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1 /****************************************************************************
2  *
3  * ttdriver.c
4  *
5  *   TrueType font driver implementation (body).
6  *
7  * Copyright 1996-2018 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 <ft2build.h>
20 #include FT_INTERNAL_DEBUG_H
21 #include FT_INTERNAL_STREAM_H
22 #include FT_INTERNAL_SFNT_H
23 #include FT_SERVICE_FONT_FORMAT_H
24 
25 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
26 #include FT_MULTIPLE_MASTERS_H
27 #include FT_SERVICE_MULTIPLE_MASTERS_H
28 #include FT_SERVICE_METRICS_VARIATIONS_H
29 #endif
30 
31 #include FT_SERVICE_TRUETYPE_ENGINE_H
32 #include FT_SERVICE_TRUETYPE_GLYF_H
33 #include FT_SERVICE_PROPERTIES_H
34 #include FT_DRIVER_H
35 
36 #include "ttdriver.h"
37 #include "ttgload.h"
38 #include "ttpload.h"
39 
40 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
41 #include "ttgxvar.h"
42 #endif
43 
44 #include "tterrors.h"
45 
46 
47   /**************************************************************************
48    *
49    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
50    * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
51    * messages during execution.
52    */
53 #undef  FT_COMPONENT
54 #define FT_COMPONENT  trace_ttdriver
55 
56 
57   /*
58    * PROPERTY SERVICE
59    *
60    */
61   static FT_Error
tt_property_set(FT_Module module,const char * property_name,const void * value,FT_Bool value_is_string)62   tt_property_set( FT_Module    module,         /* TT_Driver */
63                    const char*  property_name,
64                    const void*  value,
65                    FT_Bool      value_is_string )
66   {
67     FT_Error   error  = FT_Err_Ok;
68     TT_Driver  driver = (TT_Driver)module;
69 
70 #ifndef FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES
71     FT_UNUSED( value_is_string );
72 #endif
73 
74 
75     if ( !ft_strcmp( property_name, "interpreter-version" ) )
76     {
77       FT_UInt  interpreter_version;
78 
79 
80 #ifdef FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES
81       if ( value_is_string )
82       {
83         const char*  s = (const char*)value;
84 
85 
86         interpreter_version = (FT_UInt)ft_strtol( s, NULL, 10 );
87       }
88       else
89 #endif
90       {
91         FT_UInt*  iv = (FT_UInt*)value;
92 
93 
94         interpreter_version = *iv;
95       }
96 
97       if ( interpreter_version == TT_INTERPRETER_VERSION_35
98 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
99            || interpreter_version == TT_INTERPRETER_VERSION_38
100 #endif
101 #ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
102            || interpreter_version == TT_INTERPRETER_VERSION_40
103 #endif
104          )
105         driver->interpreter_version = interpreter_version;
106       else
107         error = FT_ERR( Unimplemented_Feature );
108 
109       return error;
110     }
111 
112     FT_TRACE0(( "tt_property_set: missing property `%s'\n",
113                 property_name ));
114     return FT_THROW( Missing_Property );
115   }
116 
117 
118   static FT_Error
tt_property_get(FT_Module module,const char * property_name,const void * value)119   tt_property_get( FT_Module    module,         /* TT_Driver */
120                    const char*  property_name,
121                    const void*  value )
122   {
123     FT_Error   error  = FT_Err_Ok;
124     TT_Driver  driver = (TT_Driver)module;
125 
126     FT_UInt  interpreter_version = driver->interpreter_version;
127 
128 
129     if ( !ft_strcmp( property_name, "interpreter-version" ) )
130     {
131       FT_UInt*  val = (FT_UInt*)value;
132 
133 
134       *val = interpreter_version;
135 
136       return error;
137     }
138 
139     FT_TRACE0(( "tt_property_get: missing property `%s'\n",
140                 property_name ));
141     return FT_THROW( Missing_Property );
142   }
143 
144 
145   FT_DEFINE_SERVICE_PROPERTIESREC(
146     tt_service_properties,
147 
148     (FT_Properties_SetFunc)tt_property_set,     /* set_property */
149     (FT_Properties_GetFunc)tt_property_get      /* get_property */
150   )
151 
152 
153   /*************************************************************************/
154   /*************************************************************************/
155   /*************************************************************************/
156   /****                                                                 ****/
157   /****                                                                 ****/
158   /****                          F A C E S                              ****/
159   /****                                                                 ****/
160   /****                                                                 ****/
161   /*************************************************************************/
162   /*************************************************************************/
163   /*************************************************************************/
164 
165 
166   /**************************************************************************
167    *
168    * @Function:
169    *   tt_get_kerning
170    *
171    * @Description:
172    *   A driver method used to return the kerning vector between two
173    *   glyphs of the same face.
