include/freetype/internal/ftdriver.h

   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 */