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/***************************************************************************/
/*                                                                         */
/*  t2load.c                                                               */
/*                                                                         */
/*    TrueType glyph data/program tables loader (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.                                        */
/*                                                                         */
/***************************************************************************/


#include <freetype/internal/ftdebug.h>
#include <freetype/internal/ftobjs.h>
#include <freetype/internal/ftstream.h>
#include <freetype/internal/psnames.h>

#include <freetype/internal/t2errors.h>
#include <freetype/tttags.h>
#include <t2load.h>
#include <t2parse.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_t2load


 /* read a CFF offset from memory */
  static
  FT_ULong  t2_get_offset( FT_Byte*  p,
                           FT_Byte   off_size )
  {
    FT_ULong  result;


    for ( result = 0; off_size > 0; off_size-- )
      result = ( result <<= 8 ) | *p++;

    return result;
  }


  static
  FT_Error  t2_new_cff_index( CFF_Index*  index,
                              FT_Stream   stream,
                              FT_Bool     load )
  {
    FT_Error  error;
    FT_Memory memory = stream->memory;
    FT_UShort count;


    MEM_Set( index, 0, sizeof ( *index ) );

    index->stream = stream;
    if ( !READ_UShort( count ) &&
          count > 0            )
    {
      FT_Byte*   p;
      FT_Byte    offsize;
      FT_ULong   data_size;
      FT_ULong*  poff;


      /* there is at least one element; read the offset size            */
      /* then access the offset table to compute the index's total size */
      if ( READ_Byte( offsize ) )
        goto Exit;

      index->stream   = stream;
      index->count    = count;
      index->off_size = offsize;
      data_size       = (FT_ULong)( count + 1 ) * offsize;

      if ( ALLOC_ARRAY( index->offsets, count + 1, FT_ULong ) ||
           ACCESS_Frame( data_size )                          )
        goto Exit;

      poff = index->offsets;
      p    = (FT_Byte*)stream->cursor;

      for ( ; (FT_Short)count >= 0; count-- )
      {
        poff[0] = t2_get_offset( p, offsize );
        poff++;
        p += offsize;
      }

      FORGET_Frame();

      index->data_offset = FILE_Pos();
      data_size          = poff[-1] - 1;

      if ( load )
      {
        /* load the data */
        if ( EXTRACT_Frame( data_size, index->bytes ) )
          goto Exit;
      }
      else
      {
        /* skip the data */
        (void)FILE_Skip( data_size );
      }
    }

  Exit:
    if ( error )
      FREE( index->offsets );

    return error;
  }


  static
  void  t2_done_cff_index( CFF_Index*  index )
  {
    if ( index->stream )
    {
      FT_Stream  stream = index->stream;
      FT_Memory  memory = stream->memory;


      if ( index->bytes )
        RELEASE_Frame( index->bytes );

      FREE( index->offsets );
      MEM_Set( index, 0, sizeof ( *index ) );
    }
  }


  static
  FT_Error  t2_explicit_cff_index( CFF_Index*  index,
                                   FT_Byte***  table )
  {
    FT_Error   error  = 0;
    FT_Memory  memory = index->stream->memory;
    FT_UInt    n, offset, old_offset;
    FT_Byte**  t;


    *table = 0;

    if ( index->count > 0 && !ALLOC_ARRAY( t, index->count + 1, FT_Byte* ) )
    {
      old_offset = 1;
      for ( n = 0; n <= index->count; n++ )
      {
        offset = index->offsets[n];
        if ( !offset )
          offset = old_offset;

        t[n] = index->bytes + offset - 1;

        old_offset = offset;
      }
      *table = t;
    }

    return error;
  }


  LOCAL_FUNC
  FT_Error  T2_Access_Element( CFF_Index*  index,
                               FT_UInt     element,
                               FT_Byte**   pbytes,
                               FT_ULong*   pbyte_len )
  {
    FT_Error  error = 0;


    if ( index && index->count > element )
    {
      /* compute start and end offsets */
      FT_ULong  off1, off2;


      off1 = index->offsets[element];
      if ( off1 )
      {
        do
        {
          element++;
          off2 = index->offsets[element];
        }
        while ( off2 == 0 && element < index->count );

        if ( !off2 )
          off1 = 0;
      }

      /* access element */
      if ( off1 )
      {
        *pbyte_len = off2 - off1;

        if ( index->bytes )
        {
          /* this index was completely loaded in memory, that's easy */
          *pbytes = index->bytes + off1 - 1;
        }
        else
        {
          /* this index is still on disk/file, access it through a frame */
          FT_Stream  stream = index->stream;


          if ( FILE_Seek( index->data_offset + off1 - 1 ) ||
               EXTRACT_Frame( off2 - off1, *pbytes )      )
            goto Exit;
        }
      }
      else
      {
        /* empty index element */
        *pbytes    = 0;
        *pbyte_len = 0;
      }
    }
    else
      error = T2_Err_Invalid_Argument;

