shithub: freetype+ttf2subf

ref: 56177261080a288a05fd305e31268c3644777d74
dir: /src/type1z/t1gload.c/

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/*******************************************************************
 *
 *  t1gload.c                                                   1.0
 *
 *    Type1 Glyph Loader.
 *
 *  Copyright 1996-1999 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 <t1gload.h>
#include <freetype/internal/ftdebug.h>
#include <freetype/internal/ftstream.h>

#undef  FT_COMPONENT
#define FT_COMPONENT  trace_t1gload

  typedef enum T1_Operator_
  {
    op_none = 0,
    op_endchar,
    op_hsbw,
    op_seac,
    op_sbw,
    op_closepath,
    op_hlineto,
    op_hmoveto,
    op_hvcurveto,
    op_rlineto,
    op_rmoveto,
    op_rrcurveto,
    op_vhcurveto,
    op_vlineto,
    op_vmoveto,
    op_dotsection,
    op_hstem,
    op_hstem3,
    op_vstem,
    op_vstem3,
    op_div,
    op_callothersubr,
    op_callsubr,
    op_pop,
    op_return,
    op_setcurrentpoint,

    op_max    /* never remove this one */

  } T1_Operator;

  static const T1_Int  t1_args_count[ op_max ] =
  {
    0, /* none */
    0, /* endchar */
    2, /* hsbw */
    5, /* seac */
    4, /* sbw */
    0, /* closepath */
    1, /* hlineto */
    1, /* hmoveto */
    4, /* hvcurveto */
    2, /* rlineto */
    2, /* rmoveto */
    6, /* rrcurveto */
    4, /* vhcurveto */
    1, /* vlineto */
    1, /* vmoveto */
    0, /* dotsection */
    2, /* hstem */
    6, /* hstem3 */
    2, /* vstem */
    6, /* vstem3 */
    2, /* div */
   -1, /* callothersubr */
    1, /* callsubr */
    0, /* pop */
    0, /* return */
    2  /* setcurrentpoint */
  };


  /**********************************************************************/
  /**********************************************************************/
  /**********************************************************************/
  /**********                                                   *********/
  /**********                                                   *********/
  /**********           GENERIC CHARSTRINGS PARSING             *********/
  /**********                                                   *********/
  /**********                                                   *********/
  /**********************************************************************/
  /**********************************************************************/
  /**********************************************************************/

/*********************************************************************
 *
 * <Function>
 *    T1_Init_Builder
 *
 * <Description>
 *    Initialise a given glyph builder.
 *
 * <Input>
 *    builder :: glyph builder to initialise
 *    face    :: current face object
 *    size    :: current size object
 *    glyph   :: current glyph object
 *
 *********************************************************************/

  LOCAL_FUNC
  void  T1_Init_Builder( T1_Builder*   builder,
                         T1_Face       face,
                         T1_Size       size,
                         T1_GlyphSlot  glyph )
  {
    builder->path_begun  = 0;
    builder->load_points = 1;

    builder->face   = face;
    builder->glyph  = glyph;
    builder->memory = face->root.memory;

    if (glyph)
    {
      builder->base         = glyph->root.outline;
      builder->max_points   = glyph->max_points;
      builder->max_contours = glyph->max_contours;
    }

    if (size)
    {
      builder->scale_x = size->root.metrics.x_scale;
      builder->scale_y = size->root.metrics.y_scale;
    }

    builder->pos_x = 0;
    builder->pos_y = 0;

    builder->left_bearing.x = 0;
    builder->left_bearing.y = 0;
    builder->advance.x      = 0;
    builder->advance.y      = 0;

    builder->base.n_points   = 0;
    builder->base.n_contours = 0;
    builder->current         = builder->base;
  }


/*********************************************************************
 *
 * <Function>
 *    T1_Done_Builder
 *
 * <Description>
 *    Finalise a given glyph builder. Its content can still be
 *    used after the call, but the function saves important information
 *    within the corresponding glyph slot.
 *
 * <Input>
 *    builder :: glyph builder to initialise
 *
 *********************************************************************/

  LOCAL_FUNC
  void T1_Done_Builder( T1_Builder*  builder )
  {
    T1_GlyphSlot  glyph = builder->glyph;

    if (glyph)
    {
      glyph->root.outline = builder->base;
      glyph->max_points   = builder->max_points;
      glyph->max_contours = builder->max_contours;
    }
  }



/*********************************************************************
 *
 * <Function>
 *    T1_Init_Decoder
 *
 * <Description>
 *    Initialise a given Type 1 decoder for parsing
 *
 * <Input>
 *    decoder :: Type 1 decoder to initialise
 *    funcs   :: hinter functions interface
 *
 *********************************************************************/

  LOCAL_FUNC
  void  T1_Init_Decoder( T1_Decoder* decoder )
  {
    decoder->top              = 0;
    decoder->zone             = 0;
    decoder->flex_state       = 0;
    decoder->num_flex_vectors = 0;
    decoder->blend            = 0;

    /* Clear loader */
    MEM_Set( &decoder->builder, 0, sizeof(decoder->builder) );
  }


