[fontconfig.git] / src / ftglue.h

/* 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 <ft2build.h>
#include FT_FREETYPE_H

FT_BEGIN_HEADER


/* utility macros */
#define  TT_Err_Ok                   FT_Err_Ok
#define  TT_Err_Invalid_Argument     FT_Err_Invalid_Argument
#define  TT_Err_Invalid_Face_Handle  FT_Err_Invalid_Face_Handle
#define  TT_Err_Table_Missing        FT_Err_Table_Missing

#define  SET_ERR(c)   ( (error = (c)) != 0 )

#ifndef FTGLUE_API
#define FTGLUE_API(x)  extern 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_Byte*)stream->cursor)-2) << 8) | \
				 *(((FT_Byte*)stream->cursor)-1) \
			 ))
#define  GET_Long()      (stream->cursor += 4, (FT_Long)( \
				(*(((FT_Byte*)stream->cursor)-4) << 24) | \
				(*(((FT_Byte*)stream->cursor)-3) << 16) | \
				(*(((FT_Byte*)stream->cursor)-2) << 8) | \
				 *(((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_Byte )
ftglue_stream_get_byte( FT_Stream  stream );

FTGLUE_API( FT_Short )
ftglue_stream_get_short( FT_Stream  stream );

FTGLUE_API( FT_Long )
ftglue_stream_get_long( FT_Stream   stream );

FTGLUE_API( FT_Error )
ftglue_face_goto_table( FT_Face    face,
                        FT_ULong   tag,
                        FT_Stream  stream );

FTGLUE_API( FT_Pointer )
ftglue_alloc( FT_Memory  memory,
              FT_ULong   size,
              FT_Error  *perror_ );

FTGLUE_API( FT_Pointer )
ftglue_realloc( FT_Memory   memory,
                FT_Pointer  block,
                FT_ULong    old_size,
                FT_ULong    new_size,
                FT_Error   *perror_ );

FTGLUE_API( void )
ftglue_free( FT_Memory   memory,
             FT_Pointer  block );

