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1 /***************************************************************************/
2 /*                                                                         */
3 /*  ttdriver.c                                                             */
4 /*                                                                         */
5 /*    TrueType font driver implementation (body).                          */
6 /*                                                                         */
7 /*  Copyright 1996-2016 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 #endif
29 
30 #include FT_SERVICE_TRUETYPE_ENGINE_H
31 #include FT_SERVICE_TRUETYPE_GLYF_H
32 #include FT_SERVICE_PROPERTIES_H
33 #include FT_TRUETYPE_DRIVER_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 #include "ttpic.h"
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     (FT_Properties_SetFunc)tt_property_set,     /* set_property */
148     (FT_Properties_GetFunc)tt_property_get )    /* get_property */
149 
150 
151   /*************************************************************************/
152   /*************************************************************************/
153   /*************************************************************************/
154   /****                                                                 ****/
155   /****                                                                 ****/
156   /****                          F A C E S                              ****/
157   /****                                                                 ****/
158   /****                                                                 ****/
159   /*************************************************************************/
160   /*************************************************************************/
161   /*************************************************************************/
162 
163 
164   /*************************************************************************/
165   /*                                                                       */
166   /* <Function>                                                            */
167   /*    tt_get_kerning                                                     */
168   /*                                                                       */
169   /* <Description>                                                         */
170   /*    A driver method used to return the kerning vector between two      */
171   /*    glyphs of the same face.                                           */
172   /*                                                                       */
173   /* <Input>                                                               */
174   /*    face        :: A handle to the source face object.                 */
175   /*                                                                       */
176   /*    left_glyph  :: The index of the left glyph in the kern pair.       */
177   /*                                                                       */
178   /*    right_glyph :: The index of the right glyph in the kern pair.      */
179   /*                                                                       */
180   /* <Output>                                                              */
181   /*    kerning     :: The kerning vector.  This is in font units for      */
182   /*                   scalable formats, and in pixels for fixed-sizes     */
183   /*                   formats.                                            */
184   /*                                                                       */
185   /* <Return>                                                              */
186   /*    FreeType error code.  0 means success.                             */
187   /*                                                                       */
188   /* <Note>                                                                */
189   /*    Only horizontal layouts (left-to-right & right-to-left) are        */
190   /*    supported by this function.  Other layouts, or more sophisticated  */
191   /*    kernings, are out of scope of this method (the basic driver        */
192   /*    interface is meant to be simple).                                  */
193   /*                                                                       */
194   /*    They can be implemented by format-specific interfaces.             */
195   /*                                                                       */
196   static FT_Error
tt_get_kerning(FT_Face ttface,FT_UInt left_glyph,FT_UInt right_glyph,FT_Vector * kerning)197   tt_get_kerning( FT_Face     ttface,          /* TT_Face */
198                   FT_UInt     left_glyph,
199                   FT_UInt     right_glyph,
200                   FT_Vector*  kerning )
201   {
202     TT_Face       face = (TT_Face)ttface;
203     SFNT_Service  sfnt = (SFNT_Service)face->sfnt;
204 
205 
206     kerning->x = 0;
207     kerning->y = 0;
208 
209     if ( sfnt )
