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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  ftdriver.h                                                             */
      4 /*                                                                         */
      5 /*    FreeType font driver interface (specification).                      */
      6 /*                                                                         */
      7 /*  Copyright 1996-2001, 2002, 2003, 2006, 2008 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   /*                        Currently not implemented.  The idea of this   */
    166   /*                        function is to be able to perform              */
    167   /*                        device-independent text layout without loading */
    168   /*                        a single glyph image.                          */
    169   /*                                                                       */
    170   /*    request_size     :: A handle to a function used to request the new */
    171   /*                        character size.  Can be set to 0 if the        */
    172   /*                        scaling done in the base layer suffices.       */
    173   /*                                                                       */
    174   /*    select_size      :: A handle to a function used to select a new    */
    175   /*                        fixed size.  It is used only if                */
    176   /*                        @FT_FACE_FLAG_FIXED_SIZES is set.  Can be set  */
    177   /*                        to 0 if the scaling done in the base layer     */
    178   /*                        suffices.                                      */
    179   /* <Note>                                                                */
    180   /*    Most function pointers, with the exception of `load_glyph', can be */
    181   /*    set to 0 to indicate a default behaviour.                          */
    182   /*                                                                       */
    183   typedef struct  FT_Driver_ClassRec_
    184   {
    185     FT_Module_Class           root;
    186 
    187     FT_Long                   face_object_size;
    188     FT_Long                   size_object_size;
    189     FT_Long                   slot_object_size;
    190 
    191     FT_Face_InitFunc          init_face;
    192     FT_Face_DoneFunc          done_face;
    193 
    194     FT_Size_InitFunc          init_size;
    195     FT_Size_DoneFunc          done_size;
    196 
    197     FT_Slot_InitFunc          init_slot;
    198     FT_Slot_DoneFunc          done_slot;
    199 
    200 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
    201 
    202     FT_Size_ResetPointsFunc   set_char_sizes;
    203     FT_Size_ResetPixelsFunc   set_pixel_sizes;
    204 
    205 #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
    206 
    207     FT_Slot_LoadFunc          load_glyph;
    208 
    209     FT_Face_GetKerningFunc    get_kerning;
    210     FT_Face_AttachFunc        attach_file;
    211     FT_Face_GetAdvancesFunc   get_advances;
    212 
    213     /* since version 2.2 */
    214     FT_Size_RequestFunc       request_size;
    215     FT_Size_SelectFunc        select_size;
    216 
    217   } FT_Driver_ClassRec, *FT_Driver_Class;
    218 
    219 
    220   /*
    221    *  The following functions are used as stubs for `set_char_sizes' and
    222    *  `set_pixel_sizes'; the code uses `request_size' and `select_size'
    223    *  functions instead.
    224    *
    225    *  Implementation is in `src/base/ftobjs.c'.