  /* check that there is enough room for "count" more points */
  static
  T1_Error  check_points( T1_Builder*  builder,
                          T1_Int       count )
  {
    FT_Outline*  base    = &builder->base;
    FT_Outline*  outline = &builder->current;

    if (!builder->load_points)
      return T1_Err_Ok;

    count += base->n_points + outline->n_points;

    /* realloc points table if necessary */
    if ( count >= builder->max_points )
    {
      T1_Error   error;
      FT_Memory  memory    = builder->memory;
      T1_Int     increment = outline->points - base->points;
      T1_Int     current   = builder->max_points;

      while ( builder->max_points < count )
        builder->max_points += 8;

      if ( REALLOC_ARRAY( base->points, current,
                          builder->max_points, T1_Vector )  ||

           REALLOC_ARRAY( base->tags, current,
                          builder->max_points, T1_Byte )    )
      {
        builder->error = error;
        return error;
      }

      outline->points = base->points + increment;
      outline->tags  = base->tags  + increment;
    }
    return T1_Err_Ok;
  }


  /* add a new point, do not check room */
  static
  void  add_point( T1_Builder*  builder,
                   FT_Pos       x,
                   FT_Pos       y,
                   FT_Byte      flag )
  {
    FT_Outline*  outline = &builder->current;

    if (builder->load_points)
    {
      FT_Vector*  point   = outline->points + outline->n_points;
      FT_Byte*    control = (FT_Byte*)outline->tags + outline->n_points;

      point->x = x;
      point->y = y;
      *control = ( flag ? FT_Curve_Tag_On : FT_Curve_Tag_Cubic );

      builder->last = *point;
    }

    outline->n_points++;
  }


  /* check room for a new on-curve point, then add it */
  static
  T1_Error  add_point1( T1_Builder*  builder,
                        FT_Pos       x,
                        FT_Pos       y )
  {
    T1_Error  error;

    error = check_points(builder,1);
    if (!error)
      add_point( builder, x, y, 1 );

    return error;
  }


  /* check room for a new contour, then add it */
  static
  T1_Error  add_contour( T1_Builder*  builder )
  {
    FT_Outline*  base    = &builder->base;
    FT_Outline*  outline = &builder->current;

    if (!builder->load_points)
    {
      outline->n_contours++;
      return T1_Err_Ok;
    }

    /* realloc contours array if necessary */
    if ( base->n_contours + outline->n_contours >= builder->max_contours &&
         builder->load_points )
    {
      T1_Error  error;
      FT_Memory memory = builder->memory;
      T1_Int    increment = outline->contours - base->contours;
      T1_Int    current   = builder->max_contours;

      builder->max_contours += 4;

      if ( REALLOC_ARRAY( base->contours,
                          current, builder->max_contours, T1_Short ) )
      {
        builder->error = error;
        return error;
      }

      outline->contours = base->contours + increment;
    }

    if (outline->n_contours > 0)
      outline->contours[ outline->n_contours-1 ] = outline->n_points-1;

    outline->n_contours++;
    return T1_Err_Ok;
  }

  /* if a path was begun, add its first on-curve point */
  static
  T1_Error  start_point( T1_Builder*  builder,
                         T1_Pos       x,
                         T1_Pos       y )
  {
    /* test wether we're building a new contour */
    if (!builder->path_begun)
    {
      T1_Error  error;

      builder->path_begun = 1;
      error = add_contour( builder );
      if (error) return error;
    }
    return add_point1( builder, x, y );
  }


  /* close the current contour */
  static
  void  close_contour( T1_Builder*  builder )
  {
    FT_Outline*  outline = &builder->current;

    if ( outline->n_contours > 0 )
      outline->contours[outline->n_contours-1] = outline->n_points-1;
  }


/*********************************************************************
 *
 * <Function>
 *    lookup_glyph_by_stdcharcode
 *
 * <Description>
 *    Lookup a given glyph by its StandardEncoding charcode. Used
 *    to implement the SEAC Type 1 operator.
 *
 * <Input>
 *    face     :: current face object
 *    charcode :: charcode to look for
 *
 * <Return>
 *    glyph index in font face. Returns -1 if the corresponding
 *    glyph wasn't found.
 *
 *********************************************************************/

  static
  T1_Int    lookup_glyph_by_stdcharcode( T1_Face  face,
                                         T1_Int   charcode )
  {
    T1_Int              n;
    const T1_String*    glyph_name;
    PSNames_Interface*  psnames = (PSNames_Interface*)face->psnames;

