1 /****************************************************************************
2 *
3 * ttdriver.c
4 *
5 * TrueType font driver implementation (body).
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 #include <freetype/internal/ftdebug.h>
20 #include <freetype/internal/ftstream.h>
21 #include <freetype/internal/sfnt.h>
22 #include <freetype/internal/services/svfntfmt.h>
23
24 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
25 #include <freetype/ftmm.h>
26 #include <freetype/internal/services/svmm.h>
27 #include <freetype/internal/services/svmetric.h>
28 #endif
29
30 #include <freetype/internal/services/svtteng.h>
31 #include <freetype/internal/services/svttglyf.h>
32 #include <freetype/internal/services/svprop.h>
33 #include <freetype/ftdriver.h>
34
35 #include "ttdriver.h"
36 #include "ttgload.h"
37 #include "ttpload.h"
38
39 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
40 #include "ttgxvar.h"
41 #endif
42
43 #include "tterrors.h"
44
45
46 /**************************************************************************
47 *
48 * The macro FT_COMPONENT is used in trace mode. It is an implicit
49 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
50 * messages during execution.
51 */
52 #undef FT_COMPONENT
53 #define FT_COMPONENT ttdriver
54
55
56 /*
57 * PROPERTY SERVICE
58 *
59 */
60 FT_CALLBACK_DEF( FT_Error )
61 tt_property_set( FT_Module module, /* TT_Driver */
62 const char* property_name,
63 const void* value,
64 FT_Bool value_is_string )
65 {
66 FT_Error error = FT_Err_Ok;
67 TT_Driver driver = (TT_Driver)module;
68
69 #ifndef FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES
70 FT_UNUSED( value_is_string );
71 #endif
72
73
74 if ( !ft_strcmp( property_name, "interpreter-version" ) )
75 {
76 FT_UInt interpreter_version;
77
78
79 #ifdef FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES
80 if ( value_is_string )
81 {
82 const char* s = (const char*)value;
83
84
85 interpreter_version = (FT_UInt)ft_strtol( s, NULL, 10 );
86 }
87 else
88 #endif
89 {
90 FT_UInt* iv = (FT_UInt*)value;
91
92
93 interpreter_version = *iv;
94 }
95
96 switch ( interpreter_version )
97 {
98 case TT_INTERPRETER_VERSION_35:
99 driver->interpreter_version = TT_INTERPRETER_VERSION_35;
100 break;
101
102 case TT_INTERPRETER_VERSION_38:
103 case TT_INTERPRETER_VERSION_40:
104 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
105 driver->interpreter_version = TT_INTERPRETER_VERSION_40;
106 break;
107 #endif
108
109 default:
110 error = FT_ERR( Unimplemented_Feature );
111 }
112
113 return error;
114 }
115
116 FT_TRACE2(( "tt_property_set: missing property `%s'\n",
117 property_name ));
118 return FT_THROW( Missing_Property );
119 }
120
121
122 FT_CALLBACK_DEF( FT_Error )
123 tt_property_get( FT_Module module, /* TT_Driver */
124 const char* property_name,
125 void* value )
126 {
127 FT_Error error = FT_Err_Ok;
128 TT_Driver driver = (TT_Driver)module;
129
130 FT_UInt interpreter_version = driver->interpreter_version;
131
132
133 if ( !ft_strcmp( property_name, "interpreter-version" ) )
134 {
135 FT_UInt* val = (FT_UInt*)value;
136
137
138 *val = interpreter_version;
139
140 return error;
141 }
142
143 FT_TRACE2(( "tt_property_get: missing property `%s'\n",
144 property_name ));
145 return FT_THROW( Missing_Property );
146 }
147
148
149 FT_DEFINE_SERVICE_PROPERTIESREC(
150 tt_service_properties,
151
152 tt_property_set, /* FT_Properties_SetFunc set_property */
153 tt_property_get /* FT_Properties_GetFunc get_property */
154 )
155
156
157 /*************************************************************************/
158 /*************************************************************************/
159 /*************************************************************************/
160 /**** ****/
161 /**** ****/
162 /**** F A C E S ****/
163 /**** ****/
164 /**** ****/
165 /*************************************************************************/
166 /*************************************************************************/
167 /*************************************************************************/
168
169
170 /**************************************************************************
171 *
172 * @Function:
173 * tt_get_kerning
174 *
175 * @Description:
176 * A driver method used to return the kerning vector between two
177 * glyphs of the same face.
178 *
179 * @Input:
180 * face ::
181 * A handle to the source face object.
182 *
183 * left_glyph ::
184 * The index of the left glyph in the kern pair.
