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/* ftglue.c: Glue code for compiling the OpenType code from
* FreeType 1 using only the public API of FreeType 2
*
* By David Turner, The FreeType Project (www.freetype.org)
*
* This code is explicitely put in the public domain
*
* ==========================================================================
*
* the OpenType parser codes was originally written as an extension to
* FreeType 1.x. As such, its source code was embedded within the library,
* and used many internal FreeType functions to deal with memory and
* stream i/o.
*
* When it was 'salvaged' for Pango and Qt, the code was "ported" to FreeType 2,
* which basically means that some macro tricks were performed in order to
* directly access FT2 _internal_ functions.
*
* these functions were never part of FT2 public API, and _did_ change between
* various releases. This created chaos for many users: when they upgraded the
* FreeType library on their system, they couldn't run Gnome anymore since
* Pango refused to link.
*
* Very fortunately, it's possible to completely avoid this problem because
* the FT_StreamRec and FT_MemoryRec structure types, which describe how
* memory and stream implementations interface with the rest of the font
* library, have always been part of the public API, and never changed.
*
* What we do thus is re-implement, within the OpenType parser, the few
* functions that depend on them. This only adds one or two kilobytes of
* code, and ensures that the parser can work with _any_ version
* of FreeType installed on your system. How sweet... !
*
* Note that we assume that Pango doesn't use any other internal functions
* from FreeType. It used to in old versions, but this should no longer
* be the case. (crossing my fingers).
*
* - David Turner
* - The FreeType Project (www.freetype.org)
*
* PS: This "glue" code is explicitely put in the public domain
*/
#ifndef __OPENTYPE_FTGLUE_H__
#define __OPENTYPE_FTGLUE_H__
#include "fcint.h"
#include <ft2build.h>
#include FT_FREETYPE_H
FT_BEGIN_HEADER
#define SET_ERR(c) ( (error = (c)) != 0 )
#ifndef FTGLUE_API
#define FTGLUE_API(x) extern FcPrivate x
#endif
#ifndef FTGLUE_APIDEF
#define FTGLUE_APIDEF(x) x
#endif
/* stream macros used by the OpenType parser */
#define FILE_Pos() ftglue_stream_pos( stream )
#define FILE_Seek(pos) SET_ERR( ftglue_stream_seek( stream, pos ) )
#define ACCESS_Frame(size) SET_ERR( ftglue_stream_frame_enter( stream, size ) )
#define FORGET_Frame() ftglue_stream_frame_exit( stream )
#define GET_Byte() (*stream->cursor++)
#define GET_Short() (stream->cursor += 2, (FT_Short)( \
((FT_ULong)*(((FT_Byte*)stream->cursor)-2) << 8) | \
(FT_ULong)*(((FT_Byte*)stream->cursor)-1) \
))
#define GET_Long() (stream->cursor += 4, (FT_Long)( \
((FT_ULong)*(((FT_Byte*)stream->cursor)-4) << 24) | \
((FT_ULong)*(((FT_Byte*)stream->cursor)-3) << 16) | \
((FT_ULong)*(((FT_Byte*)stream->cursor)-2) << 8) | \
(FT_ULong)*(((FT_Byte*)stream->cursor)-1) \
))
#define GET_Char() ((FT_Char)GET_Byte())
#define GET_UShort() ((FT_UShort)GET_Short())
#define GET_ULong() ((FT_ULong)GET_Long())
#define GET_Tag4() GET_ULong()
#define FT_SET_ERROR( expression ) \
( ( error = (expression) ) != 0 )
FTGLUE_API( FT_Long )
ftglue_stream_pos( FT_Stream stream );
FTGLUE_API( FT_Error )
ftglue_stream_seek( FT_Stream stream,
FT_Long pos );
FTGLUE_API( FT_Error )
ftglue_stream_frame_enter( FT_Stream stream,
FT_ULong size );
FTGLUE_API( void )
ftglue_stream_frame_exit( FT_Stream stream );
FTGLUE_API( FT_Error )
ftglue_face_goto_table( FT_Face face,
FT_ULong tag,
FT_Stream stream );
FT_END_HEADER
#endif /* __OPENTYPE_FTGLUE_H__ */
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