kc3-lang/freetype/src/sfnt/sfwoff2.c

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• Hash : 16586859
  Author :
  Date : 2020-06-13T21:15:45
  

  Remove redundant inclusion of `ft2build.h'. * */*: Remove `#include <ft2build.h>' where possible. * include/freetype/freetype.h: Remove cpp error about missing inclusion of `ft2build.h'.

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• src/sfnt/sfwoff2.c

• /****************************************************************************
   *
   * sfwoff2.c
   *
   *   WOFF2 format management (base).
   *
   * Copyright (C) 2019-2020 by
   * Nikhil Ramakrishnan, 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 "sfwoff2.h"
  #include "woff2tags.h"
  #include <freetype/tttags.h>
  #include <freetype/internal/ftdebug.h>
  #include <freetype/internal/ftstream.h>
  
  
  #ifdef FT_CONFIG_OPTION_USE_BROTLI
  
  #include <brotli/decode.h>
  
  #endif
  
  
    /**************************************************************************
     *
     * 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  sfwoff2
  
  
  #define READ_255USHORT( var )  FT_SET_ERROR( Read255UShort( stream, &var ) )
  
  #define READ_BASE128( var )    FT_SET_ERROR( ReadBase128( stream, &var ) )
  
  #define ROUND4( var )          ( ( var + 3 ) & ~3 )
  
  #define WRITE_USHORT( p, v )                \
            do                                \
            {                                 \
              *(p)++ = (FT_Byte)( (v) >> 8 ); \
              *(p)++ = (FT_Byte)( (v) >> 0 ); \
                                              \
            } while ( 0 )
  
  #define WRITE_ULONG( p, v )                  \
            do                                 \
            {                                  \
              *(p)++ = (FT_Byte)( (v) >> 24 ); \
              *(p)++ = (FT_Byte)( (v) >> 16 ); \
              *(p)++ = (FT_Byte)( (v) >>  8 ); \
              *(p)++ = (FT_Byte)( (v) >>  0 ); \
                                               \
            } while ( 0 )
  
  #define WRITE_SHORT( p, v )        \
            do                       \
            {                        \
              *(p)++ = ( (v) >> 8 ); \
              *(p)++ = ( (v) >> 0 ); \
                                     \
            } while ( 0 )
  
  #define WRITE_SFNT_BUF( buf, s ) \
            write_buf( &sfnt, sfnt_size, &dest_offset, buf, s, memory )
  
  #define WRITE_SFNT_BUF_AT( offset, buf, s ) \
            write_buf( &sfnt, sfnt_size, &offset, buf, s, memory )
  
  #define N_CONTOUR_STREAM    0
  #define N_POINTS_STREAM     1
  #define FLAG_STREAM         2
  #define GLYPH_STREAM        3
  #define COMPOSITE_STREAM    4
  #define BBOX_STREAM         5
  #define INSTRUCTION_STREAM  6
  
  
    static void
    stream_close( FT_Stream  stream )
    {
      FT_Memory  memory = stream->memory;
  
  
      FT_FREE( stream->base );
  
      stream->size  = 0;
      stream->base  = NULL;
      stream->close = NULL;
    }
  
  
    FT_CALLBACK_DEF( int )
    compare_tags( const void*  a,
                  const void*  b )
    {
      WOFF2_Table  table1 = *(WOFF2_Table*)a;
      WOFF2_Table  table2 = *(WOFF2_Table*)b;
  
      FT_ULong  tag1 = table1->Tag;
      FT_ULong  tag2 = table2->Tag;
  
  
      if ( tag1 > tag2 )
        return 1;
      else if ( tag1 < tag2 )
        return -1;
      else
        return 0;
    }
  
  
    static FT_Error
    Read255UShort( FT_Stream   stream,
                   FT_UShort*  value )
    {
      static const FT_Int  oneMoreByteCode1 = 255;
      static const FT_Int  oneMoreByteCode2 = 254;
      static const FT_Int  wordCode         = 253;
      static const FT_Int  lowestUCode      = 253;
  
