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1 /****************************************************************************
2  *
3  * ftgzip.h
4  *
5  *   Gzip-compressed stream support.
6  *
7  * Copyright (C) 2002-2020 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 <freetype/freetype.h>
23 
24 #ifdef FREETYPE_H
25 #error "freetype.h of FreeType 1 has been loaded!"
26 #error "Please fix the directory search order for header files"
27 #error "so that freetype.h of FreeType 2 is found first."
28 #endif
29 
30 
31 FT_BEGIN_HEADER
32 
33   /**************************************************************************
34    *
35    * @section:
36    *   gzip
37    *
38    * @title:
39    *   GZIP Streams
40    *
41    * @abstract:
42    *   Using gzip-compressed font files.
43    *
44    * @description:
45    *   In certain builds of the library, gzip compression recognition is
46    *   automatically handled when calling @FT_New_Face or @FT_Open_Face.
47    *   This means that if no font driver is capable of handling the raw
48    *   compressed file, the library will try to open a gzipped stream from it
49    *   and re-open the face with it.
50    *
51    *   The stream implementation is very basic and resets the decompression
52    *   process each time seeking backwards is needed within the stream,
53    *   which significantly undermines the performance.
54    *
55    *   This section contains the declaration of Gzip-specific functions.
56    *
57    */
58 
59 
60   /**************************************************************************
61    *
62    * @function:
63    *   FT_Stream_OpenGzip
64    *
65    * @description:
66    *   Open a new stream to parse gzip-compressed font files.  This is mainly
67    *   used to support the compressed `*.pcf.gz` fonts that come with
68    *   XFree86.
69    *
70    * @input:
71    *   stream ::
72    *     The target embedding stream.
73    *
74    *   source ::
75    *     The source stream.
76    *
77    * @return:
78    *   FreeType error code.  0~means success.
79    *
80    * @note:
81    *   The source stream must be opened _before_ calling this function.
82    *
83    *   Calling the internal function `FT_Stream_Close` on the new stream will
84    *   **not** call `FT_Stream_Close` on the source stream.  None of the
85    *   stream objects will be released to the heap.
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 */
152