1 /****************************************************************************
   2  *
   3  * ftstream.h
   4  *
   5  *   Stream handling (specification).
   6  *
   7  * Copyright (C) 1996-2019 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 
 158 #define FT_INT16( x )   ( (FT_Int16)(x)  )
 159 #define FT_UINT16( x )  ( (FT_UInt16)(x) )
 160 #define FT_INT32( x )   ( (FT_Int32)(x)  )
 161 #define FT_UINT32( x )  ( (FT_UInt32)(x) )
 162 
 163 
 164 #define FT_BYTE_U16( p, i, s )  ( FT_UINT16( FT_BYTE_( p, i ) ) << (s) )
 165 #define FT_BYTE_U32( p, i, s )  ( FT_UINT32( FT_BYTE_( p, i ) ) << (s) )
 166 
 167 
 168   /*
 169    *    function      acts on      increases  does range   for    emits
 170    *                                pointer    checking   frames  error
 171    *  -------------------------------------------------------------------
 172    *   FT_PEEK_XXX  buffer pointer      no         no        no     no
 173    *   FT_NEXT_XXX  buffer pointer     yes         no        no     no
 174    *   FT_GET_XXX   stream->cursor     yes        yes       yes     no
 175    *   FT_READ_XXX  stream->pos        yes        yes        no    yes
 176    */
 177 
 178 
 179   /*
 180    * `FT_PEEK_XXX' are generic macros to get data from a buffer position.  No
 181    * safety checks are performed.
 182    */
 183 #define FT_PEEK_SHORT( p )  FT_INT16( FT_BYTE_U16( p, 0, 8 ) | \
 184                                       FT_BYTE_U16( p, 1, 0 ) )
 185 
 186 #define FT_PEEK_USHORT( p )  FT_UINT16( FT_BYTE_U16( p, 0, 8 ) | \
 187                                         FT_BYTE_U16( p, 1, 0 ) )
 188 
 189 #define FT_PEEK_LONG( p )  FT_INT32( FT_BYTE_U32( p, 0, 24 ) | \
 190                                      FT_BYTE_U32( p, 1, 16 ) | \
 191                                      FT_BYTE_U32( p, 2,  8 ) | \
 192                                      FT_BYTE_U32( p, 3,  0 ) )
 193 
 194 #define FT_PEEK_ULONG( p )  FT_UINT32( FT_BYTE_U32( p, 0, 24 ) | \
 195                                        FT_BYTE_U32( p, 1, 16 ) | \
 196                                        FT_BYTE_U32( p, 2,  8 ) | \
 197                                        FT_BYTE_U32( p, 3,  0 ) )
 198 
 199 #define FT_PEEK_OFF3( p )  FT_INT32( FT_BYTE_U32( p, 0, 16 ) | \
 200                                      FT_BYTE_U32( p, 1,  8 ) | \
 201                                      FT_BYTE_U32( p, 2,  0 ) )
 202 
 203 #define FT_PEEK_UOFF3( p )  FT_UINT32( FT_BYTE_U32( p, 0, 16 ) | \
 204                                        FT_BYTE_U32( p, 1,  8 ) | \
 205                                        FT_BYTE_U32( p, 2,  0 ) )
 206 
 207 #define FT_PEEK_SHORT_LE( p )  FT_INT16( FT_BYTE_U16( p, 1, 8 ) | \
 208                                          FT_BYTE_U16( p, 0, 0 ) )
 209 
 210 #define FT_PEEK_USHORT_LE( p )  FT_UINT16( FT_BYTE_U16( p, 1, 8 ) |  \
 211                                            FT_BYTE_U16( p, 0, 0 ) )
 212 
 213 #define FT_PEEK_LONG_LE( p )  FT_INT32( FT_BYTE_U32( p, 3, 24 ) | \
 214                                         FT_BYTE_U32( p, 2, 16 ) | \
 215                                         FT_BYTE_U32( p, 1,  8 ) | \
 216                                         FT_BYTE_U32( p, 0,  0 ) )
