithm, optimized for standard gray-level
3540	* rendering. For monochrome output, use @FT_LOAD_TARGET_MONO instead.
3541	*
3542	* FT_LOAD_TARGET_LIGHT ::
3543	* A lighter hinting algorithm for gray-level modes. Many generated
3544	* glyphs are fuzzier but better resemble their original shape. This
3545	* is achieved by snapping glyphs to the pixel grid only vertically
3546	* (Y-axis), as is done by FreeType's new CFF engine or Microsoft's
3547	* ClearType font renderer. This preserves inter-glyph spacing in
3548	* horizontal text. The snapping is done either by the native font
3549	* driver, if the driver itself and the font support it, or by the
3550	* auto-hinter.
3551	*
3552	* Advance widths are rounded to integer values; however, using the
3553	* `lsb_delta` and `rsb_delta` fields of @FT_GlyphSlotRec, it is
3554	* possible to get fractional advance widths for subpixel positioning
3555	* (which is recommended to use).
3556	*
3557	* If configuration option `AF_CONFIG_OPTION_TT_SIZE_METRICS` is
3558	* active, TrueType-like metrics are used to make this mode behave
3559	* similarly as in unpatched FreeType versions between 2.4.6 and 2.7.1
3560	* (inclusive).
3561	*
3562	* FT_LOAD_TARGET_MONO ::
3563	* Strong hinting algorithm that should only be used for monochrome
3564	* output. The result is probably unpleasant if the glyph is rendered
3565	* in non-monochrome modes.
3566	*
3567	* Note that for outline fonts only the TrueType font driver has proper
3568	* monochrome hinting support, provided the TTFs contain hints for B/W
3569	* rendering (which most fonts no longer provide). If these conditions
3570	* are not met it is very likely that you get ugly results at smaller
3571	* sizes.
3572	*
3573	* FT_LOAD_TARGET_LCD ::
3574	* A variant of @FT_LOAD_TARGET_LIGHT optimized for horizontally
3575	* decimated LCD displays.
3576	*
3577	* FT_LOAD_TARGET_LCD_V ::
3578	* A variant of @FT_LOAD_TARGET_NORMAL optimized for vertically
3579	* decimated LCD displays.
3580	*
3581	* @note:
3582	* You should use only _one_ of the `FT_LOAD_TARGET_XXX` values in your
3583	* `load_flags`. They can't be ORed.
3584	*
3585	* If @FT_LOAD_RENDER is also set, the glyph is rendered in the
3586	* corresponding mode (i.e., the mode that matches the used algorithm
3587	* best). An exception is `FT_LOAD_TARGET_MONO` since it implies
3588	* @FT_LOAD_MONOCHROME.
3589	*
3590	* You can use a hinting algorithm that doesn't correspond to the same
3591	* rendering mode. As an example, it is possible to use the 'light'
3592	* hinting algorithm and have the results rendered in horizontal LCD
3593	* pixel mode, with code like
3594	*
3595	* ```
3596	* FT_Load_Glyph( face, glyph_index,
3597	* load_flags | FT_LOAD_TARGET_LIGHT );
3598	*
3599	* FT_Render_Glyph( face->glyph, FT_RENDER_MODE_LCD );
3600	* ```
3601	*
3602	* In general, you should stick with one rendering mode. For example,
3603	* switching between @FT_LOAD_TARGET_NORMAL and @FT_LOAD_TARGET_MONO
3604	* enforces a lot of recomputation for TrueType fonts, which is slow.
3605	* Another reason is caching: Selecting a different mode usually causes
3606	* changes in both the outlines and the rasterized bitmaps; it is thus
3607	* necessary to empty the cache after a mode switch to avoid false hits.
3608	*
3609	*/
3610	#define FT_LOAD_TARGET_( x ) ( FT_STATIC_CAST( FT_Int32, (x) & 15 ) << 16 )
3611
3612	#define FT_LOAD_TARGET_NORMAL FT_LOAD_TARGET_( FT_RENDER_MODE_NORMAL )
3613	#define FT_LOAD_TARGET_LIGHT FT_LOAD_TARGET_( FT_RENDER_MODE_LIGHT )
3614	#define FT_LOAD_TARGET_MONO FT_LOAD_TARGET_( FT_RENDER_MODE_MONO )
3615	#define FT_LOAD_TARGET_LCD FT_LOAD_TARGET_( FT_RENDER_MODE_LCD )
3616	#define FT_LOAD_TARGET_LCD_V FT_LOAD_TARGET_( FT_RENDER_MODE_LCD_V )
3617
3618
3619	/**************************************************************************
3620	*
3621	* @macro:
3622	* FT_LOAD_TARGET_MODE
3623	*
3624	* @description:
3625	* Return the @FT_Render_Mode corresponding to a given
3626	* @FT_LOAD_TARGET_XXX value.
3627	*
3628	*/
3629	#define FT_LOAD_TARGET_MODE( x ) \
3630	FT_STATIC_CAST( FT_Render_Mode, ( (x) >> 16 ) & 15 )
3631
3632
3633	/**************************************************************************
3634	*
3635	* @section:
3636	* sizing_and_scaling
3637	*
3638	*/
3639
3640	/**************************************************************************
3641	*
3642	* @function:
3643	* FT_Set_Transform
3644	*
3645	* @description:
3646	* Set the transformation that is applied to glyph images when they are
3647	* loaded into a glyph slot through @FT_Load_Glyph.
3648	*
3649	* @inout:
3650	* face ::
3651	* A handle to the source face object.
3652	*
3653	* @input:
3654	* matrix ::
3655	* A pointer to the transformation's 2x2 matrix. Use `NULL` for the
3656	* identity matrix.
3657	* delta ::
3658	* A pointer to the translation vector. Use `NULL` for the null
3659	* vector.
3660	*
3661	* @note:
3662	* This function is provided as a convenience, but keep in mind that
3663	* @FT_Matrix coefficients are only 16.16 fixed-point values, which can
3664	* limit the accuracy of the results. Using floating-point computations
3665	* to perform the transform directly in client code instead will always
3666	* yield better numbers.
3667	*
3668	* The transformation is only applied to scalable image formats after the
3669	* glyph has been loaded. It means that hinting is unaltered by the
3670	* transformation and is performed on the character size given in the
3671	* last call to @FT_Set_Char_Size or @FT_Set_Pixel_Sizes.
3672	*
3673	* Note that this also transforms the `face.glyph.advance` field, but
3674	* **not** the values in `face.glyph.metrics`.
3675	*/
3676	FT_EXPORT( void )
3677	FT_Set_Transform( FT_Face face,
3678	FT_Matrix* matrix,
3679	FT_Vector* delta );
3680
3681
3682	/**************************************************************************
3683	*
3684	* @function:
3685	* FT_Get_Transform
3686	*
3687	* @description:
3688	* Return the transformation that is applied to glyph images when they
3689	* are loaded into a glyph slot through @FT_Load_Glyph. See
3690	* @FT_Set_Transform for more details.
3691	*
3692	* @input:
3693	* face ::
3694	* A handle to the source face object.
3695	*
3696	* @output:
3697	* matrix ::
3698	* A pointer to a transformation's 2x2 matrix. Set this to NULL if you
3699	* are not interested in the value.
3700	*
3701	* delta ::
3702	* A pointer to a translation vector. Set this to NULL if you are not
3703	* interested in the value.
3704	*
3705	* @since:
3706	* 2.11
3707	*
3708	*/
3709	FT_EXPORT( void )
3710	FT_Get_Transform( FT_Face face,
3711	FT_Matrix* matrix,
3712	FT_Vector* delta );
3713
3714
3715	/**************************************************************************
3716	*
3717	* @section:
3718	* glyph_retrieval
3719	*
3720	*/
3721
3722	/**************************************************************************
3723	*
3724	* @enum:
3725	* FT_Render_Mode
3726	*
3727	* @description:
3728	* Render modes supported by FreeType~2. Each mode corresponds to a
3729	* specific type of scanline conversion performed on the outline.
3730	*
3731	* For bitmap fonts and embedded bitmaps the `bitmap->pixel_mode` field
3732	* in the @FT_GlyphSlotRec structure gives the format of the returned
3733	* bitmap.