    /* check range of standard char code */
    if (charcode < 0 || charcode > 255)
      return -1;

    glyph_name = psnames->adobe_std_strings(
                    psnames->adobe_std_encoding[charcode]);

    for ( n = 0; n < face->type1.num_glyphs; n++ )
    {
      T1_String*  name = (T1_String*)face->type1.glyph_names[n];

      if ( name && strcmp(name,glyph_name) == 0 )
        return n;
    }

    return -1;
  }



/*********************************************************************
 *
 * <Function>
 *    t1operator_seac
 *
 * <Description>
 *    Implements the "seac" Type 1 operator for a Type 1 decoder
 *
 * <Input>
 *    decoder  :: current Type 1 decoder
 *    asb      :: accent's side bearing
 *    adx      :: horizontal position of accent
 *    ady      :: vertical position of accent
 *    bchar    :: base character's StandardEncoding charcode
 *    achar    :: accent character's StandardEncoding charcode
 *
 * <Return>
 *    Error code. 0 means success.
 *
 *********************************************************************/

  static
  T1_Error  t1operator_seac( T1_Decoder*  decoder,
                             T1_Pos       asb,
                             T1_Pos       adx,
                             T1_Pos       ady,
                             T1_Int       bchar,
                             T1_Int       achar )
  {
    T1_Error     error;
    T1_Face      face = decoder->builder.face;
    T1_Int       bchar_index, achar_index, n_base_points;
    FT_Outline*  cur  = &decoder->builder.current;
    FT_Outline*  base = &decoder->builder.base;
    T1_Vector    left_bearing, advance;
    T1_Font*     type1 = &face->type1;

    bchar_index = lookup_glyph_by_stdcharcode( face, bchar );
    achar_index = lookup_glyph_by_stdcharcode( face, achar );

    if (bchar_index < 0 || achar_index < 0)
    {
      FT_ERROR(( "T1.Parse_Seac : invalid seac character code arguments\n" ));
      return T1_Err_Syntax_Error;
    }

    /* First load "bchar" in builder */
    /* now load the unscaled outline */
    cur->n_points   = 0;
    cur->n_contours = 0;
    cur->points     = base->points   + base->n_points;
    cur->tags      = base->tags    + base->n_points;
    cur->contours   = base->contours + base->n_contours;

    error = T1_Parse_CharStrings( decoder,
                                  type1->charstrings    [bchar_index],
                                  type1->charstrings_len[bchar_index],
                                  type1->num_subrs,
                                  type1->subrs,
                                  type1->subrs_len );
    if (error) return error;

    n_base_points   = cur->n_points;

    if ( decoder->builder.no_recurse )
    {
      /* if we're trying to load a composite glyph, do not load the */
      /* accent character and return the array of subglyphs..       */
      FT_GlyphSlot  glyph = (FT_GlyphSlot)decoder->builder.glyph;
      FT_SubGlyph*  subg;

      /* reallocate subglyph array if necessary */
      if (glyph->max_subglyphs < 2)
      {
        FT_Memory  memory = decoder->builder.face->root.memory;

        if ( REALLOC_ARRAY( glyph->subglyphs, glyph->max_subglyphs,
                            2, FT_SubGlyph ) )
          return error;

        glyph->max_subglyphs = 2;
      }

      subg = glyph->subglyphs;

      /* subglyph 0 = base character */
      subg->index = bchar_index;
      subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES |
                    FT_SUBGLYPH_FLAG_USE_MY_METRICS;
      subg->arg1  = 0;
      subg->arg2  = 0;
      subg++;

      /* subglyph 1 = accent character */
      subg->index = achar_index;
      subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES;
      subg->arg1  = adx - asb;
      subg->arg2  = ady;

      /* set up remaining glyph fields */
      glyph->num_subglyphs = 2;
      glyph->format        = ft_glyph_format_composite;
    }
    else
    {
      /* save the left bearing and width of the base character */
      /* as they will be erase by the next load..              */
      left_bearing = decoder->builder.left_bearing;
      advance      = decoder->builder.advance;

      decoder->builder.left_bearing.x = 0;
      decoder->builder.left_bearing.y = 0;

      /* Now load "achar" on top of */
      /* the base outline           */
      /*                            */
      cur->n_points   = 0;
      cur->n_contours = 0;
      cur->points     = base->points   + base->n_points;
      cur->tags      = base->tags    + base->n_points;
      cur->contours   = base->contours + base->n_contours;

      error = T1_Parse_CharStrings( decoder,
                                    type1->charstrings    [achar_index],
                                    type1->charstrings_len[achar_index],
                                    type1->num_subrs,
                                    type1->subrs,
                                    type1->subrs_len );
      if (error) return error;

      /* adjust contours in accented character outline */
      if (decoder->builder.load_points)
      {
        T1_Int  n;

        for ( n = 0; n < cur->n_contours; n++ )
          cur->contours[n] += n_base_points;
      }

      /* restore the left side bearing and   */
      /* advance width of the base character */
      decoder->builder.left_bearing = left_bearing;
      decoder->builder.advance      = advance;

      /* Finally, move the accent */
      if (decoder->builder.load_points)
        FT_Outline_Translate( cur, adx - asb, ady );
    }
    return T1_Err_Ok;
  }


/*********************************************************************
 *
 * <Function>
 *    T1_Parse_CharStrings
 *
 * <Description>
 *    Parses a given Type 1 charstrings program
 *
 * <Input>
 *    decoder          :: current Type 1 decoder
 *    charstring_base  :: base of the charstring stream
 *    charstring_len   :: length in bytes of the charstring stream
 *    num_subrs        :: number of sub-routines
 *    subrs_base       :: array of sub-routines addresses
 *    subrs_len        :: array of sub-routines lengths
 *
 * <Return>
 *    Error code. 0 means success.
 *
 *********************************************************************/