210       kerning->x = sfnt->get_kerning( face, left_glyph, right_glyph );
211 
212     return 0;
213   }
214 
215 
216   static FT_Error
tt_get_advances(FT_Face ttface,FT_UInt start,FT_UInt count,FT_Int32 flags,FT_Fixed * advances)217   tt_get_advances( FT_Face    ttface,
218                    FT_UInt    start,
219                    FT_UInt    count,
220                    FT_Int32   flags,
221                    FT_Fixed  *advances )
222   {
223     FT_UInt  nn;
224     TT_Face  face = (TT_Face) ttface;
225 
226 
227     /* XXX: TODO: check for sbits */
228 
229     if ( flags & FT_LOAD_VERTICAL_LAYOUT )
230     {
231       for ( nn = 0; nn < count; nn++ )
232       {
233         FT_Short   tsb;
234         FT_UShort  ah;
235 
236 
237         /* since we don't need `tsb', we use zero for `yMax' parameter */
238         TT_Get_VMetrics( face, start + nn, 0, &tsb, &ah );
239         advances[nn] = ah;
240       }
241     }
242     else
243     {
244       for ( nn = 0; nn < count; nn++ )
245       {
246         FT_Short   lsb;
247         FT_UShort  aw;
248 
249 
250         TT_Get_HMetrics( face, start + nn, &lsb, &aw );
251         advances[nn] = aw;
252       }
253     }
254 
255     return FT_Err_Ok;
256   }
257 
258 
259   /*************************************************************************/
260   /*************************************************************************/
261   /*************************************************************************/
262   /****                                                                 ****/
263   /****                                                                 ****/
264   /****                           S I Z E S                             ****/
265   /****                                                                 ****/
266   /****                                                                 ****/
267   /*************************************************************************/
268   /*************************************************************************/
269   /*************************************************************************/
270 
271 
272 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
273 
274   static FT_Error
tt_size_select(FT_Size size,FT_ULong strike_index)275   tt_size_select( FT_Size   size,
276                   FT_ULong  strike_index )
277   {
278     TT_Face   ttface = (TT_Face)size->face;
279     TT_Size   ttsize = (TT_Size)size;
280     FT_Error  error  = FT_Err_Ok;
281 
282 
283     ttsize->strike_index = strike_index;
284 
285     if ( FT_IS_SCALABLE( size->face ) )
286     {
287       /* use the scaled metrics, even when tt_size_reset fails */
288       FT_Select_Metrics( size->face, strike_index );
289 
290       tt_size_reset( ttsize ); /* ignore return value */
291     }
292     else
293     {
294       SFNT_Service      sfnt    = (SFNT_Service)ttface->sfnt;
295       FT_Size_Metrics*  metrics = &size->metrics;
296 
297 
298       error = sfnt->load_strike_metrics( ttface, strike_index, metrics );
299       if ( error )
300         ttsize->strike_index = 0xFFFFFFFFUL;
301     }
302 
303     return error;
304   }
305 
306 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
307 
308 
309   static FT_Error
tt_size_request(FT_Size size,FT_Size_Request req)310   tt_size_request( FT_Size          size,
311                    FT_Size_Request  req )
312   {
313     TT_Size   ttsize = (TT_Size)size;
314     FT_Error  error  = FT_Err_Ok;
315 
316 
317 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
318 
319     if ( FT_HAS_FIXED_SIZES( size->face ) )
320     {
321       TT_Face       ttface = (TT_Face)size->face;
322       SFNT_Service  sfnt   = (SFNT_Service)ttface->sfnt;
323       FT_ULong      strike_index;
324 
325 
326       error = sfnt->set_sbit_strike( ttface, req, &strike_index );
327 
328       if ( error )
329         ttsize->strike_index = 0xFFFFFFFFUL;
330       else
331         return tt_size_select( size, strike_index );
332     }
333 
334 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
335 
336     FT_Request_Metrics( size->face, req );
337 
338     if ( FT_IS_SCALABLE( size->face ) )
339     {
340       error = tt_size_reset( ttsize );
341       ttsize->root.metrics = ttsize->metrics;
342 
343 #ifdef TT_USE_BYTECODE_INTERPRETER
344       /* for the `MPS' bytecode instruction we need the point size */
345       {
346         FT_UInt  resolution = ttsize->metrics.x_ppem > ttsize->metrics.y_ppem
347                                 ? req->horiResolution
348                                 : req->vertResolution;
349 
350 
351         /* if we don't have a resolution value, assume 72dpi */
352         if ( req->type == FT_SIZE_REQUEST_TYPE_SCALES ||
353              !resolution                              )
354           resolution = 72;
355 
356         ttsize->point_size = FT_MulDiv( ttsize->ttmetrics.ppem,
357                                         64 * 72,
358                                         resolution );
359       }
360 #endif
361     }
362 
363     return error;
364   }
365 
366 
