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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  ftstream.h                                                             */
      4 /*                                                                         */
      5 /*    Stream handling (specification).                                     */
      6 /*                                                                         */
      7 /*  Copyright 1996-2002, 2004-2006, 2011 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 __FTSTREAM_H__
     20 #define __FTSTREAM_H__
     21 
     22 
     23 #include <ft2build.h>
     24 #include FT_SYSTEM_H
     25 #include FT_INTERNAL_OBJECTS_H
     26 
     27 
     28 FT_BEGIN_HEADER
     29 
     30 
     31   /* format of an 8-bit frame_op value:           */
     32   /*                                              */
     33   /* bit  76543210                                */
     34   /*      xxxxxxes                                */
     35   /*                                              */
     36   /* s is set to 1 if the value is signed.        */
     37   /* e is set to 1 if the value is little-endian. */
     38   /* xxx is a command.                            */
     39 
     40 #define FT_FRAME_OP_SHIFT         2
     41 #define FT_FRAME_OP_SIGNED        1
     42 #define FT_FRAME_OP_LITTLE        2
     43 #define FT_FRAME_OP_COMMAND( x )  ( x >> FT_FRAME_OP_SHIFT )
     44 
     45 #define FT_MAKE_FRAME_OP( command, little, sign ) \
     46           ( ( command << FT_FRAME_OP_SHIFT ) | ( little << 1 ) | sign )
     47 
     48 #define FT_FRAME_OP_END    0
     49 #define FT_FRAME_OP_START  1  /* start a new frame     */
     50 #define FT_FRAME_OP_BYTE   2  /* read 1-byte value     */
     51 #define FT_FRAME_OP_SHORT  3  /* read 2-byte value     */
     52 #define FT_FRAME_OP_LONG   4  /* read 4-byte value     */
     53 #define FT_FRAME_OP_OFF3   5  /* read 3-byte value     */
     54 #define FT_FRAME_OP_BYTES  6  /* read a bytes sequence */
     55 
     56 
     57   typedef enum  FT_Frame_Op_
     58   {
     59     ft_frame_end       = 0,
     60     ft_frame_start     = FT_MAKE_FRAME_OP( FT_FRAME_OP_START, 0, 0 ),
     61 
     62     ft_frame_byte      = FT_MAKE_FRAME_OP( FT_FRAME_OP_BYTE,  0, 0 ),
     63     ft_frame_schar     = FT_MAKE_FRAME_OP( FT_FRAME_OP_BYTE,  0, 1 ),
     64 
     65     ft_frame_ushort_be = FT_MAKE_FRAME_OP( FT_FRAME_OP_SHORT, 0, 0 ),
     66     ft_frame_short_be  = FT_MAKE_FRAME_OP( FT_FRAME_OP_SHORT, 0, 1 ),
     67     ft_frame_ushort_le = FT_MAKE_FRAME_OP( FT_FRAME_OP_SHORT, 1, 0 ),
     68     ft_frame_short_le  = FT_MAKE_FRAME_OP( FT_FRAME_OP_SHORT, 1, 1 ),
     69 
     70     ft_frame_ulong_be  = FT_MAKE_FRAME_OP( FT_FRAME_OP_LONG, 0, 0 ),
     71     ft_frame_long_be   = FT_MAKE_FRAME_OP( FT_FRAME_OP_LONG, 0, 1 ),
     72     ft_frame_ulong_le  = FT_MAKE_FRAME_OP( FT_FRAME_OP_LONG, 1, 0 ),
     73     ft_frame_long_le   = FT_MAKE_FRAME_OP( FT_FRAME_OP_LONG, 1, 1 ),
     74 
     75     ft_frame_uoff3_be  = FT_MAKE_FRAME_OP( FT_FRAME_OP_OFF3, 0, 0 ),
     76     ft_frame_off3_be   = FT_MAKE_FRAME_OP( FT_FRAME_OP_OFF3, 0, 1 ),
     77     ft_frame_uoff3_le  = FT_MAKE_FRAME_OP( FT_FRAME_OP_OFF3, 1, 0 ),
     78     ft_frame_off3_le   = FT_MAKE_FRAME_OP( FT_FRAME_OP_OFF3, 1, 1 ),