#define USE_ARGS(n)  top -= n; if (top < decoder->stack) goto Stack_Underflow

  LOCAL_FUNC
  T1_Error   T1_Parse_CharStrings( T1_Decoder*  decoder,
                                   T1_Byte*     charstring_base,
                                   T1_Int       charstring_len,
                                   T1_Int       num_subrs,
                                   T1_Byte**    subrs_base,
                                   T1_Int*      subrs_len )
  {
    T1_Error            error;
    T1_Decoder_Zone*    zone;
    T1_Byte*            ip;
    T1_Byte*            limit;
    T1_Builder*         builder = &decoder->builder;
    FT_Outline*         outline;
    T1_Pos              x, y;

    /* First of all, initialise the decoder */
    decoder->top  = decoder->stack;
    decoder->zone = decoder->zones;
    zone          = decoder->zones;

    builder->path_begun  = 0;

    zone->base           = charstring_base;
    limit = zone->limit  = charstring_base + charstring_len;
    ip    = zone->cursor = zone->base;

    error   = T1_Err_Ok;
    outline = &builder->current;

    x = builder->pos_x;
    y = builder->pos_y;

    /* now, execute loop */
    while ( ip < limit )
    {
      T1_Int*      top      = decoder->top;
      T1_Operator  op       = op_none;
      T1_Long      value    = 0;

      /********************************************************************/
      /*                                                                  */
      /* Decode operator or operand                                       */
      /*                                                                  */
      /*                                                                  */

      /* First of all, decompress operator or value */
      switch (*ip++)
      {
        case 1:  op = op_hstem;     break;

        case 3:  op = op_vstem;     break;
        case 4:  op = op_vmoveto;   break;
        case 5:  op = op_rlineto;   break;
        case 6:  op = op_hlineto;   break;
        case 7:  op = op_vlineto;   break;
        case 8:  op = op_rrcurveto; break;
        case 9:  op = op_closepath; break;
        case 10: op = op_callsubr;  break;
        case 11: op = op_return;    break;

        case 13: op = op_hsbw;      break;
        case 14: op = op_endchar;   break;

        case 21: op = op_rmoveto;   break;
        case 22: op = op_hmoveto;   break;

        case 30: op = op_vhcurveto; break;
        case 31: op = op_hvcurveto; break;

        case 12:
          {
            if (ip > limit)
            {
              FT_ERROR(( "T1.Parse_CharStrings : invalid escape (12+EOF)\n" ));
              goto Syntax_Error;
            }

            switch (*ip++)
            {
              case 0:  op = op_dotsection;      break;
              case 1:  op = op_vstem3;          break;
              case 2:  op = op_hstem3;          break;
              case 6:  op = op_seac;            break;
              case 7:  op = op_sbw;             break;
              case 12: op = op_div;             break;
              case 16: op = op_callothersubr;   break;
              case 17: op = op_pop;             break;
              case 33: op = op_setcurrentpoint; break;

              default:
                FT_ERROR(( "T1.Parse_CharStrings : invalid escape (12+%d)\n",
                         ip[-1] ));
                goto Syntax_Error;
            }
          }
          break;

        case 255:    /* four bytes integer */
          {
            if (ip+4 > limit)
            {
              FT_ERROR(( "T1.Parse_CharStrings : unexpected EOF in integer\n" ));
              goto Syntax_Error;
            }

            value = ((long)ip[0] << 24) |
                    ((long)ip[1] << 16) |
                    ((long)ip[2] << 8)  |
                           ip[3];
            ip += 4;
          }
          break;

        default:
          if (ip[-1] >= 32)
          {
            if (ip[-1] < 247)
              value = (long)ip[-1] - 139;
            else
            {
              if (++ip > limit)
              {
                FT_ERROR(( "T1.Parse_CharStrings : unexpected EOF in integer\n" ));
                goto Syntax_Error;
              }

              if (ip[-2] < 251)
                value =  ((long)(ip[-2]-247) << 8) + ip[-1] + 108;
              else
                value = -((((long)ip[-2]-251) << 8) + ip[-1] + 108 );
            }
          }
          else
          {
            FT_ERROR(( "T1.Parse_CharStrings : invalid byte (%d)\n",
                     ip[-1] ));
            goto Syntax_Error;
          }
      }

      /********************************************************************/
      /*                                                                  */
      /*  Push value on stack, or process operator                        */
      /*                                                                  */
      /*                                                                  */
      if ( op == op_none )
      {
        if ( top - decoder->stack >= T1_MAX_CHARSTRINGS_OPERANDS )
        {
          FT_ERROR(( "T1.Parse_CharStrings : Stack overflow !!\n" ));
          goto Syntax_Error;
        }

