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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  ftdriver.h                                                             */
      4 /*                                                                         */
      5 /*    FreeType font driver interface (specification).                      */
      6 /*                                                                         */
      7 /*  Copyright 1996-2003, 2006, 2008, 2011 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 #ifndef __FTDRIVER_H__
     20 #define __FTDRIVER_H__
     21 
     22 
     23 #include <ft2build.h>
     24 #include FT_MODULE_H
     25 
     26 
     27 FT_BEGIN_HEADER
     28 
     29 
     30   typedef FT_Error
     31   (*FT_Face_InitFunc)( FT_Stream      stream,
     32                        FT_Face        face,
     33                        FT_Int         typeface_index,
     34                        FT_Int         num_params,
     35                        FT_Parameter*  parameters );
     36 
     37   typedef void
     38   (*FT_Face_DoneFunc)( FT_Face  face );
     39 
     40 
     41   typedef FT_Error
     42   (*FT_Size_InitFunc)( FT_Size  size );
     43 
     44   typedef void
     45   (*FT_Size_DoneFunc)( FT_Size  size );
     46 
     47 
     48   typedef FT_Error
     49   (*FT_Slot_InitFunc)( FT_GlyphSlot  slot );
     50 
     51   typedef void
     52   (*FT_Slot_DoneFunc)( FT_GlyphSlot  slot );
     53 
     54 
     55   typedef FT_Error
     56   (*FT_Size_RequestFunc)( FT_Size          size,
     57                           FT_Size_Request  req );
     58 
     59   typedef FT_Error
     60   (*FT_Size_SelectFunc)( FT_Size   size,
     61                          FT_ULong  size_index );
     62 
     63 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
     64 
     65   typedef FT_Error
     66   (*FT_Size_ResetPointsFunc)( FT_Size     size,
     67                               FT_F26Dot6  char_width,
     68                               FT_F26Dot6  char_height,
     69                               FT_UInt     horz_resolution,
     70                               FT_UInt     vert_resolution );
     71 
     72   typedef FT_Error
     73   (*FT_Size_ResetPixelsFunc)( FT_Size  size,
     74                               FT_UInt  pixel_width,
     75                               FT_UInt  pixel_height );
     76 
     77 #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
     78 
     79   typedef FT_Error
     80   (*FT_Slot_LoadFunc)( FT_GlyphSlot  slot,
     81                        FT_Size       size,
     82                        FT_UInt       glyph_index,
     83                        FT_Int32      load_flags );
     84 
     85 
     86   typedef FT_UInt
     87   (*FT_CharMap_CharIndexFunc)( FT_CharMap  charmap,
     88                                FT_Long     charcode );
     89 
     90   typedef FT_Long
     91   (*FT_CharMap_CharNextFunc)( FT_CharMap  charmap,
     92                               FT_Long     charcode );
     93 
     94 
     95   typedef FT_Error
     96   (*FT_Face_GetKerningFunc)( FT_Face     face,
     97                              FT_UInt     left_glyph,
     98                              FT_UInt     right_glyph,
     99                              FT_Vector*  kerning );
    100 
    101 
    102   typedef FT_Error
    103   (*FT_Face_AttachFunc)( FT_Face    face,
    104                          FT_Stream  stream );
    105 
    106 
    107   typedef FT_Error
    108   (*FT_Face_GetAdvancesFunc)( FT_Face    face,
    109                               FT_UInt    first,
    110                               FT_UInt    count,
    111                               FT_Int32   flags,
    112                               FT_Fixed*  advances );
    113 
    114 
    115   /*************************************************************************/
    116   /*                                                                       */
    117   /* <Struct>                                                              */
    118   /*    FT_Driver_ClassRec                                                 */
    119   /*                                                                       */
    120   /* <Description>                                                         */
    121   /*    The font driver class.  This structure mostly contains pointers to */
    122   /*    driver methods.                                                    */
    123   /*                                                                       */
    124   /* <Fields>                                                              */
    125   /*    root             :: The parent module.                             */
    126   /*                                                                       */
    127   /*    face_object_size :: The size of a face object in bytes.            */
    128   /*                                                                       */
    129   /*    size_object_size :: The size of a size object in bytes.            */
    130   /*                                                                       */
    131   /*    slot_object_size :: The size of a glyph object in bytes.           */
    132   /*                                                                       */
    133   /*    init_face        :: The format-specific face constructor.          */
    134   /*                                                                       */
