/***************************************************************************/
/*                                                                         */
/*  ftstream.h                                                             */
/*                                                                         */
/*    Stream handling(specification).                                      */
/*                                                                         */
/*  Copyright 1996-2000 by                                                 */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#ifndef FTSTREAM_H
#define FTSTREAM_H

#include "ftobjs.h"


#ifdef __cplusplus
extern "C" {
#endif


/* format of an 8-bit frame_op value = [ xxxxx | e | s ] */
/* s is set to 1 if the value is signed,                 */
/* e is set to 1 if the value is little-endian           */
/* xxxxx is a command                                    */

#define FT_FRAME_OP_SHIFT         2
#define FT_FRAME_OP_SIGNED        1
#define FT_FRAME_OP_LITTLE        2
#define FT_FRAME_OP_COMMAND( x )  ( x >> FT_FRAME_OP_SHIFT )

#define FT_MAKE_FRAME_OP( command, little, sign ) \
	( ( command << FT_FRAME_OP_SHIFT ) | ( little << 1 ) | sign )

#define FT_FRAME_OP_END   0
#define FT_FRAME_OP_START 1  /* start a new frame     */
#define FT_FRAME_OP_BYTE  2  /* read 1-byte value     */
#define FT_FRAME_OP_SHORT 3  /* read 2-byte value     */
#define FT_FRAME_OP_LONG  4  /* read 4-byte value     */
#define FT_FRAME_OP_OFF3  5  /* read 3-byte value     */
#define FT_FRAME_OP_BYTES 6  /* read a bytes sequence */


typedef enum  FT_Frame_Op_
{
	ft_frame_end       = 0,
	ft_frame_start     = FT_MAKE_FRAME_OP( FT_FRAME_OP_START, 0, 0 ),

	ft_frame_byte      = FT_MAKE_FRAME_OP( FT_FRAME_OP_BYTE,  0, 0 ),
	ft_frame_schar     = FT_MAKE_FRAME_OP( FT_FRAME_OP_BYTE,  0, 1 ),

	ft_frame_ushort_be = FT_MAKE_FRAME_OP( FT_FRAME_OP_SHORT, 0, 0 ),
	ft_frame_short_be  = FT_MAKE_FRAME_OP( FT_FRAME_OP_SHORT, 0, 1 ),
	ft_frame_ushort_le = FT_MAKE_FRAME_OP( FT_FRAME_OP_SHORT, 1, 0 ),
	ft_frame_short_le  = FT_MAKE_FRAME_OP( FT_FRAME_OP_SHORT, 1, 1 ),

	ft_frame_ulong_be  = FT_MAKE_FRAME_OP( FT_FRAME_OP_LONG, 0, 0 ),
	ft_frame_ulong_le  = FT_MAKE_FRAME_OP( FT_FRAME_OP_LONG, 0, 1 ),
	ft_frame_long_be   = FT_MAKE_FRAME_OP( FT_FRAME_OP_LONG, 1, 0 ),
	ft_frame_long_le   = FT_MAKE_FRAME_OP( FT_FRAME_OP_LONG, 1, 1 ),

	ft_frame_uoff3_be  = FT_MAKE_FRAME_OP( FT_FRAME_OP_OFF3, 0, 0 ),
	ft_frame_uoff3_le  = FT_MAKE_FRAME_OP( FT_FRAME_OP_OFF3, 0, 1 ),
	ft_frame_off3_be   = FT_MAKE_FRAME_OP( FT_FRAME_OP_OFF3, 1, 0 ),
	ft_frame_off3_le   = FT_MAKE_FRAME_OP( FT_FRAME_OP_OFF3, 1, 1 ),

	ft_frame_bytes     = FT_MAKE_FRAME_OP( FT_FRAME_OP_BYTES, 0, 0 ),
	ft_frame_skip      = FT_MAKE_FRAME_OP( FT_FRAME_OP_BYTES, 0, 1 )

} FT_Frame_Op;


typedef struct  FT_Frame_Field_
{
	FT_Frame_Op value;
	char size;
	FT_UShort offset;

} FT_Frame_Field;


/* make-up a FT_Frame_Field out of a structure type and a field name */
#define FT_FIELD_REF( s, f )  ( ( (s*)0 )->f )

