1 /***************************************************************************/
2 /* */
3 /* pshints.h */
4 /* */
5 /* Interface to Postscript-specific (Type 1 and Type 2) hints */
6 /* recorders (specification only). These are used to support native */
7 /* T1/T2 hints in the `type1', `cid', and `cff' font drivers. */
8 /* */
9 /* Copyright 2001-2018 by */
10 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
11 /* */
12 /* This file is part of the FreeType project, and may only be used, */
13 /* modified, and distributed under the terms of the FreeType project */
14 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */
15 /* this file you indicate that you have read the license and */
16 /* understand and accept it fully. */
17 /* */
18 /***************************************************************************/
19
20
21 #ifndef PSHINTS_H_
22 #define PSHINTS_H_
23
24
25 #include <ft2build.h>
26 #include FT_FREETYPE_H
27 #include FT_TYPE1_TABLES_H
28
29
30 FT_BEGIN_HEADER
31
32
33 /*************************************************************************/
34 /*************************************************************************/
35 /***** *****/
36 /***** INTERNAL REPRESENTATION OF GLOBALS *****/
37 /***** *****/
38 /*************************************************************************/
39 /*************************************************************************/
40
41 typedef struct PSH_GlobalsRec_* PSH_Globals;
42
43 typedef FT_Error
44 (*PSH_Globals_NewFunc)( FT_Memory memory,
45 T1_Private* private_dict,
46 PSH_Globals* aglobals );
47
48 typedef void
49 (*PSH_Globals_SetScaleFunc)( PSH_Globals globals,
50 FT_Fixed x_scale,
51 FT_Fixed y_scale,
52 FT_Fixed x_delta,
53 FT_Fixed y_delta );
54
55 typedef void
56 (*PSH_Globals_DestroyFunc)( PSH_Globals globals );
57
58
59 typedef struct PSH_Globals_FuncsRec_
60 {
61 PSH_Globals_NewFunc create;
62 PSH_Globals_SetScaleFunc set_scale;
63 PSH_Globals_DestroyFunc destroy;
64
65 } PSH_Globals_FuncsRec, *PSH_Globals_Funcs;
66
67
68 /*************************************************************************/
69 /*************************************************************************/
70 /***** *****/
71 /***** PUBLIC TYPE 1 HINTS RECORDER *****/
72 /***** *****/
73 /*************************************************************************/
74 /*************************************************************************/
75
76 /*************************************************************************
77 *
78 * @type:
79 * T1_Hints
80 *
81 * @description:
82 * This is a handle to an opaque structure used to record glyph hints
83 * from a Type 1 character glyph character string.
84 *
85 * The methods used to operate on this object are defined by the
86 * @T1_Hints_FuncsRec structure. Recording glyph hints is normally
87 * achieved through the following scheme:
88 *
89 * - Open a new hint recording session by calling the `open' method.
90 * This rewinds the recorder and prepare it for new input.
91 *
92 * - For each hint found in the glyph charstring, call the corresponding
93 * method (`stem', `stem3', or `reset'). Note that these functions do
94 * not return an error code.
95 *
96 * - Close the recording session by calling the `close' method. It
97 * returns an error code if the hints were invalid or something
98 * strange happened (e.g., memory shortage).
99 *
100 * The hints accumulated in the object can later be used by the
101 * PostScript hinter.
102 *
103 */
104 typedef struct T1_HintsRec_* T1_Hints;
105
106
107 /*************************************************************************
108 *
109 * @type:
110 * T1_Hints_Funcs
111 *
112 * @description:
113 * A pointer to the @T1_Hints_FuncsRec structure that defines the API of
114 * a given @T1_Hints object.
115 *
116 */
117 typedef const struct T1_Hints_FuncsRec_* T1_Hints_Funcs;
118
119
120 /*************************************************************************
121 *
122 * @functype:
123 * T1_Hints_OpenFunc
124 *
125 * @description:
126 * A method of the @T1_Hints class used to prepare it for a new Type 1
127 * hints recording session.
128 *
129 * @input:
130 * hints ::
131 * A handle to the Type 1 hints recorder.
132 *
133 * @note:
134 * You should always call the @T1_Hints_CloseFunc method in order to
135 * close an opened recording session.