    135   /*    done_face        :: The format-specific face destructor.           */
    136   /*                                                                       */
    137   /*    init_size        :: The format-specific size constructor.          */
    138   /*                                                                       */
    139   /*    done_size        :: The format-specific size destructor.           */
    140   /*                                                                       */
    141   /*    init_slot        :: The format-specific slot constructor.          */
    142   /*                                                                       */
    143   /*    done_slot        :: The format-specific slot destructor.           */
    144   /*                                                                       */
    145   /*                                                                       */
    146   /*    load_glyph       :: A function handle to load a glyph to a slot.   */
    147   /*                        This field is mandatory!                       */
    148   /*                                                                       */
    149   /*    get_kerning      :: A function handle to return the unscaled       */
    150   /*                        kerning for a given pair of glyphs.  Can be    */
    151   /*                        set to 0 if the format doesn't support         */
    152   /*                        kerning.                                       */
    153   /*                                                                       */
    154   /*    attach_file      :: This function handle is used to read           */
    155   /*                        additional data for a face from another        */
    156   /*                        file/stream.  For example, this can be used to */
    157   /*                        add data from AFM or PFM files on a Type 1     */
    158   /*                        face, or a CIDMap on a CID-keyed face.         */
    159   /*                                                                       */
    160   /*    get_advances     :: A function handle used to return advance       */
    161   /*                        widths of `count' glyphs (in font units),      */
    162   /*                        starting at `first'.  The `vertical' flag must */
    163   /*                        be set to get vertical advance heights.  The   */
    164   /*                        `advances' buffer is caller-allocated.         */
    165   /*                        The idea of this function is to be able to     */
    166   /*                        perform device-independent text layout without */
    167   /*                        loading a single glyph image.                  */
    168   /*                                                                       */
    169   /*    request_size     :: A handle to a function used to request the new */
    170   /*                        character size.  Can be set to 0 if the        */
    171   /*                        scaling done in the base layer suffices.       */
    172   /*                                                                       */
    173   /*    select_size      :: A handle to a function used to select a new    */
    174   /*                        fixed size.  It is used only if                */
    175   /*                        @FT_FACE_FLAG_FIXED_SIZES is set.  Can be set  */
    176   /*                        to 0 if the scaling done in the base layer     */
    177   /*                        suffices.                                      */
    178   /* <Note>                                                                */
    179   /*    Most function pointers, with the exception of `load_glyph', can be */
    180   /*    set to 0 to indicate a default behaviour.                          */
    181   /*                                                                       */
    182   typedef struct  FT_Driver_ClassRec_
    183   {
    184     FT_Module_Class           root;
    185 
    186     FT_Long                   face_object_size;
    187     FT_Long                   size_object_size;
    188     FT_Long                   slot_object_size;
    189 
    190     FT_Face_InitFunc          init_face;
    191     FT_Face_DoneFunc          done_face;
    192 
    193     FT_Size_InitFunc          init_size;
    194     FT_Size_DoneFunc          done_size;
    195 
    196     FT_Slot_InitFunc          init_slot;
    197     FT_Slot_DoneFunc          done_slot;
    198 
    199 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
    200 
    201     FT_Size_ResetPointsFunc   set_char_sizes;
    202     FT_Size_ResetPixelsFunc   set_pixel_sizes;
    203 
    204 #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
    205 
    206     FT_Slot_LoadFunc          load_glyph;
    207 
    208     FT_Face_GetKerningFunc    get_kerning;
    209     FT_Face_AttachFunc        attach_file;
    210     FT_Face_GetAdvancesFunc   get_advances;
    211 
    212     /* since version 2.2 */
    213     FT_Size_RequestFunc       request_size;
    214     FT_Size_SelectFunc        select_size;
    215 
    216   } FT_Driver_ClassRec, *FT_Driver_Class;
    217 
    218 
    219   /*
    220    *  The following functions are used as stubs for `set_char_sizes' and
    221    *  `set_pixel_sizes'; the code uses `request_size' and `select_size'
    222    *  functions instead.
    223    *
    224    *  Implementation is in `src/base/ftobjs.c'.