174    *
175    * @Input:
176    *   face ::
177    *     A handle to the source face object.
178    *
179    *   left_glyph ::
180    *     The index of the left glyph in the kern pair.
181    *
182    *   right_glyph ::
183    *     The index of the right glyph in the kern pair.
184    *
185    * @Output:
186    *   kerning ::
187    *     The kerning vector.  This is in font units for
188    *     scalable formats, and in pixels for fixed-sizes
189    *     formats.
190    *
191    * @Return:
192    *   FreeType error code.  0 means success.
193    *
194    * @Note:
195    *   Only horizontal layouts (left-to-right & right-to-left) are
196    *   supported by this function.  Other layouts, or more sophisticated
197    *   kernings, are out of scope of this method (the basic driver
198    *   interface is meant to be simple).
199    *
200    *   They can be implemented by format-specific interfaces.
201    */
202   static FT_Error
tt_get_kerning(FT_Face ttface,FT_UInt left_glyph,FT_UInt right_glyph,FT_Vector * kerning)203   tt_get_kerning( FT_Face     ttface,          /* TT_Face */
204                   FT_UInt     left_glyph,
205                   FT_UInt     right_glyph,
206                   FT_Vector*  kerning )
207   {
208     TT_Face       face = (TT_Face)ttface;
209     SFNT_Service  sfnt = (SFNT_Service)face->sfnt;
210 
211 
212     kerning->x = 0;
213     kerning->y = 0;
214 
215     if ( sfnt )
216       kerning->x = sfnt->get_kerning( face, left_glyph, right_glyph );
217 
218     return 0;
219   }
220 
221 
222   static FT_Error
tt_get_advances(FT_Face ttface,FT_UInt start,FT_UInt count,FT_Int32 flags,FT_Fixed * advances)223   tt_get_advances( FT_Face    ttface,
224                    FT_UInt    start,
225                    FT_UInt    count,
226                    FT_Int32   flags,
227                    FT_Fixed  *advances )
228   {
229     FT_UInt  nn;
230     TT_Face  face = (TT_Face)ttface;
231 
232 
233     /* XXX: TODO: check for sbits */
234 
235     if ( flags & FT_LOAD_VERTICAL_LAYOUT )
236     {
237 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
238       /* no fast retrieval for blended MM fonts without VVAR table */
239       if ( ( FT_IS_NAMED_INSTANCE( ttface ) || FT_IS_VARIATION( ttface ) ) &&
240            !( face->variation_support & TT_FACE_FLAG_VAR_VADVANCE )        )
241         return FT_THROW( Unimplemented_Feature );
242 #endif
243 
244       for ( nn = 0; nn < count; nn++ )
245       {
246         FT_Short   tsb;
247         FT_UShort  ah;
248 
249 
250         /* since we don't need `tsb', we use zero for `yMax' parameter */
251         TT_Get_VMetrics( face, start + nn, 0, &tsb, &ah );
252         advances[nn] = ah;
253       }
254     }
255     else
256     {
257 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
258       /* no fast retrieval for blended MM fonts without HVAR table */
259       if ( ( FT_IS_NAMED_INSTANCE( ttface ) || FT_IS_VARIATION( ttface ) ) &&
260            !( face->variation_support & TT_FACE_FLAG_VAR_HADVANCE )        )
261         return FT_THROW( Unimplemented_Feature );
262 #endif
263 
264       for ( nn = 0; nn < count; nn++ )
265       {
266         FT_Short   lsb;
267         FT_UShort  aw;
268 
269 
270         TT_Get_HMetrics( face, start + nn, &lsb, &aw );
271         advances[nn] = aw;
272       }
273     }
274 
275     return FT_Err_Ok;
276   }
277 
278 
279   /*************************************************************************/
280   /*************************************************************************/
281   /*************************************************************************/
282   /****                                                                 ****/
283   /****                                                                 ****/