3734	*
3735	* All modes except @FT_RENDER_MODE_MONO use 256 levels of opacity,
3736	* indicating pixel coverage. Use linear alpha blending and gamma
3737	* correction to correctly render non-monochrome glyph bitmaps onto a
3738	* surface; see @FT_Render_Glyph.
3739	*
3740	* The @FT_RENDER_MODE_SDF is a special render mode that uses up to 256
3741	* distance values, indicating the signed distance from the grid position
3742	* to the nearest outline.
3743	*
3744	* @values:
3745	* FT_RENDER_MODE_NORMAL ::
3746	* Default render mode; it corresponds to 8-bit anti-aliased bitmaps.
3747	*
3748	* FT_RENDER_MODE_LIGHT ::
3749	* This is equivalent to @FT_RENDER_MODE_NORMAL. It is only defined as
3750	* a separate value because render modes are also used indirectly to
3751	* define hinting algorithm selectors. See @FT_LOAD_TARGET_XXX for
3752	* details.
3753	*
3754	* FT_RENDER_MODE_MONO ::
3755	* This mode corresponds to 1-bit bitmaps (with 2~levels of opacity).
3756	*
3757	* FT_RENDER_MODE_LCD ::
3758	* This mode corresponds to horizontal RGB and BGR subpixel displays
3759	* like LCD screens. It produces 8-bit bitmaps that are 3~times the
3760	* width of the original glyph outline in pixels, and which use the
3761	* @FT_PIXEL_MODE_LCD mode.
3762	*
3763	* FT_RENDER_MODE_LCD_V ::
3764	* This mode corresponds to vertical RGB and BGR subpixel displays
3765	* (like PDA screens, rotated LCD displays, etc.). It produces 8-bit
3766	* bitmaps that are 3~times the height of the original glyph outline in
3767	* pixels and use the @FT_PIXEL_MODE_LCD_V mode.
3768	*
3769	* FT_RENDER_MODE_SDF ::
3770	* This mode corresponds to 8-bit, single-channel signed distance field
3771	* (SDF) bitmaps. Each pixel in the SDF grid is the value from the
3772	* pixel's position to the nearest glyph's outline. The distances are
3773	* calculated from the center of the pixel and are positive if they are
3774	* filled by the outline (i.e., inside the outline) and negative
3775	* otherwise. Check the note below on how to convert the output values
3776	* to usable data.
3777	*
3778	* @note:
3779	* The selected render mode only affects vector glyphs of a font.
3780	* Embedded bitmaps often have a different pixel mode like
3781	* @FT_PIXEL_MODE_MONO. You can use @FT_Bitmap_Convert to transform them
3782	* into 8-bit pixmaps.
3783	*
3784	* For @FT_RENDER_MODE_SDF the output bitmap buffer contains normalized
3785	* distances that are packed into unsigned 8-bit values. To get pixel
3786	* values in floating point representation use the following pseudo-C
3787	* code for the conversion.
3788	*
3789	* ```
3790	* // Load glyph and render using FT_RENDER_MODE_SDF,
3791	* // then use the output buffer as follows.
3792	*
3793	* ...
3794	* FT_Byte buffer = glyph->bitmap->buffer;
3795	*
3796	*
3797	* for pixel in buffer
3798	* {
3799	* // `sd` is the signed distance and `spread` is the current spread;
3800	* // the default spread is 2 and can be changed.
3801	*
3802	* float sd = (float)pixel - 128.0f;
3803	*
3804	*
3805	* // Convert to pixel values.
3806	* sd = ( sd / 128.0f ) * spread;
3807	*
3808	* // Store `sd` in a buffer or use as required.
3809	* }
3810	*
3811	* ```
3812	*
3813	* FreeType has two rasterizers for generating SDF, namely:
3814	*
3815	* 1. `sdf` for generating SDF directly from glyph's outline, and
3816	*
3817	* 2. `bsdf` for generating SDF from rasterized bitmaps.
3818	*
3819	* Depending on the glyph type (i.e., outline or bitmap), one of the two
3820	* rasterizers is chosen at runtime and used for generating SDFs. To
3821	* force the use of `bsdf` you should render the glyph with any of the
3822	* FreeType's other rendering modes (e.g., `FT_RENDER_MODE_NORMAL`) and
3823	* then re-render with `FT_RENDER_MODE_SDF`.
3824	*
3825	* There are some issues with stability and possible failures of the SDF
3826	* renderers (specifically `sdf`).
3827	*
3828	* 1. The `sdf` rasterizer is sensitive to really small features (e.g.,
3829	* sharp turns that are less than 1~pixel) and imperfections in the
3830	* glyph's outline, causing artifacts in the final output.
3831	*
3832	* 2. The `sdf` rasterizer has limited support for handling intersecting
3833	* contours and *cannot* handle self-intersecting contours whatsoever.
3834	* Self-intersection happens when a single connected contour
3835	* intersects itself at some point; having these in your font
3836	* definitely poses a problem to the rasterizer and cause artifacts,
3837	* too.
3838	*
3839	* 3. Generating SDF for really small glyphs may result in undesirable
3840	* output; the pixel grid (which stores distance information) becomes
3841	* too coarse.
3842	*
3843	* 4. Since the output buffer is normalized, precision at smaller spreads
3844	* is greater than precision at larger spread values because the
3845	* output range of [0..255] gets mapped to a smaller SDF range. A
3846	* spread of~2 should be sufficient in most cases.
3847	*
3848	* Points (1) and (2) can be avoided by using the `bsdf` rasterizer,
3849	* which is more stable than the `sdf` rasterizer in general.
3850	*
3851	*/
3852	typedef enum FT_Render_Mode_
3853	{
3854	FT_RENDER_MODE_NORMAL = 0,
3855	FT_RENDER_MODE_LIGHT,
3856	FT_RENDER_MODE_MONO,
3857	FT_RENDER_MODE_LCD,
3858	FT_RENDER_MODE_LCD_V,
3859	FT_RENDER_MODE_SDF,
3860
3861	FT_RENDER_MODE_MAX
3862
3863	} FT_Render_Mode;
3864
3865
3866	/* these constants are deprecated; use the corresponding */
3867	/* `FT_Render_Mode` values instead */
3868	#define ft_render_mode_normal FT_RENDER_MODE_NORMAL
3869	#define ft_render_mode_mono FT_RENDER_MODE_MONO
3870
3871
3872	/**************************************************************************
3873	*
3874	* @function:
3875	* FT_Render_Glyph
3876	*
3877	* @description:
3878	* Convert a given glyph image to a bitmap. It does so by inspecting the
3879	* glyph image format, finding the relevant renderer, and invoking it.
3880	*
3881	* @inout:
3882	* slot ::
3883	* A handle to the glyph slot containing the image to convert.
3884	*
3885	* @input:
3886	* render_mode ::
3887	* The render mode used to render the glyph image into a bitmap. See
3888	* @FT_Render_Mode for a list of possible values.
3889	*
3890	* If @FT_RENDER_MODE_NORMAL is used, a previous call of @FT_Load_Glyph
3891	* with flag @FT_LOAD_COLOR makes `FT_Render_Glyph` provide a default
3892	* blending of colored glyph layers associated with the current glyph
3893	* slot (provided the font contains such layers) instead of rendering
3894	* the glyph slot's outline. This is an experimental feature; see
3895	* @FT_LOAD_COLOR for more information.
3896	*
3897	* @return:
3898	* FreeType error code. 0~means success.
3899	*
3900	* @note:
3901	* When FreeType outputs a bitmap of a glyph, it really outputs an alpha
3902	* coverage map. If a pixel is completely covered by a filled-in
3903	* outline, the bitmap contains 0xFF at that pixel, meaning that
3904	* 0xFF/0xFF fraction of that pixel is covered, meaning the pixel is 100%
3905	* black (or 0% bright). If a pixel is only 50% covered (value 0x80),
3906	* the pixel is made 50% black (50% bright or a middle shade of grey).
3907	* 0% covered means 0% black (100% bright or white).