        FT_TRACE4(( " %ld", value ));
        *top++       = value;
        decoder->top = top;
      }
      else if ( op == op_callothersubr )  /* callothersubr */
      {
        FT_TRACE4(( " callothersubr" ));
        if ( top - decoder->stack < 2 )
          goto Stack_Underflow;

        top -= 2;
        switch ( top[1] )
        {
          case 1: /* start flex feature ---------------------- */
            {
              if ( top[0] != 0 ) goto Unexpected_OtherSubr;

              decoder->flex_state        = 1;
              decoder->num_flex_vectors  = 0;
              if ( start_point(builder, x, y) ||
                   check_points(builder,6) ) goto Memory_Error;
            }
            break;

          case 2: /* add flex vectors ------------------------ */
            {
              T1_Int      index;

              if ( top[0] != 0 ) goto Unexpected_OtherSubr;

              /* note that we should not add a point for index 0 */
              /* this will move our current position to the flex */
              /* point without adding any point to the outline   */
              index = decoder->num_flex_vectors++;
              if (index > 0 && index < 7)
                add_point( builder,
                           x,
                           y,
                           (T1_Byte)( index==3 || index==6 ) );
            }
            break;

          case 0: /* end flex feature ------------------------- */
            {
              if ( top[0] != 3 ) goto Unexpected_OtherSubr;

              if ( decoder->flex_state       == 0 ||
                   decoder->num_flex_vectors != 7 )
              {
                FT_ERROR(( "T1.Parse_CharStrings: unexpected flex end\n" ));
                goto Syntax_Error;
              }

              /* now consume the remaining "pop pop setcurpoint" */
              if ( ip+6 > limit ||
                   ip[0] != 12  || ip[1] != 17 || /* pop */
                   ip[2] != 12  || ip[3] != 17 || /* pop */
                   ip[4] != 12  || ip[5] != 33 )  /* setcurpoint */
              {
                FT_ERROR(( "T1.Parse_CharStrings: invalid flex charstring\n" ));
                goto Syntax_Error;
              }

              ip += 6;
              decoder->flex_state = 0;
              break;
            }

          case 3:  /* change hints ---------------------------- */
            {
              if ( top[0] != 1 ) goto Unexpected_OtherSubr;

              /* eat the following "pop" */
              if (ip+2 > limit)
              {
                FT_ERROR(( "T1.Parse_CharStrings: invalid escape (12+%d)\n",
                         ip[-1] ));
                goto Syntax_Error;
              }

              if (ip[0] != 12 || ip[1] != 17)
              {
                FT_ERROR(( "T1.Parse_CharStrings: 'pop' expected, found (%d %d)\n",
                         ip[0], ip[1] ));
                goto Syntax_Error;
              }
              ip += 2;
              break;;
            }

          case 12:
          case 13:
            {
              /* counter control hints, clear stack */
              top = decoder->stack;
              break;
            }
          
          case 14:
          case 15:
          case 16:
          case 17:
          case 18: /* multiple masters */
            {
              T1_Blend*  blend = decoder->blend;
              T1_UInt    num_points, nn, mm;
              T1_Int*    delta;
              T1_Int*    values;
              
              if (!blend)
              {
                FT_ERROR(( "T1.Parse_CharStrings: unexpected multiple masters operator !!\n" ));
                goto Syntax_Error;
              }
              
              num_points = top[1] - 13 + (top[1] == 18);
              if (top[0] != num_points*blend->num_designs)
              {
                FT_ERROR(( "T1.Parse_CharStrings: incorrect number of mm arguments\n" ));
                goto Syntax_Error;
              }
              
              top       -= blend->num_designs*num_points;
              if (top < decoder->stack)
                goto Stack_Underflow;

              /* we want to compute:                                   */
              /*                                                       */
              /*  a0*w0 + a1*w1 + ... + ak*wk                          */
              /*                                                       */
              /* but we only have the a0, a1-a0, a2-a0, .. ak-a0       */
              /* however, given that w0 + w1 + ... + wk == 1, we can   */
              /* rewrite it easily as:                                 */
              /*                                                       */
              /*  a0 + (a1-a0)*w1 + (a2-a0)*w2 + .. + (ak-a0)*wk       */
              /*                                                       */
              /* where k == num_designs-1                              */
              /*                                                       */
              /* I guess that's why it's written in this "compact"     */
              /* form..                                                */
              /*                                                       */
              /*                                                       */
              delta  = top + num_points;
              values = top;
              for ( nn = 0; nn < num_points; nn++ )
              {
                T1_Int  x = values[0];
                for ( mm = 1; mm < blend->num_designs; mm++ )
                  x += FT_MulFix( *delta++, blend->weight_vector[mm] );

                *values++ = x;
              }
              /* note that "top" will be incremented later by calls to "pop" */
              break;
            }
          
          default:
          Unexpected_OtherSubr:
            FT_ERROR(( "T1.Parse_CharStrings: invalid othersubr [%d %d]!!\n",
                       top[0], top[1] ));
            goto Syntax_Error;
        }
        decoder->top = top;
      }
      else  /* general operator */
      {
        T1_Int  num_args = t1_args_count[op];

        if ( top - decoder->stack < num_args )
          goto Stack_Underflow;

        top -= num_args;

        switch (op)
        {
          case op_endchar: /*************************************************/
          {
            FT_TRACE4(( " endchar" ));
            close_contour( builder );