185 *
186 * right_glyph ::
187 * The index of the right glyph in the kern pair.
188 *
189 * @Output:
190 * kerning ::
191 * The kerning vector. This is in font units for
192 * scalable formats, and in pixels for fixed-sizes
193 * formats.
194 *
195 * @Return:
196 * FreeType error code. 0 means success.
197 *
198 * @Note:
199 * Only horizontal layouts (left-to-right & right-to-left) are
200 * supported by this function. Other layouts, or more sophisticated
201 * kernings, are out of scope of this method (the basic driver
202 * interface is meant to be simple).
203 *
204 * They can be implemented by format-specific interfaces.
205 */
206 FT_CALLBACK_DEF( FT_Error )
207 tt_get_kerning( FT_Face face, /* TT_Face */
208 FT_UInt left_glyph,
209 FT_UInt right_glyph,
210 FT_Vector* kerning )
211 {
212 TT_Face ttface = (TT_Face)face;
213 SFNT_Service sfnt = (SFNT_Service)ttface->sfnt;
214
215
216 kerning->x = 0;
217 kerning->y = 0;
218
219 if ( sfnt )
220 kerning->x = sfnt->get_kerning( ttface, left_glyph, right_glyph );
221
222 return 0;
223 }
224
225
226 FT_CALLBACK_DEF( FT_Error )
227 tt_get_advances( FT_Face face, /* TT_Face */
228 FT_UInt start,
229 FT_UInt count,
230 FT_Int32 flags,
231 FT_Fixed *advances )
232 {
233 FT_UInt nn;
234 TT_Face ttface = (TT_Face)face;
235
236
237 /* XXX: TODO: check for sbits */
238
239 if ( flags & FT_LOAD_VERTICAL_LAYOUT )
240 {
241 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
242 /* no fast retrieval for blended MM fonts without VVAR table */
243 if ( ( FT_IS_NAMED_INSTANCE( face ) || FT_IS_VARIATION( face ) ) &&
244 !( ttface->variation_support & TT_FACE_FLAG_VAR_VADVANCE ) )
245 return FT_THROW( Unimplemented_Feature );
246 #endif
247
248 for ( nn = 0; nn < count; nn++ )
249 {
250 FT_Short tsb;
251 FT_UShort ah;
252
253
254 /* since we don't need `tsb', we use zero for `yMax' parameter */
255 TT_Get_VMetrics( ttface, start + nn, 0, &tsb, &ah );
256 advances[nn] = ah;
257 }
258 }
259 else
260 {
261 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
262 /* no fast retrieval for blended MM fonts without HVAR table */
263 if ( ( FT_IS_NAMED_INSTANCE( face ) || FT_IS_VARIATION( face ) ) &&
264 !( ttface->variation_support & TT_FACE_FLAG_VAR_HADVANCE ) )
265 return FT_THROW( Unimplemented_Feature );
266 #endif
267
268 for ( nn = 0; nn < count; nn++ )
269 {
270 FT_Short lsb;
271 FT_UShort aw;
272
273
274 TT_Get_HMetrics( ttface, start + nn, &lsb, &aw );
275 advances[nn] = aw;
276 }
277 }
278
279 return FT_Err_Ok;
280 }
281
282
283 /*************************************************************************/
284 /*************************************************************************/
285 /*************************************************************************/
286 /**** ****/
287 /**** ****/
288 /**** S I Z E S ****/
289 /**** ****/
290 /**** ****/
291 /*************************************************************************/
292 /*************************************************************************/
293 /*************************************************************************/
294
295
296 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
297
298 FT_CALLBACK_DEF( FT_Error )
299 tt_size_select( FT_Size size,
300 FT_ULong strike_index )
301 {
302 TT_Face ttface = (TT_Face)size->face;
303 TT_Size ttsize = (TT_Size)size;
304 FT_Error error = FT_Err_Ok;
305
306
307 ttsize->strike_index = strike_index;
308
309 if ( FT_IS_SCALABLE( size->face ) )
310 {
311 /* use the scaled metrics, even when tt_size_reset fails */
312 FT_Select_Metrics( size->face, strike_index );
313
314 tt_size_reset( ttsize ); /* ignore return value */
315 }
316 else
317 {