 217 
 218 #define FT_PEEK_ULONG_LE( p )  FT_UINT32( FT_BYTE_U32( p, 3, 24 ) | \
 219                                           FT_BYTE_U32( p, 2, 16 ) | \
 220                                           FT_BYTE_U32( p, 1,  8 ) | \
 221                                           FT_BYTE_U32( p, 0,  0 ) )
 222 
 223 #define FT_PEEK_OFF3_LE( p )  FT_INT32( FT_BYTE_U32( p, 2, 16 ) | \
 224                                         FT_BYTE_U32( p, 1,  8 ) | \
 225                                         FT_BYTE_U32( p, 0,  0 ) )
 226 
 227 #define FT_PEEK_UOFF3_LE( p )  FT_UINT32( FT_BYTE_U32( p, 2, 16 ) | \
 228                                           FT_BYTE_U32( p, 1,  8 ) | \
 229                                           FT_BYTE_U32( p, 0,  0 ) )
 230 
 231   /*
 232    * `FT_NEXT_XXX' are generic macros to get data from a buffer position
 233    * which is then increased appropriately.  No safety checks are performed.
 234    */
 235 #define FT_NEXT_CHAR( buffer )       \
 236           ( (signed char)*buffer++ )
 237 
 238 #define FT_NEXT_BYTE( buffer )         \
 239           ( (unsigned char)*buffer++ )
 240 
 241 #define FT_NEXT_SHORT( buffer )                                   \
 242           ( (short)( buffer += 2, FT_PEEK_SHORT( buffer - 2 ) ) )
 243 
 244 #define FT_NEXT_USHORT( buffer )                                            \
 245           ( (unsigned short)( buffer += 2, FT_PEEK_USHORT( buffer - 2 ) ) )
 246 
 247 #define FT_NEXT_OFF3( buffer )                                  \
 248           ( (long)( buffer += 3, FT_PEEK_OFF3( buffer - 3 ) ) )
 249 
 250 #define FT_NEXT_UOFF3( buffer )                                           \
 251           ( (unsigned long)( buffer += 3, FT_PEEK_UOFF3( buffer - 3 ) ) )
 252 
 253 #define FT_NEXT_LONG( buffer )                                  \
 254           ( (long)( buffer += 4, FT_PEEK_LONG( buffer - 4 ) ) )
 255 
 256 #define FT_NEXT_ULONG( buffer )                                           \
 257           ( (unsigned long)( buffer += 4, FT_PEEK_ULONG( buffer - 4 ) ) )
 258 
 259 
 260 #define FT_NEXT_SHORT_LE( buffer )                                   \
 261           ( (short)( buffer += 2, FT_PEEK_SHORT_LE( buffer - 2 ) ) )
 262 
 263 #define FT_NEXT_USHORT_LE( buffer )                                            \
 264           ( (unsigned short)( buffer += 2, FT_PEEK_USHORT_LE( buffer - 2 ) ) )
 265 
 266 #define FT_NEXT_OFF3_LE( buffer )                                  \
 267           ( (long)( buffer += 3, FT_PEEK_OFF3_LE( buffer - 3 ) ) )
 268 
 269 #define FT_NEXT_UOFF3_LE( buffer )                                           \
 270           ( (unsigned long)( buffer += 3, FT_PEEK_UOFF3_LE( buffer - 3 ) ) )
 271 
 272 #define FT_NEXT_LONG_LE( buffer )                                  \
 273           ( (long)( buffer += 4, FT_PEEK_LONG_LE( buffer - 4 ) ) )
 274 
 275 #define FT_NEXT_ULONG_LE( buffer )                                           \
 276           ( (unsigned long)( buffer += 4, FT_PEEK_ULONG_LE( buffer - 4 ) ) )
 277 
 278 
 279   /**************************************************************************
 280    *
 281    * The `FT_GET_XXX` macros use an implicit 'stream' variable.