3908	*
3909	* On high-DPI screens like on smartphones and tablets, the pixels are so
3910	* small that their chance of being completely covered and therefore
3911	* completely black are fairly good. On the low-DPI screens, however,
3912	* the situation is different. The pixels are too large for most of the
3913	* details of a glyph and shades of gray are the norm rather than the
3914	* exception.
3915	*
3916	* This is relevant because all our screens have a second problem: they
3917	* are not linear. 1~+~1 is not~2. Twice the value does not result in
3918	* twice the brightness. When a pixel is only 50% covered, the coverage
3919	* map says 50% black, and this translates to a pixel value of 128 when
3920	* you use 8~bits per channel (0-255). However, this does not translate
3921	* to 50% brightness for that pixel on our sRGB and gamma~2.2 screens.
3922	* Due to their non-linearity, they dwell longer in the darks and only a
3923	* pixel value of about 186 results in 50% brightness -- 128 ends up too
3924	* dark on both bright and dark backgrounds. The net result is that dark
3925	* text looks burnt-out, pixely and blotchy on bright background, bright
3926	* text too frail on dark backgrounds, and colored text on colored
3927	* background (for example, red on green) seems to have dark halos or
3928	* 'dirt' around it. The situation is especially ugly for diagonal stems
3929	* like in 'w' glyph shapes where the quality of FreeType's anti-aliasing
3930	* depends on the correct display of grays. On high-DPI screens where
3931	* smaller, fully black pixels reign supreme, this doesn't matter, but on
3932	* our low-DPI screens with all the gray shades, it does. 0% and 100%
3933	* brightness are the same things in linear and non-linear space, just
3934	* all the shades in-between aren't.
3935	*
3936	* The blending function for placing text over a background is
3937	*
3938	* ```
3939	* dst = alpha * src + (1 - alpha) * dst ,
3940	* ```
3941	*
3942	* which is known as the OVER operator.
3943	*
3944	* To correctly composite an anti-aliased pixel of a glyph onto a
3945	* surface,
3946	*
3947	* 1. take the foreground and background colors (e.g., in sRGB space)
3948	* and apply gamma to get them in a linear space,
3949	*
3950	* 2. use OVER to blend the two linear colors using the glyph pixel
3951	* as the alpha value (remember, the glyph bitmap is an alpha coverage
3952	* bitmap), and
3953	*
3954	* 3. apply inverse gamma to the blended pixel and write it back to
3955	* the image.
3956	*
3957	* Internal testing at Adobe found that a target inverse gamma of~1.8 for
3958	* step~3 gives good results across a wide range of displays with an sRGB
3959	* gamma curve or a similar one.
3960	*
3961	* This process can cost performance. There is an approximation that
3962	* does not need to know about the background color; see
3963	* https://bel.fi/alankila/lcd/ and
3964	* https://bel.fi/alankila/lcd/alpcor.html for details.
3965	*
3966	* **ATTENTION**: Linear blending is even more important when dealing
3967	* with subpixel-rendered glyphs to prevent color-fringing! A
3968	* subpixel-rendered glyph must first be filtered with a filter that
3969	* gives equal weight to the three color primaries and does not exceed a
3970	* sum of 0x100, see section @lcd_rendering. Then the only difference to
3971	* gray linear blending is that subpixel-rendered linear blending is done
3972	* 3~times per pixel: red foreground subpixel to red background subpixel
3973	* and so on for green and blue.
3974	*/
3975	FT_EXPORT( FT_Error )
3976	FT_Render_Glyph( FT_GlyphSlot slot,
3977	FT_Render_Mode render_mode );
3978
3979
3980	/**************************************************************************
3981	*
3982	* @enum:
3983	* FT_Kerning_Mode
3984	*
3985	* @description:
3986	* An enumeration to specify the format of kerning values returned by
3987	* @FT_Get_Kerning.
3988	*
3989	* @values:
3990	* FT_KERNING_DEFAULT ::
3991	* Return grid-fitted kerning distances in 26.6 fractional pixels.
3992	*
3993	* FT_KERNING_UNFITTED ::
3994	* Return un-grid-fitted kerning distances in 26.6 fractional pixels.
3995	*
3996	* FT_KERNING_UNSCALED ::
3997	* Return the kerning vector in original font units.
3998	*
3999	* @note:
4000	* `FT_KERNING_DEFAULT` returns full pixel values; it also makes FreeType
4001	* heuristically scale down kerning distances at small ppem values so
4002	* that they don't become too big.
4003	*
4004	* Both `FT_KERNING_DEFAULT` and `FT_KERNING_UNFITTED` use the current
4005	* horizontal scaling factor (as set e.g. with @FT_Set_Char_Size) to
4006	* convert font units to pixels.
4007	*/
4008	typedef enum FT_Kerning_Mode_
4009	{
4010	FT_KERNING_DEFAULT = 0,
4011	FT_KERNING_UNFITTED,
4012	FT_KERNING_UNSCALED
4013
4014	} FT_Kerning_Mode;
4015
4016
4017	/* these constants are deprecated; use the corresponding */
4018	/* `FT_Kerning_Mode` values instead */
4019	#define ft_kerning_default FT_KERNING_DEFAULT
4020	#define ft_kerning_unfitted FT_KERNING_UNFITTED
4021	#define ft_kerning_unscaled FT_KERNING_UNSCALED
4022
4023
4024	/**************************************************************************
4025	*
4026	* @function:
4027	* FT_Get_Kerning
4028	*
4029	* @description:
4030	* Return the kerning vector between two glyphs of the same face.
4031	*
4032	* @input:
4033	* face ::
4034	* A handle to a source face object.
4035	*
4036	* left_glyph ::
4037	* The index of the left glyph in the kern pair.
4038	*
4039	* right_glyph ::
4040	* The index of the right glyph in the kern pair.
4041	*
4042	* kern_mode ::
4043	* See @FT_Kerning_Mode for more information. Determines the scale and
4044	* dimension of the returned kerning vector.
4045	*
4046	* @output:
4047	* akerning ::
4048	* The kerning vector. This is either in font units, fractional pixels
4049	* (26.6 format), or pixels for scalable formats, and in pixels for
4050	* fixed-sizes formats.
4051	*
4052	* @return:
4053	* FreeType error code. 0~means success.
4054	*
4055	* @note:
4056	* Only horizontal layouts (left-to-right & right-to-left) are supported
4057	* by this method. Other layouts, or more sophisticated kernings, are
4058	* out of the scope of this API function -- they can be implemented
4059	* through format-specific interfaces.
4060	*
4061	* Kerning for OpenType fonts implemented in a 'GPOS' table is not
4062	* supported; use @FT_HAS_KERNING to find out whether a font has data
4063	* that can be extracted with `FT_Get_Kerning`.
4064	*/
4065	FT_EXPORT( FT_Error )
4066	FT_Get_Kerning( FT_Face face,
4067	FT_UInt left_glyph,
4068	FT_UInt right_glyph,
4069	FT_UInt kern_mode,
4070	FT_Vector *akerning );
4071
4072
4073	/**************************************************************************
4074	*
4075	* @function:
4076	* FT_Get_Track_Kerning
4077	*
4078	* @description:
4079	* Return the track kerning for a given face object at a given size.
4080	*
4081	* @input:
4082	* face ::
4083	* A handle to a source face object.
4084	*
4085	* point_size ::
4086	* The point size in 16.16 fractional points.
4087	*
4088	* degree ::
4089	* The degree of tightness. Increasingly negative values represent
4090	* tighter track kerning, while increasingly positive values represent
4091	* looser track kerning. Value zero means no track kerning.
4092	*
4093	* @output:
4094	* akerning ::
4095	* The kerning in 16.16 fractional points, to be uniformly applied
4096	* between all glyphs.
4097	*
4098	* @return:
4099	* FreeType error code. 0~means success.
4100	*
4101	* @note:
4102	* Currently, only the Type~1 font driver supports track kerning, using
4103	* data from AFM files (if attached with @FT_Attach_File or
4104	* @FT_Attach_Stream).
4105	*
4106	* Only very few AFM files come with track kerning data; please refer to
4107	* Adobe's AFM specification for more details.