    226    */
    227 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
    228 
    229   FT_BASE( FT_Error )
    230   ft_stub_set_char_sizes( FT_Size     size,
    231                           FT_F26Dot6  width,
    232                           FT_F26Dot6  height,
    233                           FT_UInt     horz_res,
    234                           FT_UInt     vert_res );
    235 
    236   FT_BASE( FT_Error )
    237   ft_stub_set_pixel_sizes( FT_Size  size,
    238                            FT_UInt  width,
    239                            FT_UInt  height );
    240 
    241 #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
    242 
    243   /*************************************************************************/
    244   /*                                                                       */
    245   /* <Macro>                                                               */
    246   /*    FT_DECLARE_DRIVER                                                  */
    247   /*                                                                       */
    248   /* <Description>                                                         */
    249   /*    Used to create a forward declaration of a                          */
    250   /*    FT_Driver_ClassRec stract instance.                                */
    251   /*                                                                       */
    252   /* <Macro>                                                               */
    253   /*    FT_DEFINE_DRIVER                                                   */
    254   /*                                                                       */
    255   /* <Description>                                                         */
    256   /*    Used to initialize an instance of FT_Driver_ClassRec struct.       */
    257   /*                                                                       */
    258   /*    When FT_CONFIG_OPTION_PIC is defined a Create funtion will need    */
    259   /*    to called with a pointer where the allocated stracture is returned.*/
    260   /*    And when it is no longer needed a Destroy function needs           */
    261   /*    to be called to release that allocation.                           */
    262   /*    fcinit.c (ft_create_default_module_classes) already contains       */
    263   /*    a mechanism to call these functions for the default modules        */
    264   /*    described in ftmodule.h                                            */
    265   /*                                                                       */
    266   /*    Notice that the created Create and Destroy functions call          */
    267   /*    pic_init and pic_free function to allow you to manually allocate   */
    268   /*    and initialize any additional global data, like module specific    */
    269   /*    interface, and put them in the global pic container defined in     */
    270   /*    ftpic.h. if you don't need them just implement the functions as    */
    271   /*    empty to resolve the link error.                                   */
    272   /*                                                                       */
    273   /*    When FT_CONFIG_OPTION_PIC is not defined the struct will be        */
    274   /*    allocated in the global scope (or the scope where the macro        */
    275   /*    is used).                                                          */
    276   /*                                                                       */
    277 #ifndef FT_CONFIG_OPTION_PIC
    278 
    279 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
    280 #define FT_DEFINE_DRIVERS_OLD_INTERNALS(a_,b_) \
    281   a_, b_,
    282 #else
    283   #define FT_DEFINE_DRIVERS_OLD_INTERNALS(a_,b_)
    284 #endif
    285 
    286 #define FT_DECLARE_DRIVER(class_)    \
    287   FT_CALLBACK_TABLE                  \
    288   const FT_Driver_ClassRec  class_;
    289 
    290 #define FT_DEFINE_DRIVER(class_,                                             \
    291                          flags_, size_, name_, version_, requires_,          \
    292                          interface_, init_, done_, get_interface_,           \
    293                          face_object_size_, size_object_size_,               \
    294                          slot_object_size_, init_face_, done_face_,          \
    295                          init_size_, done_size_, init_slot_, done_slot_,     \
    296                          old_set_char_sizes_, old_set_pixel_sizes_,          \
    297                          load_glyph_, get_kerning_, attach_file_,            \
    298                          get_advances_, request_size_, select_size_ )        \
    299   FT_CALLBACK_TABLE_DEF                                                      \
    300   const FT_Driver_ClassRec class_ =                                          \
    301   {                                                                          \
    302     FT_DEFINE_ROOT_MODULE(flags_,size_,name_,version_,requires_,interface_,  \
    303                           init_,done_,get_interface_)                        \
    304                                                                              \
    305     face_object_size_,                                                       \
    306     size_object_size_,                                                       \
    307     slot_object_size_,                                                       \
    308                                                                              \
    309     init_face_,                                                              \
    310     done_face_,                                                              \
    311                                                                              \
    312     init_size_,                                                              \
    313     done_size_,                                                              \
    314                                                                              \
    315     init_slot_,                                                              \
    316     done_slot_,                                                              \
    317                                                                              \
    318     FT_DEFINE_DRIVERS_OLD_INTERNALS(old_set_char_sizes_, old_set_pixel_sizes_) \
    319                                                                              \
    320     load_glyph_,                                                             \
    321                                                                              \
    322     get_kerning_,                                                            \
    323     attach_file_,                                                            \
    324     get_advances_,                                                           \