 282    *
 283    * Note that a call to `FT_STREAM_SEEK` or `FT_STREAM_POS` has **no**
 284    * effect on `FT_GET_XXX`!  They operate on `stream->pos`, while
 285    * `FT_GET_XXX` use `stream->cursor`.
 286    */
 287 #if 0
 288 #define FT_GET_MACRO( type )    FT_NEXT_ ## type ( stream->cursor )
 289 
 290 #define FT_GET_CHAR()       FT_GET_MACRO( CHAR )
 291 #define FT_GET_BYTE()       FT_GET_MACRO( BYTE )
 292 #define FT_GET_SHORT()      FT_GET_MACRO( SHORT )
 293 #define FT_GET_USHORT()     FT_GET_MACRO( USHORT )
 294 #define FT_GET_OFF3()       FT_GET_MACRO( OFF3 )
 295 #define FT_GET_UOFF3()      FT_GET_MACRO( UOFF3 )
 296 #define FT_GET_LONG()       FT_GET_MACRO( LONG )
 297 #define FT_GET_ULONG()      FT_GET_MACRO( ULONG )
 298 #define FT_GET_TAG4()       FT_GET_MACRO( ULONG )
 299 
 300 #define FT_GET_SHORT_LE()   FT_GET_MACRO( SHORT_LE )
 301 #define FT_GET_USHORT_LE()  FT_GET_MACRO( USHORT_LE )
 302 #define FT_GET_LONG_LE()    FT_GET_MACRO( LONG_LE )
 303 #define FT_GET_ULONG_LE()   FT_GET_MACRO( ULONG_LE )
 304 
 305 #else
 306 #define FT_GET_MACRO( func, type )        ( (type)func( stream ) )
 307 
 308 #define FT_GET_CHAR()       FT_GET_MACRO( FT_Stream_GetChar, FT_Char )
 309 #define FT_GET_BYTE()       FT_GET_MACRO( FT_Stream_GetChar, FT_Byte )
 310 #define FT_GET_SHORT()      FT_GET_MACRO( FT_Stream_GetUShort, FT_Short )
 311 #define FT_GET_USHORT()     FT_GET_MACRO( FT_Stream_GetUShort, FT_UShort )
 312 #define FT_GET_OFF3()       FT_GET_MACRO( FT_Stream_GetUOffset, FT_Long )
 313 #define FT_GET_UOFF3()      FT_GET_MACRO( FT_Stream_GetUOffset, FT_ULong )
 314 #define FT_GET_LONG()       FT_GET_MACRO( FT_Stream_GetULong, FT_Long )
 315 #define FT_GET_ULONG()      FT_GET_MACRO( FT_Stream_GetULong, FT_ULong )
 316 #define FT_GET_TAG4()       FT_GET_MACRO( FT_Stream_GetULong, FT_ULong )
 317 
 318 #define FT_GET_SHORT_LE()   FT_GET_MACRO( FT_Stream_GetUShortLE, FT_Short )
 319 #define FT_GET_USHORT_LE()  FT_GET_MACRO( FT_Stream_GetUShortLE, FT_UShort )
 320 #define FT_GET_LONG_LE()    FT_GET_MACRO( FT_Stream_GetULongLE, FT_Long )
 321 #define FT_GET_ULONG_LE()   FT_GET_MACRO( FT_Stream_GetULongLE, FT_ULong )
 322 #endif
 323 
 324 
 325 #define FT_READ_MACRO( func, type, var )        \
 326           ( var = (type)func( stream, &error ), \
 327             error != FT_Err_Ok )
 328 
 329   /*
 330    * The `FT_READ_XXX' macros use implicit `stream' and `error' variables.
 331    *
 332    * `FT_READ_XXX' can be controlled with `FT_STREAM_SEEK' and
 333    * `FT_STREAM_POS'.  They use the full machinery to check whether a read is
 334    * valid.
