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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  ttdriver.c                                                             */
      4 /*                                                                         */
      5 /*    TrueType font driver implementation (body).                          */
      6 /*                                                                         */
      7 /*  Copyright 1996-2015 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
     62   tt_property_set( FT_Module    module,         /* TT_Driver */
     63                    const char*  property_name,
     64                    const void*  value )
     65   {
     66     FT_Error   error  = FT_Err_Ok;
     67     TT_Driver  driver = (TT_Driver)module;
     68 
     69 
     70     if ( !ft_strcmp( property_name, "interpreter-version" ) )
     71     {
     72       FT_UInt*  interpreter_version = (FT_UInt*)value;
     73 
     74 
     75 #ifndef TT_CONFIG_OPTION_SUBPIXEL_HINTING
     76       if ( *interpreter_version != TT_INTERPRETER_VERSION_35 )
     77         error = FT_ERR( Unimplemented_Feature );
     78       else
     79 #endif
     80         driver->interpreter_version = *interpreter_version;
     81 
     82       return error;
     83     }
     84 
     85     FT_TRACE0(( "tt_property_set: missing property `%s'\n",
     86                 property_name ));
     87     return FT_THROW( Missing_Property );
     88   }
     89 
     90 
     91   static FT_Error
     92   tt_property_get( FT_Module    module,         /* TT_Driver */
     93                    const char*  property_name,
     94                    const void*  value )
     95   {
     96     FT_Error   error  = FT_Err_Ok;
     97     TT_Driver  driver = (TT_Driver)module;
     98 
     99     FT_UInt  interpreter_version = driver->interpreter_version;
    100 
    101 
    102     if ( !ft_strcmp( property_name, "interpreter-version" ) )
    103     {
    104       FT_UInt*  val = (FT_UInt*)value;
    105 
    106 
    107       *val = interpreter_version;
    108 
    109       return error;
    110     }
    111 
    112     FT_TRACE0(( "tt_property_get: missing property `%s'\n",
    113                 property_name ));
    114     return FT_THROW( Missing_Property );
    115   }
    116 
    117 
    118   FT_DEFINE_SERVICE_PROPERTIESREC(
    119     tt_service_properties,
    120     (FT_Properties_SetFunc)tt_property_set,
    121     (FT_Properties_GetFunc)tt_property_get )
    122 
    123 
    124   /*************************************************************************/
    125   /*************************************************************************/
    126   /*************************************************************************/
    127   /****                                                                 ****/
    128   /****                                                                 ****/
    129   /****                          F A C E S                              ****/
    130   /****                                                                 ****/
    131   /****                                                                 ****/
    132   /*************************************************************************/
    133   /*************************************************************************/
    134   /*************************************************************************/
    135 
    136 
    137   /*************************************************************************/
    138   /*                                                                       */
    139   /* <Function>                                                            */
    140   /*    tt_get_kerning                                                     */
    141   /*                                                                       */
    142   /* <Description>                                                         */
    143   /*    A driver method used to return the kerning vector between two      */
    144   /*    glyphs of the same face.                                           */
    145   /*                                                                       */
    146   /* <Input>                                                               */
    147   /*    face        :: A handle to the source face object.                 */
    148   /*                                                                       */
    149   /*    left_glyph  :: The index of the left glyph in the kern pair.       */
    150   /*                                                                       */
    151   /*    right_glyph :: The index of the right glyph in the kern pair.      */
    152   /*                                                                       */
    153   /* <Output>                                                              */
    154   /*    kerning     :: The kerning vector.  This is in font units for      */
    155   /*                   scalable formats, and in pixels for fixed-sizes     */
    156   /*                   formats.                                            */
    157   /*                                                                       */
    158   /* <Return>                                                              */