284   /****                           S I Z E S                             ****/
285   /****                                                                 ****/
286   /****                                                                 ****/
287   /*************************************************************************/
288   /*************************************************************************/
289   /*************************************************************************/
290 
291 
292 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
293 
294   static FT_Error
tt_size_select(FT_Size size,FT_ULong strike_index)295   tt_size_select( FT_Size   size,
296                   FT_ULong  strike_index )
297   {
298     TT_Face   ttface = (TT_Face)size->face;
299     TT_Size   ttsize = (TT_Size)size;
300     FT_Error  error  = FT_Err_Ok;
301 
302 
303     ttsize->strike_index = strike_index;
304 
305     if ( FT_IS_SCALABLE( size->face ) )
306     {
307       /* use the scaled metrics, even when tt_size_reset fails */
308       FT_Select_Metrics( size->face, strike_index );
309 
310       tt_size_reset( ttsize, 0 ); /* ignore return value */
311     }
312     else
313     {
314       SFNT_Service      sfnt         = (SFNT_Service)ttface->sfnt;
315       FT_Size_Metrics*  size_metrics = &size->metrics;
316 
317 
318       error = sfnt->load_strike_metrics( ttface,
319                                          strike_index,
320                                          size_metrics );
321       if ( error )
322         ttsize->strike_index = 0xFFFFFFFFUL;
323     }
324 
325     return error;
326   }
327 
328 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
329 
330 
331   static FT_Error
tt_size_request(FT_Size size,FT_Size_Request req)332   tt_size_request( FT_Size          size,
333                    FT_Size_Request  req )
334   {
335     TT_Size   ttsize = (TT_Size)size;
336     FT_Error  error  = FT_Err_Ok;
337 
338 
339 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
340 
341     if ( FT_HAS_FIXED_SIZES( size->face ) )
342     {
343       TT_Face       ttface = (TT_Face)size->face;
344       SFNT_Service  sfnt   = (SFNT_Service)ttface->sfnt;
345       FT_ULong      strike_index;
346 
347 
348       error = sfnt->set_sbit_strike( ttface, req, &strike_index );
349 
350       if ( error )
351         ttsize->strike_index = 0xFFFFFFFFUL;
352       else
353         return tt_size_select( size, strike_index );
354     }
355 
356 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
357 
358     FT_Request_Metrics( size->face, req );
359 
360     if ( FT_IS_SCALABLE( size->face ) )
361     {
362       error = tt_size_reset( ttsize, 0 );
363 
364 #ifdef TT_USE_BYTECODE_INTERPRETER
365       /* for the `MPS' bytecode instruction we need the point size */
366       if ( !error )
367       {
368         FT_UInt  resolution =
369                    ttsize->metrics->x_ppem > ttsize->metrics->y_ppem
370                      ? req->horiResolution
371                      : req->vertResolution;
372 
373 
374         /* if we don't have a resolution value, assume 72dpi */
375         if ( req->type == FT_SIZE_REQUEST_TYPE_SCALES ||
376              !resolution                              )
377           resolution = 72;
378 
379         ttsize->point_size = FT_MulDiv( ttsize->ttmetrics.ppem,
380                                         64 * 72,
381                                         resolution );
382       }
383 #endif
384     }
385 
386     return error;
387   }
388 
389 
390   /**************************************************************************
391    *
392    * @Function:
393    *   tt_glyph_load
394    *
395    * @Description:
396    *   A driver method used to load a glyph within a given glyph slot.