 335    */
 336 #define FT_READ_BYTE( var )       FT_READ_MACRO( FT_Stream_ReadChar, FT_Byte, var )
 337 #define FT_READ_CHAR( var )       FT_READ_MACRO( FT_Stream_ReadChar, FT_Char, var )
 338 #define FT_READ_SHORT( var )      FT_READ_MACRO( FT_Stream_ReadUShort, FT_Short, var )
 339 #define FT_READ_USHORT( var )     FT_READ_MACRO( FT_Stream_ReadUShort, FT_UShort, var )
 340 #define FT_READ_OFF3( var )       FT_READ_MACRO( FT_Stream_ReadUOffset, FT_Long, var )
 341 #define FT_READ_UOFF3( var )      FT_READ_MACRO( FT_Stream_ReadUOffset, FT_ULong, var )
 342 #define FT_READ_LONG( var )       FT_READ_MACRO( FT_Stream_ReadULong, FT_Long, var )
 343 #define FT_READ_ULONG( var )      FT_READ_MACRO( FT_Stream_ReadULong, FT_ULong, var )
 344 
 345 #define FT_READ_SHORT_LE( var )   FT_READ_MACRO( FT_Stream_ReadUShortLE, FT_Short, var )
 346 #define FT_READ_USHORT_LE( var )  FT_READ_MACRO( FT_Stream_ReadUShortLE, FT_UShort, var )
 347 #define FT_READ_LONG_LE( var )    FT_READ_MACRO( FT_Stream_ReadULongLE, FT_Long, var )
 348 #define FT_READ_ULONG_LE( var )   FT_READ_MACRO( FT_Stream_ReadULongLE, FT_ULong, var )
 349 
 350 
 351 #ifndef FT_CONFIG_OPTION_NO_DEFAULT_SYSTEM
 352 
 353   /* initialize a stream for reading a regular system stream */
 354   FT_BASE( FT_Error )
 355   FT_Stream_Open( FT_Stream    stream,
 356                   const char*  filepathname );
 357 
 358 #endif /* FT_CONFIG_OPTION_NO_DEFAULT_SYSTEM */
 359 
 360 
 361   /* create a new (input) stream from an FT_Open_Args structure */
 362   FT_BASE( FT_Error )
 363   FT_Stream_New( FT_Library           library,
 364                  const FT_Open_Args*  args,
 365                  FT_Stream           *astream );
 366 
 367   /* free a stream */
 368   FT_BASE( void )
 369   FT_Stream_Free( FT_Stream  stream,
 370                   FT_Int     external );
 371 
 372   /* initialize a stream for reading in-memory data */
 373   FT_BASE( void )
 374   FT_Stream_OpenMemory( FT_Stream       stream,
 375                         const FT_Byte*  base,
 376                         FT_ULong        size );
 377 
 378   /* close a stream (does not destroy the stream structure) */
 379   FT_BASE( void )
 380   FT_Stream_Close( FT_Stream  stream );
 381 
 382 
 383   /* seek within a stream. position is relative to start of stream */
 384   FT_BASE( FT_Error )
 385   FT_Stream_Seek( FT_Stream  stream,
 386                   FT_ULong   pos );
 387 
 388   /* skip bytes in a stream */
 389   FT_BASE( FT_Error )
 390   FT_Stream_Skip( FT_Stream  stream,
 391                   FT_Long    distance );
 392 
 393   /* return current stream position */
 394   FT_BASE( FT_ULong )
 395   FT_Stream_Pos( FT_Stream  stream );
 396 
 397   /* read bytes from a stream into a user-allocated buffer, returns an */
 398   /* error if not all bytes could be read.                             */
 399   FT_BASE( FT_Error )
 400   FT_Stream_Read( FT_Stream  stream,
 401                   FT_Byte*   buffer,
 402                   FT_ULong   count );
 403 
 404   /* read bytes from a stream at a given position */
 405   FT_BASE( FT_Error )
 406   FT_Stream_ReadAt( FT_Stream  stream,
 407                     FT_ULong   pos,
 408                     FT_Byte*   buffer,
 409                     FT_ULong   count );
 410 
 411   /* try to read bytes at the end of a stream; return number of bytes */
 412   /* really available                                                 */
 413   FT_BASE( FT_ULong )
 414   FT_Stream_TryRead( FT_Stream  stream,
 415                      FT_Byte*   buffer,
 416                      FT_ULong   count );
 417 