/* */

FT_END_HEADER

#endif /* __OPENTYPE_FTGLUE_H__ */
Commit	Line	Data
824c7bf0 PL	1	/* ftglue.c: Glue code for compiling the OpenType code from
	2	* FreeType 1 using only the public API of FreeType 2
	3	*
	4	* By David Turner, The FreeType Project (www.freetype.org)
	5	*
	6	* This code is explicitely put in the public domain
	7	*
	8	* ==========================================================================
	9	*
	10	* the OpenType parser codes was originally written as an extension to
	11	* FreeType 1.x. As such, its source code was embedded within the library,
	12	* and used many internal FreeType functions to deal with memory and
	13	* stream i/o.
	14	*
	15	* When it was 'salvaged' for Pango and Qt, the code was "ported" to FreeType 2,
	16	* which basically means that some macro tricks were performed in order to
	17	* directly access FT2 _internal_ functions.
	18	*
	19	* these functions were never part of FT2 public API, and _did_ change between
	20	* various releases. This created chaos for many users: when they upgraded the
	21	* FreeType library on their system, they couldn't run Gnome anymore since
	22	* Pango refused to link.
	23	*
	24	* Very fortunately, it's possible to completely avoid this problem because
	25	* the FT_StreamRec and FT_MemoryRec structure types, which describe how
	26	* memory and stream implementations interface with the rest of the font
	27	* library, have always been part of the public API, and never changed.
	28	*
	29	* What we do thus is re-implement, within the OpenType parser, the few
	30	* functions that depend on them. This only adds one or two kilobytes of
	31	* code, and ensures that the parser can work with _any_ version
	32	* of FreeType installed on your system. How sweet... !
	33	*
	34	* Note that we assume that Pango doesn't use any other internal functions
	35	* from FreeType. It used to in old versions, but this should no longer
	36	* be the case. (crossing my fingers).
	37	*
	38	* - David Turner
	39	* - The FreeType Project (www.freetype.org)
	40	*
	41	* PS: This "glue" code is explicitely put in the public domain
	42	*/
	43	#ifndef __OPENTYPE_FTGLUE_H__
	44	#define __OPENTYPE_FTGLUE_H__
	45
	46	#include <ft2build.h>
	47	#include FT_FREETYPE_H
	48
	49	FT_BEGIN_HEADER
	50
	51
	52	/* utility macros */
	53	#define TT_Err_Ok FT_Err_Ok
	54	#define TT_Err_Invalid_Argument FT_Err_Invalid_Argument
	55	#define TT_Err_Invalid_Face_Handle FT_Err_Invalid_Face_Handle
	56	#define TT_Err_Table_Missing FT_Err_Table_Missing
	57
	58	#define SET_ERR(c) ( (error = (c)) != 0 )
	59
	60	#ifndef FTGLUE_API
	61	#define FTGLUE_API(x) extern x
	62	#endif
	63
	64	#ifndef FTGLUE_APIDEF
65	#define FTGLUE_APIDEF(x) x
66	#endif
67
68	/* stream macros used by the OpenType parser */
69	#define FILE_Pos() ftglue_stream_pos( stream )
70	#define FILE_Seek(pos) SET_ERR( ftglue_stream_seek( stream, pos ) )
71	#define ACCESS_Frame(size) SET_ERR( ftglue_stream_frame_enter( stream, size ) )
72	#define FORGET_Frame() ftglue_stream_frame_exit( stream )
73
d8951c0c PL	74	#define GET_Byte() (*stream->cursor++)
	75	#define GET_Short() (stream->cursor += 2, (FT_Short)( \
	76	((((FT_Byte)stream->cursor)-2) << 8) \| \
	77	(((FT_Byte)stream->cursor)-1) \
	78	))
	79	#define GET_Long() (stream->cursor += 4, (FT_Long)( \
	80	((((FT_Byte)stream->cursor)-4) << 24) \| \
	81	((((FT_Byte)stream->cursor)-3) << 16) \| \
	82	((((FT_Byte)stream->cursor)-2) << 8) \| \
	83	(((FT_Byte)stream->cursor)-1) \
	84	))
824c7bf0 PL	85
	86	#define GET_Char() ((FT_Char)GET_Byte())
	87	#define GET_UShort() ((FT_UShort)GET_Short())
	88	#define GET_ULong() ((FT_ULong)GET_Long())
	89	#define GET_Tag4() GET_ULong()
	90
	91	#define FT_SET_ERROR( expression ) \
	92	( ( error = (expression) ) != 0 )
	93
	94	FTGLUE_API( FT_Long )
	95	ftglue_stream_pos( FT_Stream stream );
	96
	97	FTGLUE_API( FT_Error )
	98	ftglue_stream_seek( FT_Stream stream,
	99	FT_Long pos );
	100
	101	FTGLUE_API( FT_Error )
	102	ftglue_stream_frame_enter( FT_Stream stream,
	103	FT_ULong size );
	104
	105	FTGLUE_API( void )
	106	ftglue_stream_frame_exit( FT_Stream stream );
	107
	108	FTGLUE_API( FT_Byte )
	109	ftglue_stream_get_byte( FT_Stream stream );
	110
	111	FTGLUE_API( FT_Short )
	112	ftglue_stream_get_short( FT_Stream stream );
	113
	114	FTGLUE_API( FT_Long )
	115	ftglue_stream_get_long( FT_Stream stream );
	116
	117	FTGLUE_API( FT_Error )
	118	ftglue_face_goto_table( FT_Face face,
	119	FT_ULong tag,
	120	FT_Stream stream );
	121
824c7bf0 PL	122	FTGLUE_API( FT_Pointer )
	123	ftglue_alloc( FT_Memory memory,
	124	FT_ULong size,
	125	FT_Error *perror_ );
	126
	127	FTGLUE_API( FT_Pointer )
	128	ftglue_realloc( FT_Memory memory,
	129	FT_Pointer block,
	130	FT_ULong old_size,
	131	FT_ULong new_size,
	132	FT_Error *perror_ );
	133
	134	FTGLUE_API( void )
	135	ftglue_free( FT_Memory memory,
	136	FT_Pointer block );
	137
	138	/* */
	139
	140	FT_END_HEADER
	141
	142	#endif /* __OPENTYPE_FTGLUE_H__ */