t1load.c

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

/*******************************************************************
 *
 *  t1load.h                                                    2.0
 *
 *    Type1 Loader.                          
 *
 *  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.
 *
 *
 *  This is the new and improved Type 1 data loader for FreeType 2.
 *  The old loader has several problems: it is slow, complex, difficult
 *  to maintain, and contains incredible hacks to make it accept some
 *  ill-formed Type 1 fonts without hiccup-ing. Moreover, about 5%
 *  of the Type 1 fonts on my machine still aren't loaded correctly
 *  by it.
 *
 *  This version is much simpler, much faster and also easier to
 *  read and maintain by a great order of magnitude. The idea behind
 *  it is to _not_ try to read the Type 1 token stream with a state
 *  machine (i.e. a Postscript-like interpreter) but rather to perform
 *  simple pattern-matching.
 *
 *  Indeed, nearly all data definitions follow a simple pattern
 *  like :
 *
 *      ..... /Field <data> ....
 *
 *  where <data> can be a number, a boolean, a string, or an 
 *  array of numbers. There are a few exceptions, namely the
 *  encoding, font name, charstrings and subrs and they are
 *  handled with a special pattern-matching routine.
 *
 *  All other common cases are handled very simply. The matching
 *  rules are defined in the file "t1tokens.h" through the use
 *  of several macros calls PARSE_XXXX
 *
 *  This file is included twice here, the first time to generate
 *  parsing callback functions, the second to generate a table
 *  of keywords (with pointers to the associated callback).
 *
 *  The function "parse_dict" simply scans *linearly* a given
 *  dictionary (either the top-level or private one) and calls
 *  the appropriate callback when it encounters an immediate
 *  keyword.
 *
 *  This is by far the fastest way one can find to parse and read
 *  all data :-)
 *
 *  This led to tremendous code size reduction. Note that later,
 *  the glyph loader will also be _greatly_ simplified, and the
 *  automatic hinter will replace the clumsy "t1hinter"..
 *
 ******************************************************************/

#include <ftdebug.h>
#include <ftconfig.h>

#include <t1types.h>
#include <t1errors.h>
#include <t1load.h>
#include <stdio.h>

#undef  FT_COMPONENT
#define FT_COMPONENT  trace_t1load

  typedef  void  (*T1_Parse_Func)( T1_Face   face, T1_Loader*  loader );

  typedef  struct T1_KeyWord_  
  {
    const char*    name;
    T1_Parse_Func  parsing;
  
  } T1_KeyWord;

  /* some handy macros used to easily define parsing callback functions */
  /* each callback is in charge of loading a value and storing it in a  */
  /* given field of the Type 1 face..                                   */
 
#define PARSE_(x)  static void parse_##x##( T1_Face  face, T1_Loader* loader )

#define PARSE_STRING(s,x)   PARSE_(x)                               \
        {                                                           \
          FACE.##x = T1_ToString(&loader->parser);                  \
          FT_TRACE2(( "type1.parse_##x##: \"%s\"\n", FACE.##x ));   \
        }

#define PARSE_NUM(s,x,t)  PARSE_(x)                                 \
        {                                                           \
          FACE.##x = (t)T1_ToInt(&loader->parser);                  \
          FT_TRACE2(( "type1.parse_##x##: \"%d\"\n", FACE.##x ));   \
        }
        
#define PARSE_INT(s,x)   PARSE_(x)                                  \
        {                                                           \
          FACE.##x = T1_ToInt(&loader->parser);                     \
          FT_TRACE2(( "type1.parse_##x##: \"%d\"\n", FACE.##x ));   \
        }

#define PARSE_BOOL(s,x)   PARSE_(x)                                 \
        {                                                           \
          FACE.##x = T1_ToBool(&loader->parser);                    \
          FT_TRACE2(( "type1.parse_##x##: \"%s\"\n",                \
                       FACE.##x ? "true" : "false" ));              \
        }
 
#define PARSE_FIXED(s,x)   PARSE_(x)                                        \
        {                                                                   \
          FACE.##x = T1_ToFixed(&loader->parser,3);                         \
          FT_TRACE2(( "type1.parse_##x##: \"%f\"\n", FACE.##x/65536.0 ));   \
        }
 
