Home | History | Annotate | Download | only in truetype
      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  ttdriver.c                                                             */
      4 /*                                                                         */
      5 /*    TrueType font driver implementation (body).                          */
      6 /*                                                                         */
      7 /*  Copyright 1996-2014 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_XFREE86_NAME_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 #undef  PAIR_TAG
    138 #define PAIR_TAG( left, right )  ( ( (FT_ULong)left << 16 ) | \
    139                                      (FT_ULong)right        )
    140 
    141 
    142   /*************************************************************************/
    143   /*                                                                       */
    144   /* <Function>                                                            */
    145   /*    tt_get_kerning                                                     */
    146   /*                                                                       */
    147   /* <Description>                                                         */
    148   /*    A driver method used to return the kerning vector between two      */
    149   /*    glyphs of the same face.                                           */
    150   /*                                                                       */
    151   /* <Input>                                                               */
    152   /*    face        :: A handle to the source face object.                 */
    153   /*                                                                       */
    154   /*    left_glyph  :: The index of the left glyph in the kern pair.       */
    155   /*                                                                       */
    156   /*    right_glyph :: The index of the right glyph in the kern pair.      */
    157   /*                                                                       */
    158   /* <Output>                                                              */
    159   /*    kerning     :: The kerning vector.  This is in font units for      */
    160   /*                   scalable formats, and in pixels for fixed-sizes     */
    161   /*                   formats.                                            */
    162   /*                                                                       */
    163   /* <Return>                                                              */
    164   /*    FreeType error code.  0 means success.                             */
    165   /*                                                                       */
    166   /* <Note>                                                                */
    167   /*    Only horizontal layouts (left-to-right & right-to-left) are        */
    168   /*    supported by this function.  Other layouts, or more sophisticated  */
    169   /*    kernings, are out of scope of this method (the basic driver        */
    170   /*    interface is meant to be simple).                                  */
    171   /*                                                                       */
    172   /*    They can be implemented by format-specific interfaces.             */
    173   /*                                                                       */
    174   static FT_Error
    175   tt_get_kerning( FT_Face     ttface,          /* TT_Face */
    176                   FT_UInt     left_glyph,
    177                   FT_UInt     right_glyph,
    178                   FT_Vector*  kerning )
    179   {
    180     TT_Face       face = (TT_Face)ttface;
    181     SFNT_Service  sfnt = (SFNT_Service)face->sfnt;
    182 
    183 
    184     kerning->x = 0;
    185     kerning->y = 0;
    186 
    187     if ( sfnt )
    188       kerning->x = sfnt->get_kerning( face, left_glyph, right_glyph );
    189 
    190     return 0;
    191   }
    192 
    193 
    194 #undef PAIR_TAG
    195 
    196 
    197   static FT_Error
    198   tt_get_advances( FT_Face    ttface,
    199                    FT_UInt    start,
    200                    FT_UInt    count,
    201                    FT_Int32   flags,
    202                    FT_Fixed  *advances )
    203   {
    204     FT_UInt  nn;
    205     TT_Face  face  = (TT_Face) ttface;
    206 
    207 
    208     /* XXX: TODO: check for sbits */
    209 
    210     if ( flags & FT_LOAD_VERTICAL_LAYOUT )
    211     {
    212       for ( nn = 0; nn < count; nn++ )
    213       {
    214         FT_Short   tsb;