4108	*/
4109	FT_EXPORT( FT_Error )
4110	FT_Get_Track_Kerning( FT_Face face,
4111	FT_Fixed point_size,
4112	FT_Int degree,
4113	FT_Fixed* akerning );
4114
4115
4116	/**************************************************************************
4117	*
4118	* @section:
4119	* character_mapping
4120	*
4121	*/
4122
4123	/**************************************************************************
4124	*
4125	* @function:
4126	* FT_Select_Charmap
4127	*
4128	* @description:
4129	* Select a given charmap by its encoding tag (as listed in
4130	* `freetype.h`).
4131	*
4132	* @inout:
4133	* face ::
4134	* A handle to the source face object.
4135	*
4136	* @input:
4137	* encoding ::
4138	* A handle to the selected encoding.
4139	*
4140	* @return:
4141	* FreeType error code. 0~means success.
4142	*
4143	* @note:
4144	* This function returns an error if no charmap in the face corresponds
4145	* to the encoding queried here.
4146	*
4147	* Because many fonts contain more than a single cmap for Unicode
4148	* encoding, this function has some special code to select the one that
4149	* covers Unicode best ('best' in the sense that a UCS-4 cmap is
4150	* preferred to a UCS-2 cmap). It is thus preferable to @FT_Set_Charmap
4151	* in this case.
4152	*/
4153	FT_EXPORT( FT_Error )
4154	FT_Select_Charmap( FT_Face face,
4155	FT_Encoding encoding );
4156
4157
4158	/**************************************************************************
4159	*
4160	* @function:
4161	* FT_Set_Charmap
4162	*
4163	* @description:
4164	* Select a given charmap for character code to glyph index mapping.
4165	*
4166	* @inout:
4167	* face ::
4168	* A handle to the source face object.
4169	*
4170	* @input:
4171	* charmap ::
4172	* A handle to the selected charmap.
4173	*
4174	* @return:
4175	* FreeType error code. 0~means success.
4176	*
4177	* @note:
4178	* This function returns an error if the charmap is not part of the face
4179	* (i.e., if it is not listed in the `face->charmaps` table).
4180	*
4181	* It also fails if an OpenType type~14 charmap is selected (which
4182	* doesn't map character codes to glyph indices at all).
4183	*/
4184	FT_EXPORT( FT_Error )
4185	FT_Set_Charmap( FT_Face face,
4186	FT_CharMap charmap );
4187
4188
4189	/**************************************************************************
4190	*
4191	* @function:
4192	* FT_Get_Charmap_Index
4193	*
4194	* @description:
4195	* Retrieve index of a given charmap.
4196	*
4197	* @input:
4198	* charmap ::
4199	* A handle to a charmap.
4200	*
4201	* @return:
4202	* The index into the array of character maps within the face to which
4203	* `charmap` belongs. If an error occurs, -1 is returned.
4204	*
4205	*/
4206	FT_EXPORT( FT_Int )
4207	FT_Get_Charmap_Index( FT_CharMap charmap );
4208
4209
4210	/**************************************************************************
4211	*
4212	* @function:
4213	* FT_Get_Char_Index
4214	*
4215	* @description:
4216	* Return the glyph index of a given character code. This function uses
4217	* the currently selected charmap to do the mapping.
4218	*
4219	* @input:
4220	* face ::
4221	* A handle to the source face object.
4222	*
4223	* charcode ::
4224	* The character code.
4225	*
4226	* @return:
4227	* The glyph index. 0~means 'undefined character code'.
4228	*
4229	* @note:
4230	* If you use FreeType to manipulate the contents of font files directly,
4231	* be aware that the glyph index returned by this function doesn't always
4232	* correspond to the internal indices used within the file. This is done
4233	* to ensure that value~0 always corresponds to the 'missing glyph'. If
4234	* the first glyph is not named '.notdef', then for Type~1 and Type~42
4235	* fonts, '.notdef' will be moved into the glyph ID~0 position, and
4236	* whatever was there will be moved to the position '.notdef' had. For
4237	* Type~1 fonts, if there is no '.notdef' glyph at all, then one will be
4238	* created at index~0 and whatever was there will be moved to the last
4239	* index -- Type~42 fonts are considered invalid under this condition.
4240	*/
4241	FT_EXPORT( FT_UInt )
4242	FT_Get_Char_Index( FT_Face face,
4243	FT_ULong charcode );
4244
4245
4246	/**************************************************************************
4247	*
4248	* @function:
4249	* FT_Get_First_Char
4250	*
4251	* @description:
4252	* Return the first character code in the current charmap of a given
4253	* face, together with its corresponding glyph index.
4254	*
4255	* @input:
4256	* face ::
4257	* A handle to the source face object.
4258	*
4259	* @output:
4260	* agindex ::
4261	* Glyph index of first character code. 0~if charmap is empty.
4262	*
4263	* @return:
4264	* The charmap's first character code.
4265	*
4266	* @note:
4267	* You should use this function together with @FT_Get_Next_Char to parse
4268	* all character codes available in a given charmap. The code should
4269	* look like this:
4270	*
4271	* ```
4272	* FT_ULong charcode;
4273	* FT_UInt gindex;
4274	*
4275	*
4276	* charcode = FT_Get_First_Char( face, &gindex );
4277	* while ( gindex != 0 )
4278	* {
4279	* ... do something with (charcode,gindex) pair ...
4280	*
4281	* charcode = FT_Get_Next_Char( face, charcode, &gindex );
4282	* }
4283	* ```
4284	*
4285	* Be aware that character codes can have values up to 0xFFFFFFFF; this
4286	* might happen for non-Unicode or malformed cmaps. However, even with
4287	* regular Unicode encoding, so-called 'last resort fonts' (using SFNT
4288	* cmap format 13, see function @FT_Get_CMap_Format) normally have
4289	* entries for all Unicode characters up to 0x1FFFFF, which can cause *a
4290	* lot* of iterations.
4291	*
4292	* Note that `*agindex` is set to~0 if the charmap is empty. The result
4293	* itself can be~0 in two cases: if the charmap is empty or if the
4294	* value~0 is the first valid character code.
4295	*/
4296	FT_EXPORT( FT_ULong )
4297	FT_Get_First_Char( FT_Face face,
4298	FT_UInt *agindex );
4299
4300
4301	/**************************************************************************
4302	*
4303	* @function:
4304	* FT_Get_Next_Char
4305	*
4306	* @description:
4307	* Return the next character code in the current charmap of a given face
4308	* following the value `char_code`, as well as the corresponding glyph
4309	* index.
4310	*
4311	* @input:
4312	* face ::
4313	* A handle to the source face object.
4314	*
4315	* char_code ::
4316	* The starting character code.
4317	*
4318	* @output:
4319	* agindex ::
4320	* Glyph index of next character code. 0~if charmap is empty.
4321	*
4322	* @return:
4323	* The charmap's next character code.
4324	*
4325	* @note:
4326	* You should use this function with @FT_Get_First_Char to walk over all
4327	* character codes available in a given charmap. See the note for that
4328	* function for a simple code example.
4329	*
4330	* Note that `*agindex` is set to~0 when there are no more codes in the
4331	* charmap.
4332	*/
4333	FT_EXPORT( FT_ULong )
4334	FT_Get_Next_Char( FT_Face face,
4335	FT_ULong char_code,
4336	FT_UInt *agindex );
4337
4338
4339	/**************************************************************************
4340	*
4341	* @section:
4342	* face_creation
4343	*
4344	*/
4345
4346	/**************************************************************************
4347	*
4348	* @function:
4349	* FT_Face_Properties
4350	*
4351	* @description:
4352	* Set or override certain (library or module-wide) properties on a
4353	* face-by-face basis. Useful for finer-grained control and avoiding
4354	* locks on shared structures (threads can modify their own faces as they
4355	* see fit).
4356	*
4357	* Contrary to @FT_Property_Set, this function uses @FT_Parameter so that
4358	* you can pass multiple properties to the target face in one call. Note
4359	* that only a subset of the available properties can be controlled.
4360	*
4361	* * @FT_PARAM_TAG_STEM_DARKENING (stem darkening, corresponding to the
4362	* property `no-stem-darkening` provided by the 'autofit', 'cff',
4363	* 'type1', and 't1cid' modules; see @no-stem-darkening).