     79 
     80     ft_frame_bytes     = FT_MAKE_FRAME_OP( FT_FRAME_OP_BYTES, 0, 0 ),
     81     ft_frame_skip      = FT_MAKE_FRAME_OP( FT_FRAME_OP_BYTES, 0, 1 )
     82 
     83   } FT_Frame_Op;
     84 
     85 
     86   typedef struct  FT_Frame_Field_
     87   {
     88     FT_Byte    value;
     89     FT_Byte    size;
     90     FT_UShort  offset;
     91 
     92   } FT_Frame_Field;
     93 
     94 
     95   /* Construct an FT_Frame_Field out of a structure type and a field name. */
     96   /* The structure type must be set in the FT_STRUCTURE macro before       */
     97   /* calling the FT_FRAME_START() macro.                                   */
     98   /*                                                                       */
     99 #define FT_FIELD_SIZE( f ) \
    100           (FT_Byte)sizeof ( ((FT_STRUCTURE*)0)->f )
    101 
    102 #define FT_FIELD_SIZE_DELTA( f ) \
    103           (FT_Byte)sizeof ( ((FT_STRUCTURE*)0)->f[0] )
    104 
    105 #define FT_FIELD_OFFSET( f ) \
    106           (FT_UShort)( offsetof( FT_STRUCTURE, f ) )
    107 
    108 #define FT_FRAME_FIELD( frame_op, field ) \
    109           {                               \
    110             frame_op,                     \
    111             FT_FIELD_SIZE( field ),       \
    112             FT_FIELD_OFFSET( field )      \
    113           }
    114 
    115 #define FT_MAKE_EMPTY_FIELD( frame_op )  { frame_op, 0, 0 }
    116 
    117 #define FT_FRAME_START( size )   { ft_frame_start, 0, size }
    118 #define FT_FRAME_END             { ft_frame_end, 0, 0 }
    119 
    120 #define FT_FRAME_LONG( f )       FT_FRAME_FIELD( ft_frame_long_be, f )
    121 #define FT_FRAME_ULONG( f )      FT_FRAME_FIELD( ft_frame_ulong_be, f )
    122 #define FT_FRAME_SHORT( f )      FT_FRAME_FIELD( ft_frame_short_be, f )
    123 #define FT_FRAME_USHORT( f )     FT_FRAME_FIELD( ft_frame_ushort_be, f )
    124 #define FT_FRAME_OFF3( f )       FT_FRAME_FIELD( ft_frame_off3_be, f )
    125 #define FT_FRAME_UOFF3( f )      FT_FRAME_FIELD( ft_frame_uoff3_be, f )
    126 #define FT_FRAME_BYTE( f )       FT_FRAME_FIELD( ft_frame_byte, f )
    127 #define FT_FRAME_CHAR( f )       FT_FRAME_FIELD( ft_frame_schar, f )
    128 
    129 #define FT_FRAME_LONG_LE( f )    FT_FRAME_FIELD( ft_frame_long_le, f )
    130 #define FT_FRAME_ULONG_LE( f )   FT_FRAME_FIELD( ft_frame_ulong_le, f )
    131 #define FT_FRAME_SHORT_LE( f )   FT_FRAME_FIELD( ft_frame_short_le, f )
    132 #define FT_FRAME_USHORT_LE( f )  FT_FRAME_FIELD( ft_frame_ushort_le, f )
    133 #define FT_FRAME_OFF3_LE( f )    FT_FRAME_FIELD( ft_frame_off3_le, f )
    134 #define FT_FRAME_UOFF3_LE( f )   FT_FRAME_FIELD( ft_frame_uoff3_le, f )
    135 
    136 #define FT_FRAME_SKIP_LONG       { ft_frame_long_be, 0, 0 }
    137 #define FT_FRAME_SKIP_SHORT      { ft_frame_short_be, 0, 0 }
    138 #define FT_FRAME_SKIP_BYTE       { ft_frame_byte, 0, 0 }
    139 
    140 #define FT_FRAME_BYTES( field, count ) \
    141           {                            \
    142             ft_frame_bytes,            \
    143             count,                     \
    144             FT_FIELD_OFFSET( field )   \
    145           }
    146 
    147 #define FT_FRAME_SKIP_BYTES( count )  { ft_frame_skip, count, 0 }
    148 
    149 
