xref: /external/freetype/src/cff/cf2read.c

/***************************************************************************/
/*                                                                         */
/*  cf2read.c                                                              */
/*                                                                         */
/*    Adobe's code for stream handling (body).                             */
/*                                                                         */
/*  Copyright 2007-2013 Adobe Systems Incorporated.                        */
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/*  object code form as indicated by the copyright notice(s) included      */
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/*                                                                         */
/***************************************************************************/


#include "cf2ft.h"
#include FT_INTERNAL_DEBUG_H

#include "cf2glue.h"

#include "cf2error.h"


  /* Define CF2_IO_FAIL as 1 to enable random errors and random */
  /* value errors in I/O.                                       */
#define CF2_IO_FAIL  0


#if CF2_IO_FAIL

  /* set the .00 value to a nonzero probability */
  static int
  randomError2( void )
  {
    /* for region buffer ReadByte (interp) function */
    return (double)rand() / RAND_MAX < .00;
  }

  /* set the .00 value to a nonzero probability */
  static CF2_Int
  randomValue()
  {
    return (double)rand() / RAND_MAX < .00 ? rand() : 0;
  }

#endif /* CF2_IO_FAIL */


  /* Region Buffer                                      */
  /*                                                    */
  /* Can be constructed from a copied buffer managed by */
  /* `FCM_getDatablock'.                                */
  /* Reads bytes with check for end of buffer.          */

  /* reading past the end of the buffer sets error and returns zero */
  FT_LOCAL_DEF( CF2_Int )
  cf2_buf_readByte( CF2_Buffer  buf )
  {
    if ( buf->ptr < buf->end )
    {
#if CF2_IO_FAIL
      if ( randomError2() )
      {
        CF2_SET_ERROR( buf->error, Invalid_Stream_Operation );
        return 0;
      }

      return *(buf->ptr)++ + randomValue();
#else
      return *(buf->ptr)++;
#endif
    }
    else
    {
      CF2_SET_ERROR( buf->error, Invalid_Stream_Operation );
      return 0;
    }
  }


  /* note: end condition can occur without error */
  FT_LOCAL_DEF( FT_Bool )
  cf2_buf_isEnd( CF2_Buffer  buf )
  {
    return (FT_Bool)( buf->ptr >= buf->end );
  }


/* END */