freetype2/include/freetype/ftlzw.h

101 lines
2.7 KiB
C

/****************************************************************************
*
* ftlzw.h
*
* LZW-compressed stream support.
*
* Copyright (C) 2004-2020 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 */