318 SFNT_Service sfnt = (SFNT_Service)ttface->sfnt;
319 FT_Size_Metrics* size_metrics = &size->metrics;
320
321
322 error = sfnt->load_strike_metrics( ttface,
323 strike_index,
324 size_metrics );
325 if ( error )
326 ttsize->strike_index = 0xFFFFFFFFUL;
327 }
328
329 return error;
330 }
331
332 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
333
334
335 FT_CALLBACK_DEF( FT_Error )
336 tt_size_request( FT_Size size,
337 FT_Size_Request req )
338 {
339 TT_Size ttsize = (TT_Size)size;
340 FT_Error error = FT_Err_Ok;
341
342
343 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
344
345 if ( FT_HAS_FIXED_SIZES( size->face ) )
346 {
347 TT_Face ttface = (TT_Face)size->face;
348 SFNT_Service sfnt = (SFNT_Service)ttface->sfnt;
349 FT_ULong strike_index;
350
351
352 error = sfnt->set_sbit_strike( ttface, req, &strike_index );
353
354 if ( error )
355 ttsize->strike_index = 0xFFFFFFFFUL;
356 else
357 return tt_size_select( size, strike_index );
358 }
359
360 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
361
362 {
363 FT_Error err = FT_Request_Metrics( size->face, req );
364
365
366 if ( err )
367 {
368 error = err;
369 goto Exit;
370 }
371 }
372
373 if ( FT_IS_SCALABLE( size->face ) )
374 {
375 error = tt_size_reset( ttsize );
376
377 #ifdef TT_USE_BYTECODE_INTERPRETER
378 /* for the `MPS' bytecode instruction we need the point size */
379 if ( !error )
380 {
381 FT_UInt resolution =
382 ttsize->metrics->x_ppem > ttsize->metrics->y_ppem
383 ? req->horiResolution
384 : req->vertResolution;
385
386
387 /* if we don't have a resolution value, assume 72dpi */
388 if ( req->type == FT_SIZE_REQUEST_TYPE_SCALES ||
389 !resolution )
390 resolution = 72;
391
392 ttsize->point_size = FT_MulDiv( ttsize->ttmetrics.ppem,
393 64 * 72,
394 resolution );
395 }
396 #endif
397 }
398
399 Exit:
400 return error;
401 }
402
403
404 /**************************************************************************
405 *
406 * @Function:
407 * tt_glyph_load
408 *
409 * @Description:
410 * A driver method used to load a glyph within a given glyph slot.
411 *
412 * @Input:
413 * slot ::
414 * A handle to the target slot object where the glyph
415 * will be loaded.
416 *
417 * size ::
418 * A handle to the source face size at which the glyph
419 * must be scaled, loaded, etc.
420 *
421 * glyph_index ::
422 * The index of the glyph in the font file.
423 *
424 * load_flags ::
425 * A flag indicating what to load for this glyph. The
426 * FT_LOAD_XXX constants can be used to control the
427 * glyph loading process (e.g., whether the outline
428 * should be scaled, whether to load bitmaps or not,
429 * whether to hint the outline, etc).
430 *
431 * @Return:
432 * FreeType error code. 0 means success.
433 */
434 FT_CALLBACK_DEF( FT_Error )
435 tt_glyph_load( FT_GlyphSlot slot, /* TT_GlyphSlot */
436 FT_Size size, /* TT_Size */
437 FT_UInt glyph_index,
438 FT_Int32 load_flags )
439 {
440 TT_GlyphSlot ttslot = (TT_GlyphSlot)slot;
441 TT_Size ttsize = (TT_Size)size;
442 FT_Face face = ttslot->face;
443 FT_Error error;
444
445
446 if ( !slot )
447 return FT_THROW( Invalid_Slot_Handle );
448
449 if ( !size )
450 return FT_THROW( Invalid_Size_Handle );
451
452 if ( !face )
453 return FT_THROW( Invalid_Face_Handle );
454
455 #ifdef FT_CONFIG_OPTION_INCREMENTAL
456 if ( glyph_index >= (FT_UInt)face->num_glyphs &&
457 !face->internal->incremental_interface )
458 #else
459 if ( glyph_index >= (FT_UInt)face->num_glyphs )
460 #endif
461 return FT_THROW( Invalid_Argument );
462
463 if ( load_flags & FT_LOAD_NO_HINTING )
464 {
465 /* both FT_LOAD_NO_HINTING and FT_LOAD_NO_AUTOHINT */
466 /* are necessary to disable hinting for tricky fonts */
467