367   /*************************************************************************/
368   /*                                                                       */
369   /* <Function>                                                            */
370   /*    tt_glyph_load                                                      */
371   /*                                                                       */
372   /* <Description>                                                         */
373   /*    A driver method used to load a glyph within a given glyph slot.    */
374   /*                                                                       */
375   /* <Input>                                                               */
376   /*    slot        :: A handle to the target slot object where the glyph  */
377   /*                   will be loaded.                                     */
378   /*                                                                       */
379   /*    size        :: A handle to the source face size at which the glyph */
380   /*                   must be scaled, loaded, etc.                        */
381   /*                                                                       */
382   /*    glyph_index :: The index of the glyph in the font file.            */
383   /*                                                                       */
384   /*    load_flags  :: A flag indicating what to load for this glyph.  The */
385   /*                   FT_LOAD_XXX constants can be used to control the    */
386   /*                   glyph loading process (e.g., whether the outline    */
387   /*                   should be scaled, whether to load bitmaps or not,   */
388   /*                   whether to hint the outline, etc).                  */
389   /*                                                                       */
390   /* <Return>                                                              */
391   /*    FreeType error code.  0 means success.                             */
392   /*                                                                       */
393   static FT_Error
tt_glyph_load(FT_GlyphSlot ttslot,FT_Size ttsize,FT_UInt glyph_index,FT_Int32 load_flags)394   tt_glyph_load( FT_GlyphSlot  ttslot,      /* TT_GlyphSlot */
395                  FT_Size       ttsize,      /* TT_Size      */
396                  FT_UInt       glyph_index,
397                  FT_Int32      load_flags )
398   {
399     TT_GlyphSlot  slot = (TT_GlyphSlot)ttslot;
400     TT_Size       size = (TT_Size)ttsize;
401     FT_Face       face = ttslot->face;
402     FT_Error      error;
403 
404 
405     if ( !slot )
406       return FT_THROW( Invalid_Slot_Handle );
407 
408     if ( !size )
409       return FT_THROW( Invalid_Size_Handle );
410 
411     if ( !face )
412       return FT_THROW( Invalid_Face_Handle );
413 
414 #ifdef FT_CONFIG_OPTION_INCREMENTAL
415     if ( glyph_index >= (FT_UInt)face->num_glyphs &&
416          !face->internal->incremental_interface   )
417 #else
418     if ( glyph_index >= (FT_UInt)face->num_glyphs )
419 #endif
420       return FT_THROW( Invalid_Argument );
421 
422     if ( load_flags & FT_LOAD_NO_HINTING )
423     {
424       /* both FT_LOAD_NO_HINTING and FT_LOAD_NO_AUTOHINT   */
425       /* are necessary to disable hinting for tricky fonts */
426 
427       if ( FT_IS_TRICKY( face ) )
428         load_flags &= ~FT_LOAD_NO_HINTING;
429 
430       if ( load_flags & FT_LOAD_NO_AUTOHINT )
431         load_flags |= FT_LOAD_NO_HINTING;
432     }
433 
434     if ( load_flags & ( FT_LOAD_NO_RECURSE | FT_LOAD_NO_SCALE ) )
435     {
436       load_flags |= FT_LOAD_NO_BITMAP | FT_LOAD_NO_SCALE;
437 
438       if ( !FT_IS_TRICKY( face ) )
439         load_flags |= FT_LOAD_NO_HINTING;
440     }
441 
442     /* now load the glyph outline if necessary */
443     error = TT_Load_Glyph( size, slot, glyph_index, load_flags );
444 
445     /* force drop-out mode to 2 - irrelevant now */
446     /* slot->outline.dropout_mode = 2; */
447 
448     return error;
449   }
450 
451 
452   /*************************************************************************/
453   /*************************************************************************/
454   /*************************************************************************/
455   /****                                                                 ****/
456   /****                                                                 ****/
457   /****                D R I V E R  I N T E R F A C E                   ****/
458   /****                                                                 ****/
459   /****                                                                 ****/
460   /*************************************************************************/
461   /*************************************************************************/
462   /*************************************************************************/
463 
464 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
465   FT_DEFINE_SERVICE_MULTIMASTERSREC(
466     tt_service_gx_multi_masters,