    150   /*************************************************************************/
    151   /*                                                                       */
    152   /* Integer extraction macros -- the `buffer' parameter must ALWAYS be of */
    153   /* type `char*' or equivalent (1-byte elements).                         */
    154   /*                                                                       */
    155 
    156 #define FT_BYTE_( p, i )  ( ((const FT_Byte*)(p))[(i)] )
    157 #define FT_INT8_( p, i )  ( ((const FT_Char*)(p))[(i)] )
    158 
    159 #define FT_INT16( x )   ( (FT_Int16)(x)  )
    160 #define FT_UINT16( x )  ( (FT_UInt16)(x) )
    161 #define FT_INT32( x )   ( (FT_Int32)(x)  )
    162 #define FT_UINT32( x )  ( (FT_UInt32)(x) )
    163 
    164 #define FT_BYTE_I16( p, i, s )  ( FT_INT16(  FT_BYTE_( p, i ) ) << (s) )
    165 #define FT_BYTE_U16( p, i, s )  ( FT_UINT16( FT_BYTE_( p, i ) ) << (s) )
    166 #define FT_BYTE_I32( p, i, s )  ( FT_INT32(  FT_BYTE_( p, i ) ) << (s) )
    167 #define FT_BYTE_U32( p, i, s )  ( FT_UINT32( FT_BYTE_( p, i ) ) << (s) )
    168 
    169 #define FT_INT8_I16( p, i, s )  ( FT_INT16(  FT_INT8_( p, i ) ) << (s) )
    170 #define FT_INT8_U16( p, i, s )  ( FT_UINT16( FT_INT8_( p, i ) ) << (s) )
    171 #define FT_INT8_I32( p, i, s )  ( FT_INT32(  FT_INT8_( p, i ) ) << (s) )
    172 #define FT_INT8_U32( p, i, s )  ( FT_UINT32( FT_INT8_( p, i ) ) << (s) )
    173 
    174 
    175 #define FT_PEEK_SHORT( p )  FT_INT16( FT_INT8_I16( p, 0, 8) | \
    176                                       FT_BYTE_I16( p, 1, 0) )
    177 
    178 #define FT_PEEK_USHORT( p )  FT_UINT16( FT_BYTE_U16( p, 0, 8 ) | \
    179                                         FT_BYTE_U16( p, 1, 0 ) )
    180 
    181 #define FT_PEEK_LONG( p )  FT_INT32( FT_INT8_I32( p, 0, 24 ) | \
    182                                      FT_BYTE_I32( p, 1, 16 ) | \
    183                                      FT_BYTE_I32( p, 2,  8 ) | \
    184                                      FT_BYTE_I32( p, 3,  0 ) )
    185 
    186 #define FT_PEEK_ULONG( p )  FT_UINT32( FT_BYTE_U32( p, 0, 24 ) | \
    187                                        FT_BYTE_U32( p, 1, 16 ) | \
    188                                        FT_BYTE_U32( p, 2,  8 ) | \
    189                                        FT_BYTE_U32( p, 3,  0 ) )
    190 
    191 #define FT_PEEK_OFF3( p )  FT_INT32( FT_INT8_I32( p, 0, 16 ) | \
    192                                      FT_BYTE_I32( p, 1,  8 ) | \
    193                                      FT_BYTE_I32( p, 2,  0 ) )
    194 
    195 #define FT_PEEK_UOFF3( p )  FT_UINT32( FT_BYTE_U32( p, 0, 16 ) | \
    196                                        FT_BYTE_U32( p, 1,  8 ) | \
    197                                        FT_BYTE_U32( p, 2,  0 ) )
    198 
    199 #define FT_PEEK_SHORT_LE( p )  FT_INT16( FT_INT8_I16( p, 1, 8 ) | \
    200                                          FT_BYTE_I16( p, 0, 0 ) )
    201 
    202 #define FT_PEEK_USHORT_LE( p )  FT_UINT16( FT_BYTE_U16( p, 1, 8 ) |  \
    203                                            FT_BYTE_U16( p, 0, 0 ) )
    204 
    205 #define FT_PEEK_LONG_LE( p )  FT_INT32( FT_INT8_I32( p, 3, 24 ) | \
    206                                         FT_BYTE_I32( p, 2, 16 ) | \
    207                                         FT_BYTE_I32( p, 1,  8 ) | \