      FT_Error   error        = FT_Err_Ok;
      FT_Byte    code;
      FT_Byte    result_byte  = 0;
      FT_UShort  result_short = 0;
  
  
      if ( FT_READ_BYTE( code ) )
        return error;
      if ( code == wordCode )
      {
        /* Read next two bytes and store `FT_UShort' value. */
        if ( FT_READ_USHORT( result_short ) )
          return error;
        *value = result_short;
        return FT_Err_Ok;
      }
      else if ( code == oneMoreByteCode1 )
      {
        if ( FT_READ_BYTE( result_byte ) )
          return error;
        *value = result_byte + lowestUCode;
        return FT_Err_Ok;
      }
      else if ( code == oneMoreByteCode2 )
      {
        if ( FT_READ_BYTE( result_byte ) )
          return error;
        *value = result_byte + lowestUCode * 2;
        return FT_Err_Ok;
      }
      else
      {
        *value = code;
        return FT_Err_Ok;
      }
    }
  
  
    static FT_Error
    ReadBase128( FT_Stream  stream,
                 FT_ULong*  value )
    {
      FT_ULong  result = 0;
      FT_Int    i;
      FT_Byte   code;
      FT_Error  error  = FT_Err_Ok;
  
  
      for ( i = 0; i < 5; ++i )
      {
        code = 0;
        if ( FT_READ_BYTE( code ) )
          return error;
  
        /* Leading zeros are invalid. */
        if ( i == 0 && code == 0x80 )
          return FT_THROW( Invalid_Table );
  
        /* If any of top seven bits are set then we're about to overflow. */
        if ( result & 0xfe000000 )
          return FT_THROW( Invalid_Table );
  
        result = ( result << 7 ) | ( code & 0x7f );
  
        /* Spin until most significant bit of data byte is false. */
        if ( ( code & 0x80 ) == 0 )
        {
          *value = result;
          return FT_Err_Ok;
        }
      }
  
      /* Make sure not to exceed the size bound. */
      return FT_THROW( Invalid_Table );
    }
  
  
    /* Extend memory of `dst_bytes' buffer and copy data from `src'. */
    static FT_Error
    write_buf( FT_Byte**  dst_bytes,
               FT_ULong*  dst_size,
               FT_ULong*  offset,
               FT_Byte*   src,
               FT_ULong   size,
               FT_Memory  memory )
    {
      FT_Error  error = FT_Err_Ok;
      /* We are reallocating memory for `dst', so its pointer may change. */
      FT_Byte*  dst   = *dst_bytes;
  
  
      /* Check whether we are within limits. */
      if ( ( *offset + size ) > WOFF2_DEFAULT_MAX_SIZE  )
        return FT_THROW( Array_Too_Large );
  
      /* Reallocate `dst'. */
      if ( ( *offset + size ) > *dst_size )
      {
        FT_TRACE6(( "Reallocating %lu to %lu.\n",
                    *dst_size, (*offset + size) ));
        if ( FT_REALLOC( dst,
                         (FT_ULong)( *dst_size ),
                         (FT_ULong)( *offset + size ) ) )
          goto Exit;
  
        *dst_size = *offset + size;
      }
  
      /* Copy data. */
      ft_memcpy( dst + *offset, src, size );
  
      *offset += size;
      /* Set pointer of `dst' to its correct value. */
      *dst_bytes = dst;
  
    Exit:
      return error;
    }
  
  
    /* Pad buffer to closest multiple of 4. */
    static FT_Error
    pad4( FT_Byte**  sfnt_bytes,
          FT_ULong*  sfnt_size,
          FT_ULong*  out_offset,
          FT_Memory  memory )
    {
      FT_Byte*  sfnt        = *sfnt_bytes;
      FT_ULong  dest_offset = *out_offset;
  