#define FT_FRAME_FIELD( frame_op, struct_type, field )			  \
	{														\
		frame_op,											  \
		sizeof( FT_FIELD_REF( struct_type,field ) ),		 \
		(FT_UShort)(char*)&FT_FIELD_REF( struct_type, field ) \
	}

#define FT_MAKE_EMPTY_FIELD( frame_op )  { frame_op, 0, 0 }

#define FT_FRAME_START( s )         { ft_frame_start, 0, s }
#define FT_FRAME_END                { ft_frame_end, 0, 0 }

#define FT_FRAME_LONG( s, f )       FT_FRAME_FIELD( ft_frame_long_be, s, f )
#define FT_FRAME_ULONG( s, f )      FT_FRAME_FIELD( ft_frame_ulong_be, s, f )
#define FT_FRAME_SHORT( s, f )      FT_FRAME_FIELD( ft_frame_short_be, s, f )
#define FT_FRAME_USHORT( s, f )     FT_FRAME_FIELD( ft_frame_ushort_be, s, f )
#define FT_FRAME_BYTE( s, f )       FT_FRAME_FIELD( ft_frame_byte, s, f )
#define FT_FRAME_CHAR( s, f )       FT_FRAME_FIELD( ft_frame_schar, s, f )

#define FT_FRAME_LONG_LE( s, f )    FT_FRAME_FIELD( ft_frame_long_le, s, f )
#define FT_FRAME_ULONG_LE( s, f )   FT_FRAME_FIELD( ft_frame_ulong_le, s, f )
#define FT_FRAME_SHORT_LE( s, f )   FT_FRAME_FIELD( ft_frame_short_le, s, f )
#define FT_FRAME_USHORT_LE( s, f )  FT_FRAME_FIELD( ft_frame_ushort_le, s, f )

#define FT_FRAME_SKIP_LONG          { ft_frame_long_be, 0, 0 }
#define FT_FRAME_SKIP_SHORT         { ft_frame_short_be, 0, 0 }
#define FT_FRAME_SKIP_BYTE          { ft_frame_byte, 0, 0 }

#define FT_FRAME_BYTES( struct_type, field, count )				  \
	{														\
		ft_frame_bytes,										  \
		count,												  \
		(FT_UShort)(char*)&FT_FIELD_REF( struct_type, field ) \
	}
#define FT_FRAME_SKIP_BYTES( count )  { ft_frame_skip, count, 0 }



/*************************************************************************/
/*                                                                       */
/* integer extraction macros -- the `buffer' parameter must ALWAYS be of */
/* type `char*' or equivalent (1-byte elements).                         */
/*                                                                       */
#define NEXT_Char( buffer )			   \
	( (signed char)*buffer++ )
#define NEXT_Byte( buffer )			   \
	( (unsigned char)*buffer++ )

#define NEXT_Short( buffer )							  \
	( buffer += 2,									\
	  ( (short)( (signed char)buffer[-2] << 8 ) | \
			  (unsigned char)buffer[-1]        ) )

#define NEXT_UShort( buffer )					   \
	( (unsigned short)NEXT_Short( buffer ) )

#define NEXT_Offset( buffer )							  \
	( buffer += 3,									\
	  ( ( (long)(signed char)buffer[-3] << 16 ) | \
			  ( (long)(unsigned char)buffer[-2] <<  8 ) | \
			  (long)(unsigned char)buffer[-1]         ) )

#define NEXT_UOffset( buffer )					   \
	( (unsigned long)NEXT_Offset( buffer ) )

#define NEXT_Long( buffer )								  \
	( buffer += 4,									\
	  ( ( (long)(signed char)buffer[-4] << 24 ) | \
			  ( (long)(unsigned char)buffer[-3] << 16 ) | \
			  ( (long)(unsigned char)buffer[-2] <<  8 ) | \
			  (long)(unsigned char)buffer[-1]         ) )

#define NEXT_ULong( buffer )					 \
	( (unsigned long)NEXT_Long( buffer ) )


#define NEXT_ShortLE( buffer )							  \
	( buffer += 2,									\
	  ( (short)( (signed char)buffer[-1] << 8 ) | \
			  (unsigned char)buffer[-2]        ) )