    215         FT_UShort  ah;
    216 
    217 
    218         /* since we don't need `tsb', we use zero for `yMax' parameter */
    219         TT_Get_VMetrics( face, start + nn, 0, &tsb, &ah );
    220         advances[nn] = ah;
    221       }
    222     }
    223     else
    224     {
    225       for ( nn = 0; nn < count; nn++ )
    226       {
    227         FT_Short   lsb;
    228         FT_UShort  aw;
    229 
    230 
    231         TT_Get_HMetrics( face, start + nn, &lsb, &aw );
    232         advances[nn] = aw;
    233       }
    234     }
    235 
    236     return FT_Err_Ok;
    237   }
    238 
    239   /*************************************************************************/
    240   /*************************************************************************/
    241   /*************************************************************************/
    242   /****                                                                 ****/
    243   /****                                                                 ****/
    244   /****                           S I Z E S                             ****/
    245   /****                                                                 ****/
    246   /****                                                                 ****/
    247   /*************************************************************************/
    248   /*************************************************************************/
    249   /*************************************************************************/
    250 
    251 
    252 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    253 
    254   static FT_Error
    255   tt_size_select( FT_Size   size,
    256                   FT_ULong  strike_index )
    257   {
    258     TT_Face   ttface = (TT_Face)size->face;
    259     TT_Size   ttsize = (TT_Size)size;
    260     FT_Error  error  = FT_Err_Ok;
    261 
    262 
    263     ttsize->strike_index = strike_index;
    264 
    265     if ( FT_IS_SCALABLE( size->face ) )
    266     {
    267       /* use the scaled metrics, even when tt_size_reset fails */
    268       FT_Select_Metrics( size->face, strike_index );
    269 
    270       tt_size_reset( ttsize ); /* ignore return value */
    271     }
    272     else
    273     {
    274       SFNT_Service      sfnt    = (SFNT_Service) ttface->sfnt;
    275       FT_Size_Metrics*  metrics = &size->metrics;
    276 
    277 
    278       error = sfnt->load_strike_metrics( ttface, strike_index, metrics );
    279       if ( error )
    280         ttsize->strike_index = 0xFFFFFFFFUL;
    281     }
    282 
    283     return error;
    284   }
    285 
    286 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
    287 
    288 
    289   static FT_Error
    290   tt_size_request( FT_Size          size,
    291                    FT_Size_Request  req )
    292   {
    293     TT_Size   ttsize = (TT_Size)size;
    294     FT_Error  error  = FT_Err_Ok;
    295 
    296 
    297 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    298 
    299     if ( FT_HAS_FIXED_SIZES( size->face ) )
    300     {
    301       TT_Face       ttface = (TT_Face)size->face;
    302       SFNT_Service  sfnt   = (SFNT_Service) ttface->sfnt;
    303       FT_ULong      strike_index;
    304 
    305 
    306       error = sfnt->set_sbit_strike( ttface, req, &strike_index );
    307 
    308       if ( error )
    309         ttsize->strike_index = 0xFFFFFFFFUL;
    310       else
    311         return tt_size_select( size, strike_index );
    312     }
    313 
    314 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
    315 
    316     FT_Request_Metrics( size->face, req );
    317 
    318     if ( FT_IS_SCALABLE( size->face ) )
    319     {
    320       error = tt_size_reset( ttsize );
    321       ttsize->root.metrics = ttsize->metrics;
    322     }
    323 
    324     return error;
    325   }
    326 
    327 
    328   /*************************************************************************/
    329   /*                                                                       */
    330   /* <Function>                                                            */
    331   /*    tt_glyph_load                                                      */
    332   /*                                                                       */
    333   /* <Description>                                                         */
    334   /*    A driver method used to load a glyph within a given glyph slot.    */
    335   /*                                                                       */
    336   /* <Input>                                                               */