4364	*
4365	* * @FT_PARAM_TAG_LCD_FILTER_WEIGHTS (LCD filter weights, corresponding
4366	* to function @FT_Library_SetLcdFilterWeights).
4367	*
4368	* * @FT_PARAM_TAG_RANDOM_SEED (seed value for the CFF, Type~1, and CID
4369	* 'random' operator, corresponding to the `random-seed` property
4370	* provided by the 'cff', 'type1', and 't1cid' modules; see
4371	* @random-seed).
4372	*
4373	* Pass `NULL` as `data` in @FT_Parameter for a given tag to reset the
4374	* option and use the library or module default again.
4375	*
4376	* @input:
4377	* face ::
4378	* A handle to the source face object.
4379	*
4380	* num_properties ::
4381	* The number of properties that follow.
4382	*
4383	* properties ::
4384	* A handle to an @FT_Parameter array with `num_properties` elements.
4385	*
4386	* @return:
4387	* FreeType error code. 0~means success.
4388	*
4389	* @example:
4390	* Here is an example that sets three properties. You must define
4391	* `FT_CONFIG_OPTION_SUBPIXEL_RENDERING` to make the LCD filter examples
4392	* work.
4393	*
4394	* ```
4395	* FT_Parameter property1;
4396	* FT_Bool darken_stems = 1;
4397	*
4398	* FT_Parameter property2;
4399	* FT_LcdFiveTapFilter custom_weight =
4400	* { 0x11, 0x44, 0x56, 0x44, 0x11 };
4401	*
4402	* FT_Parameter property3;
4403	* FT_Int32 random_seed = 314159265;
4404	*
4405	* FT_Parameter properties[3] = { property1,
4406	* property2,
4407	* property3 };
4408	*
4409	*
4410	* property1.tag = FT_PARAM_TAG_STEM_DARKENING;
4411	* property1.data = &darken_stems;
4412	*
4413	* property2.tag = FT_PARAM_TAG_LCD_FILTER_WEIGHTS;
4414	* property2.data = custom_weight;
4415	*
4416	* property3.tag = FT_PARAM_TAG_RANDOM_SEED;
4417	* property3.data = &random_seed;
4418	*
4419	* FT_Face_Properties( face, 3, properties );
4420	* ```
4421	*
4422	* The next example resets a single property to its default value.
4423	*
4424	* ```
4425	* FT_Parameter property;
4426	*
4427	*
4428	* property.tag = FT_PARAM_TAG_LCD_FILTER_WEIGHTS;
4429	* property.data = NULL;
4430	*
4431	* FT_Face_Properties( face, 1, &property );
4432	* ```
4433	*
4434	* @since:
4435	* 2.8
4436	*
4437	*/
4438	FT_EXPORT( FT_Error )
4439	FT_Face_Properties( FT_Face face,
4440	FT_UInt num_properties,
4441	FT_Parameter* properties );
4442
4443
4444	/**************************************************************************
4445	*
4446	* @section:
4447	* information_retrieval
4448	*
4449	*/
4450
4451	/**************************************************************************
4452	*
4453	* @function:
4454	* FT_Get_Name_Index
4455	*
4456	* @description:
4457	* Return the glyph index of a given glyph name. This only works
4458	* for those faces where @FT_HAS_GLYPH_NAMES returns true.
4459	*
4460	* @input:
4461	* face ::
4462	* A handle to the source face object.
4463	*
4464	* glyph_name ::
4465	* The glyph name.
4466	*
4467	* @return:
4468	* The glyph index. 0~means 'undefined character code'.
4469	*
4470	* @note:
4471	* Acceptable glyph names might come from the [Adobe Glyph
4472	* List](https://github.com/adobe-type-tools/agl-aglfn). See
4473	* @FT_Get_Glyph_Name for the inverse functionality.
4474	*
4475	* This function has limited capabilities if the config macro
4476	* `FT_CONFIG_OPTION_POSTSCRIPT_NAMES` is not defined in `ftoption.h`:
4477	* It then works only for fonts that actually embed glyph names (which
4478	* many recent OpenType fonts do not).
4479	*/
4480	FT_EXPORT( FT_UInt )
4481	FT_Get_Name_Index( FT_Face face,
4482	const FT_String* glyph_name );
4483
4484
4485	/**************************************************************************
4486	*
4487	* @function:
4488	* FT_Get_Glyph_Name
4489	*
4490	* @description:
4491	* Retrieve the ASCII name of a given glyph in a face. This only works
4492	* for those faces where @FT_HAS_GLYPH_NAMES returns true.
4493	*
4494	* @input:
4495	* face ::
4496	* A handle to a source face object.
4497	*
4498	* glyph_index ::
4499	* The glyph index.
4500	*
4501	* buffer_max ::
4502	* The maximum number of bytes available in the buffer.
4503	*
4504	* @output:
4505	* buffer ::
4506	* A pointer to a target buffer where the name is copied to.
4507	*
4508	* @return:
4509	* FreeType error code. 0~means success.
4510	*
4511	* @note:
4512	* An error is returned if the face doesn't provide glyph names or if the
4513	* glyph index is invalid. In all cases of failure, the first byte of
4514	* `buffer` is set to~0 to indicate an empty name.
4515	*
4516	* The glyph name is truncated to fit within the buffer if it is too
4517	* long. The returned string is always zero-terminated.
4518	*
4519	* Be aware that FreeType reorders glyph indices internally so that glyph
4520	* index~0 always corresponds to the 'missing glyph' (called '.notdef').
4521	*
4522	* This function has limited capabilities if the config macro
4523	* `FT_CONFIG_OPTION_POSTSCRIPT_NAMES` is not defined in `ftoption.h`:
4524	* It then works only for fonts that actually embed glyph names (which
4525	* many recent OpenType fonts do not).
4526	*/
4527	FT_EXPORT( FT_Error )
4528	FT_Get_Glyph_Name( FT_Face face,
4529	FT_UInt glyph_index,
4530	FT_Pointer buffer,
4531	FT_UInt buffer_max );
4532
4533
4534	/**************************************************************************
4535	*
4536	* @function:
4537	* FT_Get_Postscript_Name
4538	*
4539	* @description:
4540	* Retrieve the ASCII PostScript name of a given face, if available.
4541	* This only works with PostScript, TrueType, and OpenType fonts.
4542	*
4543	* @input:
4544	* face ::
4545	* A handle to the source face object.
4546	*
4547	* @return:
4548	* A pointer to the face's PostScript name. `NULL` if unavailable.
4549	*
4550	* @note:
4551	* The returned pointer is owned by the face and is destroyed with it.
4552	*
4553	* For variation fonts, this string changes if you select a different
4554	* instance, and you have to call `FT_Get_PostScript_Name` again to
4555	* retrieve it. FreeType follows Adobe TechNote #5902, 'Generating
4556	* PostScript Names for Fonts Using OpenType Font Variations'.
4557	*
4558	* https://download.macromedia.com/pub/developer/opentype/tech-notes/5902.AdobePSNameGeneration.html
4559	*
4560	* [Since 2.9] Special PostScript names for named instances are only
4561	* returned if the named instance is set with @FT_Set_Named_Instance (and
4562	* the font has corresponding entries in its 'fvar' table or is the
4563	* default named instance). If @FT_IS_VARIATION returns true, the
4564	* algorithmically derived PostScript name is provided, not looking up
4565	* special entries for named instances.
4566	*/
4567	FT_EXPORT( const char* )
4568	FT_Get_Postscript_Name( FT_Face face );
4569
4570
4571	/**************************************************************************
4572	*
4573	* @enum:
4574	* FT_SUBGLYPH_FLAG_XXX
4575	*
4576	* @description:
4577	* A list of constants describing subglyphs. Please refer to the 'glyf'
4578	* table description in the OpenType specification for the meaning of the
4579	* various flags (which get synthesized for non-OpenType subglyphs).