 418   /* Enter a frame of `count' consecutive bytes in a stream.  Returns an */
 419   /* error if the frame could not be read/accessed.  The caller can use  */
 420   /* the `FT_Stream_GetXXX' functions to retrieve frame data without     */
 421   /* error checks.                                                       */
 422   /*                                                                     */
 423   /* You must _always_ call `FT_Stream_ExitFrame' once you have entered  */
 424   /* a stream frame!                                                     */
 425   /*                                                                     */
 426   /* Nested frames are not permitted.                                    */
 427   /*                                                                     */
 428   FT_BASE( FT_Error )
 429   FT_Stream_EnterFrame( FT_Stream  stream,
 430                         FT_ULong   count );
 431 
 432   /* exit a stream frame */
 433   FT_BASE( void )
 434   FT_Stream_ExitFrame( FT_Stream  stream );
 435 
 436 
 437   /* Extract a stream frame.  If the stream is disk-based, a heap block */
 438   /* is allocated and the frame bytes are read into it.  If the stream  */
 439   /* is memory-based, this function simply sets a pointer to the data.  */
 440   /*                                                                    */
 441   /* Useful to optimize access to memory-based streams transparently.   */
 442   /*                                                                    */
 443   /* `FT_Stream_GetXXX' functions can't be used.                        */
 444   /*                                                                    */
 445   /* An extracted frame must be `freed' with a call to the function     */
 446   /* `FT_Stream_ReleaseFrame'.                                          */
 447   /*                                                                    */
 448   FT_BASE( FT_Error )
 449   FT_Stream_ExtractFrame( FT_Stream  stream,
 450                           FT_ULong   count,
 451                           FT_Byte**  pbytes );
 452 
 453   /* release an extract frame (see `FT_Stream_ExtractFrame') */
 454   FT_BASE( void )
 455   FT_Stream_ReleaseFrame( FT_Stream  stream,
 456                           FT_Byte**  pbytes );
 457 
 458 
 459   /* read a byte from an entered frame */
 460   FT_BASE( FT_Char )
 461   FT_Stream_GetChar( FT_Stream  stream );
 462 
 463   /* read a 16-bit big-endian unsigned integer from an entered frame */
 464   FT_BASE( FT_UShort )
 465   FT_Stream_GetUShort( FT_Stream  stream );
 466 
 467   /* read a 24-bit big-endian unsigned integer from an entered frame */
 468   FT_BASE( FT_ULong )
 469   FT_Stream_GetUOffset( FT_Stream  stream );
 470 
 471   /* read a 32-bit big-endian unsigned integer from an entered frame */
 472   FT_BASE( FT_ULong )
 473   FT_Stream_GetULong( FT_Stream  stream );
 474 
 475   /* read a 16-bit little-endian unsigned integer from an entered frame */
 476   FT_BASE( FT_UShort )
 477   FT_Stream_GetUShortLE( FT_Stream  stream );
 478 
 479   /* read a 32-bit little-endian unsigned integer from an entered frame */
 480   FT_BASE( FT_ULong )
 481   FT_Stream_GetULongLE( FT_Stream  stream );
 482 
 483 
 484   /* read a byte from a stream */
 485   FT_BASE( FT_Char )
 486   FT_Stream_ReadChar( FT_Stream  stream,
 487                       FT_Error*  error );
 488 
 489   /* read a 16-bit big-endian unsigned integer from a stream */
 490   FT_BASE( FT_UShort )
 491   FT_Stream_ReadUShort( FT_Stream  stream,
 492                         FT_Error*  error );
 493 
 494   /* read a 24-bit big-endian unsigned integer from a stream */