    225    */
    226 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
    227 
    228   FT_BASE( FT_Error )
    229   ft_stub_set_char_sizes( FT_Size     size,
    230                           FT_F26Dot6  width,
    231                           FT_F26Dot6  height,
    232                           FT_UInt     horz_res,
    233                           FT_UInt     vert_res );
    234 
    235   FT_BASE( FT_Error )
    236   ft_stub_set_pixel_sizes( FT_Size  size,
    237                            FT_UInt  width,
    238                            FT_UInt  height );
    239 
    240 #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
    241 
    242   /*************************************************************************/
    243   /*                                                                       */
    244   /* <Macro>                                                               */
    245   /*    FT_DECLARE_DRIVER                                                  */
    246   /*                                                                       */
    247   /* <Description>                                                         */
    248   /*    Used to create a forward declaration of a                          */
    249   /*    FT_Driver_ClassRec stract instance.                                */
    250   /*                                                                       */
    251   /* <Macro>                                                               */
    252   /*    FT_DEFINE_DRIVER                                                   */
    253   /*                                                                       */
    254   /* <Description>                                                         */
    255   /*    Used to initialize an instance of FT_Driver_ClassRec struct.       */
    256   /*                                                                       */
    257   /*    When FT_CONFIG_OPTION_PIC is defined a Create funtion will need    */
    258   /*    to called with a pointer where the allocated stracture is returned.*/
    259   /*    And when it is no longer needed a Destroy function needs           */
    260   /*    to be called to release that allocation.                           */
    261   /*    fcinit.c (ft_create_default_module_classes) already contains       */
    262   /*    a mechanism to call these functions for the default modules        */
    263   /*    described in ftmodule.h                                            */
    264   /*                                                                       */
    265   /*    Notice that the created Create and Destroy functions call          */
    266   /*    pic_init and pic_free function to allow you to manually allocate   */
    267   /*    and initialize any additional global data, like module specific    */
    268   /*    interface, and put them in the global pic container defined in     */
    269   /*    ftpic.h. if you don't need them just implement the functions as    */
    270   /*    empty to resolve the link error.  Also the pic_init and pic_free   */
    271   /*    functions should be declared in pic.h, to be referred by driver    */
    272   /*    definition calling FT_DEFINE_DRIVER() in following.                */
    273   /*                                                                       */
    274   /*    When FT_CONFIG_OPTION_PIC is not defined the struct will be        */
    275   /*    allocated in the global scope (or the scope where the macro        */
    276   /*    is used).                                                          */
    277   /*                                                                       */
    278 #ifndef FT_CONFIG_OPTION_PIC
    279 
    280 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
    281 #define FT_DEFINE_DRIVERS_OLD_INTERNALS(a_,b_) \
    282   a_, b_,
    283 #else
    284   #define FT_DEFINE_DRIVERS_OLD_INTERNALS(a_,b_)
    285 #endif
    286 
    287 #define FT_DECLARE_DRIVER(class_)    \
    288   FT_CALLBACK_TABLE                  \
    289   const FT_Driver_ClassRec  class_;
    290 
    291 #define FT_DEFINE_DRIVER(class_,                                             \
    292                          flags_, size_, name_, version_, requires_,          \
    293                          interface_, init_, done_, get_interface_,           \
    294                          face_object_size_, size_object_size_,               \
    295                          slot_object_size_, init_face_, done_face_,          \
    296                          init_size_, done_size_, init_slot_, done_slot_,     \
    297                          old_set_char_sizes_, old_set_pixel_sizes_,          \
    298                          load_glyph_, get_kerning_, attach_file_,            \
    299                          get_advances_, request_size_, select_size_ )        \
    300   FT_CALLBACK_TABLE_DEF                                                      \
    301   const FT_Driver_ClassRec class_ =                                          \
    302   {                                                                          \
    303     FT_DEFINE_ROOT_MODULE(flags_,size_,name_,version_,requires_,interface_,  \
    304                           init_,done_,get_interface_)                        \
    305                                                                              \
    306     face_object_size_,                                                       \
    307     size_object_size_,                                                       \
    308     slot_object_size_,                                                       \
    309                                                                              \
    310     init_face_,                                                              \
    311     done_face_,                                                              \
    312                                                                              \
    313     init_size_,                                                              \
    314     done_size_,                                                              \
    315                                                                              \
    316     init_slot_,                                                              \
    317     done_slot_,                                                              \
    318                                                                              \
    319     FT_DEFINE_DRIVERS_OLD_INTERNALS(old_set_char_sizes_, old_set_pixel_sizes_) \
    320                                                                              \
    321     load_glyph_,                                                             \
    322                                                                              \
    323     get_kerning_,                                                            \