4580	*
4581	* https://docs.microsoft.com/en-us/typography/opentype/spec/glyf#composite-glyph-description
4582	*
4583	* @values:
4584	* FT_SUBGLYPH_FLAG_ARGS_ARE_WORDS ::
4585	* FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES ::
4586	* FT_SUBGLYPH_FLAG_ROUND_XY_TO_GRID ::
4587	* FT_SUBGLYPH_FLAG_SCALE ::
4588	* FT_SUBGLYPH_FLAG_XY_SCALE ::
4589	* FT_SUBGLYPH_FLAG_2X2 ::
4590	* FT_SUBGLYPH_FLAG_USE_MY_METRICS ::
4591	*
4592	*/
4593	#define FT_SUBGLYPH_FLAG_ARGS_ARE_WORDS 1
4594	#define FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES 2
4595	#define FT_SUBGLYPH_FLAG_ROUND_XY_TO_GRID 4
4596	#define FT_SUBGLYPH_FLAG_SCALE 8
4597	#define FT_SUBGLYPH_FLAG_XY_SCALE 0x40
4598	#define FT_SUBGLYPH_FLAG_2X2 0x80
4599	#define FT_SUBGLYPH_FLAG_USE_MY_METRICS 0x200
4600
4601
4602	/**************************************************************************
4603	*
4604	* @function:
4605	* FT_Get_SubGlyph_Info
4606	*
4607	* @description:
4608	* Retrieve a description of a given subglyph. Only use it if
4609	* `glyph->format` is @FT_GLYPH_FORMAT_COMPOSITE; an error is returned
4610	* otherwise.
4611	*
4612	* @input:
4613	* glyph ::
4614	* The source glyph slot.
4615	*
4616	* sub_index ::
4617	* The index of the subglyph. Must be less than
4618	* `glyph->num_subglyphs`.
4619	*
4620	* @output:
4621	* p_index ::
4622	* The glyph index of the subglyph.
4623	*
4624	* p_flags ::
4625	* The subglyph flags, see @FT_SUBGLYPH_FLAG_XXX.
4626	*
4627	* p_arg1 ::
4628	* The subglyph's first argument (if any).
4629	*
4630	* p_arg2 ::
4631	* The subglyph's second argument (if any).
4632	*
4633	* p_transform ::
4634	* The subglyph transformation (if any).
4635	*
4636	* @return:
4637	* FreeType error code. 0~means success.
4638	*
4639	* @note:
4640	* The values of `*p_arg1`, `*p_arg2`, and `*p_transform` must be
4641	* interpreted depending on the flags returned in `*p_flags`. See the
4642	* OpenType specification for details.
4643	*
4644	* https://docs.microsoft.com/en-us/typography/opentype/spec/glyf#composite-glyph-description
4645	*
4646	*/
4647	FT_EXPORT( FT_Error )
4648	FT_Get_SubGlyph_Info( FT_GlyphSlot glyph,
4649	FT_UInt sub_index,
4650	FT_Int *p_index,
4651	FT_UInt *p_flags,
4652	FT_Int *p_arg1,
4653	FT_Int *p_arg2,
4654	FT_Matrix *p_transform );
4655
4656
4657	/**************************************************************************
4658	*
4659	* @enum:
4660	* FT_FSTYPE_XXX
4661	*
4662	* @description:
4663	* A list of bit flags used in the `fsType` field of the OS/2 table in a
4664	* TrueType or OpenType font and the `FSType` entry in a PostScript font.
4665	* These bit flags are returned by @FT_Get_FSType_Flags; they inform
4666	* client applications of embedding and subsetting restrictions
4667	* associated with a font.
4668	*
4669	* See
4670	* https://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/FontPolicies.pdf
4671	* for more details.
4672	*
4673	* @values:
4674	* FT_FSTYPE_INSTALLABLE_EMBEDDING ::
4675	* Fonts with no fsType bit set may be embedded and permanently
4676	* installed on the remote system by an application.
4677	*
4678	* FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING ::
4679	* Fonts that have only this bit set must not be modified, embedded or
4680	* exchanged in any manner without first obtaining permission of the
4681	* font software copyright owner.
4682	*
4683	* FT_FSTYPE_PREVIEW_AND_PRINT_EMBEDDING ::
4684	* The font may be embedded and temporarily loaded on the remote
4685	* system. Documents containing Preview & Print fonts must be opened
4686	* 'read-only'; no edits can be applied to the document.
4687	*
4688	* FT_FSTYPE_EDITABLE_EMBEDDING ::
4689	* The font may be embedded but must only be installed temporarily on
4690	* other systems. In contrast to Preview & Print fonts, documents
4691	* containing editable fonts may be opened for reading, editing is
4692	* permitted, and changes may be saved.
4693	*
4694	* FT_FSTYPE_NO_SUBSETTING ::
4695	* The font may not be subsetted prior to embedding.
4696	*
4697	* FT_FSTYPE_BITMAP_EMBEDDING_ONLY ::
4698	* Only bitmaps contained in the font may be embedded; no outline data
4699	* may be embedded. If there are no bitmaps available in the font,
4700	* then the font is unembeddable.
4701	*
4702	* @note:
4703	* The flags are ORed together, thus more than a single value can be
4704	* returned.
4705	*
4706	* While the `fsType` flags can indicate that a font may be embedded, a
4707	* license with the font vendor may be separately required to use the
4708	* font in this way.
4709	*/
4710	#define FT_FSTYPE_INSTALLABLE_EMBEDDING 0x0000
4711	#define FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING 0x0002
4712	#define FT_FSTYPE_PREVIEW_AND_PRINT_EMBEDDING 0x0004
4713	#define FT_FSTYPE_EDITABLE_EMBEDDING 0x0008
4714	#define FT_FSTYPE_NO_SUBSETTING 0x0100
4715	#define FT_FSTYPE_BITMAP_EMBEDDING_ONLY 0x0200
4716
4717
4718	/**************************************************************************
4719	*
4720	* @function:
4721	* FT_Get_FSType_Flags
4722	*
4723	* @description:
4724	* Return the `fsType` flags for a font.
4725	*
4726	* @input:
4727	* face ::
4728	* A handle to the source face object.
4729	*
4730	* @return:
4731	* The `fsType` flags, see @FT_FSTYPE_XXX.
4732	*
4733	* @note:
4734	* Use this function rather than directly reading the `fs_type` field in
4735	* the @PS_FontInfoRec structure, which is only guaranteed to return the
4736	* correct results for Type~1 fonts.
4737	*
4738	* @since:
4739	* 2.3.8
4740	*
4741	*/
4742	FT_EXPORT( FT_UShort )
4743	FT_Get_FSType_Flags( FT_Face face );
4744
4745
4746	/**************************************************************************
4747	*
4748	* @section:
4749	* glyph_variants
4750	*
4751	* @title:
4752	* Unicode Variation Sequences
4753	*
4754	* @abstract:
4755	* The FreeType~2 interface to Unicode Variation Sequences (UVS), using
4756	* the SFNT cmap format~14.
4757	*
4758	* @description:
4759	* Many characters, especially for CJK scripts, have variant forms. They
4760	* are a sort of grey area somewhere between being totally irrelevant and
4761	* semantically distinct; for this reason, the Unicode consortium decided
4762	* to introduce Variation Sequences (VS), consisting of a Unicode base
4763	* character and a variation selector instead of further extending the
4764	* already huge number of characters.
4765	*
4766	* Unicode maintains two different sets, namely 'Standardized Variation
4767	* Sequences' and registered 'Ideographic Variation Sequences' (IVS),
4768	* collected in the 'Ideographic Variation Database' (IVD).
4769	*
4770	* https://unicode.org/Public/UCD/latest/ucd/StandardizedVariants.txt
4771	* https://unicode.org/reports/tr37/ https://unicode.org/ivd/
4772	*
4773	* To date (January 2017), the character with the most ideographic
4774	* variations is U+9089, having 32 such IVS.
4775	*
4776	* Three Mongolian Variation Selectors have the values U+180B-U+180D; 256
4777	* generic Variation Selectors are encoded in the ranges U+FE00-U+FE0F
4778	* and U+E0100-U+E01EF. IVS currently use Variation Selectors from the
4779	* range U+E0100-U+E01EF only.