397    *
398    * @Input:
399    *   slot ::
400    *     A handle to the target slot object where the glyph
401    *     will be loaded.
402    *
403    *   size ::
404    *     A handle to the source face size at which the glyph
405    *     must be scaled, loaded, etc.
406    *
407    *   glyph_index ::
408    *     The index of the glyph in the font file.
409    *
410    *   load_flags ::
411    *     A flag indicating what to load for this glyph.  The
412    *     FT_LOAD_XXX constants can be used to control the
413    *     glyph loading process (e.g., whether the outline
414    *     should be scaled, whether to load bitmaps or not,
415    *     whether to hint the outline, etc).
416    *
417    * @Return:
418    *   FreeType error code.  0 means success.
419    */
420   static FT_Error
tt_glyph_load(FT_GlyphSlot ttslot,FT_Size ttsize,FT_UInt glyph_index,FT_Int32 load_flags)421   tt_glyph_load( FT_GlyphSlot  ttslot,      /* TT_GlyphSlot */
422                  FT_Size       ttsize,      /* TT_Size      */
423                  FT_UInt       glyph_index,
424                  FT_Int32      load_flags )
425   {
426     TT_GlyphSlot  slot = (TT_GlyphSlot)ttslot;
427     TT_Size       size = (TT_Size)ttsize;
428     FT_Face       face = ttslot->face;
429     FT_Error      error;
430 
431 
432     if ( !slot )
433       return FT_THROW( Invalid_Slot_Handle );
434 
435     if ( !size )
436       return FT_THROW( Invalid_Size_Handle );
437 
438     if ( !face )
439       return FT_THROW( Invalid_Face_Handle );
440 
441 #ifdef FT_CONFIG_OPTION_INCREMENTAL
442     if ( glyph_index >= (FT_UInt)face->num_glyphs &&
443          !face->internal->incremental_interface   )
444 #else
445     if ( glyph_index >= (FT_UInt)face->num_glyphs )
446 #endif
447       return FT_THROW( Invalid_Argument );
448 
449     if ( load_flags & FT_LOAD_NO_HINTING )
450     {
451       /* both FT_LOAD_NO_HINTING and FT_LOAD_NO_AUTOHINT   */
452       /* are necessary to disable hinting for tricky fonts */
453 
454       if ( FT_IS_TRICKY( face ) )
455         load_flags &= ~FT_LOAD_NO_HINTING;
456 
457       if ( load_flags & FT_LOAD_NO_AUTOHINT )
458         load_flags |= FT_LOAD_NO_HINTING;
459     }
460 
461     if ( load_flags & ( FT_LOAD_NO_RECURSE | FT_LOAD_NO_SCALE ) )
462     {
463       load_flags |= FT_LOAD_NO_BITMAP | FT_LOAD_NO_SCALE;
464 
465       if ( !FT_IS_TRICKY( face ) )
466         load_flags |= FT_LOAD_NO_HINTING;
467     }
468 
469     /* use hinted metrics only if we load a glyph with hinting */
470     size->metrics = ( load_flags & FT_LOAD_NO_HINTING )
471                       ? &ttsize->metrics
472                       : &size->hinted_metrics;
473 
474     /* now fill in the glyph slot with outline/bitmap/layered */
475     error = TT_Load_Glyph( size, slot, glyph_index, load_flags );
476 
477     /* force drop-out mode to 2 - irrelevant now */
478     /* slot->outline.dropout_mode = 2; */
479 
480     return error;
481   }
482 
483 
484   /*************************************************************************/
485   /*************************************************************************/
486   /*************************************************************************/
487   /****                                                                 ****/
488   /****                                                                 ****/