    337   /*    slot        :: A handle to the target slot object where the glyph  */
    338   /*                   will be loaded.                                     */
    339   /*                                                                       */
    340   /*    size        :: A handle to the source face size at which the glyph */
    341   /*                   must be scaled, loaded, etc.                        */
    342   /*                                                                       */
    343   /*    glyph_index :: The index of the glyph in the font file.            */
    344   /*                                                                       */
    345   /*    load_flags  :: A flag indicating what to load for this glyph.  The */
    346   /*                   FT_LOAD_XXX constants can be used to control the    */
    347   /*                   glyph loading process (e.g., whether the outline    */
    348   /*                   should be scaled, whether to load bitmaps or not,   */
    349   /*                   whether to hint the outline, etc).                  */
    350   /*                                                                       */
    351   /* <Return>                                                              */
    352   /*    FreeType error code.  0 means success.                             */
    353   /*                                                                       */
    354   static FT_Error
    355   tt_glyph_load( FT_GlyphSlot  ttslot,      /* TT_GlyphSlot */
    356                  FT_Size       ttsize,      /* TT_Size      */
    357                  FT_UInt       glyph_index,
    358                  FT_Int32      load_flags )
    359   {
    360     TT_GlyphSlot  slot = (TT_GlyphSlot)ttslot;
    361     TT_Size       size = (TT_Size)ttsize;
    362     FT_Face       face = ttslot->face;
    363     FT_Error      error;
    364 
    365 
    366     if ( !slot )
    367       return FT_THROW( Invalid_Slot_Handle );
    368 
    369     if ( !size )
    370       return FT_THROW( Invalid_Size_Handle );
    371 
    372     if ( !face )
    373       return FT_THROW( Invalid_Face_Handle );
    374 
    375 #ifdef FT_CONFIG_OPTION_INCREMENTAL
    376     if ( glyph_index >= (FT_UInt)face->num_glyphs &&
    377          !face->internal->incremental_interface   )
    378 #else
    379     if ( glyph_index >= (FT_UInt)face->num_glyphs )
    380 #endif
    381       return FT_THROW( Invalid_Argument );
    382 
    383     if ( load_flags & FT_LOAD_NO_HINTING )
    384     {
    385       /* both FT_LOAD_NO_HINTING and FT_LOAD_NO_AUTOHINT   */
    386       /* are necessary to disable hinting for tricky fonts */
    387 
    388       if ( FT_IS_TRICKY( face ) )
    389         load_flags &= ~FT_LOAD_NO_HINTING;
    390 
    391       if ( load_flags & FT_LOAD_NO_AUTOHINT )
    392         load_flags |= FT_LOAD_NO_HINTING;
    393     }
    394 
    395     if ( load_flags & ( FT_LOAD_NO_RECURSE | FT_LOAD_NO_SCALE ) )
    396     {
    397       load_flags |= FT_LOAD_NO_BITMAP | FT_LOAD_NO_SCALE;
    398 
    399       if ( !FT_IS_TRICKY( face ) )
    400         load_flags |= FT_LOAD_NO_HINTING;
    401     }
    402 
    403     /* now load the glyph outline if necessary */
    404     error = TT_Load_Glyph( size, slot, glyph_index, load_flags );
    405 
    406     /* force drop-out mode to 2 - irrelevant now */
    407     /* slot->outline.dropout_mode = 2; */
    408 
    409     return error;
    410   }
    411 
    412 
    413   /*************************************************************************/
    414   /*************************************************************************/
    415   /*************************************************************************/
    416   /****                                                                 ****/
    417   /****                                                                 ****/
    418   /****                D R I V E R  I N T E R F A C E                   ****/
    419   /****                                                                 ****/
    420   /****                                                                 ****/
    421   /*************************************************************************/
    422   /*************************************************************************/
    423   /*************************************************************************/
    424 
    425 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    426   FT_DEFINE_SERVICE_MULTIMASTERSREC(
    427     tt_service_gx_multi_masters,
    428     (FT_Get_MM_Func)        NULL,
    429     (FT_Set_MM_Design_Func) NULL,
    430     (FT_Set_MM_Blend_Func)  TT_Set_MM_Blend,
