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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  ttdriver.c                                                             */
      4 /*                                                                         */
      5 /*    TrueType font driver implementation (body).                          */
      6 /*                                                                         */
      7 /*  Copyright 1996-2012 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 
     33 #include "ttdriver.h"
     34 #include "ttgload.h"
     35 #include "ttpload.h"
     36 
     37 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
     38 #include "ttgxvar.h"
     39 #endif
     40 
     41 #include "tterrors.h"
     42 
     43 #include "ttpic.h"
     44 
     45   /*************************************************************************/
     46   /*                                                                       */
     47   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
     48   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
     49   /* messages during execution.                                            */
     50   /*                                                                       */
     51 #undef  FT_COMPONENT
     52 #define FT_COMPONENT  trace_ttdriver
     53 
     54 
     55   /*************************************************************************/
     56   /*************************************************************************/
     57   /*************************************************************************/
     58   /****                                                                 ****/
     59   /****                                                                 ****/
     60   /****                          F A C E S                              ****/
     61   /****                                                                 ****/
     62   /****                                                                 ****/
     63   /*************************************************************************/
     64   /*************************************************************************/
     65   /*************************************************************************/
     66 
     67 
     68 #undef  PAIR_TAG
     69 #define PAIR_TAG( left, right )  ( ( (FT_ULong)left << 16 ) | \
     70                                      (FT_ULong)right        )
     71 
     72 
     73   /*************************************************************************/
     74   /*                                                                       */
     75   /* <Function>                                                            */
     76   /*    tt_get_kerning                                                     */
     77   /*                                                                       */
     78   /* <Description>                                                         */
     79   /*    A driver method used to return the kerning vector between two      */
     80   /*    glyphs of the same face.                                           */
     81   /*                                                                       */
     82   /* <Input>                                                               */
     83   /*    face        :: A handle to the source face object.                 */
     84   /*                                                                       */
     85   /*    left_glyph  :: The index of the left glyph in the kern pair.       */
     86   /*                                                                       */
     87   /*    right_glyph :: The index of the right glyph in the kern pair.      */
     88   /*                                                                       */
     89   /* <Output>                                                              */
     90   /*    kerning     :: The kerning vector.  This is in font units for      */
     91   /*                   scalable formats, and in pixels for fixed-sizes     */
     92   /*                   formats.                                            */
     93   /*                                                                       */
     94   /* <Return>                                                              */
     95   /*    FreeType error code.  0 means success.                             */
     96   /*                                                                       */
     97   /* <Note>                                                                */
     98   /*    Only horizontal layouts (left-to-right & right-to-left) are        */
     99   /*    supported by this function.  Other layouts, or more sophisticated  */
    100   /*    kernings, are out of scope of this method (the basic driver        */
    101   /*    interface is meant to be simple).                                  */
    102   /*                                                                       */
    103   /*    They can be implemented by format-specific interfaces.             */
