ftcimage.h

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/***************************************************************************/
/*                                                                         */
/*  ftcimage.h                                                             */
/*                                                                         */
/*    FreeType Image cache (specification).                                */
/*                                                                         */
/*  Copyright 2000-2001, 2002, 2003 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.                                        */
/*                                                                         */
/***************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* Each image cache really manages FT_Glyph objects.                     */
  /*                                                                       */
  /*************************************************************************/


#ifndef __FTCIMAGE_H__
#define __FTCIMAGE_H__


#include <ft2build.h>
#include FT_CACHE_H


FT_BEGIN_HEADER


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


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


 /**************************************************************************
  *
  * @struct:
  *   FTC_ImageTypeRec
  *
  * @description:
  *   A simple structure used to describe the type of glyph image to be
  *   loaded into the cache.
  *
  * @fields:
  *   font  :: An @FTC_FontRec used to describe the glyph's face and size.
  *
  *   flags :: The load flags to be applied when loading the glyph; see
  *            the @FT_LOAD_XXX constants for details.
  *
  * @note:
  *   This type completely replaces the @FTC_Image_Desc structure which is
  *   now obsolete.
  */
  typedef struct  FTC_ImageTypeRec_
  {
    FTC_FontRec  font;
    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.                */
  /*                                                                       */
  /*    type   :: A pointer to a glyph image type descriptor.              */
  /*                                                                       */
  /*    gindex :: The glyph index to retrieve.                             */
  /*                                                                       */
  /* <Output>                                                              */
  /*    aglyph :: The corresponding @FT_Glyph object.  0 in case of        */
  /*              failure.                                                 */
  /*                                                                       */
  /*    anode  :: Used to return the address of of the corresponding cache */
  /*              node after incrementing its reference count (see note    */
  /*              below).                                                  */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  /* <Note>                                                                */
  /*    The returned glyph is owned and managed by the glyph image cache.  */