t2parse.c

qt-embedded-2.3.8.tar.gz源码

/***************************************************************************/
/*                                                                         */
/*  t2parse.c                                                              */
/*                                                                         */
/*    OpenType parser (body).                                              */
/*                                                                         */
/*  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.                                        */
/*                                                                         */
/***************************************************************************/


#ifdef FT_FLAT_COMPILE

#include "t2parse.h"

#else

#include <cff/t2parse.h>

#endif


#include <freetype/internal/t2errors.h>
#include <freetype/internal/ftstream.h>


  /*************************************************************************/
  /*                                                                       */
  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  /* messages during execution.                                            */
  /*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_t2parse


#define T2_Err_Stack_Underflow   FT_Err_Invalid_Argument
#define T2_Err_Syntax_Error      FT_Err_Invalid_Argument


  enum
  {
    t2_kind_none = 0,
    t2_kind_num,
    t2_kind_fixed,
    t2_kind_string,
    t2_kind_bool,
    t2_kind_delta,
    t2_kind_callback,

    t2_kind_max  /* do not remove */
  };


  /* now generate handlers for the most simple fields */
  typedef FT_Error  (*T2_Field_Reader)( T2_Parser*  parser );

  typedef struct  T2_Field_Handler_
  {
    int              kind;
    int              code;
    FT_UInt          offset;
    FT_Byte          size;
    T2_Field_Reader  reader;
    FT_UInt          array_max;
    FT_UInt          count_offset;

  } T2_Field_Handler;


  FT_LOCAL_DEF
  void  T2_Parser_Init( T2_Parser*  parser,
                        FT_UInt     code,
                        void*       object )
  {
    MEM_Set( parser, 0, sizeof ( *parser ) );

    parser->top         = parser->stack;
    parser->object_code = code;
    parser->object      = object;
  }


  /* reads an integer */
  static
  FT_Long  parse_t2_integer( FT_Byte*  start,
                             FT_Byte*  limit )
  {
    FT_Byte*  p   = start;
    FT_Int    v   = *p++;
    FT_Long   val = 0;


    if ( v == 28 )
    {
      if ( p + 2 > limit )
        goto Bad;

      val = (FT_Short)( ( (FT_Int)p[0] << 8 ) | p[1] );
      p  += 2;
    }
    else if ( v == 29 )
    {
      if ( p + 4 > limit )
        goto Bad;

      val = ( (FT_Long)p[0] << 24 ) |
            ( (FT_Long)p[1] << 16 ) |
            ( (FT_Long)p[2] <<  8 ) |
                       p[3];
      p += 4;
    }
    else if ( v < 247 )
    {
      val = v - 139;
    }
    else if ( v < 251 )
    {
      if ( p + 1 > limit )
        goto Bad;

      val = ( v - 247 ) * 256 + p[0] + 108;
      p++;
    }
    else
    {
      if ( p + 1 > limit )
        goto Bad;

      val = -( v - 251 ) * 256 - p[0] - 108;
      p++;
    }

  Exit:
    return val;

  Bad:
    val = 0;
    goto Exit;
  }


  /* read a real */
  static
  FT_Fixed  parse_t2_real( FT_Byte*  start,
                           FT_Byte*  limit,
                           FT_Int    power_ten )
  {
    FT_Byte*  p    = start;
    FT_Long   num, divider, result, exp;
    FT_Int    sign = 0, exp_sign = 0;
    FT_Byte   nib;
    FT_Byte   phase;


    result  = 0;
    num     = 0;
    divider = 1;

    /* first of all, read the integer part */
    phase = 4;

    for (;;)
    {

      /* If we entered this iteration with phase == 4, we need to */
      /* read a new byte.  This also skips past the intial 0x1E.  */
      if ( phase )
        p++;

      /* Make sure we don't read past the end. */
      if ( p >= limit )
        goto Bad;

      /* Get the nibble. */
      nib   = ( p[0] >> phase ) & 0xF;
      phase = 4 - phase;

      if ( nib == 0xE )
        sign = 1;
      else if ( nib > 9 )
        break;
      else
        result = result * 10 + nib;
    }

    /* read decimal part, if any */
    if ( nib == 0xa )
      for (;;)
      {

        /* If we entered this iteration with phase == 4, we need */
        /* to read a new byte.                                   */
        if ( phase )
          p++;

        /* Make sure we don't read past the end. */
        if ( p >= limit )
          goto Bad;

        /* Get the nibble. */
        nib   = ( p[0] >> phase ) & 0xF;
        phase = 4 - phase;
        if ( nib >= 10 )
          break;

        if (divider < 10000000L)
        {
          num      = num * 10 + nib;
          divider *= 10;
        }
      }

    /* read exponent, if any */
    if ( nib == 12 )
    {
      exp_sign = 1;
      nib      = 11;
    }

    if ( nib == 11 )
    {
      exp = 0;

      for (;;)
      {
        /* If we entered this iteration with phase == 4, we need */
        /* to read a new byte.                                   */
        if ( phase )
          p++;

        /* Make sure we don't read past the end. */
        if ( p >= limit )
          goto Bad;

        /* Get the nibble. */
        nib   = ( p[0] >> phase ) & 0xF;
        phase = 4 - phase;
        if ( nib >= 10 )
          break;

        exp = exp * 10 + nib;
      }

      if ( exp_sign )
        exp = -exp;

      power_ten += exp;
    }

    /* raise to power of ten if needed */
    while ( power_ten > 0 )
    {
      result = result * 10;
      num    = num * 10;

      power_ten--;
    }

    while ( power_ten < 0 )
    {
      result  = result / 10;
      divider = divider * 10;

      power_ten++;
    }

    if ( num )
      result += FT_DivFix( num, divider );

    if ( sign )
      result = -result;

  Exit:
    return result;

  Bad:
    result = 0;
    goto Exit;
  }


  /* read a number, either integer or real */
  static
  FT_Long  t2_parse_num( FT_Byte**  d )
  {
    return ( **d == 30 ? ( parse_t2_real( d[0], d[1], 0 ) >> 16 )
                       : parse_t2_integer( d[0], d[1] ) );
  }


  /* reads a floating point number, either integer or real */
  static
  FT_Fixed  t2_parse_fixed( FT_Byte**  d )
  {
    return ( **d == 30 ? parse_t2_real( d[0], d[1], 0 )
                       : parse_t2_integer( d[0], d[1] ) << 16 );
  }


  static
  FT_Error  parse_font_matrix( T2_Parser*  parser )
  {
    CFF_Font_Dict*  dict   = (CFF_Font_Dict*)parser->object;
    FT_Matrix*      matrix = &dict->font_matrix;
    FT_Byte**       data   = parser->stack;
    FT_Error        error;


    error = T2_Err_Stack_Underflow;

    if ( parser->top >= parser->stack + 4 )
    {
      matrix->xx = t2_parse_fixed( data++ );
      matrix->yx = t2_parse_fixed( data++ );
      matrix->xy = t2_parse_fixed( data++ );
      matrix->yy = t2_parse_fixed( data   );
      error = T2_Err_Ok;
    }

    return error;