ftimage.h

qt-embedded-2.3.8.tar.gz源码

  /*                                                                       */
  /*    If the ft_raster_flag_direct bit flag is set in `flags', the       */
  /*    raster will call the `gray_spans' callback to draw gray pixel      */
  /*    spans, in the case of an aa glyph bitmap, it will call             */
  /*    `black_spans', and `bit_test' and `bit_set' in the case of a       */
  /*    monochrome bitmap.  This allows direct composition over a          */
  /*    pre-existing bitmap through user-provided callbacks to perform the */
  /*    span drawing/composition.                                          */
  /*                                                                       */
  /*    Note that the `bit_test' and `bit_set' callbacks are required when */
  /*    rendering a monochrome bitmap, as they are crucial to implement    */
  /*    correct drop-out control as defined in the TrueType specification. */
  /*                                                                       */
  typedef struct  FT_Raster_Params_
  {
    FT_Bitmap*              target;
    void*                   source;
    int                     flags;
    FT_Raster_Span_Func     gray_spans;
    FT_Raster_Span_Func     black_spans;
    FT_Raster_BitTest_Func  bit_test;
    FT_Raster_BitSet_Func   bit_set;
    void*                   user;

  } FT_Raster_Params;


  /*************************************************************************/
  /*                                                                       */
  /* <FuncType>                                                            */
  /*    FT_Raster_New_Func                                                 */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A function used to create a new raster object.                     */
  /*                                                                       */
  /* <Input>                                                               */
  /*    memory :: A handle to the memory allocator.                        */
  /*                                                                       */
  /* <Output>                                                              */
  /*    raster :: A handle to the new raster object.                       */
  /*                                                                       */
  /* <Return>                                                              */
  /*    Error code.  0 means success.                                      */
  /*                                                                       */
  /* <Note>                                                                */
  /*    The `memory' parameter is a typeless pointer in order to avoid     */
  /*    un-wanted dependencies on the rest of the FreeType code.  In       */
  /*    practice, it is a FT_Memory, i.e., a handle to the standard        */
  /*    FreeType memory allocator.  However, this field can be completely  */
  /*    ignored by a given raster implementation.                          */
  /*                                                                       */
  typedef int  (*FT_Raster_New_Func)( void*       memory,
                                      FT_Raster*  raster );


  /*************************************************************************/
  /*                                                                       */
  /* <FuncType>                                                            */
  /*    FT_Raster_Done_Func                                                */
  /*                                                                       */
  /* <Description>                                                         */
  /*    A function used to destroy a given raster object.                  */
  /*                                                                       */
  /* <Input>                                                               */
  /*    raster :: A handle to the raster object.                           */
  /*                                                                       */
  typedef void  (*FT_Raster_Done_Func)( FT_Raster  raster );


  /*************************************************************************/
  /*                                                                       */
  /* <FuncType>                                                            */
  /*    FT_Raster_Reset_Func                                               */
  /*                                                                       */
  /* <Description>                                                         */
  /*    FreeType provides an area of memory called the `render pool',      */
  /*    available to all registered rasters.  This pool can be freely used */
  /*    during a given scan-conversion but is shared by all rasters.  Its  */
  /*    content is thus transient.                                         */
  /*                                                                       */
  /*    This function is called each time the render pool changes, or just */
  /*    after a new raster object is created.                              */
  /*                                                                       */
  /* <Input>                                                               */
  /*    raster    :: A handle to the new raster object.                    */
  /*                                                                       */
  /*    pool_base :: The address in memory of the render pool.             */
  /*                                                                       */
  /*    pool_size :: The size in bytes of the render pool.                 */
  /*                                                                       */
  /* <Note>                                                                */
  /*    Rasters can ignore the render pool and rely on dynamic memory      */
  /*    allocation if they want to (a handle to the memory allocator is    */
  /*    passed to the raster constructor).  However, this is not           */
  /*    recommended for efficiency purposes.                               */
  /*                                                                       */
  typedef void  (*FT_Raster_Reset_Func)( FT_Raster       raster,
                                         unsigned char*  pool_base,
                                         unsigned long   pool_size );