      FT_Byte   zeroes[] = { 0, 0, 0 };
      FT_ULong  pad_bytes;
  
  
      if ( dest_offset + 3 < dest_offset )
        return FT_THROW( Invalid_Table );
  
      pad_bytes = ROUND4( dest_offset ) - dest_offset;
      if ( pad_bytes > 0 )
      {
        if ( WRITE_SFNT_BUF( &zeroes[0], pad_bytes ) )
          return FT_THROW( Invalid_Table );
      }
  
      *sfnt_bytes = sfnt;
      *out_offset = dest_offset;
      return FT_Err_Ok;
    }
  
  
    /* Calculate table checksum of `buf'. */
    static FT_Long
    compute_ULong_sum( FT_Byte*  buf,
                       FT_ULong  size )
    {
      FT_ULong  checksum     = 0;
      FT_ULong  aligned_size = size & ~3;
      FT_ULong  i;
      FT_ULong  v;
  
  
      for ( i = 0; i < aligned_size; i += 4 )
        checksum += ( (FT_ULong)buf[i    ] << 24 ) |
                    ( (FT_ULong)buf[i + 1] << 16 ) |
                    ( (FT_ULong)buf[i + 2] <<  8 ) |
                    ( (FT_ULong)buf[i + 3] <<  0 );
  
      /* If size is not aligned to 4, treat as if it is padded with 0s. */
      if ( size != aligned_size )
      {
        v = 0;
        for ( i = aligned_size ; i < size; ++i )
          v |= (FT_ULong)buf[i] << ( 24 - 8 * ( i & 3 ) );
        checksum += v;
      }
  
      return checksum;
    }
  
  
    static FT_Error
    woff2_decompress( FT_Byte*        dst,
                      FT_ULong        dst_size,
                      const FT_Byte*  src,
                      FT_ULong        src_size )
    {
  #ifdef FT_CONFIG_OPTION_USE_BROTLI
  
      FT_ULong             uncompressed_size = dst_size;
      BrotliDecoderResult  result;
  
  
      result = BrotliDecoderDecompress( src_size,
                                        src,
                                        &uncompressed_size,
                                        dst );
  
      if ( result != BROTLI_DECODER_RESULT_SUCCESS ||
           uncompressed_size != dst_size           )
      {
        FT_ERROR(( "woff2_decompress: Stream length mismatch.\n" ));
        return FT_THROW( Invalid_Table );
      }
  
      FT_TRACE2(( "woff2_decompress: Brotli stream decompressed.\n" ));
      return FT_Err_Ok;
  
  #else /* !FT_CONFIG_OPTION_USE_BROTLI */
  
      FT_ERROR(( "woff2_decompress: Brotli support not available.\n" ));
      return FT_THROW( Unimplemented_Feature );
  
  #endif /* !FT_CONFIG_OPTION_USE_BROTLI */
    }
  
  
    static WOFF2_Table
    find_table( WOFF2_Table*  tables,
                FT_UShort     num_tables,
                FT_ULong      tag )
    {
      FT_Int  i;
  
  
      for ( i = 0; i < num_tables; i++ )
      {
        if ( tables[i]->Tag == tag )
          return tables[i];
      }
      return NULL;
    }
  
  
    /* Read `numberOfHMetrics' field from `hhea' table. */
    static FT_Error
    read_num_hmetrics( FT_Stream   stream,
                       FT_UShort*  num_hmetrics )
    {
      FT_Error   error = FT_Err_Ok;
      FT_UShort  num_metrics;
  
  
      if ( FT_STREAM_SKIP( 34 )  )
        return FT_THROW( Invalid_Table );
  
      if ( FT_READ_USHORT( num_metrics ) )
        return FT_THROW( Invalid_Table );
  
      *num_hmetrics = num_metrics;
  
      return error;
    }
  
  
    /* An auxiliary function for overflow-safe addition. */
    static FT_Int
    with_sign( FT_Byte  flag,
               FT_Int   base_val )
    {
      /* Precondition: 0 <= base_val < 65536 (to avoid overflow). */
      return ( flag & 1 ) ? base_val : -base_val;
    }
  