 495   FT_BASE( FT_ULong )
 496   FT_Stream_ReadUOffset( FT_Stream  stream,
 497                          FT_Error*  error );
 498 
 499   /* read a 32-bit big-endian integer from a stream */
 500   FT_BASE( FT_ULong )
 501   FT_Stream_ReadULong( FT_Stream  stream,
 502                        FT_Error*  error );
 503 
 504   /* read a 16-bit little-endian unsigned integer from a stream */
 505   FT_BASE( FT_UShort )
 506   FT_Stream_ReadUShortLE( FT_Stream  stream,
 507                           FT_Error*  error );
 508 
 509   /* read a 32-bit little-endian unsigned integer from a stream */
 510   FT_BASE( FT_ULong )
 511   FT_Stream_ReadULongLE( FT_Stream  stream,
 512                          FT_Error*  error );
 513 
 514   /* Read a structure from a stream.  The structure must be described */
 515   /* by an array of FT_Frame_Field records.                           */
 516   FT_BASE( FT_Error )
 517   FT_Stream_ReadFields( FT_Stream              stream,
 518                         const FT_Frame_Field*  fields,
 519                         void*                  structure );
 520 
 521 
 522 #define FT_STREAM_POS()           \
 523           FT_Stream_Pos( stream )
 524 
 525 #define FT_STREAM_SEEK( position )                               \
 526           FT_SET_ERROR( FT_Stream_Seek( stream,                  \
 527                                         (FT_ULong)(position) ) )
 528 
 529 #define FT_STREAM_SKIP( distance )                              \
 530           FT_SET_ERROR( FT_Stream_Skip( stream,                 \
 531                                         (FT_Long)(distance) ) )
 532 
 533 #define FT_STREAM_READ( buffer, count )                       \
 534           FT_SET_ERROR( FT_Stream_Read( stream,               \
 535                                         (FT_Byte*)(buffer),   \
 536                                         (FT_ULong)(count) ) )
 537 
 538 #define FT_STREAM_READ_AT( position, buffer, count )            \
 539           FT_SET_ERROR( FT_Stream_ReadAt( stream,               \
 540                                           (FT_ULong)(position), \
 541                                           (FT_Byte*)(buffer),   \
 542                                           (FT_ULong)(count) ) )
 543 
 544 #define FT_STREAM_READ_FIELDS( fields, object )                          \
 545           FT_SET_ERROR( FT_Stream_ReadFields( stream, fields, object ) )
 546 
 547 
 548 #define FT_FRAME_ENTER( size )                                           \
 549           FT_SET_ERROR(                                                  \
 550             FT_DEBUG_INNER( FT_Stream_EnterFrame( stream,                \
 551                                                   (FT_ULong)(size) ) ) )
 552 
 553 #define FT_FRAME_EXIT()                                   \
 554           FT_DEBUG_INNER( FT_Stream_ExitFrame( stream ) )
 555 
 556 #define FT_FRAME_EXTRACT( size, bytes )                                       \
 557           FT_SET_ERROR(                                                       \
 558             FT_DEBUG_INNER( FT_Stream_ExtractFrame( stream,                   \
 559                                                     (FT_ULong)(size),         \
 560                                                     (FT_Byte**)&(bytes) ) ) )
 561 
 562 #define FT_FRAME_RELEASE( bytes )                                         \
 563           FT_DEBUG_INNER( FT_Stream_ReleaseFrame( stream,                 \
 564                                                   (FT_Byte**)&(bytes) ) )
 565 
 566 
 567 FT_END_HEADER
 568 
 569 #endif /* FTSTREAM_H_ */
 570 
 571 
 572 /* END */