#define NEXT_UShortLE( buffer )						 \
	( (unsigned short)NEXT_ShortLE( buffer ) )

#define NEXT_OffsetLE( buffer )							  \
	( buffer += 3,									\
	  ( ( (long)(signed char)buffer[-1] << 16 ) | \
			  ( (long)(unsigned char)buffer[-2] <<  8 ) | \
			  (long)(unsigned char)buffer[-3]         ) )

#define NEXT_UOffsetLE( buffer )					 \
	( (unsigned long)NEXT_OffsetLE( buffer ) )


#define NEXT_LongLE( buffer )							  \
	( buffer += 4,									\
	  ( ( (long)(signed char)buffer[-1] << 24 ) | \
			  ( (long)(unsigned char)buffer[-2] << 16 ) | \
			  ( (long)(unsigned char)buffer[-3] <<  8 ) | \
			  (long)(unsigned char)buffer[-4]         ) )

#define NEXT_ULongLE( buffer )					   \
	( (unsigned long)NEXT_LongLE( buffer ) )


/*************************************************************************/
/*                                                                       */
/* Each GET_xxxx() macro uses an implicit `stream' variable.             */
/*                                                                       */
#define FT_GET_MACRO( func, type )        ( (type)func( stream ) )

#define GET_Char()      FT_GET_MACRO( FT_Get_Char, FT_Char )
#define GET_Byte()      FT_GET_MACRO( FT_Get_Char, FT_Byte )
#define GET_Short()     FT_GET_MACRO( FT_Get_Short, FT_Short )
#define GET_UShort()    FT_GET_MACRO( FT_Get_Short, FT_UShort )
#define GET_Offset()    FT_GET_MACRO( FT_Get_Offset, FT_Long )
#define GET_UOffset()   FT_GET_MACRO( FT_Get_Offset, FT_ULong )
#define GET_Long()      FT_GET_MACRO( FT_Get_Long, FT_Long )
#define GET_ULong()     FT_GET_MACRO( FT_Get_Long, FT_ULong )
#define GET_Tag4()      FT_GET_MACRO( FT_Get_Long, FT_ULong )

#define GET_ShortLE()   FT_GET_MACRO( FT_Get_ShortLE, FT_Short )
#define GET_UShortLE()  FT_GET_MACRO( FT_Get_ShortLE, FT_UShort )
#define GET_LongLE()    FT_GET_MACRO( FT_Get_LongLE, FT_Short )
#define GET_ULongLE()   FT_GET_MACRO( FT_Get_LongLE, FT_Short )

#define FT_READ_MACRO( func, type, var )		\
	( var = (type)func( stream, &error ), \
	  error != FT_Err_Ok )

#define READ_Byte( var )      FT_READ_MACRO( FT_Read_Char, FT_Byte, var )
#define READ_Char( var )      FT_READ_MACRO( FT_Read_Char, FT_Char, var )
#define READ_Short( var )     FT_READ_MACRO( FT_Read_Short, FT_Short, var )
#define READ_UShort( var )    FT_READ_MACRO( FT_Read_Short, FT_UShort, var )
#define READ_Offset( var )    FT_READ_MACRO( FT_Read_Offset, FT_Long, var )
#define READ_UOffset( var )   FT_READ_MACRO( FT_Read_Offset, FT_ULong, var )
#define READ_Long( var )      FT_READ_MACRO( FT_Read_Long, FT_Long, var )
#define READ_ULong( var )     FT_READ_MACRO( FT_Read_Long, FT_ULong, var )

#define READ_ShortLE( var )   FT_READ_MACRO( FT_Read_ShortLE, FT_Short, var )
#define READ_UShortLE( var )  FT_READ_MACRO( FT_Read_ShortLE, FT_UShort, var )
#define READ_LongLE( var )    FT_READ_MACRO( FT_Read_LongLE, FT_Long, var )
#define READ_ULongLE( var )   FT_READ_MACRO( FT_Read_LongLE, FT_ULong, var )


BASE_DEF( void )  FT_New_Memory_Stream( FT_Library library,
										FT_Byte *    base,
										FT_ULong size,
										FT_Stream stream );