136 *
137 */
138 typedef void
139 (*T1_Hints_OpenFunc)( T1_Hints hints );
140
141
142 /*************************************************************************
143 *
144 * @functype:
145 * T1_Hints_SetStemFunc
146 *
147 * @description:
148 * A method of the @T1_Hints class used to record a new horizontal or
149 * vertical stem. This corresponds to the Type 1 `hstem' and `vstem'
150 * operators.
151 *
152 * @input:
153 * hints ::
154 * A handle to the Type 1 hints recorder.
155 *
156 * dimension ::
157 * 0 for horizontal stems (hstem), 1 for vertical ones (vstem).
158 *
159 * coords ::
160 * Array of 2 coordinates in 16.16 format, used as (position,length)
161 * stem descriptor.
162 *
163 * @note:
164 * Use vertical coordinates (y) for horizontal stems (dim=0). Use
165 * horizontal coordinates (x) for vertical stems (dim=1).
166 *
167 * `coords[0]' is the absolute stem position (lowest coordinate);
168 * `coords[1]' is the length.
169 *
170 * The length can be negative, in which case it must be either -20 or
171 * -21. It is interpreted as a `ghost' stem, according to the Type 1
172 * specification.
173 *
174 * If the length is -21 (corresponding to a bottom ghost stem), then
175 * the real stem position is `coords[0]+coords[1]'.
176 *
177 */
178 typedef void
179 (*T1_Hints_SetStemFunc)( T1_Hints hints,
180 FT_UInt dimension,
181 FT_Fixed* coords );
182
183
184 /*************************************************************************
185 *
186 * @functype:
187 * T1_Hints_SetStem3Func
188 *
189 * @description:
190 * A method of the @T1_Hints class used to record three
191 * counter-controlled horizontal or vertical stems at once.
192 *
193 * @input:
194 * hints ::
195 * A handle to the Type 1 hints recorder.
196 *
197 * dimension ::
198 * 0 for horizontal stems, 1 for vertical ones.
199 *
200 * coords ::
201 * An array of 6 values in 16.16 format, holding 3 (position,length)
202 * pairs for the counter-controlled stems.
203 *
204 * @note:
205 * Use vertical coordinates (y) for horizontal stems (dim=0). Use
206 * horizontal coordinates (x) for vertical stems (dim=1).
207 *
208 * The lengths cannot be negative (ghost stems are never
209 * counter-controlled).
210 *
211 */
212 typedef void
213 (*T1_Hints_SetStem3Func)( T1_Hints hints,
214 FT_UInt dimension,
215 FT_Fixed* coords );
216
217
218 /*************************************************************************
219 *
220 * @functype:
221 * T1_Hints_ResetFunc
222 *
223 * @description:
224 * A method of the @T1_Hints class used to reset the stems hints in a
225 * recording session.
226 *
227 * @input:
228 * hints ::
229 * A handle to the Type 1 hints recorder.
230 *
231 * end_point ::
232 * The index of the last point in the input glyph in which the
233 * previously defined hints apply.
234 *
235 */
236 typedef void
237 (*T1_Hints_ResetFunc)( T1_Hints hints,
238 FT_UInt end_point );
239
240
241 /*************************************************************************
242 *
243 * @functype:
244 * T1_Hints_CloseFunc
245 *
246 * @description:
247 * A method of the @T1_Hints class used to close a hint recording
248 * session.
249 *
250 * @input:
251 * hints ::
252 * A handle to the Type 1 hints recorder.
253 *
254 * end_point ::
255 * The index of the last point in the input glyph.
256 *
257 * @return:
258 * FreeType error code. 0 means success.
259 *
260 * @note:
261 * The error code is set to indicate that an error occurred during the
262 * recording session.
263 *
264 */
265 typedef FT_Error
266 (*T1_Hints_CloseFunc)( T1_Hints hints,
267 FT_UInt end_point );
268
269
270 /*************************************************************************
271 *
272 * @functype:
273 * T1_Hints_ApplyFunc
274 *
275 * @description:
276 * A method of the @T1_Hints class used to apply hints to the
277 * corresponding glyph outline. Must be called once all hints have been
278 * recorded.
279 *
280 * @input:
281 * hints ::
282 * A handle to the Type 1 hints recorder.
283 *
284 * outline ::
285 * A pointer to the target outline descriptor.