    325                                                                              \
    326     request_size_,                                                           \
    327     select_size_                                                             \
    328   };
    329 
    330 #else /* FT_CONFIG_OPTION_PIC */
    331 
    332 #ifdef FT_CONFIG_OPTION_OLD_INTERNALS
    333 #define FT_DEFINE_DRIVERS_OLD_INTERNALS(a_,b_) \
    334   clazz->set_char_sizes = a_; \
    335   clazz->set_pixel_sizes = b_;
    336 #else
    337   #define FT_DEFINE_DRIVERS_OLD_INTERNALS(a_,b_)
    338 #endif
    339 
    340 #define FT_DECLARE_DRIVER(class_)    FT_DECLARE_MODULE(class_)
    341 
    342 #define FT_DEFINE_DRIVER(class_,                                             \
    343                          flags_, size_, name_, version_, requires_,          \
    344                          interface_, init_, done_, get_interface_,           \
    345                          face_object_size_, size_object_size_,               \
    346                          slot_object_size_, init_face_, done_face_,          \
    347                          init_size_, done_size_, init_slot_, done_slot_,     \
    348                          old_set_char_sizes_, old_set_pixel_sizes_,          \
    349                          load_glyph_, get_kerning_, attach_file_,            \
    350                          get_advances_, request_size_, select_size_ )        \
    351   void class_##_pic_free( FT_Library library );                              \
    352   FT_Error class_##_pic_init( FT_Library library );                          \
    353                                                                              \
    354   void                                                                       \
    355   FT_Destroy_Class_##class_( FT_Library        library,                      \
    356                              FT_Module_Class*  clazz )                       \
    357   {                                                                          \
    358     FT_Memory       memory = library->memory;                                \
    359     FT_Driver_Class dclazz = (FT_Driver_Class)clazz;                         \
    360     class_##_pic_free( library );                                            \
    361     if ( dclazz )                                                            \
    362       FT_FREE( dclazz );                                                     \
    363   }                                                                          \
    364                                                                              \
    365   FT_Error                                                                   \
    366   FT_Create_Class_##class_( FT_Library        library,                       \
    367                             FT_Module_Class**  output_class )                \
    368   {                                                                          \
    369     FT_Driver_Class  clazz;                                                  \
    370     FT_Error         error;                                                  \
    371     FT_Memory        memory = library->memory;                               \
    372                                                                              \
    373     if ( FT_ALLOC( clazz, sizeof(*clazz) ) )                                 \
    374       return error;                                                          \
    375                                                                              \
    376     error = class_##_pic_init( library );                                    \
    377     if(error)                                                                \
    378     {                                                                        \
    379       FT_FREE( clazz );                                                      \
    380       return error;                                                          \
    381     }                                                                        \
    382                                                                              \
    383     FT_DEFINE_ROOT_MODULE(flags_,size_,name_,version_,requires_,interface_,  \
    384                           init_,done_,get_interface_)                        \
    385                                                                              \
    386     clazz->face_object_size    = face_object_size_;                          \
    387     clazz->size_object_size    = size_object_size_;                          \
    388     clazz->slot_object_size    = slot_object_size_;                          \
    389                                                                              \
    390     clazz->init_face           = init_face_;                                 \
    391     clazz->done_face           = done_face_;                                 \
    392                                                                              \
    393     clazz->init_size           = init_size_;                                 \
    394     clazz->done_size           = done_size_;                                 \
    395                                                                              \
    396     clazz->init_slot           = init_slot_;                                 \
    397     clazz->done_slot           = done_slot_;                                 \
    398                                                                              \
    399     FT_DEFINE_DRIVERS_OLD_INTERNALS(old_set_char_sizes_, old_set_pixel_sizes_) \
    400                                                                              \
    401     clazz->load_glyph          = load_glyph_;                                \
    402                                                                              \
    403     clazz->get_kerning         = get_kerning_;                               \
    404     clazz->attach_file         = attach_file_;                               \
    405     clazz->get_advances        = get_advances_;                              \
    406                                                                              \
    407     clazz->request_size        = request_size_;                              \
    408     clazz->select_size         = select_size_;                               \
    409                                                                              \
    410     *output_class = (FT_Module_Class*)clazz;                                 \
    411     return FT_Err_Ok;                                                        \
    412   }
    413 
    414 
    415 #endif /* FT_CONFIG_OPTION_PIC */
    416 
    417 FT_END_HEADER
    418 
    419 #endif /* __FTDRIVER_H__ */
    420 
    421 
    422 /* END */
    423