BASE_DEF( FT_Error )  FT_Seek_Stream( FT_Stream stream,
									  FT_ULong pos );

BASE_DEF( FT_Error )  FT_Skip_Stream( FT_Stream stream,
									  FT_Long distance );

BASE_DEF( FT_Long )  FT_Stream_Pos( FT_Stream stream );


BASE_DEF( FT_Error )  FT_Read_Stream( FT_Stream stream,
									  FT_Byte *   buffer,
									  FT_ULong count );

BASE_DEF( FT_Error )  FT_Read_Stream_At( FT_Stream stream,
										 FT_ULong pos,
										 FT_Byte *   buffer,
										 FT_ULong count );

BASE_DEF( FT_Error )  FT_Access_Frame( FT_Stream stream,
									   FT_ULong count );

BASE_DEF( void )  FT_Forget_Frame( FT_Stream stream );

BASE_DEF( FT_Error )  FT_Extract_Frame( FT_Stream stream,
										FT_ULong count,
										FT_Byte * *pbytes );

BASE_DEF( void )  FT_Release_Frame( FT_Stream stream,
									FT_Byte * *pbytes );

BASE_DEF( FT_Char )  FT_Get_Char( FT_Stream stream );

BASE_DEF( FT_Short )  FT_Get_Short( FT_Stream stream );

BASE_DEF( FT_Long )  FT_Get_Offset( FT_Stream stream );

BASE_DEF( FT_Long )  FT_Get_Long( FT_Stream stream );

BASE_DEF( FT_Short )  FT_Get_ShortLE( FT_Stream stream );

BASE_DEF( FT_Long )  FT_Get_LongLE( FT_Stream stream );


BASE_DEF( FT_Char )  FT_Read_Char( FT_Stream stream,
								   FT_Error *  error );

BASE_DEF( FT_Short )  FT_Read_Short( FT_Stream stream,
									 FT_Error *  error );

BASE_DEF( FT_Long )  FT_Read_Offset( FT_Stream stream,
									 FT_Error *  error );

BASE_DEF( FT_Long )  FT_Read_Long( FT_Stream stream,
								   FT_Error *  error );

BASE_DEF( FT_Short )  FT_Read_ShortLE( FT_Stream stream,
									   FT_Error *  error );

BASE_DEF( FT_Long )  FT_Read_LongLE( FT_Stream stream,
									 FT_Error *  error );

BASE_DEF( FT_Error )  FT_Read_Fields( FT_Stream stream,
									  const FT_Frame_Field *  fields,
									  void*                  structure );


#define USE_Stream( resource, stream )						 \
	FT_SET_ERROR( FT_Open_Stream( resource, stream ) )

#define DONE_Stream( stream )	   \
	FT_Done_Stream( stream )


#define ACCESS_Frame( size )							  \
	FT_SET_ERROR( FT_Access_Frame( stream, size ) )

#define FORGET_Frame()				\
	FT_Forget_Frame( stream )

#define EXTRACT_Frame( size, bytes )							  \
	FT_SET_ERROR( FT_Extract_Frame( stream, size,			\
									(FT_Byte**)&( bytes ) ) )

#define RELEASE_Frame( bytes )							  \
	FT_Release_Frame( stream, (FT_Byte**)&( bytes ) )

#define FILE_Seek( position )								 \
	FT_SET_ERROR( FT_Seek_Stream( stream, position ) )

#define FILE_Skip( distance )								 \
	FT_SET_ERROR( FT_Skip_Stream( stream, distance ) )

#define FILE_Pos()				  \
	FT_Stream_Pos( stream )

#define FILE_Read( buffer, count )						  \
	FT_SET_ERROR( FT_Read_Stream( stream,			\
								  (FT_Byte*)buffer,	\
								  count ) )

#define FILE_Read_At( position, buffer, count )				 \
	FT_SET_ERROR( FT_Read_Stream_At( stream,		   \
									 position,		   \
									 (FT_Byte*)buffer, \
									 count ) )

#define READ_Fields( fields, object )  \
	( ( error = FT_Read_Fields( stream, fields, object ) ) != FT_Err_Ok )


#ifdef __cplusplus
}
#endif


#endif /* FTSTREAM_H */


/* END */