    104   /*                                                                       */
    105   static FT_Error
    106   tt_get_kerning( FT_Face     ttface,          /* TT_Face */
    107                   FT_UInt     left_glyph,
    108                   FT_UInt     right_glyph,
    109                   FT_Vector*  kerning )
    110   {
    111     TT_Face       face = (TT_Face)ttface;
    112     SFNT_Service  sfnt = (SFNT_Service)face->sfnt;
    113 
    114 
    115     kerning->x = 0;
    116     kerning->y = 0;
    117 
    118     if ( sfnt )
    119       kerning->x = sfnt->get_kerning( face, left_glyph, right_glyph );
    120 
    121     return 0;
    122   }
    123 
    124 
    125 #undef PAIR_TAG
    126 
    127 
    128   static FT_Error
    129   tt_get_advances( FT_Face    ttface,
    130                    FT_UInt    start,
    131                    FT_UInt    count,
    132                    FT_Int32   flags,
    133                    FT_Fixed  *advances )
    134   {
    135     FT_UInt  nn;
    136     TT_Face  face  = (TT_Face) ttface;
    137 
    138 
    139     /* XXX: TODO: check for sbits */
    140 
    141     if ( flags & FT_LOAD_VERTICAL_LAYOUT )
    142     {
    143       for ( nn = 0; nn < count; nn++ )
    144       {
    145         FT_Short   tsb;
    146         FT_UShort  ah;
    147 
    148 
    149         TT_Get_VMetrics( face, start + nn, &tsb, &ah );
    150         advances[nn] = ah;
    151       }
    152     }
    153     else
    154     {
    155       for ( nn = 0; nn < count; nn++ )
    156       {
    157         FT_Short   lsb;
    158         FT_UShort  aw;
    159 
    160 
    161         TT_Get_HMetrics( face, start + nn, &lsb, &aw );
    162         advances[nn] = aw;
    163       }
    164     }
    165 
    166     return TT_Err_Ok;
    167   }
    168 
    169   /*************************************************************************/
    170   /*************************************************************************/
    171   /*************************************************************************/
    172   /****                                                                 ****/
    173   /****                                                                 ****/
    174   /****                           S I Z E S                             ****/
    175   /****                                                                 ****/
    176   /****                                                                 ****/
    177   /*************************************************************************/
    178   /*************************************************************************/
    179   /*************************************************************************/
    180 
    181 
    182 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    183 
    184   static FT_Error
    185   tt_size_select( FT_Size   size,
    186                   FT_ULong  strike_index )
    187   {
    188     TT_Face   ttface = (TT_Face)size->face;
    189     TT_Size   ttsize = (TT_Size)size;
    190     FT_Error  error  = TT_Err_Ok;
    191 
    192 
    193     ttsize->strike_index = strike_index;
    194 
    195     if ( FT_IS_SCALABLE( size->face ) )
    196     {
    197       /* use the scaled metrics, even when tt_size_reset fails */
    198       FT_Select_Metrics( size->face, strike_index );
    199 
    200       tt_size_reset( ttsize );
    201     }
    202     else
    203     {
    204       SFNT_Service      sfnt    = (SFNT_Service) ttface->sfnt;
    205       FT_Size_Metrics*  metrics = &size->metrics;
    206 
    207 
    208       error = sfnt->load_strike_metrics( ttface, strike_index, metrics );
    209       if ( error )
    210         ttsize->strike_index = 0xFFFFFFFFUL;
    211     }
    212 
    213     return error;
    214   }
    215 
    216 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
    217 
    218 
    219   static FT_Error
    220   tt_size_request( FT_Size          size,
    221                    FT_Size_Request  req )
    222   {
    223     TT_Size   ttsize = (TT_Size)size;
    224     FT_Error  error  = TT_Err_Ok;
    225 
    226 
    227 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    228 
    229     if ( FT_HAS_FIXED_SIZES( size->face ) )
    230     {
    231       TT_Face       ttface = (TT_Face)size->face;
    232       SFNT_Service  sfnt   = (SFNT_Service) ttface->sfnt;
    233       FT_ULong      strike_index;
    234 
    235 
    236       error = sfnt->set_sbit_strike( ttface, req, &strike_index );
    237 
    238       if ( error )
    239         ttsize->strike_index = 0xFFFFFFFFUL;
    240       else
    241         return tt_size_select( size, strike_index );
    242     }
    243 
    244 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
    245 
    246     FT_Request_Metrics( size->face, req );
    247 
    248     if ( FT_IS_SCALABLE( size->face ) )
    249     {
    250       error = tt_size_reset( ttsize );
    251       ttsize->root.metrics = ttsize->metrics;
    252     }
    253 
    254     return error;