468 if ( FT_IS_TRICKY( face ) )
469 load_flags &= ~FT_LOAD_NO_HINTING;
470
471 if ( load_flags & FT_LOAD_NO_AUTOHINT )
472 load_flags |= FT_LOAD_NO_HINTING;
473 }
474
475 if ( load_flags & ( FT_LOAD_NO_RECURSE | FT_LOAD_NO_SCALE ) )
476 {
477 load_flags |= FT_LOAD_NO_BITMAP | FT_LOAD_NO_SCALE;
478
479 if ( !FT_IS_TRICKY( face ) )
480 load_flags |= FT_LOAD_NO_HINTING;
481 }
482
483 /* use hinted metrics only if we load a glyph with hinting */
484 ttsize->metrics = ( load_flags & FT_LOAD_NO_HINTING )
485 ? &size->metrics
486 : &ttsize->hinted_metrics;
487
488 /* now fill in the glyph slot with outline/bitmap/layered */
489 error = TT_Load_Glyph( ttsize, ttslot, glyph_index, load_flags );
490
491 /* force drop-out mode to 2 - irrelevant now */
492 /* slot->outline.dropout_mode = 2; */
493
494 return error;
495 }
496
497
498 /*************************************************************************/
499 /*************************************************************************/
500 /*************************************************************************/
501 /**** ****/
502 /**** ****/
503 /**** D R I V E R I N T E R F A C E ****/
504 /**** ****/
505 /**** ****/
506 /*************************************************************************/
507 /*************************************************************************/
508 /*************************************************************************/
509
510 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
511
512 FT_DEFINE_SERVICE_MULTIMASTERSREC(
513 tt_service_gx_multi_masters,
514
515 NULL, /* FT_Get_MM_Func get_mm */
516 NULL, /* FT_Set_MM_Design_Func set_mm_design */
517 TT_Set_MM_Blend, /* FT_Set_MM_Blend_Func set_mm_blend */
518 TT_Get_MM_Blend, /* FT_Get_MM_Blend_Func get_mm_blend */
519 TT_Get_MM_Var, /* FT_Get_MM_Var_Func get_mm_var */
520 TT_Set_Var_Design, /* FT_Set_Var_Design_Func set_var_design */
521 TT_Get_Var_Design, /* FT_Get_Var_Design_Func get_var_design */
522 TT_Set_Named_Instance, /* FT_Set_Named_Instance_Func set_named_instance */
523 TT_Get_Default_Named_Instance,
524 /* FT_Get_Default_Named_Instance_Func get_default_named_instance */
525 NULL, /* FT_Set_MM_WeightVector_Func set_mm_weightvector */
526 NULL, /* FT_Get_MM_WeightVector_Func get_mm_weightvector */
527
528 tt_construct_ps_name, /* FT_Construct_PS_Name_Func construct_ps_name */
529 tt_var_load_delta_set_index_mapping,
530 /* FT_Var_Load_Delta_Set_Idx_Map_Func load_delta_set_idx_map */
531 tt_var_load_item_variation_store,
532 /* FT_Var_Load_Item_Var_Store_Func load_item_variation_store */
533 tt_var_get_item_delta, /* FT_Var_Get_Item_Delta_Func get_item_delta */
534 tt_var_done_item_variation_store,
535 /* FT_Var_Done_Item_Var_Store_Func done_item_variation_store */
536 tt_var_done_delta_set_index_map,
537 /* FT_Var_Done_Delta_Set_Idx_Map_Func done_delta_set_index_map */
538 tt_get_var_blend, /* FT_Get_Var_Blend_Func get_var_blend */
539 tt_done_blend /* FT_Done_Blend_Func done_blend */
540 )
541
542 FT_DEFINE_SERVICE_METRICSVARIATIONSREC(
543 tt_service_metrics_variations,
544
545 tt_hadvance_adjust, /* FT_HAdvance_Adjust_Func hadvance_adjust */
546 NULL, /* FT_LSB_Adjust_Func lsb_adjust */
547 NULL, /* FT_RSB_Adjust_Func rsb_adjust */
548
549 tt_vadvance_adjust, /* FT_VAdvance_Adjust_Func vadvance_adjust */
550 NULL, /* FT_TSB_Adjust_Func tsb_adjust */
551 NULL, /* FT_BSB_Adjust_Func bsb_adjust */
552 NULL, /* FT_VOrg_Adjust_Func vorg_adjust */
553
554 tt_apply_mvar, /* FT_Metrics_Adjust_Func metrics_adjust */
555 tt_size_reset_height /* FT_Size_Reset_Func size_reset */
556 )
557
558 #endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
559
560