            /* add current outline to the glyph slot */
            builder->base.n_points   += builder->current.n_points;
            builder->base.n_contours += builder->current.n_contours;

            /* return now !! */
            FT_TRACE4(( "\n\n" ));
            return T1_Err_Ok;
          }


          case op_hsbw: /****************************************************/
          {
            FT_TRACE4(( " hsbw" ));
            builder->left_bearing.x += top[0];
            builder->advance.x       = top[1];
            builder->advance.y       = 0;

            builder->last.x = x = top[0];
            builder->last.y = y = 0;

            /* the "metrics_only" indicates that we only want to compute */
            /* the glyph's metrics (lsb + advance width), not load the   */
            /* rest of it.. so exit immediately                          */
            if (builder->metrics_only)
              return T1_Err_Ok;

            break;
          }


          case op_seac: /****************************************************/
            /* return immediately after the processing */
            return t1operator_seac( decoder, top[0], top[1],
                                             top[2], top[3], top[4] );

          case op_sbw:  /****************************************************/
          {
            FT_TRACE4(( " sbw" ));
            builder->left_bearing.x += top[0];
            builder->left_bearing.y += top[1];
            builder->advance.x       = top[2];
            builder->advance.y       = top[3];

            builder->last.x = x = top[0];
            builder->last.y = y = top[1];

            /* the "metrics_only" indicates that we only want to compute */
            /* the glyph's metrics (lsb + advance width), not load the   */
            /* rest of it.. so exit immediately                          */
            if (builder->metrics_only)
              return T1_Err_Ok;

            break;
          }


          case op_closepath:  /**********************************************/
          {
            FT_TRACE4(( " closepath" ));
            close_contour( builder );
            builder->path_begun = 0;
          }
          break;


          case op_hlineto:  /************************************************/
          {
            FT_TRACE4(( " hlineto" ));
            if ( start_point( builder, x, y ) ) goto Memory_Error;

            x += top[0];
            goto Add_Line;
          }


          case op_hmoveto:  /************************************************/
          {
            FT_TRACE4(( " hmoveto" ));
            x += top[0];
            break;
          }


          case op_hvcurveto:  /**********************************************/
          {
            FT_TRACE4(( " hvcurveto" ));
            if ( start_point( builder, x, y ) ||
                 check_points( builder, 3 )   ) goto Memory_Error;

            x += top[0];
            add_point( builder, x, y, 0 );
            x += top[1];
            y += top[2];
            add_point( builder, x, y, 0 );
            y += top[3];
            add_point( builder, x, y, 1 );
            break;
          }


          case op_rlineto: /*************************************************/
          {
            FT_TRACE4(( " rlineto" ));
            if ( start_point( builder, x, y ) ) goto Memory_Error;

            x += top[0];
            y += top[1];
   Add_Line:
            if (add_point1( builder, x, y )) goto Memory_Error;
            break;
          }


          case op_rmoveto: /*************************************************/
          {
            FT_TRACE4(( " rmoveto" ));
            x += top[0];
            y += top[1];
            break;
          }

          case op_rrcurveto: /***********************************************/
          {
            FT_TRACE4(( " rcurveto" ));
            if ( start_point( builder, x, y ) ||
                 check_points( builder, 3 )   ) goto Memory_Error;

            x += top[0];
            y += top[1];
            add_point( builder, x, y, 0 );

            x += top[2];
            y += top[3];
            add_point( builder, x, y, 0 );

            x += top[4];
            y += top[5];
            add_point( builder, x, y, 1 );
            break;
          }


          case op_vhcurveto:  /**********************************************/
          {
            FT_TRACE4(( " vhcurveto" ));
            if ( start_point( builder, x, y ) ||
                 check_points( builder, 3 )   ) goto Memory_Error;

            y += top[0];
            add_point( builder, x, y, 0 );
            x += top[1];
            y += top[2];
            add_point( builder, x, y, 0 );
            x += top[3];
            add_point( builder, x, y, 1 );
            break;
          }


          case op_vlineto:  /************************************************/
            {
              FT_TRACE4(( " vlineto" ));
              if ( start_point( builder, x, y ) ) goto Memory_Error;

              y += top[0];
              goto Add_Line;
            }


          case op_vmoveto:  /************************************************/
            {
              FT_TRACE4(( " vmoveto" ));
              y += top[0];
              break;
            }


          case op_div:  /****************************************************/
          {
            FT_TRACE4(( " div" ));
            if (top[1])
              *top++ = top[0] / top[1];
            else
            {
              FT_ERROR(( "T1.Parse_CharStrings : division by 0\n" ));
              goto Syntax_Error;
            }
            break;
          }


          case op_callsubr:  /***********************************************/
          {
            T1_Int  index;