  
    /* An auxiliary function for overflow-safe addition. */
    static FT_Int
    safe_int_addition( FT_Int   a,
                       FT_Int   b,
                       FT_Int*  result )
    {
      if ( ( ( a > 0 ) && ( b > FT_INT_MAX - a ) ) ||
           ( ( a < 0 ) && ( b < FT_INT_MIN - a ) ) )
        return FT_THROW( Invalid_Table );
  
      *result = a + b;
      return FT_Err_Ok;
    }
  
  
    /*
     * Decode variable-length (flag, xCoordinate, yCoordinate) triplet for a
     * simple glyph.  See
     *
     *   https://www.w3.org/TR/WOFF2/#triplet_decoding
     */
    static FT_Error
    triplet_decode( const FT_Byte*  flags_in,
                    const FT_Byte*  in,
                    FT_ULong        in_size,
                    FT_ULong        n_points,
                    WOFF2_Point     result,
                    FT_ULong*       in_bytes_used )
    {
      FT_Int  x = 0;
      FT_Int  y = 0;
      FT_Int  dx;
      FT_Int  dy;
      FT_Int  b0, b1, b2;
  
      FT_ULong  triplet_index = 0;
      FT_ULong  data_bytes;
  
      FT_UInt  i;
  
  
      if ( n_points > in_size )
        return FT_THROW( Invalid_Table );
  
      for ( i = 0; i < n_points; ++i )
      {
        FT_Byte  flag     = flags_in[i];
        FT_Bool  on_curve = !( flag >> 7 );
  
  
        flag &= 0x7f;
        if ( flag < 84 )
          data_bytes = 1;
        else if ( flag < 120 )
          data_bytes = 2;
        else if ( flag < 124 )
          data_bytes = 3;
        else
          data_bytes = 4;
  
        /* Overflow checks */
        if ( triplet_index + data_bytes > in_size       ||
             triplet_index + data_bytes < triplet_index )
          return FT_THROW( Invalid_Table );
  
        if ( flag < 10 )
        {
          dx = 0;
          dy = with_sign( flag,
                          ( ( flag & 14 ) << 7 ) + in[triplet_index] );
        }
        else if ( flag < 20 )
        {
          dx = with_sign( flag,
                          ( ( ( flag - 10 ) & 14 ) << 7 ) +
                            in[triplet_index] );
          dy = 0;
        }
        else if ( flag < 84 )
        {
          b0 = flag - 20;
          b1 = in[triplet_index];
          dx = with_sign( flag,
                          1 + ( b0 & 0x30 ) + ( b1 >> 4 ) );
          dy = with_sign( flag >> 1,
                          1 + ( ( b0 & 0x0c ) << 2 ) + ( b1 & 0x0f ) );
        }
        else if ( flag < 120 )
        {
          b0 = flag - 84;
          dx = with_sign( flag,
                          1 + ( ( b0 / 12 ) << 8 ) + in[triplet_index] );
          dy = with_sign( flag >> 1,
                          1 + ( ( ( b0 % 12 ) >> 2 ) << 8 ) +
                            in[triplet_index + 1] );
        }
        else if ( flag < 124 )
        {
          b2 = in[triplet_index + 1];
          dx = with_sign( flag,
                          ( in[triplet_index] << 4 ) + ( b2 >> 4 ) );
          dy = with_sign( flag >> 1,
                          ( ( b2 & 0x0f ) << 8 ) + in[triplet_index + 2] );
        }
        else
        {
          dx = with_sign( flag,
                          ( in[triplet_index] << 8 ) +
                            in[triplet_index + 1] );
          dy = with_sign( flag >> 1,
                          ( in[triplet_index + 2] << 8 ) +
                            in[triplet_index + 3] );
        }
  
        triplet_index += data_bytes;
  
        if ( safe_int_addition( x, dx, &x ) )
          return FT_THROW( Invalid_Table );
  
        if ( safe_int_addition( y, dy, &y ) )
          return FT_THROW( Invalid_Table );
  
        result[i].x        = x;
        result[i].y        = y;
        result[i].on_curve = on_curve;
      }
  