489   /****                D R I V E R  I N T E R F A C E                   ****/
490   /****                                                                 ****/
491   /****                                                                 ****/
492   /*************************************************************************/
493   /*************************************************************************/
494   /*************************************************************************/
495 
496 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
497 
498   FT_DEFINE_SERVICE_MULTIMASTERSREC(
499     tt_service_gx_multi_masters,
500 
501     (FT_Get_MM_Func)        NULL,                   /* get_mm         */
502     (FT_Set_MM_Design_Func) NULL,                   /* set_mm_design  */
503     (FT_Set_MM_Blend_Func)  TT_Set_MM_Blend,        /* set_mm_blend   */
504     (FT_Get_MM_Blend_Func)  TT_Get_MM_Blend,        /* get_mm_blend   */
505     (FT_Get_MM_Var_Func)    TT_Get_MM_Var,          /* get_mm_var     */
506     (FT_Set_Var_Design_Func)TT_Set_Var_Design,      /* set_var_design */
507     (FT_Get_Var_Design_Func)TT_Get_Var_Design,      /* get_var_design */
508     (FT_Set_Instance_Func)  TT_Set_Named_Instance,  /* set_instance   */
509 
510     (FT_Get_Var_Blend_Func) tt_get_var_blend,       /* get_var_blend  */
511     (FT_Done_Blend_Func)    tt_done_blend           /* done_blend     */
512   )
513 
514   FT_DEFINE_SERVICE_METRICSVARIATIONSREC(
515     tt_service_metrics_variations,
516 
517     (FT_HAdvance_Adjust_Func)tt_hadvance_adjust,     /* hadvance_adjust */
518     (FT_LSB_Adjust_Func)     NULL,                   /* lsb_adjust      */
519     (FT_RSB_Adjust_Func)     NULL,                   /* rsb_adjust      */
520 
521     (FT_VAdvance_Adjust_Func)tt_vadvance_adjust,     /* vadvance_adjust */
522     (FT_TSB_Adjust_Func)     NULL,                   /* tsb_adjust      */
523     (FT_BSB_Adjust_Func)     NULL,                   /* bsb_adjust      */
524     (FT_VOrg_Adjust_Func)    NULL,                   /* vorg_adjust     */
525 
526     (FT_Metrics_Adjust_Func) tt_apply_mvar           /* metrics_adjust  */
527   )
528 
529 #endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
530 
531 
532   static const FT_Service_TrueTypeEngineRec  tt_service_truetype_engine =
533   {
534 #ifdef TT_USE_BYTECODE_INTERPRETER
535 
536     FT_TRUETYPE_ENGINE_TYPE_PATENTED
537 
538 #else /* !TT_USE_BYTECODE_INTERPRETER */
539 
540     FT_TRUETYPE_ENGINE_TYPE_NONE
541 
542 #endif /* TT_USE_BYTECODE_INTERPRETER */
543   };
544 
545 
546   FT_DEFINE_SERVICE_TTGLYFREC(
547     tt_service_truetype_glyf,
548 
549     (TT_Glyf_GetLocationFunc)tt_face_get_location      /* get_location */
550   )
551 
552 
553 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
554   FT_DEFINE_SERVICEDESCREC6(
555     tt_services,
556 
557     FT_SERVICE_ID_FONT_FORMAT,        FT_FONT_FORMAT_TRUETYPE,
558     FT_SERVICE_ID_MULTI_MASTERS,      &tt_service_gx_multi_masters,
559     FT_SERVICE_ID_METRICS_VARIATIONS, &tt_service_metrics_variations,
560     FT_SERVICE_ID_TRUETYPE_ENGINE,    &tt_service_truetype_engine,
561     FT_SERVICE_ID_TT_GLYF,            &tt_service_truetype_glyf,
562     FT_SERVICE_ID_PROPERTIES,         &tt_service_properties )
563 #else
564   FT_DEFINE_SERVICEDESCREC4(
565     tt_services,
566 