    208                                         FT_BYTE_I32( p, 0,  0 ) )
    209 
    210 #define FT_PEEK_ULONG_LE( p )  FT_UINT32( FT_BYTE_U32( p, 3, 24 ) | \
    211                                           FT_BYTE_U32( p, 2, 16 ) | \
    212                                           FT_BYTE_U32( p, 1,  8 ) | \
    213                                           FT_BYTE_U32( p, 0,  0 ) )
    214 
    215 #define FT_PEEK_OFF3_LE( p )  FT_INT32( FT_INT8_I32( p, 2, 16 ) | \
    216                                         FT_BYTE_I32( p, 1,  8 ) | \
    217                                         FT_BYTE_I32( p, 0,  0 ) )
    218 
    219 #define FT_PEEK_UOFF3_LE( p )  FT_UINT32( FT_BYTE_U32( p, 2, 16 ) | \
    220                                           FT_BYTE_U32( p, 1,  8 ) | \
    221                                           FT_BYTE_U32( p, 0,  0 ) )
    222 
    223 
    224 #define FT_NEXT_CHAR( buffer )       \
    225           ( (signed char)*buffer++ )
    226 
    227 #define FT_NEXT_BYTE( buffer )         \
    228           ( (unsigned char)*buffer++ )
    229 
    230 #define FT_NEXT_SHORT( buffer )                                   \
    231           ( (short)( buffer += 2, FT_PEEK_SHORT( buffer - 2 ) ) )
    232 
    233 #define FT_NEXT_USHORT( buffer )                                            \
    234           ( (unsigned short)( buffer += 2, FT_PEEK_USHORT( buffer - 2 ) ) )
    235 
    236 #define FT_NEXT_OFF3( buffer )                                  \
    237           ( (long)( buffer += 3, FT_PEEK_OFF3( buffer - 3 ) ) )
    238 
    239 #define FT_NEXT_UOFF3( buffer )                                           \
    240           ( (unsigned long)( buffer += 3, FT_PEEK_UOFF3( buffer - 3 ) ) )
    241 
    242 #define FT_NEXT_LONG( buffer )                                  \
    243           ( (long)( buffer += 4, FT_PEEK_LONG( buffer - 4 ) ) )
    244 
    245 #define FT_NEXT_ULONG( buffer )                                           \
    246           ( (unsigned long)( buffer += 4, FT_PEEK_ULONG( buffer - 4 ) ) )
    247 
    248 
    249 #define FT_NEXT_SHORT_LE( buffer )                                   \
    250           ( (short)( buffer += 2, FT_PEEK_SHORT_LE( buffer - 2 ) ) )
    251 
    252 #define FT_NEXT_USHORT_LE( buffer )                                            \
    253           ( (unsigned short)( buffer += 2, FT_PEEK_USHORT_LE( buffer - 2 ) ) )
    254 
    255 #define FT_NEXT_OFF3_LE( buffer )                                  \
    256           ( (long)( buffer += 3, FT_PEEK_OFF3_LE( buffer - 3 ) ) )
    257 
    258 #define FT_NEXT_UOFF3_LE( buffer )                                           \
    259           ( (unsigned long)( buffer += 3, FT_PEEK_UOFF3_LE( buffer - 3 ) ) )
    260 
    261 #define FT_NEXT_LONG_LE( buffer )                                  \
    262           ( (long)( buffer += 4, FT_PEEK_LONG_LE( buffer - 4 ) ) )
    263 
    264 #define FT_NEXT_ULONG_LE( buffer )                                           \
    265           ( (unsigned long)( buffer += 4, FT_PEEK_ULONG_LE( buffer - 4 ) ) )
    266 
    267 
    268   /*************************************************************************/
    269   /*                                                                       */