561 static const FT_Service_TrueTypeEngineRec tt_service_truetype_engine =
562 {
563 #ifdef TT_USE_BYTECODE_INTERPRETER
564
565 FT_TRUETYPE_ENGINE_TYPE_PATENTED
566
567 #else /* !TT_USE_BYTECODE_INTERPRETER */
568
569 FT_TRUETYPE_ENGINE_TYPE_NONE
570
571 #endif /* TT_USE_BYTECODE_INTERPRETER */
572 };
573
574
575 FT_DEFINE_SERVICE_TTGLYFREC(
576 tt_service_truetype_glyf,
577
578 (TT_Glyf_GetLocationFunc)tt_face_get_location /* get_location */
579 )
580
581
582 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
583 FT_DEFINE_SERVICEDESCREC6(
584 tt_services,
585
586 FT_SERVICE_ID_FONT_FORMAT, FT_FONT_FORMAT_TRUETYPE,
587 FT_SERVICE_ID_MULTI_MASTERS, &tt_service_gx_multi_masters,
588 FT_SERVICE_ID_METRICS_VARIATIONS, &tt_service_metrics_variations,
589 FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
590 FT_SERVICE_ID_TT_GLYF, &tt_service_truetype_glyf,
591 FT_SERVICE_ID_PROPERTIES, &tt_service_properties )
592 #else
593 FT_DEFINE_SERVICEDESCREC4(
594 tt_services,
595
596 FT_SERVICE_ID_FONT_FORMAT, FT_FONT_FORMAT_TRUETYPE,
597 FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
598 FT_SERVICE_ID_TT_GLYF, &tt_service_truetype_glyf,
599 FT_SERVICE_ID_PROPERTIES, &tt_service_properties )
600 #endif
601
602
603 FT_CALLBACK_DEF( FT_Module_Interface )
604 tt_get_interface( FT_Module driver, /* TT_Driver */
605 const char* tt_interface )
606 {
607 FT_Library library;
608 FT_Module_Interface result;
609 FT_Module sfntd;
610 SFNT_Service sfnt;
611
612
613 result = ft_service_list_lookup( tt_services, tt_interface );
614 if ( result )
615 return result;
616
617 if ( !driver )
618 return NULL;
619 library = driver->library;
620 if ( !library )
621 return NULL;
622
623 /* only return the default interface from the SFNT module */
624 sfntd = FT_Get_Module( library, "sfnt" );
625 if ( sfntd )
626 {
627 sfnt = (SFNT_Service)( sfntd->clazz->module_interface );
628 if ( sfnt )
629 return sfnt->get_interface( driver, tt_interface );
630 }
631
632 return 0;
633 }
634
635
636 /* The FT_DriverInterface structure is defined in ftdriver.h. */
637
638 #ifdef TT_USE_BYTECODE_INTERPRETER
639 #define TT_HINTER_FLAG FT_MODULE_DRIVER_HAS_HINTER
640 #else
641 #define TT_HINTER_FLAG 0
642 #endif
643
644 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
645 #define TT_SIZE_SELECT tt_size_select
646 #else
647 #define TT_SIZE_SELECT 0
648 #endif
649
650 FT_DEFINE_DRIVER(
651 tt_driver_class,
652
653 FT_MODULE_FONT_DRIVER |
654 FT_MODULE_DRIVER_SCALABLE |
655 TT_HINTER_FLAG,
656
657 sizeof ( TT_DriverRec ),
658
659 "truetype", /* driver name */
660 0x10000L, /* driver version == 1.0 */
661 0x20000L, /* driver requires FreeType 2.0 or above */
662
663 NULL, /* module-specific interface */
664
665 tt_driver_init, /* FT_Module_Constructor module_init */
666 tt_driver_done, /* FT_Module_Destructor module_done */
667 tt_get_interface, /* FT_Module_Requester get_interface */
668
669 sizeof ( TT_FaceRec ),
670 sizeof ( TT_SizeRec ),
671 sizeof ( FT_GlyphSlotRec ),
672
673 tt_face_init, /* FT_Face_InitFunc init_face */
674 tt_face_done, /* FT_Face_DoneFunc done_face */
675 tt_size_init, /* FT_Size_InitFunc init_size */
676 tt_size_done, /* FT_Size_DoneFunc done_size */
677 tt_slot_init, /* FT_Slot_InitFunc init_slot */
678 NULL, /* FT_Slot_DoneFunc done_slot */
679
680 tt_glyph_load, /* FT_Slot_LoadFunc load_glyph */
681
682 tt_get_kerning, /* FT_Face_GetKerningFunc get_kerning */
683 NULL, /* FT_Face_AttachFunc attach_file */
684 tt_get_advances, /* FT_Face_GetAdvancesFunc get_advances */
685
686 tt_size_request, /* FT_Size_RequestFunc request_size */
687 TT_SIZE_SELECT /* FT_Size_SelectFunc select_size */
688 )
689
690
691 /* END */