#define PARSE_COORDS(s,c,m,x)   PARSE_(x)                                         \
        {                                                                         \
          FACE.##c = T1_ToCoordArray(&loader->parser, m, (T1_Short*)FACE.##x );   \
          FT_TRACE2(( "type1.parse_##x##\n" ));                                   \
        }
           
#define PARSE_FIXEDS(s,c,m,x)   PARSE_(x)                                           \
        {                                                                           \
          FACE.##c = T1_ToFixedArray(&loader->parser, m, (T1_Fixed*)FACE.##x, 3 );  \
          FT_TRACE2(( "type1.parse_##x##\n" ));                                     \
        }


#define PARSE_COORDS2(s,m,x)   PARSE_(x)                                     \
        {                                                                    \
          (void)T1_ToCoordArray( &loader->parser, m, (T1_Short*)&FACE.##x );  \
          FT_TRACE2(( "type1.parse_##x##\n" ));                              \
        }

#define PARSE_FIXEDS2(s,m,x)   PARSE_(x)                                           \
        {                                                                           \
          (void)T1_ToFixedArray(&loader->parser, m, (T1_Fixed*)&FACE.##x, 3 );  \
          FT_TRACE2(( "type1.parse_##x##\n" ));                                     \
        }


/* define all parsing callbacks */
#include <t1tokens.h>


  static
  int  is_space( char c )
  {
    return ( c == ' ' || c == '\t' || c == '\r' || c == '\n' );
  }

  static
  int  is_alpha( char c )
  {
    return ( (c >= 'A' && c <= 'Z') ||
             (c >= 'a' && c <= 'z') ||
             (c >= '0' && c <= '9') ||
             (c == '.')             ||
             (c == '_') );
  }

  static
  void  skip_whitespace( T1_Parser* parser )
  {
    T1_Byte*  cur = parser->cursor;
    
    while ( cur < parser->limit && is_space(*cur) )
      cur++;
      
    parser->cursor = cur;
  }
  
  static
  void skip_blackspace( T1_Parser* parser )
  {
    T1_Byte*  cur = parser->cursor;
    
    while ( cur < parser->limit && !is_space(*cur) )
      cur++;
      
    parser->cursor = cur;
  }
  
  static
  int   read_binary_data( T1_Parser*  parser, T1_Int *size, T1_Byte* *base )
  {
    T1_Byte*  cur;
    T1_Byte*  limit = parser->limit;
    
    /* the binary data has the following format */
    /*                                          */
    /* "size" [white*] RD white ....... ND      */
    /*                                          */
    
    skip_whitespace(parser);
    cur = parser->cursor;
    
    if ( cur < limit && (T1_Byte)(*cur-'0') < 10 )
    {
      *size = T1_ToInt(parser);
      
      skip_whitespace(parser);
      skip_blackspace(parser);  /* "RD" or "-|" or something else */
      
      /* there is only one whitespace char after the */
      /* "RD" or "-|" token                          */
      *base = parser->cursor + 1;
      
      parser->cursor += *size+1;
      return 1;
    }

    FT_ERROR(( "type1.read_binary_data: invalid size field\n" ));
    parser->error = FT_Err_Invalid_File_Format;
    return 0;
  }


  /* we will now define the routines used to handle */
  /* the /Encoding, /Subrs and /CharStrings         */
  /* dictionaries..                                 */

  static
  void  parse_font_name( T1_Face  face, T1_Loader*  loader )
  {
    T1_Parser*  parser = &loader->parser;
    FT_Error    error;
    FT_Memory   memory = parser->memory;
    T1_Int      len;
    T1_Byte*    cur;
    T1_Byte*    cur2;
    T1_Byte*    limit;
    
    skip_whitespace(parser);
    cur   = parser->cursor;
    limit = parser->limit;
    if ( cur >= limit-1 || *cur != '/' ) return;
    
    cur++;
    cur2 = cur;
    while (cur2 < limit && is_alpha(*cur2)) cur2++;
    len = cur2-cur;
    if (len > 0)
    {
      if ( ALLOC( face->type1.font_name, len+1 ) )
      {
        parser->error = error;
        return;
      }
      
