ftcache.h

一个类似windows

  /*                                                                       */
  /* <Output>                                                              */
  /*    asize   :: A handle to the size object.                            */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  /* <Note>                                                                */
  /*    The returned @FT_Size object is always owned by the manager.  You  */
  /*    should never try to discard it by yourself.                        */
  /*                                                                       */
  /*    You can access the parent @FT_Face object simply as `size->face'   */
  /*    if you need it.  Note that this object is also owned by the        */
  /*    manager.                                                           */
  /*                                                                       */
  FT_EXPORT( FT_Error )
  FTC_Manager_LookupSize( FTC_Manager  manager,
                          FTC_Scaler   scaler,
                          FT_Size     *asize );


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    FTC_Node_Unref                                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Decrement a cache node's internal reference count.  When the count */
  /*    reaches 0, it is not destroyed but becomes eligible for subsequent */
  /*    cache flushes.                                                     */
  /*                                                                       */
  /* <Input>                                                               */
  /*    node    :: The cache node handle.                                  */
  /*                                                                       */
  /*    manager :: The cache manager handle.                               */
  /*                                                                       */
  FT_EXPORT( void )
  FTC_Node_Unref( FTC_Node     node,
                  FTC_Manager  manager );


  /* remove all nodes belonging to a given face_id */
  FT_EXPORT( void )
  FTC_Manager_RemoveFaceID( FTC_Manager  manager,
                            FTC_FaceID   face_id );


  /*************************************************************************/
  /*                                                                       */
  /* <Section>                                                             */
  /*    cache_subsystem                                                    */
  /*                                                                       */
  /*************************************************************************/

  /************************************************************************
   *
   * @type:
   *    FTC_CMapCache
   *
   * @description:
   *    An opaque handle used to manager a charmap cache.  This cache is
   *    to hold character codes -> glyph indices mappings.
   */
  typedef struct FTC_CMapCacheRec_*  FTC_CMapCache;


  /*************************************************************************/
  /*                                                                       */
  /* @function:                                                            */
  /*    FTC_CMapCache_New                                                  */
  /*                                                                       */
  /* @description:                                                         */
  /*    Create a new charmap cache.                                        */
  /*                                                                       */
  /* @input:                                                               */
  /*    manager :: A handle to the cache manager.                          */
  /*                                                                       */
  /* @output:                                                              */
  /*    acache  :: A new cache handle.  NULL in case of error.             */
  /*                                                                       */
  /* @return:                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  /* @note:                                                                */
  /*    Like all other caches, this one will be destroyed with the cache   */
  /*    manager.                                                           */
  /*                                                                       */
  FT_EXPORT( FT_Error )
  FTC_CMapCache_New( FTC_Manager     manager,
                     FTC_CMapCache  *acache );


  /*************************************************************************/
  /*                                                                       */
  /* @function:                                                            */
  /*    FTC_CMapCache_Lookup                                               */
  /*                                                                       */
  /* @description:                                                         */
  /*    Translate a character code into a glyph index, using the charmap   */
  /*    cache.                                                             */
  /*                                                                       */
  /* @input:                                                               */
  /*    cache      :: A charmap cache handle.                              */
  /*                                                                       */
  /*    face_id    :: The source face ID.                                  */
  /*                                                                       */
  /*    cmap_index :: The index of the charmap in the source face.         */
  /*                                                                       */
  /*    char_code  :: The character code (in the corresponding charmap).   */
  /*                                                                       */
  /* @return:                                                              */
  /*    Glyph index.  0 means `no glyph'.                                  */
  /*                                                                       */
  FT_EXPORT( FT_UInt )
  FTC_CMapCache_Lookup( FTC_CMapCache  cache,
                        FTC_FaceID     face_id,
                        FT_Int         cmap_index,
                        FT_UInt32      char_code );


  /*************************************************************************/
  /*                                                                       */
  /* <Section>                                                             */
  /*    cache_subsystem                                                    */
  /*                                                                       */
  /*************************************************************************/


  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       IMAGE CACHE OBJECT                      *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/

  typedef struct  FTC_ImageTypeRec_
  {
    FTC_FaceID   face_id;
    FT_Int       width;
    FT_Int       height;
    FT_Int32     flags;

  } FTC_ImageTypeRec;

  typedef struct FTC_ImageTypeRec_*   FTC_ImageType;

 /* */

#define FTC_IMAGE_TYPE_COMPARE( d1, d2 )                    \
          ( FTC_FONT_COMPARE( &(d1)->font, &(d2)->font ) && \
            (d1)->flags == (d2)->flags                   )

#define FTC_IMAGE_TYPE_HASH( d )                    \
          (FT_UFast)( FTC_FONT_HASH( &(d)->font ) ^ \
                      ( (d)->flags << 4 )         )


  /*************************************************************************/
  /*                                                                       */
  /* <Type>                                                                */
  /*    FTC_ImageCache                                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A handle to an glyph image cache object.  They are designed to     */
  /*    hold many distinct glyph images while not exceeding a certain      */
  /*    memory threshold.                                                  */
  /*                                                                       */
  typedef struct FTC_ImageCacheRec_*  FTC_ImageCache;


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    FTC_ImageCache_New                                                 */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Creates a new glyph image cache.                                   */
  /*                                                                       */
  /* <Input>                                                               */
  /*    manager :: The parent manager for the image cache.                 */
  /*                                                                       */
  /* <Output>                                                              */
  /*    acache  :: A handle to the new glyph image cache object.           */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_EXPORT( FT_Error )
  FTC_ImageCache_New( FTC_Manager      manager,
                      FTC_ImageCache  *acache );


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    FTC_ImageCache_Lookup                                              */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Retrieves a given glyph image from a glyph image cache.            */
  /*                                                                       */
  /* <Input>                                                               */
  /*    cache  :: A handle to the source glyph image cache.                */