    255   }
    256 
    257 
    258   /*************************************************************************/
    259   /*                                                                       */
    260   /* <Function>                                                            */
    261   /*    tt_glyph_load                                                      */
    262   /*                                                                       */
    263   /* <Description>                                                         */
    264   /*    A driver method used to load a glyph within a given glyph slot.    */
    265   /*                                                                       */
    266   /* <Input>                                                               */
    267   /*    slot        :: A handle to the target slot object where the glyph  */
    268   /*                   will be loaded.                                     */
    269   /*                                                                       */
    270   /*    size        :: A handle to the source face size at which the glyph */
    271   /*                   must be scaled, loaded, etc.                        */
    272   /*                                                                       */
    273   /*    glyph_index :: The index of the glyph in the font file.            */
    274   /*                                                                       */
    275   /*    load_flags  :: A flag indicating what to load for this glyph.  The */
    276   /*                   FT_LOAD_XXX constants can be used to control the    */
    277   /*                   glyph loading process (e.g., whether the outline    */
    278   /*                   should be scaled, whether to load bitmaps or not,   */
    279   /*                   whether to hint the outline, etc).                  */
    280   /*                                                                       */
    281   /* <Return>                                                              */
    282   /*    FreeType error code.  0 means success.                             */
    283   /*                                                                       */
    284   static FT_Error
    285   tt_glyph_load( FT_GlyphSlot  ttslot,      /* TT_GlyphSlot */
    286                  FT_Size       ttsize,      /* TT_Size      */
    287                  FT_UInt       glyph_index,
    288                  FT_Int32      load_flags )
    289   {
    290     TT_GlyphSlot  slot = (TT_GlyphSlot)ttslot;
    291     TT_Size       size = (TT_Size)ttsize;
    292     FT_Face       face = ttslot->face;
    293     FT_Error      error;
    294 
    295 
    296     if ( !slot )
    297       return TT_Err_Invalid_Slot_Handle;
    298 
    299     if ( !size )
    300       return TT_Err_Invalid_Size_Handle;
    301 
    302     if ( !face )
    303       return TT_Err_Invalid_Argument;
    304 
    305 #ifdef FT_CONFIG_OPTION_INCREMENTAL
    306     if ( glyph_index >= (FT_UInt)face->num_glyphs &&
    307          !face->internal->incremental_interface   )
    308 #else
    309     if ( glyph_index >= (FT_UInt)face->num_glyphs )
    310 #endif
    311       return TT_Err_Invalid_Argument;
    312 
    313     if ( load_flags & FT_LOAD_NO_HINTING )
    314     {
    315       /* both FT_LOAD_NO_HINTING and FT_LOAD_NO_AUTOHINT   */
    316       /* are necessary to disable hinting for tricky fonts */
    317 
    318       if ( FT_IS_TRICKY( face ) )
    319         load_flags &= ~FT_LOAD_NO_HINTING;
    320 
    321       if ( load_flags & FT_LOAD_NO_AUTOHINT )
    322         load_flags |= FT_LOAD_NO_HINTING;
    323     }
    324 
    325     if ( load_flags & ( FT_LOAD_NO_RECURSE | FT_LOAD_NO_SCALE ) )
    326     {
    327       load_flags |= FT_LOAD_NO_BITMAP | FT_LOAD_NO_SCALE;
    328 
    329       if ( !FT_IS_TRICKY( face ) )
    330         load_flags |= FT_LOAD_NO_HINTING;
    331     }
    332 
    333     /* now load the glyph outline if necessary */
    334     error = TT_Load_Glyph( size, slot, glyph_index, load_flags );
    335 
    336     /* force drop-out mode to 2 - irrelevant now */
    337     /* slot->outline.dropout_mode = 2; */
    338 
    339     return error;
    340   }
    341 
    342 
    343   /*************************************************************************/
    344   /*************************************************************************/
    345   /*************************************************************************/
    346   /****                                                                 ****/
    347   /****                                                                 ****/
    348   /****                D R I V E R  I N T E R F A C E                   ****/
    349   /****                                                                 ****/
    350   /****                                                                 ****/
    351   /*************************************************************************/
    352   /*************************************************************************/