            FT_TRACE4(( " callsubr" ));
            index = top[0];
            if ( index < 0 || index >= num_subrs )
            {
              FT_ERROR(( "T1.Parse_CharStrings : invalid subrs index\n" ));
              goto Syntax_Error;
            }

            if ( zone - decoder->zones >= T1_MAX_SUBRS_CALLS )
            {
              FT_ERROR(( "T1.Parse_CharStrings : too many nested subrs\n" ));
              goto Syntax_Error;
            }

            zone->cursor = ip;  /* save current instruction pointer */

            zone++;
            zone->base    = subrs_base[index];
            zone->limit   = zone->base + subrs_len[index];
            zone->cursor  = zone->base;

            if (!zone->base)
            {
              FT_ERROR(( "T1.Parse_CharStrings : invoking empty subrs !!\n" ));
              goto Syntax_Error;
            }

            decoder->zone = zone;
            ip            = zone->base;
            limit         = zone->limit;
            break;
          }


          case op_pop:  /****************************************************/
          {
            FT_TRACE4(( " pop" ));
            /* theorically, the arguments are already on the stack */
            top++;
            break;
          }


          case op_return:  /************************************************/
          {
            FT_TRACE4(( " return" ));
            if ( zone <= decoder->zones )
            {
              FT_ERROR(( "T1.Parse_CharStrings : unexpected return\n" ));
              goto Syntax_Error;
            }

            zone--;
            ip            = zone->cursor;
            limit         = zone->limit;
            decoder->zone = zone;
            break;
          }

          case op_dotsection:  /*********************************************/
          {
            FT_TRACE4(( " dotsection" ));
            break;
          }

          case op_hstem:  /**************************************************/
          {
            FT_TRACE4(( " hstem" ));
            break;
          }

          case op_hstem3:  /*************************************************/
          {
            FT_TRACE4(( " hstem3" ));
            break;
          }

          case op_vstem:  /**************************************************/
          {
            FT_TRACE4(( " vstem" ));
            break;
          }

          case op_vstem3:  /*************************************************/
          {
            FT_TRACE4(( " vstem3" ));
            break;
          }

          case op_setcurrentpoint:  /*****************************************/
          {
            FT_TRACE4(( " setcurrentpoint" ));
            FT_ERROR(( "T1.Parse_CharStrings : unexpected SETCURRENTPOINT\n" ));
            goto Syntax_Error;
          }

          default:
            FT_ERROR(( "T1.Parse_CharStrings : unhandled opcode %d\n", op ));
            goto Syntax_Error;
        }

        decoder->top = top;

      } /* general operator processing */


    } /* while ip < limit */
    FT_TRACE4(( "..end..\n\n" ));
    return error;

  Syntax_Error:
    return T1_Err_Syntax_Error;

  Stack_Underflow:
    return T1_Err_Stack_Underflow;

  Memory_Error:
    return builder->error;
  }



  /**********************************************************************/
  /**********************************************************************/
  /**********************************************************************/
  /**********                                                   *********/
  /**********                                                   *********/
  /**********           COMPUTE THE MAXIMUM ADVANCE WIDTH       *********/
  /**********                                                   *********/
  /**********   The following code is in charge of computing    *********/
  /**********   the maximum advance width of the font. It       *********/
  /**********   quickly process each glyph charstring to        *********/
  /**********   extract the value from either a "sbw" or "seac" *********/
  /**********   operator.                                       *********/
  /**********                                                   *********/
  /**********************************************************************/
  /**********************************************************************/
  /**********************************************************************/

  LOCAL_FUNC
  T1_Error  T1_Compute_Max_Advance( T1_Face  face,
                                    T1_Int  *max_advance )
  {
    T1_Error    error;
    T1_Decoder  decoder;
    T1_Int      glyph_index;
    T1_Font*    type1 = &face->type1;

    *max_advance = 0;

    /* Initialise load decoder */
    T1_Init_Decoder( &decoder );
    T1_Init_Builder( &decoder.builder, face, 0, 0 );

    decoder.blend                = face->blend;
    decoder.builder.metrics_only = 1;
    decoder.builder.load_points  = 0;

    /* For each glyph, parse the glyph charstring and extract */
    /* the advance width..                                    */
    for ( glyph_index = 0; glyph_index < type1->num_glyphs; glyph_index++ )
    {
      /* now get load the unscaled outline */
      error = T1_Parse_CharStrings( &decoder,
                                    type1->charstrings    [glyph_index],
                                    type1->charstrings_len[glyph_index],
                                    type1->num_subrs,
                                    type1->subrs,
                                    type1->subrs_len );
      /* ignore the error if one occured - skip to next glyph */
    }

    *max_advance = decoder.builder.advance.x;
    return T1_Err_Ok;
  }


  /**********************************************************************/
  /**********************************************************************/
  /**********************************************************************/
  /**********                                                   *********/
  /**********                                                   *********/
  /**********              UNHINTED GLYPH LOADER                *********/
  /**********                                                   *********/
  /**********   The following code is in charge of loading a    *********/
  /**********   single outline. It completely ignores hinting   *********/
  /**********   and is used when FT_LOAD_NO_HINTING is set.     *********/
  /**********                                                   *********/
  /**********************************************************************/
  /**********************************************************************/
  /**********************************************************************/