  Exit:
    return error;
  }


  LOCAL_FUNC
  void  T2_Forget_Element( CFF_Index*  index,
                           FT_Byte**   pbytes )
  {
    if ( index->bytes == 0 )
    {
      FT_Stream  stream = index->stream;


      RELEASE_Frame( *pbytes );
    }
  }


  LOCAL_FUNC
  FT_String*  T2_Get_Name( CFF_Index*  index,
                           FT_UInt     element )
  {
    FT_Memory   memory = index->stream->memory;
    FT_Byte*    bytes;
    FT_ULong    byte_len;
    FT_Error    error;
    FT_String*  name = 0;


    error = T2_Access_Element( index, element, &bytes, &byte_len );
    if ( error )
      goto Exit;

    if ( !ALLOC( name, byte_len + 1 ) )
    {
      MEM_Copy( name, bytes, byte_len );
      name[byte_len] = 0;
    }
    T2_Forget_Element( index, &bytes );

  Exit:
    return name;
  }


#if 0 /* unused until we fully support pure-CFF fonts */

  LOCAL_FUNC
  FT_String*  T2_Get_String( CFF_Index*          index,
                             FT_UInt             sid,
                             PSNames_Interface*  interface )
  {
    /* if it is not a standard string, return it */
    if ( sid > 390 )
      return T2_Get_Name( index, sid - 390 );

    /* that's a standard string, fetch a copy from the PSName module */
    {
      FT_String*   name       = 0;
      const char*  adobe_name = interface->adobe_std_strings( sid );
      FT_UInt      len;


      if ( adobe_name )
      {
        FT_Memory memory = index->stream->memory;
        FT_Error  error;


        len = (FT_UInt)strlen( adobe_name );
        if ( !ALLOC( name, len + 1 ) )
        {
          MEM_Copy( name, adobe_name, len );
          name[len] = 0;
        }
      }

      return name;
    }
  }

#endif /* 0 */


  LOCAL_FUNC
  FT_Error  T2_Load_CFF_Font( FT_Stream  stream,
                              FT_Int     face_index,
                              CFF_Font*  font )
  {
    static const FT_Frame_Field  cff_header_fields[] =
    {
      FT_FRAME_START( 4 ),
        FT_FRAME_BYTE( CFF_Font, version_major ),
        FT_FRAME_BYTE( CFF_Font, version_minor ),
        FT_FRAME_BYTE( CFF_Font, header_size ),
        FT_FRAME_BYTE( CFF_Font, absolute_offsize ),
      FT_FRAME_END
    };

    FT_Error   error;
    FT_Memory  memory = stream->memory;
    FT_ULong   base_offset;


    MEM_Set( font, 0, sizeof ( *font ) );
    font->stream = stream;
    font->memory = memory;
    base_offset  = FILE_Pos();

    /* read CFF font header */
    if ( READ_Fields( cff_header_fields, font ) )
      goto Exit;

    /* check format */
    if ( font->version_major   != 1 ||
         font->header_size      < 4 ||
         font->absolute_offsize > 4 )
    {
      FT_ERROR(( "incorrect CFF font header!\n" ));
      error = FT_Err_Unknown_File_Format;
      goto Exit;
    }

    /* skip the rest of the header */
    (void)FILE_Skip( font->header_size - 4 );

    /* read the name, top dict, string and global subrs index */
    error = t2_new_cff_index( &font->name_index, stream, 0 )       ||
            t2_new_cff_index( &font->top_dict_index, stream, 0 )   ||
            t2_new_cff_index( &font->string_index, stream, 0 )     ||
            t2_new_cff_index( &font->global_subrs_index, stream, 1 );
    if ( error )
      goto Exit;