    270   /* Each GET_xxxx() macro uses an implicit `stream' variable.             */
    271   /*                                                                       */
    272 #if 0
    273 #define FT_GET_MACRO( type )    FT_NEXT_ ## type ( stream->cursor )
    274 
    275 #define FT_GET_CHAR()       FT_GET_MACRO( CHAR )
    276 #define FT_GET_BYTE()       FT_GET_MACRO( BYTE )
    277 #define FT_GET_SHORT()      FT_GET_MACRO( SHORT )
    278 #define FT_GET_USHORT()     FT_GET_MACRO( USHORT )
    279 #define FT_GET_OFF3()       FT_GET_MACRO( OFF3 )
    280 #define FT_GET_UOFF3()      FT_GET_MACRO( UOFF3 )
    281 #define FT_GET_LONG()       FT_GET_MACRO( LONG )
    282 #define FT_GET_ULONG()      FT_GET_MACRO( ULONG )
    283 #define FT_GET_TAG4()       FT_GET_MACRO( ULONG )
    284 
    285 #define FT_GET_SHORT_LE()   FT_GET_MACRO( SHORT_LE )
    286 #define FT_GET_USHORT_LE()  FT_GET_MACRO( USHORT_LE )
    287 #define FT_GET_LONG_LE()    FT_GET_MACRO( LONG_LE )
    288 #define FT_GET_ULONG_LE()   FT_GET_MACRO( ULONG_LE )
    289 
    290 #else
    291 #define FT_GET_MACRO( func, type )        ( (type)func( stream ) )
    292 
    293 #define FT_GET_CHAR()       FT_GET_MACRO( FT_Stream_GetChar, FT_Char )
    294 #define FT_GET_BYTE()       FT_GET_MACRO( FT_Stream_GetChar, FT_Byte )
    295 #define FT_GET_SHORT()      FT_GET_MACRO( FT_Stream_GetUShort, FT_Short )
    296 #define FT_GET_USHORT()     FT_GET_MACRO( FT_Stream_GetUShort, FT_UShort )
    297 #define FT_GET_OFF3()       FT_GET_MACRO( FT_Stream_GetUOffset, FT_Long )
    298 #define FT_GET_UOFF3()      FT_GET_MACRO( FT_Stream_GetUOffset, FT_ULong )
    299 #define FT_GET_LONG()       FT_GET_MACRO( FT_Stream_GetULong, FT_Long )
    300 #define FT_GET_ULONG()      FT_GET_MACRO( FT_Stream_GetULong, FT_ULong )
    301 #define FT_GET_TAG4()       FT_GET_MACRO( FT_Stream_GetULong, FT_ULong )
    302 
    303 #define FT_GET_SHORT_LE()   FT_GET_MACRO( FT_Stream_GetUShortLE, FT_Short )
    304 #define FT_GET_USHORT_LE()  FT_GET_MACRO( FT_Stream_GetUShortLE, FT_UShort )
    305 #define FT_GET_LONG_LE()    FT_GET_MACRO( FT_Stream_GetULongLE, FT_Long )
    306 #define FT_GET_ULONG_LE()   FT_GET_MACRO( FT_Stream_GetULongLE, FT_ULong )
    307 #endif
    308 
    309 #define FT_READ_MACRO( func, type, var )        \
    310           ( var = (type)func( stream, &error ), \
    311             error != FT_Err_Ok )
    312 
    313 #define FT_READ_BYTE( var )       FT_READ_MACRO( FT_Stream_ReadChar, FT_Byte, var )
    314 #define FT_READ_CHAR( var )       FT_READ_MACRO( FT_Stream_ReadChar, FT_Char, var )
    315 #define FT_READ_SHORT( var )      FT_READ_MACRO( FT_Stream_ReadUShort, FT_Short, var )
    316 #define FT_READ_USHORT( var )     FT_READ_MACRO( FT_Stream_ReadUShort, FT_UShort, var )
    317 #define FT_READ_OFF3( var )       FT_READ_MACRO( FT_Stream_ReadUOffset, FT_Long, var )
    318 #define FT_READ_UOFF3( var )      FT_READ_MACRO( FT_Stream_ReadUOffset, FT_ULong, var )
    319 #define FT_READ_LONG( var )       FT_READ_MACRO( FT_Stream_ReadULong, FT_Long, var )
    320 #define FT_READ_ULONG( var )      FT_READ_MACRO( FT_Stream_ReadULong, FT_ULong, var )
    321 
    322 #define FT_READ_SHORT_LE( var )   FT_READ_MACRO( FT_Stream_ReadUShortLE, FT_Short, var )
    323 #define FT_READ_USHORT_LE( var )  FT_READ_MACRO( FT_Stream_ReadUShortLE, FT_UShort, var )
