include/freetype/ftlzw.h

/****************************************************************************
 *
 * ftlzw.h
 *
 *   LZW-compressed stream support.
 *
 * Copyright (C) 2004-2022 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 FTLZW_H_
#define FTLZW_H_

#include <freetype/freetype.h>

#ifdef FREETYPE_H
#error "freetype.h of FreeType 1 has been loaded!"
#error "Please fix the directory search order for header files"
#error "so that freetype.h of FreeType 2 is found first."
#endif


FT_BEGIN_HEADER

  /**************************************************************************
   *
   * @section:
   *   lzw
   *
   * @title:
   *   LZW Streams
   *
   * @abstract:
   *   Using LZW-compressed font files.
   *
   * @description:
   *   In certain builds of the library, LZW compression recognition is
   *   automatically handled when calling @FT_New_Face or @FT_Open_Face.
   *   This means that if no font driver is capable of handling the raw
   *   compressed file, the library will try to open a LZW stream from it and
   *   re-open the face with it.
   *
   *   The stream implementation is very basic and resets the decompression
   *   process each time seeking backwards is needed within the stream,
   *   which significantly undermines the performance.
   *
   *   This section contains the declaration of LZW-specific functions.
   *
   */

  /**************************************************************************
   *
   * @function:
   *   FT_Stream_OpenLZW
   *
   * @description:
   *   Open a new stream to parse LZW-compressed font files.  This is mainly
   *   used to support the compressed `*.pcf.Z` fonts that come with XFree86.
   *
   * @input:
   *   stream ::
   *     The target embedding stream.
   *
   *   source ::
   *     The source stream.
   *
   * @return:
   *   FreeType error code.  0~means success.
   *
   * @note:
   *   The source stream must be opened _before_ calling this function.
   *
   *   Calling the internal function `FT_Stream_Close` on the new stream will
   *   **not** call `FT_Stream_Close` on the source stream.  None of the
   *   stream objects will be released to the heap.
   *
   *   This function may return `FT_Err_Unimplemented_Feature` if your build
   *   of FreeType was not compiled with LZW support.
   */
  FT_EXPORT( FT_Error )
  FT_Stream_OpenLZW( FT_Stream  stream,
                     FT_Stream  source );

  /* */


FT_END_HEADER

#endif /* FTLZW_H_ */


/* END */