  LOCAL_FUNC
  T1_Error  T1_Load_Glyph( T1_GlyphSlot  glyph,
                           T1_Size       size,
                           T1_Int        glyph_index,
                           T1_Int        load_flags )
  {
    T1_Error        error;
    T1_Decoder      decoder;
    T1_Face         face = (T1_Face)glyph->root.face;
    T1_Bool         hinting;
    T1_Font*        type1 = &face->type1;

    if (load_flags & FT_LOAD_NO_RECURSE)
      load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING;

    glyph->x_scale = size->root.metrics.x_scale;
    glyph->y_scale = size->root.metrics.y_scale;

    glyph->root.outline.n_points   = 0;
    glyph->root.outline.n_contours = 0;

    hinting = ( load_flags & FT_LOAD_NO_SCALE   ) == 0 &&
              ( load_flags & FT_LOAD_NO_HINTING ) == 0;

    glyph->root.format = ft_glyph_format_none;

    {
      T1_Init_Decoder( &decoder );
      T1_Init_Builder( &decoder.builder, face, size, glyph );

      decoder.blend              = ((T1_Face)glyph->root.face)->blend;
      decoder.builder.no_recurse = (FT_Bool)!!(load_flags & FT_LOAD_NO_RECURSE);

      /* now load the unscaled outline */
      error = T1_Parse_CharStrings( &decoder,
                                    type1->charstrings    [glyph_index],
                                    type1->charstrings_len[glyph_index],
                                    type1->num_subrs,
                                    type1->subrs,
                                    type1->subrs_len );

      /* save new glyph tables */
      T1_Done_Builder( &decoder.builder );
    }

    /* Now, set the metrics.. - this is rather simple, as : */
    /* the left side bearing is the xMin, and the top side  */
    /* bearing the yMax..                                   */
    if (!error)
    {
      /* for composite glyphs, return only the left side bearing and the */
      /* advance width..                                                 */
      if ( load_flags & FT_LOAD_NO_RECURSE )
      {
        glyph->root.metrics.horiBearingX = decoder.builder.left_bearing.x;
        glyph->root.metrics.horiAdvance  = decoder.builder.advance.x;
      }
      else
      {
        FT_BBox           cbox;
        FT_Glyph_Metrics* metrics = &glyph->root.metrics;

        /* copy the _unscaled_ advance width */
        metrics->horiAdvance  = decoder.builder.advance.x;

        /* make up vertical metrics */
        metrics->vertBearingX = 0;
        metrics->vertBearingY = 0;
        metrics->vertAdvance  = 0;

        glyph->root.format = ft_glyph_format_outline;

        glyph->root.outline.flags &= ft_outline_owner;
        if ( size && size->root.metrics.y_ppem < 24 )
          glyph->root.outline.flags |= ft_outline_high_precision;

        glyph->root.outline.flags |= ft_outline_reverse_fill;

        /*
        glyph->root.outline.second_pass    = TRUE;
        glyph->root.outline.high_precision = ( size->root.metrics.y_ppem < 24 );
        glyph->root.outline.dropout_mode   = 2;
        */

        if ( (load_flags & FT_LOAD_NO_SCALE) == 0 )
        {
          /* scale the outline and the metrics */
          T1_Int       n;
          FT_Outline*  cur = &decoder.builder.base;
          T1_Vector*   vec = cur->points;
          T1_Fixed     x_scale = glyph->x_scale;
          T1_Fixed     y_scale = glyph->y_scale;

          /* First of all, scale the points */
          for ( n = cur->n_points; n > 0; n--, vec++ )
          {
            vec->x = FT_MulFix( vec->x, x_scale );
            vec->y = FT_MulFix( vec->y, y_scale );
          }

          FT_Outline_Get_CBox( &glyph->root.outline, &cbox );

          /* Then scale the metrics */
          metrics->horiAdvance  = FT_MulFix( metrics->horiAdvance,  x_scale );

          metrics->vertBearingX = FT_MulFix( metrics->vertBearingX, x_scale );
          metrics->vertBearingY = FT_MulFix( metrics->vertBearingY, y_scale );
          metrics->vertAdvance  = FT_MulFix( metrics->vertAdvance,  x_scale );
        }

        /* apply the font matrix */
        FT_Outline_Transform( &glyph->root.outline, &face->type1.font_matrix );

        /* compute the other metrics */
        FT_Outline_Get_CBox( &glyph->root.outline, &cbox );

        /* grid fit the bounding box if necessary */
        if (hinting)
        {
          cbox.xMin &= -64;
          cbox.yMin &= -64;
          cbox.xMax = ( cbox.xMax+63 ) & -64;
          cbox.yMax = ( cbox.yMax+63 ) & -64;
        }

        metrics->width  = cbox.xMax - cbox.xMin;
        metrics->height = cbox.yMax - cbox.yMin;

        metrics->horiBearingX = cbox.xMin;
        metrics->horiBearingY = cbox.yMax;
      }
    }
    return error;
  }