    /* well, we don't really forget the `disabled' fonts... */
    font->num_faces = font->name_index.count;
    if ( face_index >= font->num_faces )
    {
      FT_ERROR(( "T2_Load_CFF_Font: incorrect face index = %d\n",
                 face_index ));
      error = T2_Err_Invalid_Argument;
    }

    /* in case of a font format check, simply exit now */
    if ( face_index >= 0 )
    {
      T2_Parser      parser;
      FT_Byte*       dict;
      FT_ULong       dict_len;
      CFF_Index*     index = &font->top_dict_index;
      CFF_Top_Dict*  top   = &font->top_dict;


      /* parse the top-level font dictionary */
      T2_Parser_Init( &parser, T2CODE_TOPDICT, &font->top_dict );

      /* set defaults */
      memset( top, 0, sizeof ( *top ) );

      top->underline_position  = -100;
      top->underline_thickness = 50;
      top->charstring_type     = 2;
      top->font_matrix.xx      = 0x10000L;
      top->font_matrix.yy      = 0x10000L;
      top->cid_count           = 8720;

      error = T2_Access_Element( index, face_index, &dict, &dict_len ) ||
              T2_Parser_Run( &parser, dict, dict + dict_len );

      T2_Forget_Element( &font->top_dict_index, &dict );

      if ( error )
        goto Exit;

      /* parse the private dictionary, if any */
      if (font->top_dict.private_offset && font->top_dict.private_size)
      {
        CFF_Private*  priv = &font->private_dict;


        /* set defaults */
        priv->blue_shift       = 7;
        priv->blue_fuzz        = 1;
        priv->lenIV            = -1;
        priv->expansion_factor = (FT_Fixed)0.06 * 0x10000L;
        priv->blue_scale       = (FT_Fixed)0.039625 * 0x10000L;

        T2_Parser_Init( &parser, T2CODE_PRIVATE, priv );

        if ( FILE_Seek( base_offset + font->top_dict.private_offset ) ||
             ACCESS_Frame( font->top_dict.private_size )               )
          goto Exit;

        error = T2_Parser_Run( &parser,
                               (FT_Byte*)stream->cursor,
                               (FT_Byte*)stream->limit );
        FORGET_Frame();
        if ( error )
          goto Exit;
      }

      /* read the charstrings index now */
      if ( font->top_dict.charstrings_offset == 0 )
      {
        FT_ERROR(( "T2_Load_CFF_Font: no charstrings offset!\n" ));
        error = FT_Err_Unknown_File_Format;
        goto Exit;
      }

      if ( FILE_Seek( base_offset + font->top_dict.charstrings_offset ) )
        goto Exit;

      error = t2_new_cff_index( &font->charstrings_index, stream, 0 );
      if ( error )
        goto Exit;

      /* read the local subrs, if any */

      if ( font->private_dict.local_subrs_offset )
      {
        if ( FILE_Seek( base_offset + font->top_dict.private_offset +
                        font->private_dict.local_subrs_offset ) )
          goto Exit;

        error = t2_new_cff_index( &font->local_subrs_index, stream, 1 );
        if ( error )
          goto Exit;
      }

      /* explicit the global and local subrs */

      if ( font->private_dict.local_subrs_offset )
        font->num_local_subrs = font->local_subrs_index.count;
      else
        font->num_local_subrs = 0;

      font->num_global_subrs = font->global_subrs_index.count;

      error = t2_explicit_cff_index( &font->global_subrs_index,
                                     &font->global_subrs ) ;

      if ( font->private_dict.local_subrs_offset )
        error |= t2_explicit_cff_index( &font->local_subrs_index,
                                        &font->local_subrs ) ;

      if ( error )
        goto Exit;
    }

    /* get the font name */
    font->font_name = T2_Get_Name( &font->name_index, face_index );

  Exit:
    return error;
  }


  LOCAL_FUNC
  void  T2_Done_CFF_Font( CFF_Font*  font )
  {
    FT_Memory  memory = font->memory;


    t2_done_cff_index( &font->global_subrs_index );
    t2_done_cff_index( &font->string_index );
    t2_done_cff_index( &font->top_dict_index );
    t2_done_cff_index( &font->name_index );
    t2_done_cff_index( &font->charstrings_index );

    FREE( font->local_subrs );
    FREE( font->global_subrs );
    FREE( font->font_name );
  }


/* END */
kc3-lang/freetype/src/cff/t2load.c

Commit

src/cff/t2load.c