    353   /*************************************************************************/
    354 
    355 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    356   FT_DEFINE_SERVICE_MULTIMASTERSREC(tt_service_gx_multi_masters,
    357     (FT_Get_MM_Func)        NULL,
    358     (FT_Set_MM_Design_Func) NULL,
    359     (FT_Set_MM_Blend_Func)  TT_Set_MM_Blend,
    360     (FT_Get_MM_Var_Func)    TT_Get_MM_Var,
    361     (FT_Set_Var_Design_Func)TT_Set_Var_Design
    362   )
    363 #endif
    364 
    365   static const FT_Service_TrueTypeEngineRec  tt_service_truetype_engine =
    366   {
    367 #ifdef TT_USE_BYTECODE_INTERPRETER
    368 
    369 #ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING
    370     FT_TRUETYPE_ENGINE_TYPE_UNPATENTED
    371 #else
    372     FT_TRUETYPE_ENGINE_TYPE_PATENTED
    373 #endif
    374 
    375 #else /* !TT_USE_BYTECODE_INTERPRETER */
    376 
    377     FT_TRUETYPE_ENGINE_TYPE_NONE
    378 
    379 #endif /* TT_USE_BYTECODE_INTERPRETER */
    380   };
    381 
    382   FT_DEFINE_SERVICE_TTGLYFREC(tt_service_truetype_glyf,
    383     (TT_Glyf_GetLocationFunc)tt_face_get_location
    384   )
    385 
    386 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    387   FT_DEFINE_SERVICEDESCREC4(tt_services,
    388     FT_SERVICE_ID_XF86_NAME,       FT_XF86_FORMAT_TRUETYPE,
    389     FT_SERVICE_ID_MULTI_MASTERS,   &FT_TT_SERVICE_GX_MULTI_MASTERS_GET,
    390     FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
    391     FT_SERVICE_ID_TT_GLYF,         &FT_TT_SERVICE_TRUETYPE_GLYF_GET
    392   )
    393 #else
    394   FT_DEFINE_SERVICEDESCREC3(tt_services,
    395     FT_SERVICE_ID_XF86_NAME,       FT_XF86_FORMAT_TRUETYPE,
    396     FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
    397     FT_SERVICE_ID_TT_GLYF,         &FT_TT_SERVICE_TRUETYPE_GLYF_GET
    398   )
    399 #endif
    400 
    401   FT_CALLBACK_DEF( FT_Module_Interface )
    402   tt_get_interface( FT_Module    driver,    /* TT_Driver */
    403                     const char*  tt_interface )
    404   {
    405     FT_Library           library;
    406     FT_Module_Interface  result;
    407     FT_Module            sfntd;
    408     SFNT_Service         sfnt;
    409 
    410 
    411     /* FT_TT_SERVICES_GET derefers `library' in PIC mode */
    412 #ifdef FT_CONFIG_OPTION_PIC
    413     if ( !driver )
    414       return NULL;
    415     library = driver->library;
    416     if ( !library )
    417       return NULL;
    418 #endif
    419 
    420     result = ft_service_list_lookup( FT_TT_SERVICES_GET, tt_interface );
    421     if ( result != NULL )
    422       return result;
    423 
    424 #ifndef FT_CONFIG_OPTION_PIC
    425     if ( !driver )
    426       return NULL;
    427     library = driver->library;
    428     if ( !library )
    429       return NULL;
    430 #endif
    431 
    432     /* only return the default interface from the SFNT module */
    433     sfntd = FT_Get_Module( library, "sfnt" );
    434     if ( sfntd )
    435     {
    436       sfnt = (SFNT_Service)( sfntd->clazz->module_interface );
    437       if ( sfnt )
    438         return sfnt->get_interface( driver, tt_interface );
    439     }
    440 
    441     return 0;
    442   }
    443 
    444 
    445   /* The FT_DriverInterface structure is defined in ftdriver.h. */
    446 
    447 #ifdef TT_USE_BYTECODE_INTERPRETER
    448 #define TT_HINTER_FLAG   FT_MODULE_DRIVER_HAS_HINTER
    449 #else
    450 #define TT_HINTER_FLAG   0
    451 #endif
    452 
    453 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
    454 #define TT_SIZE_SELECT    tt_size_select
    455 #else
    456 #define TT_SIZE_SELECT    0
    457 #endif
    458 
    459   FT_DEFINE_DRIVER( tt_driver_class,
    460 
    461       FT_MODULE_FONT_DRIVER     |
    462       FT_MODULE_DRIVER_SCALABLE |
    463       TT_HINTER_FLAG,
    464 
    465       sizeof ( TT_DriverRec ),
    466 
    467       "truetype",      /* driver name                           */
    468       0x10000L,        /* driver version == 1.0                 */
    469       0x20000L,        /* driver requires FreeType 2.0 or above */
    470 
    471       (void*)0,        /* driver specific interface */
    472 
    473       tt_driver_init,
    474       tt_driver_done,
    475       tt_get_interface,
    476 
    477     sizeof ( TT_FaceRec ),
    478     sizeof ( TT_SizeRec ),
    479     sizeof ( FT_GlyphSlotRec ),
    480 
    481     tt_face_init,
    482     tt_face_done,
    483     tt_size_init,
    484     tt_size_done,
    485     tt_slot_init,
    486     0,                       /* FT_Slot_DoneFunc */
    487 
    488     ft_stub_set_char_sizes,  /* FT_CONFIG_OPTION_OLD_INTERNALS */
    489     ft_stub_set_pixel_sizes, /* FT_CONFIG_OPTION_OLD_INTERNALS */
    490 
    491     tt_glyph_load,
    492 
    493     tt_get_kerning,
    494     0,                       /* FT_Face_AttachFunc */
    495     tt_get_advances,
    496 
    497     tt_size_request,
    498     TT_SIZE_SELECT
    499   )
    500 
    501 
    502 /* END */
    503