    431     (FT_Get_MM_Var_Func)    TT_Get_MM_Var,
    432     (FT_Set_Var_Design_Func)TT_Set_Var_Design )
    433 #endif
    434 
    435   static const FT_Service_TrueTypeEngineRec  tt_service_truetype_engine =
    436   {
    437 #ifdef TT_USE_BYTECODE_INTERPRETER
    438 
    439 #ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING
    440     FT_TRUETYPE_ENGINE_TYPE_UNPATENTED
    441 #else
    442     FT_TRUETYPE_ENGINE_TYPE_PATENTED
    443 #endif
    444 
    445 #else /* !TT_USE_BYTECODE_INTERPRETER */
    446 
    447     FT_TRUETYPE_ENGINE_TYPE_NONE
    448 
    449 #endif /* TT_USE_BYTECODE_INTERPRETER */
    450   };
    451 
    452   FT_DEFINE_SERVICE_TTGLYFREC(
    453     tt_service_truetype_glyf,
    454     (TT_Glyf_GetLocationFunc)tt_face_get_location )
    455 
    456 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    457   FT_DEFINE_SERVICEDESCREC5(
    458     tt_services,
    459     FT_SERVICE_ID_XF86_NAME,       FT_XF86_FORMAT_TRUETYPE,
    460     FT_SERVICE_ID_MULTI_MASTERS,   &TT_SERVICE_GX_MULTI_MASTERS_GET,
    461     FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
    462     FT_SERVICE_ID_TT_GLYF,         &TT_SERVICE_TRUETYPE_GLYF_GET,
    463     FT_SERVICE_ID_PROPERTIES,      &TT_SERVICE_PROPERTIES_GET )
    464 #else
    465   FT_DEFINE_SERVICEDESCREC4(
    466     tt_services,
    467     FT_SERVICE_ID_XF86_NAME,       FT_XF86_FORMAT_TRUETYPE,
    468     FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
    469     FT_SERVICE_ID_TT_GLYF,         &TT_SERVICE_TRUETYPE_GLYF_GET,
    470     FT_SERVICE_ID_PROPERTIES,      &TT_SERVICE_PROPERTIES_GET )
    471 #endif
    472 
    473 
    474   FT_CALLBACK_DEF( FT_Module_Interface )
    475   tt_get_interface( FT_Module    driver,    /* TT_Driver */
    476                     const char*  tt_interface )
    477   {
    478     FT_Library           library;
    479     FT_Module_Interface  result;
    480     FT_Module            sfntd;
    481     SFNT_Service         sfnt;
    482 
    483 
    484     /* TT_SERVICES_GET derefers `library' in PIC mode */
    485 #ifdef FT_CONFIG_OPTION_PIC
    486     if ( !driver )
    487       return NULL;
    488     library = driver->library;
    489     if ( !library )
    490       return NULL;
    491 #endif
    492 
    493     result = ft_service_list_lookup( TT_SERVICES_GET, tt_interface );
    494     if ( result != NULL )
    495       return result;
    496 
    497 #ifndef FT_CONFIG_OPTION_PIC
    498     if ( !driver )
    499       return NULL;
    500     library = driver->library;
    501     if ( !library )
    502       return NULL;
    503 #endif
    504 
    505     /* only return the default interface from the SFNT module */
    506     sfntd = FT_Get_Module( library, "sfnt" );
    507     if ( sfntd )
    508     {
    509       sfnt = (SFNT_Service)( sfntd->clazz->module_interface );
    510       if ( sfnt )
    511         return sfnt->get_interface( driver, tt_interface );
    512     }
    513 
    514     return 0;
    515   }
    516 
    517 
    518   /* The FT_DriverInterface structure is defined in ftdriver.h. */
    519 
    520 #ifdef TT_USE_BYTECODE_INTERPRETER
    521 #define TT_HINTER_FLAG  FT_MODULE_DRIVER_HAS_HINTER
    522 #else
    523 #define TT_HINTER_FLAG  0
    524 #endif
    525 
    526 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    527 #define TT_SIZE_SELECT  tt_size_select
    528 #else
    529 #define TT_SIZE_SELECT  0
    530 #endif
    531 
    532   FT_DEFINE_DRIVER(
    533     tt_driver_class,
    534 
    535       FT_MODULE_FONT_DRIVER     |
    536       FT_MODULE_DRIVER_SCALABLE |
    537       TT_HINTER_FLAG,
    538 
    539       sizeof ( TT_DriverRec ),
    540 
    541       "truetype",      /* driver name                           */
    542       0x10000L,        /* driver version == 1.0                 */
    543       0x20000L,        /* driver requires FreeType 2.0 or above */
    544 
    545       (void*)0,        /* driver specific interface */
    546 
    547       tt_driver_init,
    548       tt_driver_done,
    549       tt_get_interface,
    550 
    551     sizeof ( TT_FaceRec ),
    552     sizeof ( TT_SizeRec ),
    553     sizeof ( FT_GlyphSlotRec ),
    554 
    555     tt_face_init,
    556     tt_face_done,
    557     tt_size_init,
    558     tt_size_done,
    559     tt_slot_init,
    560     0,                       /* FT_Slot_DoneFunc */
    561 
    562     tt_glyph_load,
    563 
    564     tt_get_kerning,
    565     0,                       /* FT_Face_AttachFunc */
    566     tt_get_advances,
    567 
    568     tt_size_request,
    569     TT_SIZE_SELECT
    570   )
    571 
    572 
    573 /* END */
    574