  /*************************************************************************/
  /*                                                                       */
  /* <FuncType>                                                            */
  /*    FT_Raster_Set_Mode_Func                                            */
  /*                                                                       */
  /* <Description>                                                         */
  /*    This function is a generic facility to change modes or attributes  */
  /*    in a given raster.  This can be used for debugging purposes, or    */
  /*    simply to allow implementation-specific `features' in a given      */
  /*    raster module.                                                     */
  /*                                                                       */
  /* <Input>                                                               */
  /*    raster :: A handle to the new raster object.                       */
  /*                                                                       */
  /*    mode   :: A 4-byte tag used to name the mode or property.          */
  /*                                                                       */
  /*    args   :: A pointer to the new mode/property to use.               */
  /*                                                                       */
  typedef int  (*FT_Raster_Set_Mode_Func)( FT_Raster      raster,
                                           unsigned long  mode,
                                           void*          args );


  /*************************************************************************/
  /*                                                                       */
  /* <FuncType>                                                            */
  /*    FT_Raster_Render_Func                                              */
  /*                                                                       */
  /* <Description>                                                         */
  /*   Invokes a given raster to scan-convert a given glyph image into a   */
  /*   target bitmap.                                                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    raster :: A handle to the raster object.                           */
  /*                                                                       */
  /*    params :: A pointer to a FT_Raster_Params structure used to store  */
  /*              the rendering parameters.                                */
  /*                                                                       */
  /* <Return>                                                              */
  /*    Error code.  0 means success.                                      */
  /*                                                                       */
  /* <Note>                                                                */
  /*    The exact format of the source image depends on the raster's glyph */
  /*    format defined in its FT_Raster_Funcs structure.  It can be an     */
  /*    FT_Outline or anything else in order to support a large array of   */
  /*    glyph formats.                                                     */
  /*                                                                       */
  /*    Note also that the render function can fail and return a           */
  /*    FT_Err_Unimplemented_Feature error code if the raster used does    */
  /*    not support direct composition.                                    */
  /*                                                                       */
  /*    XXX: For now, the standard raster doesn't support direct           */
  /*         composition but this should change for the final release (see */
  /*         the files demos/src/ftgrays.c and demos/src/ftgrays2.c for    */
  /*         examples of distinct implementations which support direct     */
  /*         composition).                                                 */
  /*                                                                       */
  typedef int  (*FT_Raster_Render_Func)( FT_Raster          raster,
                                         FT_Raster_Params*  params );


  /*************************************************************************/
  /*                                                                       */
  /* <Struct>                                                              */
  /*    FT_Raster_Funcs                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*   A structure used to describe a given raster class to the library.   */
  /*                                                                       */
  /* <Fields>                                                              */
  /*    glyph_format  :: The supported glyph format for this raster.       */
  /*                                                                       */
  /*    raster_new    :: The raster constructor.                           */
  /*                                                                       */
  /*    raster_reset  :: Used to reset the render pool within the raster.  */
  /*                                                                       */
  /*    raster_render :: A function to render a glyph into a given bitmap. */
  /*                                                                       */
  /*    raster_done   :: The raster destructor.                            */
  /*                                                                       */
  typedef struct  FT_Raster_Funcs_
  {
    FT_Glyph_Format          glyph_format;
    FT_Raster_New_Func       raster_new;
    FT_Raster_Reset_Func     raster_reset;
    FT_Raster_Set_Mode_Func  raster_set_mode;
    FT_Raster_Render_Func    raster_render;
    FT_Raster_Done_Func      raster_done;

  } FT_Raster_Funcs;


FT_END_HEADER


#endif /* __FTIMAGE_H__ */


/* END */