286 *
287 * globals ::
288 * The hinter globals for this font.
289 *
290 * hint_mode ::
291 * Hinting information.
292 *
293 * @return:
294 * FreeType error code. 0 means success.
295 *
296 * @note:
297 * On input, all points within the outline are in font coordinates. On
298 * output, they are in 1/64th of pixels.
299 *
300 * The scaling transformation is taken from the `globals' object which
301 * must correspond to the same font as the glyph.
302 *
303 */
304 typedef FT_Error
305 (*T1_Hints_ApplyFunc)( T1_Hints hints,
306 FT_Outline* outline,
307 PSH_Globals globals,
308 FT_Render_Mode hint_mode );
309
310
311 /*************************************************************************
312 *
313 * @struct:
314 * T1_Hints_FuncsRec
315 *
316 * @description:
317 * The structure used to provide the API to @T1_Hints objects.
318 *
319 * @fields:
320 * hints ::
321 * A handle to the T1 Hints recorder.
322 *
323 * open ::
324 * The function to open a recording session.
325 *
326 * close ::
327 * The function to close a recording session.
328 *
329 * stem ::
330 * The function to set a simple stem.
331 *
332 * stem3 ::
333 * The function to set counter-controlled stems.
334 *
335 * reset ::
336 * The function to reset stem hints.
337 *
338 * apply ::
339 * The function to apply the hints to the corresponding glyph outline.
340 *
341 */
342 typedef struct T1_Hints_FuncsRec_
343 {
344 T1_Hints hints;
345 T1_Hints_OpenFunc open;
346 T1_Hints_CloseFunc close;
347 T1_Hints_SetStemFunc stem;
348 T1_Hints_SetStem3Func stem3;
349 T1_Hints_ResetFunc reset;
350 T1_Hints_ApplyFunc apply;
351
352 } T1_Hints_FuncsRec;
353
354
355 /*************************************************************************/
356 /*************************************************************************/
357 /***** *****/
358 /***** PUBLIC TYPE 2 HINTS RECORDER *****/
359 /***** *****/
360 /*************************************************************************/
361 /*************************************************************************/
362
363 /*************************************************************************
364 *
365 * @type:
366 * T2_Hints
367 *
368 * @description:
369 * This is a handle to an opaque structure used to record glyph hints
370 * from a Type 2 character glyph character string.
371 *
372 * The methods used to operate on this object are defined by the
373 * @T2_Hints_FuncsRec structure. Recording glyph hints is normally
374 * achieved through the following scheme:
375 *
376 * - Open a new hint recording session by calling the `open' method.
377 * This rewinds the recorder and prepare it for new input.
378 *
379 * - For each hint found in the glyph charstring, call the corresponding
380 * method (`stems', `hintmask', `counters'). Note that these
381 * functions do not return an error code.
382 *
383 * - Close the recording session by calling the `close' method. It
384 * returns an error code if the hints were invalid or something
385 * strange happened (e.g., memory shortage).
386 *
387 * The hints accumulated in the object can later be used by the
388 * Postscript hinter.
389 *
390 */
391 typedef struct T2_HintsRec_* T2_Hints;
392
393
394 /*************************************************************************
395 *
396 * @type:
397 * T2_Hints_Funcs
398 *
399 * @description:
400 * A pointer to the @T2_Hints_FuncsRec structure that defines the API of
401 * a given @T2_Hints object.
402 *
403 */
404 typedef const struct T2_Hints_FuncsRec_* T2_Hints_Funcs;
405
406
407 /*************************************************************************
408 *
409 * @functype:
410 * T2_Hints_OpenFunc
411 *
412 * @description:
413 * A method of the @T2_Hints class used to prepare it for a new Type 2
414 * hints recording session.
415 *
416 * @input:
417 * hints ::
418 * A handle to the Type 2 hints recorder.
419 *
420 * @note:
421 * You should always call the @T2_Hints_CloseFunc method in order to
422 * close an opened recording session.
423 *
424 */
425 typedef void
426 (*T2_Hints_OpenFunc)( T2_Hints hints );
427
428
429 /*************************************************************************
430 *
431 * @functype:
432 * T2_Hints_StemsFunc
433 *
434 * @description:
435 * A method of the @T2_Hints class used to set the table of stems in
436 * either the vertical or horizontal dimension. Equivalent to the
437 * `hstem', `vstem', `hstemhm', and `vstemhm' Type 2 operators.