567     FT_SERVICE_ID_FONT_FORMAT,     FT_FONT_FORMAT_TRUETYPE,
568     FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
569     FT_SERVICE_ID_TT_GLYF,         &tt_service_truetype_glyf,
570     FT_SERVICE_ID_PROPERTIES,      &tt_service_properties )
571 #endif
572 
573 
FT_CALLBACK_DEF(FT_Module_Interface)574   FT_CALLBACK_DEF( FT_Module_Interface )
575   tt_get_interface( FT_Module    driver,    /* TT_Driver */
576                     const char*  tt_interface )
577   {
578     FT_Library           library;
579     FT_Module_Interface  result;
580     FT_Module            sfntd;
581     SFNT_Service         sfnt;
582 
583 
584     result = ft_service_list_lookup( tt_services, tt_interface );
585     if ( result )
586       return result;
587 
588     if ( !driver )
589       return NULL;
590     library = driver->library;
591     if ( !library )
592       return NULL;
593 
594     /* only return the default interface from the SFNT module */
595     sfntd = FT_Get_Module( library, "sfnt" );
596     if ( sfntd )
597     {
598       sfnt = (SFNT_Service)( sfntd->clazz->module_interface );
599       if ( sfnt )
600         return sfnt->get_interface( driver, tt_interface );
601     }
602 
603     return 0;
604   }
605 
606 
607   /* The FT_DriverInterface structure is defined in ftdriver.h. */
608 
609 #ifdef TT_USE_BYTECODE_INTERPRETER
610 #define TT_HINTER_FLAG  FT_MODULE_DRIVER_HAS_HINTER
611 #else
612 #define TT_HINTER_FLAG  0
613 #endif
614 
615 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
616 #define TT_SIZE_SELECT  tt_size_select
617 #else
618 #define TT_SIZE_SELECT  0
619 #endif
620 
621   FT_DEFINE_DRIVER(
622     tt_driver_class,
623 
624       FT_MODULE_FONT_DRIVER     |
625       FT_MODULE_DRIVER_SCALABLE |
626       TT_HINTER_FLAG,
627 
628       sizeof ( TT_DriverRec ),
629 
630       "truetype",      /* driver name                           */
631       0x10000L,        /* driver version == 1.0                 */
632       0x20000L,        /* driver requires FreeType 2.0 or above */
633 
634       NULL,    /* module-specific interface */
635 
636       tt_driver_init,           /* FT_Module_Constructor  module_init   */
637       tt_driver_done,           /* FT_Module_Destructor   module_done   */
638       tt_get_interface,         /* FT_Module_Requester    get_interface */
639 
640     sizeof ( TT_FaceRec ),
641     sizeof ( TT_SizeRec ),
642     sizeof ( FT_GlyphSlotRec ),
643 
644     tt_face_init,               /* FT_Face_InitFunc  init_face */
645     tt_face_done,               /* FT_Face_DoneFunc  done_face */
646     tt_size_init,               /* FT_Size_InitFunc  init_size */
647     tt_size_done,               /* FT_Size_DoneFunc  done_size */
648     tt_slot_init,               /* FT_Slot_InitFunc  init_slot */
649     NULL,                       /* FT_Slot_DoneFunc  done_slot */
650 
651     tt_glyph_load,              /* FT_Slot_LoadFunc  load_glyph */
652 
653     tt_get_kerning,             /* FT_Face_GetKerningFunc   get_kerning  */
654     NULL,                       /* FT_Face_AttachFunc       attach_file  */
655     tt_get_advances,            /* FT_Face_GetAdvancesFunc  get_advances */
656 
657     tt_size_request,            /* FT_Size_RequestFunc  request_size */
658     TT_SIZE_SELECT              /* FT_Size_SelectFunc   select_size  */
659   )
660 
661 
662 /* END */
663