    324     attach_file_,                                                            \
    325     get_advances_,                                                           \
    326                                                                              \
    327     request_size_,                                                           \
    328     select_size_                                                             \
    329   };
    330 
    331 #else /* FT_CONFIG_OPTION_PIC */
    332 
    333 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
    334 #define FT_DEFINE_DRIVERS_OLD_INTERNALS(a_,b_) \
    335   clazz->set_char_sizes = a_; \
    336   clazz->set_pixel_sizes = b_;
    337 #else
    338   #define FT_DEFINE_DRIVERS_OLD_INTERNALS(a_,b_)
    339 #endif
    340 
    341 #define FT_DECLARE_DRIVER(class_)    FT_DECLARE_MODULE(class_)
    342 
    343 #define FT_DEFINE_DRIVER(class_,                                             \
    344                          flags_, size_, name_, version_, requires_,          \
    345                          interface_, init_, done_, get_interface_,           \
    346                          face_object_size_, size_object_size_,               \
    347                          slot_object_size_, init_face_, done_face_,          \
    348                          init_size_, done_size_, init_slot_, done_slot_,     \
    349                          old_set_char_sizes_, old_set_pixel_sizes_,          \
    350                          load_glyph_, get_kerning_, attach_file_,            \
    351                          get_advances_, request_size_, select_size_ )        \
    352                                                                              \
    353   void                                                                       \
    354   FT_Destroy_Class_##class_( FT_Library        library,                      \
    355                              FT_Module_Class*  clazz )                       \
    356   {                                                                          \
    357     FT_Memory       memory = library->memory;                                \
    358     FT_Driver_Class dclazz = (FT_Driver_Class)clazz;                         \
    359     class_##_pic_free( library );                                            \
    360     if ( dclazz )                                                            \
    361       FT_FREE( dclazz );                                                     \
    362   }                                                                          \
    363                                                                              \
    364   FT_Error                                                                   \
    365   FT_Create_Class_##class_( FT_Library        library,                       \
    366                             FT_Module_Class**  output_class )                \
    367   {                                                                          \
    368     FT_Driver_Class  clazz;                                                  \
    369     FT_Error         error;                                                  \
    370     FT_Memory        memory = library->memory;                               \
    371                                                                              \
    372     if ( FT_ALLOC( clazz, sizeof(*clazz) ) )                                 \
    373       return error;                                                          \
    374                                                                              \
    375     error = class_##_pic_init( library );                                    \
    376     if(error)                                                                \
    377     {                                                                        \
    378       FT_FREE( clazz );                                                      \
    379       return error;                                                          \
    380     }                                                                        \
    381                                                                              \
    382     FT_DEFINE_ROOT_MODULE(flags_,size_,name_,version_,requires_,interface_,  \
    383                           init_,done_,get_interface_)                        \
    384                                                                              \
    385     clazz->face_object_size    = face_object_size_;                          \
    386     clazz->size_object_size    = size_object_size_;                          \
    387     clazz->slot_object_size    = slot_object_size_;                          \
    388                                                                              \
    389     clazz->init_face           = init_face_;                                 \
    390     clazz->done_face           = done_face_;                                 \
    391                                                                              \
    392     clazz->init_size           = init_size_;                                 \
    393     clazz->done_size           = done_size_;                                 \
    394                                                                              \
    395     clazz->init_slot           = init_slot_;                                 \
    396     clazz->done_slot           = done_slot_;                                 \
    397                                                                              \
    398     FT_DEFINE_DRIVERS_OLD_INTERNALS(old_set_char_sizes_, old_set_pixel_sizes_) \
    399                                                                              \
    400     clazz->load_glyph          = load_glyph_;                                \
    401                                                                              \
    402     clazz->get_kerning         = get_kerning_;                               \
    403     clazz->attach_file         = attach_file_;                               \
    404     clazz->get_advances        = get_advances_;                              \
    405                                                                              \
    406     clazz->request_size        = request_size_;                              \
    407     clazz->select_size         = select_size_;                               \
    408                                                                              \
    409     *output_class = (FT_Module_Class*)clazz;                                 \
    410     return FT_Err_Ok;                                                        \
    411   }
    412 
    413 
    414 #endif /* FT_CONFIG_OPTION_PIC */
    415 
    416 FT_END_HEADER
    417 
    418 #endif /* __FTDRIVER_H__ */
    419 
    420 
    421 /* END */
    422