4780	*
4781	* A VS consists of the base character value followed by a single
4782	* Variation Selector. For example, to get the first variation of
4783	* U+9089, you have to write the character sequence `U+9089 U+E0100`.
4784	*
4785	* Adobe and MS decided to support both standardized and ideographic VS
4786	* with a new cmap subtable (format~14). It is an odd subtable because
4787	* it is not a mapping of input code points to glyphs, but contains lists
4788	* of all variations supported by the font.
4789	*
4790	* A variation may be either 'default' or 'non-default' for a given font.
4791	* A default variation is the one you will get for that code point if you
4792	* look it up in the standard Unicode cmap. A non-default variation is a
4793	* different glyph.
4794	*
4795	*/
4796
4797
4798	/**************************************************************************
4799	*
4800	* @function:
4801	* FT_Face_GetCharVariantIndex
4802	*
4803	* @description:
4804	* Return the glyph index of a given character code as modified by the
4805	* variation selector.
4806	*
4807	* @input:
4808	* face ::
4809	* A handle to the source face object.
4810	*
4811	* charcode ::
4812	* The character code point in Unicode.
4813	*
4814	* variantSelector ::
4815	* The Unicode code point of the variation selector.
4816	*
4817	* @return:
4818	* The glyph index. 0~means either 'undefined character code', or
4819	* 'undefined selector code', or 'no variation selector cmap subtable',
4820	* or 'current CharMap is not Unicode'.
4821	*
4822	* @note:
4823	* If you use FreeType to manipulate the contents of font files directly,
4824	* be aware that the glyph index returned by this function doesn't always
4825	* correspond to the internal indices used within the file. This is done
4826	* to ensure that value~0 always corresponds to the 'missing glyph'.
4827	*
4828	* This function is only meaningful if
4829	* a) the font has a variation selector cmap sub table, and
4830	* b) the current charmap has a Unicode encoding.
4831	*
4832	* @since:
4833	* 2.3.6
4834	*
4835	*/
4836	FT_EXPORT( FT_UInt )
4837	FT_Face_GetCharVariantIndex( FT_Face face,
4838	FT_ULong charcode,
4839	FT_ULong variantSelector );
4840
4841
4842	/**************************************************************************
4843	*
4844	* @function:
4845	* FT_Face_GetCharVariantIsDefault
4846	*
4847	* @description:
4848	* Check whether this variation of this Unicode character is the one to
4849	* be found in the charmap.
4850	*
4851	* @input:
4852	* face ::
4853	* A handle to the source face object.
4854	*
4855	* charcode ::
4856	* The character codepoint in Unicode.
4857	*
4858	* variantSelector ::
4859	* The Unicode codepoint of the variation selector.
4860	*
4861	* @return:
4862	* 1~if found in the standard (Unicode) cmap, 0~if found in the variation
4863	* selector cmap, or -1 if it is not a variation.
4864	*
4865	* @note:
4866	* This function is only meaningful if the font has a variation selector
4867	* cmap subtable.
4868	*
4869	* @since:
4870	* 2.3.6
4871	*
4872	*/
4873	FT_EXPORT( FT_Int )
4874	FT_Face_GetCharVariantIsDefault( FT_Face face,
4875	FT_ULong charcode,
4876	FT_ULong variantSelector );
4877
4878
4879	/**************************************************************************
4880	*
4881	* @function:
4882	* FT_Face_GetVariantSelectors
4883	*
4884	* @description:
4885	* Return a zero-terminated list of Unicode variation selectors found in
4886	* the font.
4887	*
4888	* @input:
4889	* face ::
4890	* A handle to the source face object.
4891	*
4892	* @return:
4893	* A pointer to an array of selector code points, or `NULL` if there is
4894	* no valid variation selector cmap subtable.
4895	*
4896	* @note:
4897	* The last item in the array is~0; the array is owned by the @FT_Face
4898	* object but can be overwritten or released on the next call to a
4899	* FreeType function.
4900	*
4901	* @since:
4902	* 2.3.6
4903	*
4904	*/
4905	FT_EXPORT( FT_UInt32* )
4906	FT_Face_GetVariantSelectors( FT_Face face );
4907
4908
4909	/**************************************************************************
4910	*
4911	* @function:
4912	* FT_Face_GetVariantsOfChar
4913	*
4914	* @description:
4915	* Return a zero-terminated list of Unicode variation selectors found for
4916	* the specified character code.
4917	*
4918	* @input:
4919	* face ::
4920	* A handle to the source face object.
4921	*
4922	* charcode ::
4923	* The character codepoint in Unicode.
4924	*
4925	* @return:
4926	* A pointer to an array of variation selector code points that are
4927	* active for the given character, or `NULL` if the corresponding list is
4928	* empty.
4929	*
4930	* @note:
4931	* The last item in the array is~0; the array is owned by the @FT_Face
4932	* object but can be overwritten or released on the next call to a
4933	* FreeType function.
4934	*
4935	* @since:
4936	* 2.3.6
4937	*
4938	*/
4939	FT_EXPORT( FT_UInt32* )
4940	FT_Face_GetVariantsOfChar( FT_Face face,
4941	FT_ULong charcode );
4942
4943
4944	/**************************************************************************
4945	*
4946	* @function:
4947	* FT_Face_GetCharsOfVariant
4948	*
4949	* @description:
4950	* Return a zero-terminated list of Unicode character codes found for the
4951	* specified variation selector.
4952	*
4953	* @input:
4954	* face ::
4955	* A handle to the source face object.
4956	*
4957	* variantSelector ::
4958	* The variation selector code point in Unicode.
4959	*
4960	* @return:
4961	* A list of all the code points that are specified by this selector
4962	* (both default and non-default codes are returned) or `NULL` if there
4963	* is no valid cmap or the variation selector is invalid.
4964	*
4965	* @note:
4966	* The last item in the array is~0; the array is owned by the @FT_Face
4967	* object but can be overwritten or released on the next call to a
4968	* FreeType function.
4969	*
4970	* @since:
4971	* 2.3.6
4972	*
4973	*/
4974	FT_EXPORT( FT_UInt32* )
4975	FT_Face_GetCharsOfVariant( FT_Face face,
4976	FT_ULong variantSelector );
4977
4978
4979	/**************************************************************************
4980	*
4981	* @section:
4982	* computations
4983	*
4984	* @title:
4985	* Computations
4986	*
4987	* @abstract:
4988	* Crunching fixed numbers and vectors.
4989	*
4990	* @description:
4991	* This section contains various functions used to perform computations
4992	* on 16.16 fixed-point numbers or 2D vectors. FreeType does not use
4993	* floating-point data types.
4994	*
4995	* **Attention**: Most arithmetic functions take `FT_Long` as arguments.
4996	* For historical reasons, FreeType was designed under the assumption
4997	* that `FT_Long` is a 32-bit integer; results can thus be undefined if
4998	* the arguments don't fit into 32 bits.
4999	*
5000	* @order:
5001	* FT_MulDiv
5002	* FT_MulFix
5003	* FT_DivFix
5004	* FT_RoundFix
5005	* FT_CeilFix
5006	* FT_FloorFix
5007	* FT_Vector_Transform
5008	* FT_Matrix_Multiply
5009	* FT_Matrix_Invert
5010	*
5011	*/
5012
5013
5014	/**************************************************************************
5015	*
5016	* @function:
5017	* FT_MulDiv
5018	*
5019	* @description:
5020	* Compute `(a*b)/c` with maximum accuracy, using a 64-bit intermediate
5021	* integer whenever necessary.
5022	*
5023	* This function isn't necessarily as fast as some processor-specific
5024	* operations, but is at least completely portable.
5025	*
5026	* @input:
5027	* a ::
5028	* The first multiplier.
5029	*
5030	* b ::
5031	* The second multiplier.
5032	*
5033	* c ::
5034	* The divisor.
5035	*
5036	* @return:
5037	* The result of `(a*b)/c`. This function never traps when trying to
5038	* divide by zero; it simply returns 'MaxInt' or 'MinInt' depending on
5039	* the signs of `a` and `b`.
