1 /****************************************************************************
   2  *
   3  * ftgzip.h
   4  *
   5  *   Gzip-compressed stream support.
   6  *
   7  * Copyright (C) 2002-2019 by
   8  * David Turner, Robert Wilhelm, and Werner Lemberg.
   9  *
  10  * This file is part of the FreeType project, and may only be used,
  11  * modified, and distributed under the terms of the FreeType project
  12  * license, LICENSE.TXT.  By continuing to use, modify, or distribute
  13  * this file you indicate that you have read the license and
  14  * understand and accept it fully.
  15  *
  16  */
  17 
  18 
  19 #ifndef FTGZIP_H_
  20 #define FTGZIP_H_
  21 
  22 #include <ft2build.h>
  23 #include FT_FREETYPE_H
  24 
  25 #ifdef FREETYPE_H
  26 #error "freetype.h of FreeType 1 has been loaded!"
  27 #error "Please fix the directory search order for header files"
  28 #error "so that freetype.h of FreeType 2 is found first."
  29 #endif
  30 
  31 
  32 FT_BEGIN_HEADER
  33 
  34   /**************************************************************************
  35    *
  36    * @section:
  37    *   gzip
  38    *
  39    * @title:
  40    *   GZIP Streams
  41    *
  42    * @abstract:
  43    *   Using gzip-compressed font files.
  44    *
  45    * @description:
  46    *   This section contains the declaration of Gzip-specific functions.
  47    *
  48    */
  49 
  50 
  51   /**************************************************************************
  52    *
  53    * @function:
  54    *   FT_Stream_OpenGzip
  55    *
  56    * @description:
  57    *   Open a new stream to parse gzip-compressed font files.  This is mainly
  58    *   used to support the compressed `*.pcf.gz` fonts that come with
  59    *   XFree86.
  60    *
  61    * @input:
  62    *   stream ::
  63    *     The target embedding stream.
  64    *
  65    *   source ::
  66    *     The source stream.
  67    *
  68    * @return:
  69    *   FreeType error code.  0~means success.
  70    *
  71    * @note:
  72    *   The source stream must be opened _before_ calling this function.
  73    *
  74    *   Calling the internal function `FT_Stream_Close` on the new stream will
  75    *   **not** call `FT_Stream_Close` on the source stream.  None of the
  76    *   stream objects will be released to the heap.
  77    *
  78    *   The stream implementation is very basic and resets the decompression
  79    *   process each time seeking backwards is needed within the stream.
  80    *
  81    *   In certain builds of the library, gzip compression recognition is
  82    *   automatically handled when calling @FT_New_Face or @FT_Open_Face.
  83    *   This means that if no font driver is capable of handling the raw
  84    *   compressed file, the library will try to open a gzipped stream from it
  85    *   and re-open the face with it.
  86    *
  87    *   This function may return `FT_Err_Unimplemented_Feature` if your build
  88    *   of FreeType was not compiled with zlib support.
  89    */
  90   FT_EXPORT( FT_Error )
  91   FT_Stream_OpenGzip( FT_Stream  stream,
  92                       FT_Stream  source );
  93 
  94 
  95   /**************************************************************************
  96    *
  97    * @function:
  98    *   FT_Gzip_Uncompress
  99    *
 100    * @description:
 101    *   Decompress a zipped input buffer into an output buffer.  This function
 102    *   is modeled after zlib's `uncompress` function.
 103    *
 104    * @input:
 105    *   memory ::
 106    *     A FreeType memory handle.
 107    *
 108    *   input ::
 109    *     The input buffer.
 110    *
 111    *   input_len ::
 112    *     The length of the input buffer.
 113    *
 114    * @output:
 115    *   output ::
 116    *     The output buffer.
 117    *
 118    * @inout:
 119    *   output_len ::
 120    *     Before calling the function, this is the total size of the output
 121    *     buffer, which must be large enough to hold the entire uncompressed
 122    *     data (so the size of the uncompressed data must be known in
 123    *     advance).  After calling the function, `output_len` is the size of
 124    *     the used data in `output`.
 125    *
 126    * @return:
 127    *   FreeType error code.  0~means success.
 128    *
 129    * @note:
 130    *   This function may return `FT_Err_Unimplemented_Feature` if your build
 131    *   of FreeType was not compiled with zlib support.
 132    *
 133    * @since:
 134    *   2.5.1
 135    */
 136   FT_EXPORT( FT_Error )
 137   FT_Gzip_Uncompress( FT_Memory       memory,
 138                       FT_Byte*        output,
 139                       FT_ULong*       output_len,
 140                       const FT_Byte*  input,
 141                       FT_ULong        input_len );
 142 
 143   /* */
 144 
 145 
 146 FT_END_HEADER
 147 
 148 #endif /* FTGZIP_H_ */
 149 
 150 
 151 /* END */