/* 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__ */