    159   /*    FreeType error code.  0 means success.                             */
    160   /*                                                                       */
    161   /* <Note>                                                                */
    162   /*    Only horizontal layouts (left-to-right & right-to-left) are        */
    163   /*    supported by this function.  Other layouts, or more sophisticated  */
    164   /*    kernings, are out of scope of this method (the basic driver        */
    165   /*    interface is meant to be simple).                                  */
    166   /*                                                                       */
    167   /*    They can be implemented by format-specific interfaces.             */
    168   /*                                                                       */
    169   static FT_Error
    170   tt_get_kerning( FT_Face     ttface,          /* TT_Face */
    171                   FT_UInt     left_glyph,
    172                   FT_UInt     right_glyph,
    173                   FT_Vector*  kerning )
    174   {
    175     TT_Face       face = (TT_Face)ttface;
    176     SFNT_Service  sfnt = (SFNT_Service)face->sfnt;
    177 
    178 
    179     kerning->x = 0;
    180     kerning->y = 0;
    181 
    182     if ( sfnt )
    183       kerning->x = sfnt->get_kerning( face, left_glyph, right_glyph );
    184 
    185     return 0;
    186   }
    187 
    188 
    189   static FT_Error
    190   tt_get_advances( FT_Face    ttface,
    191                    FT_UInt    start,
    192                    FT_UInt    count,
    193                    FT_Int32   flags,
    194                    FT_Fixed  *advances )
    195   {
    196     FT_UInt  nn;
    197     TT_Face  face  = (TT_Face) ttface;
    198 
    199 
    200     /* XXX: TODO: check for sbits */
    201 
    202     if ( flags & FT_LOAD_VERTICAL_LAYOUT )
    203     {
    204       for ( nn = 0; nn < count; nn++ )
    205       {
    206         FT_Short   tsb;
    207         FT_UShort  ah;
    208 
    209 
    210         /* since we don't need `tsb', we use zero for `yMax' parameter */
    211         TT_Get_VMetrics( face, start + nn, 0, &tsb, &ah );
    212         advances[nn] = ah;
    213       }
    214     }
    215     else
    216     {
    217       for ( nn = 0; nn < count; nn++ )
    218       {
    219         FT_Short   lsb;
    220         FT_UShort  aw;
    221 
    222 
    223         TT_Get_HMetrics( face, start + nn, &lsb, &aw );
    224         advances[nn] = aw;
    225       }
    226     }
    227 
    228     return FT_Err_Ok;
    229   }
    230 
    231   /*************************************************************************/
    232   /*************************************************************************/
    233   /*************************************************************************/
    234   /****                                                                 ****/
    235   /****                                                                 ****/
    236   /****                           S I Z E S                             ****/
    237   /****                                                                 ****/
    238   /****                                                                 ****/
    239   /*************************************************************************/
    240   /*************************************************************************/
    241   /*************************************************************************/
    242 
    243 
    244 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    245 
    246   static FT_Error
    247   tt_size_select( FT_Size   size,
    248                   FT_ULong  strike_index )
    249   {
    250     TT_Face   ttface = (TT_Face)size->face;
    251     TT_Size   ttsize = (TT_Size)size;
    252     FT_Error  error  = FT_Err_Ok;
    253 
    254 
    255     ttsize->strike_index = strike_index;
    256 
    257     if ( FT_IS_SCALABLE( size->face ) )
    258     {
    259       /* use the scaled metrics, even when tt_size_reset fails */
    260       FT_Select_Metrics( size->face, strike_index );
    261 
    262       tt_size_reset( ttsize ); /* ignore return value */
    263     }
    264     else
    265     {
    266       SFNT_Service      sfnt    = (SFNT_Service) ttface->sfnt;
    267       FT_Size_Metrics*  metrics = &size->metrics;
    268 
    269 
    270       error = sfnt->load_strike_metrics( ttface, strike_index, metrics );
    271       if ( error )
    272         ttsize->strike_index = 0xFFFFFFFFUL;
    273     }
    274 
    275     return error;
    276   }
    277 
    278 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
    279 
    280 
    281   static FT_Error
    282   tt_size_request( FT_Size          size,
    283                    FT_Size_Request  req )
    284   {
    285     TT_Size   ttsize = (TT_Size)size;
    286     FT_Error  error  = FT_Err_Ok;
    287 
    288 
    289 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    290 
    291     if ( FT_HAS_FIXED_SIZES( size->face ) )
    292     {
    293       TT_Face       ttface = (TT_Face)size->face;
    294       SFNT_Service  sfnt   = (SFNT_Service) ttface->sfnt;
    295       FT_ULong      strike_index;
    296 
    297 
    298       error = sfnt->set_sbit_strike( ttface, req, &strike_index );
