ftrender.h

一个Xpdf应用的例子

/***************************************************************************/
/*                                                                         */
/*  ftrender.h                                                             */
/*                                                                         */
/*    FreeType renderer modules public interface (specification).          */
/*                                                                         */
/*  Copyright 1996-2001 by                                                 */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#ifndef __FTRENDER_H__
#define __FTRENDER_H__


#include <ft2build.h>
#include FT_MODULE_H
#include FT_GLYPH_H


FT_BEGIN_HEADER


  /*************************************************************************/
  /*                                                                       */
  /* <Section>                                                             */
  /*    module_management                                                  */
  /*                                                                       */
  /*************************************************************************/


  /* create a new glyph object */
  typedef FT_Error
  (*FT_Glyph_Init_Func)( FT_Glyph      glyph,
                         FT_GlyphSlot  slot );

  /* destroys a given glyph object */
  typedef void
  (*FT_Glyph_Done_Func)( FT_Glyph  glyph );

  typedef void
  (*FT_Glyph_Transform_Func)( FT_Glyph    glyph,
                              FT_Matrix*  matrix,
                              FT_Vector*  delta );

  typedef void
  (*FT_Glyph_BBox_Func)( FT_Glyph  glyph,
                         FT_BBox*  abbox );

  typedef FT_Error
  (*FT_Glyph_Copy_Func)( FT_Glyph   source,
                         FT_Glyph   target );

  typedef FT_Error
  (*FT_Glyph_Prepare_Func)( FT_Glyph      glyph,
                            FT_GlyphSlot  slot );


  struct  FT_Glyph_Class_
  {
    FT_UInt                  glyph_size;
    FT_Glyph_Format          glyph_format;
    FT_Glyph_Init_Func       glyph_init;
    FT_Glyph_Done_Func       glyph_done;
    FT_Glyph_Copy_Func       glyph_copy;
    FT_Glyph_Transform_Func  glyph_transform;
    FT_Glyph_BBox_Func       glyph_bbox;
    FT_Glyph_Prepare_Func    glyph_prepare;
  };


  typedef FT_Error
  (*FTRenderer_render)( FT_Renderer   renderer,
                        FT_GlyphSlot  slot,
                        FT_UInt       mode,
                        FT_Vector*    origin );

  typedef FT_Error
  (*FTRenderer_transform)( FT_Renderer   renderer,
                           FT_GlyphSlot  slot,
                           FT_Matrix*    matrix,
                           FT_Vector*    delta );

  typedef void
  (*FTRenderer_getCBox)( FT_Renderer   renderer,
                         FT_GlyphSlot  slot,
                         FT_BBox*      cbox );

  typedef FT_Error
  (*FTRenderer_setMode)( FT_Renderer  renderer,
                         FT_ULong     mode_tag,
                         FT_Pointer   mode_ptr );


  /*************************************************************************/
  /*                                                                       */
  /* <Struct>                                                              */
  /*    FT_Renderer_Class                                                  */
  /*                                                                       */
  /* <Description>                                                         */
  /*    The renderer module class descriptor.                              */
  /*                                                                       */
  /* <Fields>                                                              */
  /*    root         :: The root FT_Module_Class fields.                   */
  /*                                                                       */
  /*    glyph_format :: The glyph image format this renderer handles.      */
  /*                                                                       */
  /*    render_glyph :: A method used to render the image that is in a     */
  /*                    given glyph slot into a bitmap.                    */
  /*                                                                       */
  /*    set_mode     :: A method used to pass additional parameters.       */
  /*                                                                       */
  /*    raster_class :: For `ft_glyph_format_outline' renderers only, this */
  /*                    is a pointer to its raster's class.                */
  /*                                                                       */
  /*    raster       :: For `ft_glyph_format_outline' renderers only. this */
  /*                    is a pointer to the corresponding raster object,   */
  /*                    if any.                                            */
  /*                                                                       */
  typedef struct  FT_Renderer_Class_
  {
    FT_Module_Class       root;

    FT_Glyph_Format       glyph_format;

    FTRenderer_render     render_glyph;
    FTRenderer_transform  transform_glyph;
    FTRenderer_getCBox    get_glyph_cbox;
    FTRenderer_setMode    set_mode;

    FT_Raster_Funcs*      raster_class;

  } FT_Renderer_Class;


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    FT_Get_Renderer                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Retrieves the current renderer for a given glyph format.           */
  /*                                                                       */
  /* <Input>                                                               */
  /*    library :: A handle to the library object.                         */
  /*                                                                       */
  /*    format  :: The glyph format.                                       */
  /*                                                                       */
  /* <Return>                                                              */
  /*    A renderer handle.  0 if none found.                               */
  /*                                                                       */
  /* <Note>                                                                */
  /*    An error will be returned if a module already exists by that name, */
  /*    or if the module requires a version of FreeType that is too great. */
  /*                                                                       */
  /*    To add a new renderer, simply use FT_Add_Module().  To retrieve a  */
  /*    renderer by its name, use FT_Get_Module().                         */
  /*                                                                       */
  FT_EXPORT( FT_Renderer )
  FT_Get_Renderer( FT_Library       library,
                   FT_Glyph_Format  format );


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    FT_Set_Renderer                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Sets the current renderer to use, and set additional mode.         */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    library    :: A handle to the library object.                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    renderer   :: A handle to the renderer object.                     */
  /*                                                                       */
  /*    num_params :: The number of additional parameters.                 */
  /*                                                                       */
  /*    parameters :: Additional parameters.                               */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  /* <Note>                                                                */
  /*    In case of success, the renderer will be used to convert glyph     */
  /*    images in the renderer's known format into bitmaps.                */
  /*                                                                       */
  /*    This doesn't change the current renderer for other formats.        */
  /*                                                                       */
  FT_EXPORT( FT_Error )
  FT_Set_Renderer( FT_Library     library,
                   FT_Renderer    renderer,
                   FT_UInt        num_params,
                   FT_Parameter*  parameters );


  /* */


FT_END_HEADER

#endif /* __FTRENDER_H__ */


/* END */