freetype2/include/ftrender.h

/***************************************************************************/
/*                                                                         */
/*  ftrender.h                                                             */
/*                                                                         */
/*    FreeType renderer modules public interface (specification).          */
/*                                                                         */
/*  Copyright 1996-2001, 2005, 2006, 2010 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_InitFunc)( FT_Glyph      glyph,
                        FT_GlyphSlot  slot );

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

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

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

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

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

/* deprecated */
#define FT_Glyph_Init_Func       FT_Glyph_InitFunc
#define FT_Glyph_Done_Func       FT_Glyph_DoneFunc
#define FT_Glyph_Transform_Func  FT_Glyph_TransformFunc
#define FT_Glyph_BBox_Func       FT_Glyph_GetBBoxFunc
#define FT_Glyph_Copy_Func       FT_Glyph_CopyFunc
#define FT_Glyph_Prepare_Func    FT_Glyph_PrepareFunc


  struct  FT_Glyph_Class_
  {
    FT_Long                 glyph_size;
    FT_Glyph_Format         glyph_format;
    FT_Glyph_InitFunc       glyph_init;
    FT_Glyph_DoneFunc       glyph_done;
    FT_Glyph_CopyFunc       glyph_copy;
    FT_Glyph_TransformFunc  glyph_transform;
    FT_Glyph_GetBBoxFunc    glyph_bbox;
    FT_Glyph_PrepareFunc    glyph_prepare;
  };


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

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


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


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

/* deprecated identifiers */
#define FTRenderer_render  FT_Renderer_RenderFunc
#define FTRenderer_transform  FT_Renderer_TransformFunc
#define FTRenderer_getCBox  FT_Renderer_GetCBoxFunc
#define FTRenderer_setMode  FT_Renderer_SetModeFunc


  /*************************************************************************/
  /*                                                                       */
  /* <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.                 */
  /*                                                                       */
  /*    transform_glyph :: A method used to transform the image that is in */
  /*                       a given glyph slot.                             */
  /*                                                                       */
  /*    get_glyph_cbox  :: A method used to access the glyph's cbox.       */
  /*                                                                       */
  /*    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.        */
  /*                                                                       */
  typedef struct  FT_Renderer_Class_
  {
    FT_Module_Class            root;

    FT_Glyph_Format            glyph_format;

    FT_Renderer_RenderFunc     render_glyph;
    FT_Renderer_TransformFunc  transform_glyph;
    FT_Renderer_GetCBoxFunc    get_glyph_cbox;
    FT_Renderer_SetModeFunc    set_mode;

    FT_Raster_Funcs*           raster_class;

  } FT_Renderer_Class;


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    FT_Get_Renderer                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Retrieve 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>                                                         */
  /*    Set 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.        */
  /*                                                                       */
  /*    Currently, only the B/W renderer, if compiled with                 */
  /*    FT_RASTER_OPTION_ANTI_ALIASING (providing a 5-levels               */
  /*    anti-aliasing mode; this option must be set directly in            */
  /*    `ftraster.c' and is undefined by default) accepts a single tag     */
  /*    `pal5' to set its gray palette as a character string with          */
  /*    5~elements.  Consequently, the third and fourth argument are zero  */
  /*    normally.                                                          */
  /*                                                                       */
  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 */