    299 
    300       if ( error )
    301         ttsize->strike_index = 0xFFFFFFFFUL;
    302       else
    303         return tt_size_select( size, strike_index );
    304     }
    305 
    306 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
    307 
    308     FT_Request_Metrics( size->face, req );
    309 
    310     if ( FT_IS_SCALABLE( size->face ) )
    311     {
    312       error = tt_size_reset( ttsize );
    313       ttsize->root.metrics = ttsize->metrics;
    314     }
    315 
    316     return error;
    317   }
    318 
    319 
    320   /*************************************************************************/
    321   /*                                                                       */
    322   /* <Function>                                                            */
    323   /*    tt_glyph_load                                                      */
    324   /*                                                                       */
    325   /* <Description>                                                         */
    326   /*    A driver method used to load a glyph within a given glyph slot.    */
    327   /*                                                                       */
    328   /* <Input>                                                               */
    329   /*    slot        :: A handle to the target slot object where the glyph  */
    330   /*                   will be loaded.                                     */
    331   /*                                                                       */
    332   /*    size        :: A handle to the source face size at which the glyph */
    333   /*                   must be scaled, loaded, etc.                        */
    334   /*                                                                       */
    335   /*    glyph_index :: The index of the glyph in the font file.            */
    336   /*                                                                       */
    337   /*    load_flags  :: A flag indicating what to load for this glyph.  The */
    338   /*                   FT_LOAD_XXX constants can be used to control the    */
    339   /*                   glyph loading process (e.g., whether the outline    */
    340   /*                   should be scaled, whether to load bitmaps or not,   */
    341   /*                   whether to hint the outline, etc).                  */
    342   /*                                                                       */
    343   /* <Return>                                                              */
    344   /*    FreeType error code.  0 means success.                             */
    345   /*                                                                       */
    346   static FT_Error
    347   tt_glyph_load( FT_GlyphSlot  ttslot,      /* TT_GlyphSlot */
    348                  FT_Size       ttsize,      /* TT_Size      */
    349                  FT_UInt       glyph_index,
    350                  FT_Int32      load_flags )
    351   {
    352     TT_GlyphSlot  slot = (TT_GlyphSlot)ttslot;
    353     TT_Size       size = (TT_Size)ttsize;
    354     FT_Face       face = ttslot->face;
    355     FT_Error      error;
    356 
    357 
    358     if ( !slot )
    359       return FT_THROW( Invalid_Slot_Handle );
    360 
    361     if ( !size )
    362       return FT_THROW( Invalid_Size_Handle );
    363 
    364     if ( !face )
    365       return FT_THROW( Invalid_Face_Handle );
    366 
    367 #ifdef FT_CONFIG_OPTION_INCREMENTAL
    368     if ( glyph_index >= (FT_UInt)face->num_glyphs &&
    369          !face->internal->incremental_interface   )
    370 #else
    371     if ( glyph_index >= (FT_UInt)face->num_glyphs )
    372 #endif
    373       return FT_THROW( Invalid_Argument );
    374 
    375     if ( load_flags & FT_LOAD_NO_HINTING )
    376     {
    377       /* both FT_LOAD_NO_HINTING and FT_LOAD_NO_AUTOHINT   */
    378       /* are necessary to disable hinting for tricky fonts */
    379 
    380       if ( FT_IS_TRICKY( face ) )
    381         load_flags &= ~FT_LOAD_NO_HINTING;
    382 
    383       if ( load_flags & FT_LOAD_NO_AUTOHINT )
    384         load_flags |= FT_LOAD_NO_HINTING;
    385     }
    386 
    387     if ( load_flags & ( FT_LOAD_NO_RECURSE | FT_LOAD_NO_SCALE ) )
    388     {
    389       load_flags |= FT_LOAD_NO_BITMAP | FT_LOAD_NO_SCALE;
    390 
    391       if ( !FT_IS_TRICKY( face ) )
    392         load_flags |= FT_LOAD_NO_HINTING;
    393     }
    394 
    395     /* now load the glyph outline if necessary */
    396     error = TT_Load_Glyph( size, slot, glyph_index, load_flags );
    397 
    398     /* force drop-out mode to 2 - irrelevant now */
    399     /* slot->outline.dropout_mode = 2; */
    400 
    401     return error;
    402   }
    403 
    404 
    405   /*************************************************************************/
    406   /*************************************************************************/
    407   /*************************************************************************/
    408   /****                                                                 ****/
    409   /****                                                                 ****/
    410   /****                D R I V E R  I N T E R F A C E                   ****/