5040	*/
5041	FT_EXPORT( FT_Long )
5042	FT_MulDiv( FT_Long a,
5043	FT_Long b,
5044	FT_Long c );
5045
5046
5047	/**************************************************************************
5048	*
5049	* @function:
5050	* FT_MulFix
5051	*
5052	* @description:
5053	* Compute `(a*b)/0x10000` with maximum accuracy. Its main use is to
5054	* multiply a given value by a 16.16 fixed-point factor.
5055	*
5056	* @input:
5057	* a ::
5058	* The first multiplier.
5059	*
5060	* b ::
5061	* The second multiplier. Use a 16.16 factor here whenever possible
5062	* (see note below).
5063	*
5064	* @return:
5065	* The result of `(a*b)/0x10000`.
5066	*
5067	* @note:
5068	* This function has been optimized for the case where the absolute value
5069	* of `a` is less than 2048, and `b` is a 16.16 scaling factor. As this
5070	* happens mainly when scaling from notional units to fractional pixels
5071	* in FreeType, it resulted in noticeable speed improvements between
5072	* versions 2.x and 1.x.
5073	*
5074	* As a conclusion, always try to place a 16.16 factor as the _second_
5075	* argument of this function; this can make a great difference.
5076	*/
5077	FT_EXPORT( FT_Long )
5078	FT_MulFix( FT_Long a,
5079	FT_Long b );
5080
5081
5082	/**************************************************************************
5083	*
5084	* @function:
5085	* FT_DivFix
5086	*
5087	* @description:
5088	* Compute `(a*0x10000)/b` with maximum accuracy. Its main use is to
5089	* divide a given value by a 16.16 fixed-point factor.
5090	*
5091	* @input:
5092	* a ::
5093	* The numerator.
5094	*
5095	* b ::
5096	* The denominator. Use a 16.16 factor here.
5097	*
5098	* @return:
5099	* The result of `(a*0x10000)/b`.
5100	*/
5101	FT_EXPORT( FT_Long )
5102	FT_DivFix( FT_Long a,
5103	FT_Long b );
5104
5105
5106	/**************************************************************************
5107	*
5108	* @function:
5109	* FT_RoundFix
5110	*
5111	* @description:
5112	* Round a 16.16 fixed number.
5113	*
5114	* @input:
5115	* a ::
5116	* The number to be rounded.
5117	*
5118	* @return:
5119	* `a` rounded to the nearest 16.16 fixed integer, halfway cases away
5120	* from zero.
5121	*
5122	* @note:
5123	* The function uses wrap-around arithmetic.
5124	*/
5125	FT_EXPORT( FT_Fixed )
5126	FT_RoundFix( FT_Fixed a );
5127
5128
5129	/**************************************************************************
5130	*
5131	* @function:
5132	* FT_CeilFix
5133	*
5134	* @description:
5135	* Compute the smallest following integer of a 16.16 fixed number.
5136	*
5137	* @input:
5138	* a ::
5139	* The number for which the ceiling function is to be computed.
5140	*
5141	* @return:
5142	* `a` rounded towards plus infinity.
5143	*
5144	* @note:
5145	* The function uses wrap-around arithmetic.
5146	*/
5147	FT_EXPORT( FT_Fixed )
5148	FT_CeilFix( FT_Fixed a );
5149
5150
5151	/**************************************************************************
5152	*
5153	* @function:
5154	* FT_FloorFix
5155	*
5156	* @description:
5157	* Compute the largest previous integer of a 16.16 fixed number.
5158	*
5159	* @input:
5160	* a ::
5161	* The number for which the floor function is to be computed.
5162	*
5163	* @return:
5164	* `a` rounded towards minus infinity.
5165	*/
5166	FT_EXPORT( FT_Fixed )
5167	FT_FloorFix( FT_Fixed a );
5168
5169
5170	/**************************************************************************
5171	*
5172	* @function:
5173	* FT_Vector_Transform
5174	*
5175	* @description:
5176	* Transform a single vector through a 2x2 matrix.
5177	*
5178	* @inout:
5179	* vector ::
5180	* The target vector to transform.
5181	*
5182	* @input:
5183	* matrix ::
5184	* A pointer to the source 2x2 matrix.
5185	*
5186	* @note:
5187	* The result is undefined if either `vector` or `matrix` is invalid.
5188	*/
5189	FT_EXPORT( void )
5190	FT_Vector_Transform( FT_Vector* vector,
5191	const FT_Matrix* matrix );
5192
5193
5194	/**************************************************************************
5195	*
5196	* @section:
5197	* library_setup
5198	*
5199	*/
5200
5201	/**************************************************************************
5202	*
5203	* @enum:
5204	* FREETYPE_XXX
5205	*
5206	* @description:
5207	* These three macros identify the FreeType source code version. Use
5208	* @FT_Library_Version to access them at runtime.
5209	*
5210	* @values:
5211	* FREETYPE_MAJOR ::
5212	* The major version number.
5213	* FREETYPE_MINOR ::
5214	* The minor version number.
5215	* FREETYPE_PATCH ::
5216	* The patch level.
5217	*
5218	* @note:
5219	* The version number of FreeType if built as a dynamic link library with
5220	* the 'libtool' package is _not_ controlled by these three macros.
5221	*
5222	*/
5223	#define FREETYPE_MAJOR 2
5224	#define FREETYPE_MINOR 13
5225	#define FREETYPE_PATCH 2
5226
5227
5228	/**************************************************************************
5229	*
5230	* @function:
5231	* FT_Library_Version
5232	*
5233	* @description:
5234	* Return the version of the FreeType library being used. This is useful
5235	* when dynamically linking to the library, since one cannot use the
5236	* macros @FREETYPE_MAJOR, @FREETYPE_MINOR, and @FREETYPE_PATCH.
5237	*
5238	* @input:
5239	* library ::
5240	* A source library handle.
5241	*
5242	* @output:
5243	* amajor ::
5244	* The major version number.
5245	*
5246	* aminor ::
5247	* The minor version number.
5248	*
5249	* apatch ::
5250	* The patch version number.
5251	*
5252	* @note:
5253	* The reason why this function takes a `library` argument is because
5254	* certain programs implement library initialization in a custom way that
5255	* doesn't use @FT_Init_FreeType.
5256	*
5257	* In such cases, the library version might not be available before the
5258	* library object has been created.
5259	*/
5260	FT_EXPORT( void )
5261	FT_Library_Version( FT_Library library,
5262	FT_Int *amajor,
5263	FT_Int *aminor,
5264	FT_Int *apatch );
5265
5266
5267	/**************************************************************************
5268	*
5269	* @section:
5270	* other_api_data
5271	*
5272	*/
5273
5274	/**************************************************************************
5275	*
5276	* @function:
5277	* FT_Face_CheckTrueTypePatents
5278	*
5279	* @description:
5280	* Deprecated, does nothing.
5281	*
5282	* @input:
5283	* face ::
5284	* A face handle.
5285	*
5286	* @return:
5287	* Always returns false.
5288	*
5289	* @note:
5290	* Since May 2010, TrueType hinting is no longer patented.
5291	*
5292	* @since:
5293	* 2.3.5
5294	*
5295	*/
5296	FT_EXPORT( FT_Bool )
5297	FT_Face_CheckTrueTypePatents( FT_Face face );
5298
5299
5300	/**************************************************************************
5301	*
5302	* @function:
5303	* FT_Face_SetUnpatentedHinting
5304	*
5305	* @description:
5306	* Deprecated, does nothing.
5307	*
5308	* @input:
5309	* face ::
5310	* A face handle.
5311	*
5312	* value ::
5313	* New boolean setting.
5314	*
5315	* @return:
5316	* Always returns false.
5317	*
5318	* @note:
5319	* Since May 2010, TrueType hinting is no longer patented.
5320	*
5321	* @since:
5322	* 2.3.5
5323	*
5324	*/
5325	FT_EXPORT( FT_Bool )
5326	FT_Face_SetUnpatentedHinting( FT_Face face,
5327	FT_Bool value );
5328
5329	/* */
5330
5331
5332	FT_END_HEADER
5333
5334	#endif /* FREETYPE_H_ */
5335
5336
5337	/* END */
5338