438 *
439 * @input:
440 * hints ::
441 * A handle to the Type 2 hints recorder.
442 *
443 * dimension ::
444 * 0 for horizontal stems (hstem), 1 for vertical ones (vstem).
445 *
446 * count ::
447 * The number of stems.
448 *
449 * coords ::
450 * An array of `count' (position,length) pairs in 16.16 format.
451 *
452 * @note:
453 * Use vertical coordinates (y) for horizontal stems (dim=0). Use
454 * horizontal coordinates (x) for vertical stems (dim=1).
455 *
456 * There are `2*count' elements in the `coords' array. Each even
457 * element is an absolute position in font units, each odd element is a
458 * length in font units.
459 *
460 * A length can be negative, in which case it must be either -20 or
461 * -21. It is interpreted as a `ghost' stem, according to the Type 1
462 * specification.
463 *
464 */
465 typedef void
466 (*T2_Hints_StemsFunc)( T2_Hints hints,
467 FT_UInt dimension,
468 FT_Int count,
469 FT_Fixed* coordinates );
470
471
472 /*************************************************************************
473 *
474 * @functype:
475 * T2_Hints_MaskFunc
476 *
477 * @description:
478 * A method of the @T2_Hints class used to set a given hintmask (this
479 * corresponds to the `hintmask' Type 2 operator).
480 *
481 * @input:
482 * hints ::
483 * A handle to the Type 2 hints recorder.
484 *
485 * end_point ::
486 * The glyph index of the last point to which the previously defined
487 * or activated hints apply.
488 *
489 * bit_count ::
490 * The number of bits in the hint mask.
491 *
492 * bytes ::
493 * An array of bytes modelling the hint mask.
494 *
495 * @note:
496 * If the hintmask starts the charstring (before any glyph point
497 * definition), the value of `end_point' should be 0.
498 *
499 * `bit_count' is the number of meaningful bits in the `bytes' array; it
500 * must be equal to the total number of hints defined so far (i.e.,
501 * horizontal+verticals).
502 *
503 * The `bytes' array can come directly from the Type 2 charstring and
504 * respects the same format.
505 *
506 */
507 typedef void
508 (*T2_Hints_MaskFunc)( T2_Hints hints,
509 FT_UInt end_point,
510 FT_UInt bit_count,
511 const FT_Byte* bytes );
512
513
514 /*************************************************************************
515 *
516 * @functype:
517 * T2_Hints_CounterFunc
518 *
519 * @description:
520 * A method of the @T2_Hints class used to set a given counter mask
521 * (this corresponds to the `hintmask' Type 2 operator).
522 *
523 * @input:
524 * hints ::
525 * A handle to the Type 2 hints recorder.
526 *
527 * end_point ::
528 * A glyph index of the last point to which the previously defined or
529 * active hints apply.
530 *
531 * bit_count ::
532 * The number of bits in the hint mask.
533 *
534 * bytes ::
535 * An array of bytes modelling the hint mask.
536 *
537 * @note:
538 * If the hintmask starts the charstring (before any glyph point
539 * definition), the value of `end_point' should be 0.
540 *
541 * `bit_count' is the number of meaningful bits in the `bytes' array; it
542 * must be equal to the total number of hints defined so far (i.e.,
543 * horizontal+verticals).
544 *
545 * The `bytes' array can come directly from the Type 2 charstring and
546 * respects the same format.
547 *
548 */
549 typedef void
550 (*T2_Hints_CounterFunc)( T2_Hints hints,
551 FT_UInt bit_count,
552 const FT_Byte* bytes );
553
554
555 /*************************************************************************
556 *
557 * @functype:
558 * T2_Hints_CloseFunc
559 *
560 * @description:
561 * A method of the @T2_Hints class used to close a hint recording
562 * session.
563 *
564 * @input:
565 * hints ::
566 * A handle to the Type 2 hints recorder.
567 *
568 * end_point ::
569 * The index of the last point in the input glyph.
570 *
571 * @return:
572 * FreeType error code. 0 means success.
573 *
574 * @note:
575 * The error code is set to indicate that an error occurred during the
576 * recording session.