    324 #define FT_READ_LONG_LE( var )    FT_READ_MACRO( FT_Stream_ReadULongLE, FT_Long, var )
    325 #define FT_READ_ULONG_LE( var )   FT_READ_MACRO( FT_Stream_ReadULongLE, FT_ULong, var )
    326 
    327 
    328 #ifndef FT_CONFIG_OPTION_NO_DEFAULT_SYSTEM
    329 
    330   /* initialize a stream for reading a regular system stream */
    331   FT_BASE( FT_Error )
    332   FT_Stream_Open( FT_Stream    stream,
    333                   const char*  filepathname );
    334 
    335 #endif /* FT_CONFIG_OPTION_NO_DEFAULT_SYSTEM */
    336 
    337 
    338   /* create a new (input) stream from an FT_Open_Args structure */
    339   FT_BASE( FT_Error )
    340   FT_Stream_New( FT_Library           library,
    341                  const FT_Open_Args*  args,
    342                  FT_Stream           *astream );
    343 
    344   /* free a stream */
    345   FT_BASE( void )
    346   FT_Stream_Free( FT_Stream  stream,
    347                   FT_Int     external );
    348 
    349   /* initialize a stream for reading in-memory data */
    350   FT_BASE( void )
    351   FT_Stream_OpenMemory( FT_Stream       stream,
    352                         const FT_Byte*  base,
    353                         FT_ULong        size );
    354 
    355   /* close a stream (does not destroy the stream structure) */
    356   FT_BASE( void )
    357   FT_Stream_Close( FT_Stream  stream );
    358 
    359 
    360   /* seek within a stream. position is relative to start of stream */
    361   FT_BASE( FT_Error )
    362   FT_Stream_Seek( FT_Stream  stream,
    363                   FT_ULong   pos );
    364 
    365   /* skip bytes in a stream */
    366   FT_BASE( FT_Error )
    367   FT_Stream_Skip( FT_Stream  stream,
    368                   FT_Long    distance );
    369 
    370   /* return current stream position */
    371   FT_BASE( FT_Long )
    372   FT_Stream_Pos( FT_Stream  stream );
    373 
    374   /* read bytes from a stream into a user-allocated buffer, returns an */
    375   /* error if not all bytes could be read.                             */
    376   FT_BASE( FT_Error )
    377   FT_Stream_Read( FT_Stream  stream,
    378                   FT_Byte*   buffer,
    379                   FT_ULong   count );
    380 
    381   /* read bytes from a stream at a given position */
    382   FT_BASE( FT_Error )
    383   FT_Stream_ReadAt( FT_Stream  stream,
    384                     FT_ULong   pos,
    385                     FT_Byte*   buffer,
    386                     FT_ULong   count );
    387 
    388   /* try to read bytes at the end of a stream; return number of bytes */
    389   /* really available                                                 */
    390   FT_BASE( FT_ULong )
    391   FT_Stream_TryRead( FT_Stream  stream,
    392                      FT_Byte*   buffer,
    393                      FT_ULong   count );
    394 
    395   /* Enter a frame of `count' consecutive bytes in a stream.  Returns an */
    396   /* error if the frame could not be read/accessed.  The caller can use  */
    397   /* the FT_Stream_Get_XXX functions to retrieve frame data without      */
    398   /* error checks.                                                       */
    399   /*                                                                     */
