cffparse.c

奇趣公司比较新的qt/emd版本

/***************************************************************************/
/*                                                                         */
/*  cffparse.c                                                             */
/*                                                                         */
/*    CFF token stream parser (body)                                       */
/*                                                                         */
/*  Copyright 1996-2001, 2002, 2003, 2004, 2007 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.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include "cffparse.h"
#include FT_INTERNAL_STREAM_H

#include "cfferrs.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_cffparse


  enum
  {
    cff_kind_none = 0,
    cff_kind_num,
    cff_kind_fixed,
    cff_kind_fixed_thousand,
    cff_kind_string,
    cff_kind_bool,
    cff_kind_delta,
    cff_kind_callback,

    cff_kind_max  /* do not remove */
  };


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

  typedef struct  CFF_Field_Handler_
  {
    int               kind;
    int               code;
    FT_UInt           offset;
    FT_Byte           size;
    CFF_Field_Reader  reader;
    FT_UInt           array_max;
    FT_UInt           count_offset;

  } CFF_Field_Handler;


  FT_LOCAL_DEF( void )
  cff_parser_init( CFF_Parser  parser,
                   FT_UInt     code,
                   void*       object )
  {
    FT_MEM_ZERO( parser, sizeof ( *parser ) );

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


  /* read an integer */
  static FT_Long
  cff_parse_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
  cff_parse_real( FT_Byte*  start,
                  FT_Byte*  limit,
                  FT_Int    power_ten )
  {
    FT_Byte*  p    = start;
    FT_Long   num, divider, result, exponent;
    FT_Int    sign = 0, exponent_sign = 0;
    FT_UInt   nib;
    FT_UInt   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 initial 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 )
    {
      exponent_sign = 1;
      nib           = 11;
    }

    if ( nib == 11 )
    {
      exponent = 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;

        exponent = exponent * 10 + nib;
      }

      if ( exponent_sign )
        exponent = -exponent;

      power_ten += (FT_Int)exponent;
    }

    /* 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++;
    }

    /* Move the integer part into the high 16 bits. */
    result <<= 16;

    /* Place the decimal part into the low 16 bits. */
    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
  cff_parse_num( FT_Byte**  d )
  {
    return ( **d == 30 ? ( cff_parse_real   ( d[0], d[1], 0 ) >> 16 )
                       :   cff_parse_integer( d[0], d[1] ) );
  }


  /* read a floating point number, either integer or real */
  static FT_Fixed
  cff_parse_fixed( FT_Byte**  d )
  {
    return ( **d == 30 ? cff_parse_real   ( d[0], d[1], 0 )
                       : cff_parse_integer( d[0], d[1] ) << 16 );
  }

  /* read a floating point number, either integer or real, */
  /* but return 1000 times the number read in.             */
  static FT_Fixed
  cff_parse_fixed_thousand( FT_Byte**  d )
  {
    return **d ==
      30 ? cff_parse_real     ( d[0], d[1], 3 )
         : (FT_Fixed)FT_MulFix( cff_parse_integer( d[0], d[1] ) << 16, 1000 );
  }

  static FT_Error
  cff_parse_font_matrix( CFF_Parser  parser )
  {
    CFF_FontRecDict  dict   = (CFF_FontRecDict)parser->object;
    FT_Matrix*       matrix = &dict->font_matrix;
    FT_Vector*       offset = &dict->font_offset;
    FT_UShort*       upm    = &dict->units_per_em;
    FT_Byte**        data   = parser->stack;
    FT_Error         error;
    FT_Fixed         temp;


    error = CFF_Err_Stack_Underflow;

    if ( parser->top >= parser->stack + 6 )
    {
      matrix->xx = cff_parse_fixed_thousand( data++ );
      matrix->yx = cff_parse_fixed_thousand( data++ );
      matrix->xy = cff_parse_fixed_thousand( data++ );
      matrix->yy = cff_parse_fixed_thousand( data++ );
      offset->x  = cff_parse_fixed_thousand( data++ );
      offset->y  = cff_parse_fixed_thousand( data   );

      temp = FT_ABS( matrix->yy );

      *upm = (FT_UShort)FT_DivFix( 0x10000L, FT_DivFix( temp, 1000 ) );

      if ( temp != 0x10000L )
      {
        matrix->xx = FT_DivFix( matrix->xx, temp );
        matrix->yx = FT_DivFix( matrix->yx, temp );
        matrix->xy = FT_DivFix( matrix->xy, temp );