467     (FT_Get_MM_Func)        NULL,                   /* get_mm         */
468     (FT_Set_MM_Design_Func) NULL,                   /* set_mm_design  */
469     (FT_Set_MM_Blend_Func)  TT_Set_MM_Blend,        /* set_mm_blend   */
470     (FT_Get_MM_Var_Func)    TT_Get_MM_Var,          /* get_mm_var     */
471     (FT_Set_Var_Design_Func)TT_Set_Var_Design )     /* set_var_design */
472 #endif
473 
474 
475   static const FT_Service_TrueTypeEngineRec  tt_service_truetype_engine =
476   {
477 #ifdef TT_USE_BYTECODE_INTERPRETER
478 
479     FT_TRUETYPE_ENGINE_TYPE_PATENTED
480 
481 #else /* !TT_USE_BYTECODE_INTERPRETER */
482 
483     FT_TRUETYPE_ENGINE_TYPE_NONE
484 
485 #endif /* TT_USE_BYTECODE_INTERPRETER */
486   };
487 
488 
489   FT_DEFINE_SERVICE_TTGLYFREC(
490     tt_service_truetype_glyf,
491     (TT_Glyf_GetLocationFunc)tt_face_get_location )    /* get_location */
492 
493 
494 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
495   FT_DEFINE_SERVICEDESCREC5(
496     tt_services,
497     FT_SERVICE_ID_FONT_FORMAT,     FT_FONT_FORMAT_TRUETYPE,
498     FT_SERVICE_ID_MULTI_MASTERS,   &TT_SERVICE_GX_MULTI_MASTERS_GET,
499     FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
500     FT_SERVICE_ID_TT_GLYF,         &TT_SERVICE_TRUETYPE_GLYF_GET,
501     FT_SERVICE_ID_PROPERTIES,      &TT_SERVICE_PROPERTIES_GET )
502 #else
503   FT_DEFINE_SERVICEDESCREC4(
504     tt_services,
505     FT_SERVICE_ID_FONT_FORMAT,     FT_FONT_FORMAT_TRUETYPE,
506     FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
507     FT_SERVICE_ID_TT_GLYF,         &TT_SERVICE_TRUETYPE_GLYF_GET,
508     FT_SERVICE_ID_PROPERTIES,      &TT_SERVICE_PROPERTIES_GET )
509 #endif
510 
511 
FT_CALLBACK_DEF(FT_Module_Interface)512   FT_CALLBACK_DEF( FT_Module_Interface )
513   tt_get_interface( FT_Module    driver,    /* TT_Driver */
514                     const char*  tt_interface )
515   {
516     FT_Library           library;
517     FT_Module_Interface  result;
518     FT_Module            sfntd;
519     SFNT_Service         sfnt;
520 
521 
522     /* TT_SERVICES_GET dereferences `library' in PIC mode */
523 #ifdef FT_CONFIG_OPTION_PIC
524     if ( !driver )
525       return NULL;
526     library = driver->library;
527     if ( !library )
528       return NULL;
529 #endif
530 
531     result = ft_service_list_lookup( TT_SERVICES_GET, tt_interface );
532     if ( result != NULL )
533       return result;
534 
535 #ifndef FT_CONFIG_OPTION_PIC
536     if ( !driver )
537       return NULL;
538     library = driver->library;
539     if ( !library )
540       return NULL;
541 #endif
542 
543     /* only return the default interface from the SFNT module */
544     sfntd = FT_Get_Module( library, "sfnt" );
545     if ( sfntd )
546     {
547       sfnt = (SFNT_Service)( sfntd->clazz->module_interface );
548       if ( sfnt )
549         return sfnt->get_interface( driver, tt_interface );
550     }
551 
552     return 0;
553   }
554 
555 
556   /* The FT_DriverInterface structure is defined in ftdriver.h. */
557 
558 #ifdef TT_USE_BYTECODE_INTERPRETER
559 #define TT_HINTER_FLAG  FT_MODULE_DRIVER_HAS_HINTER
560 #else
561 #define TT_HINTER_FLAG  0
562 #endif
563 
564 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
565 #define TT_SIZE_SELECT  tt_size_select
566 #else
567 #define TT_SIZE_SELECT  0
568 #endif
569 
570   FT_DEFINE_DRIVER(
571     tt_driver_class,
572 
573       FT_MODULE_FONT_DRIVER     |
574       FT_MODULE_DRIVER_SCALABLE |
575       TT_HINTER_FLAG,
576 
577       sizeof ( TT_DriverRec ),
578 
579       "truetype",      /* driver name                           */
580       0x10000L,        /* driver version == 1.0                 */
581       0x20000L,        /* driver requires FreeType 2.0 or above */
582 
583       0,    /* module-specific interface */
584 
585       tt_driver_init,           /* FT_Module_Constructor  module_init   */
586       tt_driver_done,           /* FT_Module_Destructor   module_done   */
587       tt_get_interface,         /* FT_Module_Requester    get_interface */
588 
589     sizeof ( TT_FaceRec ),
590     sizeof ( TT_SizeRec ),
591     sizeof ( FT_GlyphSlotRec ),
592 
593     tt_face_init,               /* FT_Face_InitFunc  init_face */
594     tt_face_done,               /* FT_Face_DoneFunc  done_face */
595     tt_size_init,               /* FT_Size_InitFunc  init_size */
596     tt_size_done,               /* FT_Size_DoneFunc  done_size */
597     tt_slot_init,               /* FT_Slot_InitFunc  init_slot */
598     0,                          /* FT_Slot_DoneFunc  done_slot */
599 
600     tt_glyph_load,              /* FT_Slot_LoadFunc  load_glyph */
601 
602     tt_get_kerning,             /* FT_Face_GetKerningFunc   get_kerning  */
603     0,                          /* FT_Face_AttachFunc       attach_file  */
604     tt_get_advances,            /* FT_Face_GetAdvancesFunc  get_advances */
605 
606     tt_size_request,            /* FT_Size_RequestFunc  request_size */
607     TT_SIZE_SELECT              /* FT_Size_SelectFunc   select_size  */
608   )
609 
610 
611 /* END */
612