577 *
578 */
579 typedef FT_Error
580 (*T2_Hints_CloseFunc)( T2_Hints hints,
581 FT_UInt end_point );
582
583
584 /*************************************************************************
585 *
586 * @functype:
587 * T2_Hints_ApplyFunc
588 *
589 * @description:
590 * A method of the @T2_Hints class used to apply hints to the
591 * corresponding glyph outline. Must be called after the `close'
592 * method.
593 *
594 * @input:
595 * hints ::
596 * A handle to the Type 2 hints recorder.
597 *
598 * outline ::
599 * A pointer to the target outline descriptor.
600 *
601 * globals ::
602 * The hinter globals for this font.
603 *
604 * hint_mode ::
605 * Hinting information.
606 *
607 * @return:
608 * FreeType error code. 0 means success.
609 *
610 * @note:
611 * On input, all points within the outline are in font coordinates. On
612 * output, they are in 1/64th of pixels.
613 *
614 * The scaling transformation is taken from the `globals' object which
615 * must correspond to the same font than the glyph.
616 *
617 */
618 typedef FT_Error
619 (*T2_Hints_ApplyFunc)( T2_Hints hints,
620 FT_Outline* outline,
621 PSH_Globals globals,
622 FT_Render_Mode hint_mode );
623
624
625 /*************************************************************************
626 *
627 * @struct:
628 * T2_Hints_FuncsRec
629 *
630 * @description:
631 * The structure used to provide the API to @T2_Hints objects.
632 *
633 * @fields:
634 * hints ::
635 * A handle to the T2 hints recorder object.
636 *
637 * open ::
638 * The function to open a recording session.
639 *
640 * close ::
641 * The function to close a recording session.
642 *
643 * stems ::
644 * The function to set the dimension's stems table.
645 *
646 * hintmask ::
647 * The function to set hint masks.
648 *
649 * counter ::
650 * The function to set counter masks.
651 *
652 * apply ::
653 * The function to apply the hints on the corresponding glyph outline.
654 *
655 */
656 typedef struct T2_Hints_FuncsRec_
657 {
658 T2_Hints hints;
659 T2_Hints_OpenFunc open;
660 T2_Hints_CloseFunc close;
661 T2_Hints_StemsFunc stems;
662 T2_Hints_MaskFunc hintmask;
663 T2_Hints_CounterFunc counter;
664 T2_Hints_ApplyFunc apply;
665
666 } T2_Hints_FuncsRec;
667
668
669 /* */
670
671
672 typedef struct PSHinter_Interface_
673 {
674 PSH_Globals_Funcs (*get_globals_funcs)( FT_Module module );
675 T1_Hints_Funcs (*get_t1_funcs) ( FT_Module module );
676 T2_Hints_Funcs (*get_t2_funcs) ( FT_Module module );
677
678 } PSHinter_Interface;
679
680 typedef PSHinter_Interface* PSHinter_Service;
681
682
683 #ifndef FT_CONFIG_OPTION_PIC
684
685 #define FT_DEFINE_PSHINTER_INTERFACE( \
686 class_, \
687 get_globals_funcs_, \
688 get_t1_funcs_, \
689 get_t2_funcs_ ) \
690 static const PSHinter_Interface class_ = \
691 { \
692 get_globals_funcs_, \
693 get_t1_funcs_, \
694 get_t2_funcs_ \
695 };
696
697 #else /* FT_CONFIG_OPTION_PIC */
698
699 #define FT_DEFINE_PSHINTER_INTERFACE( \
700 class_, \
701 get_globals_funcs_, \
702 get_t1_funcs_, \
703 get_t2_funcs_ ) \
704 void \
705 FT_Init_Class_ ## class_( FT_Library library, \
706 PSHinter_Interface* clazz ) \
707 { \
708 FT_UNUSED( library ); \
709 \
710 clazz->get_globals_funcs = get_globals_funcs_; \
711 clazz->get_t1_funcs = get_t1_funcs_; \
712 clazz->get_t2_funcs = get_t2_funcs_; \
713 }
714
715 #endif /* FT_CONFIG_OPTION_PIC */
716
717 FT_END_HEADER
718
719 #endif /* PSHINTS_H_ */
720
721
722 /* END */