    400   /* You must _always_ call FT_Stream_ExitFrame() once you have entered  */
    401   /* a stream frame!                                                     */
    402   /*                                                                     */
    403   FT_BASE( FT_Error )
    404   FT_Stream_EnterFrame( FT_Stream  stream,
    405                         FT_ULong   count );
    406 
    407   /* exit a stream frame */
    408   FT_BASE( void )
    409   FT_Stream_ExitFrame( FT_Stream  stream );
    410 
    411   /* Extract a stream frame.  If the stream is disk-based, a heap block */
    412   /* is allocated and the frame bytes are read into it.  If the stream  */
    413   /* is memory-based, this function simply set a pointer to the data.   */
    414   /*                                                                    */
    415   /* Useful to optimize access to memory-based streams transparently.   */
    416   /*                                                                    */
    417   /* All extracted frames must be `freed' with a call to the function   */
    418   /* FT_Stream_ReleaseFrame().                                          */
    419   /*                                                                    */
    420   FT_BASE( FT_Error )
    421   FT_Stream_ExtractFrame( FT_Stream  stream,
    422                           FT_ULong   count,
    423                           FT_Byte**  pbytes );
    424 
    425   /* release an extract frame (see FT_Stream_ExtractFrame) */
    426   FT_BASE( void )
    427   FT_Stream_ReleaseFrame( FT_Stream  stream,
    428                           FT_Byte**  pbytes );
    429 
    430   /* read a byte from an entered frame */
    431   FT_BASE( FT_Char )
    432   FT_Stream_GetChar( FT_Stream  stream );
    433 
    434   /* read a 16-bit big-endian unsigned integer from an entered frame */
    435   FT_BASE( FT_UShort )
    436   FT_Stream_GetUShort( FT_Stream  stream );
    437 
    438   /* read a 24-bit big-endian unsigned integer from an entered frame */
    439   FT_BASE( FT_ULong )
    440   FT_Stream_GetUOffset( FT_Stream  stream );
    441 
    442   /* read a 32-bit big-endian unsigned integer from an entered frame */
    443   FT_BASE( FT_ULong )
    444   FT_Stream_GetULong( FT_Stream  stream );
    445 
    446   /* read a 16-bit little-endian unsigned integer from an entered frame */
    447   FT_BASE( FT_UShort )
    448   FT_Stream_GetUShortLE( FT_Stream  stream );
    449 
    450   /* read a 32-bit little-endian unsigned integer from an entered frame */
    451   FT_BASE( FT_ULong )
    452   FT_Stream_GetULongLE( FT_Stream  stream );
    453 
    454 
    455   /* read a byte from a stream */
    456   FT_BASE( FT_Char )
    457   FT_Stream_ReadChar( FT_Stream  stream,
    458                       FT_Error*  error );
    459 
    460   /* read a 16-bit big-endian unsigned integer from a stream */
    461   FT_BASE( FT_UShort )
    462   FT_Stream_ReadUShort( FT_Stream  stream,
    463                         FT_Error*  error );
    464 
    465   /* read a 24-bit big-endian unsigned integer from a stream */
    466   FT_BASE( FT_ULong )
    467   FT_Stream_ReadUOffset( FT_Stream  stream,
    468                          FT_Error*  error );
    469 