    411   /****                                                                 ****/
    412   /****                                                                 ****/
    413   /*************************************************************************/
    414   /*************************************************************************/
    415   /*************************************************************************/
    416 
    417 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    418   FT_DEFINE_SERVICE_MULTIMASTERSREC(
    419     tt_service_gx_multi_masters,
    420     (FT_Get_MM_Func)        NULL,
    421     (FT_Set_MM_Design_Func) NULL,
    422     (FT_Set_MM_Blend_Func)  TT_Set_MM_Blend,
    423     (FT_Get_MM_Var_Func)    TT_Get_MM_Var,
    424     (FT_Set_Var_Design_Func)TT_Set_Var_Design )
    425 #endif
    426 
    427   static const FT_Service_TrueTypeEngineRec  tt_service_truetype_engine =
    428   {
    429 #ifdef TT_USE_BYTECODE_INTERPRETER
    430 
    431 #ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING
    432     FT_TRUETYPE_ENGINE_TYPE_UNPATENTED
    433 #else
    434     FT_TRUETYPE_ENGINE_TYPE_PATENTED
    435 #endif
    436 
    437 #else /* !TT_USE_BYTECODE_INTERPRETER */
    438 
    439     FT_TRUETYPE_ENGINE_TYPE_NONE
    440 
    441 #endif /* TT_USE_BYTECODE_INTERPRETER */
    442   };
    443 
    444   FT_DEFINE_SERVICE_TTGLYFREC(
    445     tt_service_truetype_glyf,
    446     (TT_Glyf_GetLocationFunc)tt_face_get_location )
    447 
    448 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    449   FT_DEFINE_SERVICEDESCREC5(
    450     tt_services,
    451     FT_SERVICE_ID_FONT_FORMAT,     FT_FONT_FORMAT_TRUETYPE,
    452     FT_SERVICE_ID_MULTI_MASTERS,   &TT_SERVICE_GX_MULTI_MASTERS_GET,
    453     FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
    454     FT_SERVICE_ID_TT_GLYF,         &TT_SERVICE_TRUETYPE_GLYF_GET,
    455     FT_SERVICE_ID_PROPERTIES,      &TT_SERVICE_PROPERTIES_GET )
    456 #else
    457   FT_DEFINE_SERVICEDESCREC4(
    458     tt_services,
    459     FT_SERVICE_ID_FONT_FORMAT,     FT_FONT_FORMAT_TRUETYPE,
    460     FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
    461     FT_SERVICE_ID_TT_GLYF,         &TT_SERVICE_TRUETYPE_GLYF_GET,
    462     FT_SERVICE_ID_PROPERTIES,      &TT_SERVICE_PROPERTIES_GET )
    463 #endif
    464 
    465 
    466   FT_CALLBACK_DEF( FT_Module_Interface )
    467   tt_get_interface( FT_Module    driver,    /* TT_Driver */
    468                     const char*  tt_interface )
    469   {
    470     FT_Library           library;
    471     FT_Module_Interface  result;
    472     FT_Module            sfntd;
    473     SFNT_Service         sfnt;
    474 
    475 
    476     /* TT_SERVICES_GET dereferences `library' in PIC mode */
    477 #ifdef FT_CONFIG_OPTION_PIC
    478     if ( !driver )
    479       return NULL;
    480     library = driver->library;
    481     if ( !library )
    482       return NULL;
    483 #endif
    484 
    485     result = ft_service_list_lookup( TT_SERVICES_GET, tt_interface );
    486     if ( result != NULL )
    487       return result;
    488 
    489 #ifndef FT_CONFIG_OPTION_PIC
    490     if ( !driver )
    491       return NULL;
    492     library = driver->library;
    493     if ( !library )
    494       return NULL;
    495 #endif
    496 
    497     /* only return the default interface from the SFNT module */
    498     sfntd = FT_Get_Module( library, "sfnt" );
    499     if ( sfntd )
    500     {
    501       sfnt = (SFNT_Service)( sfntd->clazz->module_interface );
    502       if ( sfnt )
    503         return sfnt->get_interface( driver, tt_interface );
    504     }
    505 
    506     return 0;
    507   }
    508 
    509 
    510   /* The FT_DriverInterface structure is defined in ftdriver.h. */
    511 
    512 #ifdef TT_USE_BYTECODE_INTERPRETER
    513 #define TT_HINTER_FLAG  FT_MODULE_DRIVER_HAS_HINTER
    514 #else
    515 #define TT_HINTER_FLAG  0
    516 #endif
    517 
    518 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    519 #define TT_SIZE_SELECT  tt_size_select
    520 #else
    521 #define TT_SIZE_SELECT  0
    522 #endif
    523 
    524   FT_DEFINE_DRIVER(
    525     tt_driver_class,
    526 
    527       FT_MODULE_FONT_DRIVER     |
    528       FT_MODULE_DRIVER_SCALABLE |
    529       TT_HINTER_FLAG,
    530 
    531       sizeof ( TT_DriverRec ),
    532 
    533       "truetype",      /* driver name                           */
    534       0x10000L,        /* driver version == 1.0                 */
    535       0x20000L,        /* driver requires FreeType 2.0 or above */
    536 
    537       (void*)0,        /* driver specific interface */
    538 
    539       tt_driver_init,
    540       tt_driver_done,
    541       tt_get_interface,
    542 
    543     sizeof ( TT_FaceRec ),
    544     sizeof ( TT_SizeRec ),
    545     sizeof ( FT_GlyphSlotRec ),
    546 
    547     tt_face_init,
    548     tt_face_done,
    549     tt_size_init,
    550     tt_size_done,
    551     tt_slot_init,
    552     0,                       /* FT_Slot_DoneFunc */
    553 
    554     tt_glyph_load,
    555 
    556     tt_get_kerning,
    557     0,                       /* FT_Face_AttachFunc */
    558     tt_get_advances,
    559 
    560     tt_size_request,
    561     TT_SIZE_SELECT
    562   )
    563 
    564 
    565 /* END */
    566