      MEM_Copy( face->type1.font_name, cur, len );
      face->type1.font_name[len] = '\0';
    }
    parser->cursor = cur2;
  }

  static
  void  parse_font_bbox( T1_Face  face, T1_Loader*  loader )
  {
    T1_Parser*  parser = &loader->parser;
    T1_Short    temp[4];
    T1_BBox*    bbox = &face->type1.font_bbox;
    
    (void)T1_ToCoordArray( parser, 4, temp );
    bbox->xMin = temp[0];
    bbox->yMin = temp[1];
    bbox->xMax = temp[2];
    bbox->yMax = temp[3];
  }

  static
  void  parse_encoding( T1_Face  face, T1_Loader*  loader )
  {
    T1_Parser*  parser = &loader->parser;
    T1_Byte*    cur   = parser->cursor;
    T1_Byte*    limit = parser->limit;
    
    /* skip whitespace */
    while (is_space(*cur))
    {
      cur++;
      if (cur >= limit)
      {
        FT_ERROR(( "type1.parse_encoding: out of bounds !!\n" ));
        parser->error = FT_Err_Invalid_File_Format;
        return;
      }
    }
    
    /* if we have a number, then the encoding is an array, */
    /* and we must load it now                             */
    if ((T1_Byte)(*cur - '0') < 10)
    {
      T1_Encoding*  encode     = &face->type1.encoding;
      T1_Int        count, n;
      T1_Table*     char_table = &loader->encoding_table;
      FT_Memory     memory     = parser->memory;
      FT_Error      error;
      
      /* read the number of entries in the encoding, should be 256 */
      count = T1_ToInt( parser );
      if (parser->error) return;

      /* we use a T1_Table to store our charnames */
      encode->num_chars = count;
      if ( ALLOC_ARRAY( encode->char_index, count, T1_Short   ) ||
           ALLOC_ARRAY( encode->char_name,  count, T1_String* ) ||
           (error = T1_New_Table( char_table, count, memory )) != 0     )
      {
        parser->error = error;
        return;
      }
      
      /* now, we will need to read a record of the form         */
      /* ... charcode /charname ... for each entry in our table */
      /*                                                        */
      /* we simply look for a number followed by an immediate   */
      /* name. Note that this ignores correctly the sequence    */
      /* that is often seen in type1 fonts :                    */
      /*                                                        */
      /*   0 1 255 { 1 index exch /.notdef put } for dup        */
      /*                                                        */
      /* used to clean the encoding array before anything else  */
      /*                                                        */
      /* we stop when we encounter a "def"                      */
      /*                                                        */

      cur   = parser->cursor;
      limit = parser->limit;
      n     = 0;

      for ( ; cur < limit; )
      {
        T1_Byte  c;
        
        c = *cur;
        
        /* we stop when we encounter a 'def' */
        if ( c == 'd' && cur+3 < limit )
        {
          if ( cur[1] == 'e' &&
               cur[2] == 'f' &&
               is_space(cur[-1]) &&
               is_space(cur[3]) )
          {
              FT_TRACE6(( "encoding end\n" ));
              break;
          }
        }
        
        /* otherwise, we must find a number before anything else */
        if ( (T1_Byte)(c-'0') < 10 )
        {
          T1_Int  charcode;
          
          parser->cursor = cur;
          charcode = T1_ToInt(parser);
          cur = parser->cursor;
          
          /* skip whitespace */
          while (cur < limit && is_space(*cur)) cur++;
          
          if (cur < limit && *cur == '/')
          {
            /* bingo, we have an immediate name - it must be a */
            /* character name                                  */
            FT_Byte*  cur2 = cur+1;
            T1_Int    len;
            
            while (cur2 < limit && is_alpha(*cur2)) cur2++;
            len = cur2-cur-1;
            parser->error = T1_Add_Table( char_table, charcode, cur+1, len+1 );
            char_table->elements[charcode][len] = '\0';
            if (parser->error) return;
            
            cur = cur2;
          }
        }
        else
          cur++;
      }
      
      face->type1.encoding_type = t1_encoding_array;
      parser->cursor            = cur;
    }
    /* Otherwise, we should have either "StandardEncoding" or */
    /* "ExpertEncoding"                                       */
    else
    {
      if ( cur+17 < limit &&
           strncmp( (const char*)cur, "StandardEncoding", 16 ) == 0 )