    470   /* read a 32-bit big-endian integer from a stream */
    471   FT_BASE( FT_ULong )
    472   FT_Stream_ReadULong( FT_Stream  stream,
    473                        FT_Error*  error );
    474 
    475   /* read a 16-bit little-endian unsigned integer from a stream */
    476   FT_BASE( FT_UShort )
    477   FT_Stream_ReadUShortLE( FT_Stream  stream,
    478                           FT_Error*  error );
    479 
    480   /* read a 32-bit little-endian unsigned integer from a stream */
    481   FT_BASE( FT_ULong )
    482   FT_Stream_ReadULongLE( FT_Stream  stream,
    483                          FT_Error*  error );
    484 
    485   /* Read a structure from a stream.  The structure must be described */
    486   /* by an array of FT_Frame_Field records.                           */
    487   FT_BASE( FT_Error )
    488   FT_Stream_ReadFields( FT_Stream              stream,
    489                         const FT_Frame_Field*  fields,
    490                         void*                  structure );
    491 
    492 
    493 #define FT_STREAM_POS()           \
    494           FT_Stream_Pos( stream )
    495 
    496 #define FT_STREAM_SEEK( position )                           \
    497           FT_SET_ERROR( FT_Stream_Seek( stream, position ) )
    498 
    499 #define FT_STREAM_SKIP( distance )                           \
    500           FT_SET_ERROR( FT_Stream_Skip( stream, distance ) )
    501 
    502 #define FT_STREAM_READ( buffer, count )                   \
    503           FT_SET_ERROR( FT_Stream_Read( stream,           \
    504                                         (FT_Byte*)buffer, \
    505                                         count ) )
    506 
    507 #define FT_STREAM_READ_AT( position, buffer, count )         \
    508           FT_SET_ERROR( FT_Stream_ReadAt( stream,            \
    509                                            position,         \
    510                                            (FT_Byte*)buffer, \
    511                                            count ) )
    512 
    513 #define FT_STREAM_READ_FIELDS( fields, object )                          \
    514           FT_SET_ERROR( FT_Stream_ReadFields( stream, fields, object ) )
    515 
    516 
    517 #define FT_FRAME_ENTER( size )                                       \
    518           FT_SET_ERROR(                                              \
    519             FT_DEBUG_INNER( FT_Stream_EnterFrame( stream, size ) ) )
    520 
    521 #define FT_FRAME_EXIT()                 \
    522           FT_DEBUG_INNER( FT_Stream_ExitFrame( stream ) )
    523 
    524 #define FT_FRAME_EXTRACT( size, bytes )                                       \
    525           FT_SET_ERROR(                                                       \
    526             FT_DEBUG_INNER( FT_Stream_ExtractFrame( stream, size,             \
    527                                                     (FT_Byte**)&(bytes) ) ) )
    528 
    529 #define FT_FRAME_RELEASE( bytes )                                         \
    530           FT_DEBUG_INNER( FT_Stream_ReleaseFrame( stream,                 \
    531                                                   (FT_Byte**)&(bytes) ) )
    532 
    533 
    534 FT_END_HEADER
    535 
    536 #endif /* __FTSTREAM_H__ */
    537 
    538 
    539 /* END */
    540