      *in_bytes_used = triplet_index;
      return FT_Err_Ok;
    }
  
  
    /* Store decoded points in glyph buffer. */
    static FT_Error
    store_points( FT_ULong           n_points,
                  const WOFF2_Point  points,
                  FT_UShort          n_contours,
                  FT_UShort          instruction_len,
                  FT_Byte*           dst,
                  FT_ULong           dst_size,
                  FT_ULong*          glyph_size )
    {
      FT_UInt   flag_offset  = 10 + ( 2 * n_contours ) + 2 + instruction_len;
      FT_Int    last_flag    = -1;
      FT_Int    repeat_count =  0;
      FT_Int    last_x       =  0;
      FT_Int    last_y       =  0;
      FT_UInt   x_bytes      =  0;
      FT_UInt   y_bytes      =  0;
      FT_UInt   xy_bytes;
      FT_UInt   i;
      FT_UInt   x_offset;
      FT_UInt   y_offset;
      FT_Byte*  pointer;
  
  
      for ( i = 0; i < n_points; ++i )
      {
        const WOFF2_PointRec  point = points[i];
  
        FT_Int  flag = point.on_curve ? GLYF_ON_CURVE : 0;
        FT_Int  dx   = point.x - last_x;
        FT_Int  dy   = point.y - last_y;
  
  
        if ( dx == 0 )
          flag |= GLYF_THIS_X_IS_SAME;
        else if ( dx > -256 && dx < 256 )
        {
          flag |= GLYF_X_SHORT | ( dx > 0 ? GLYF_THIS_X_IS_SAME : 0 );
          x_bytes += 1;
        }
        else
          x_bytes += 2;
  
        if ( dy == 0 )
          flag |= GLYF_THIS_Y_IS_SAME;
        else if ( dy > -256 && dy < 256 )
        {
          flag |= GLYF_Y_SHORT | ( dy > 0 ? GLYF_THIS_Y_IS_SAME : 0 );
          y_bytes += 1;
        }
        else
          y_bytes += 2;
  
        if ( flag == last_flag && repeat_count != 255 )
        {
          dst[flag_offset - 1] |= GLYF_REPEAT;
          repeat_count++;
        }
        else
        {
          if ( repeat_count != 0 )
          {
            if ( flag_offset >= dst_size )
              return FT_THROW( Invalid_Table );
  
            dst[flag_offset++] = repeat_count;
          }
          if ( flag_offset >= dst_size )
            return FT_THROW( Invalid_Table );
  
          dst[flag_offset++] = flag;
          repeat_count       = 0;
        }
  
        last_x    = point.x;
        last_y    = point.y;
        last_flag = flag;
      }
  
      if ( repeat_count != 0 )
      {
        if ( flag_offset >= dst_size )
          return FT_THROW( Invalid_Table );
  
        dst[flag_offset++] = repeat_count;
      }
  
      xy_bytes = x_bytes + y_bytes;
      if ( xy_bytes < x_bytes                   ||
           flag_offset + xy_bytes < flag_offset ||
           flag_offset + xy_bytes > dst_size    )
        return FT_THROW( Invalid_Table );
  
      x_offset = flag_offset;
      y_offset = flag_offset + x_bytes;
      last_x = 0;
      last_y = 0;
  
      for ( i = 0; i < n_points; ++i )
      {
        FT_Int  dx = points[i].x - last_x;
        FT_Int  dy = points[i].y - last_y;
  
  
        if ( dx == 0 )
          ;
        else if ( dx > -256 && dx < 256 )
          dst[x_offset++] = FT_ABS( dx );
        else
        {
          pointer = dst + x_offset;
          WRITE_SHORT( pointer, dx );
          x_offset += 2;
        }
  
        last_x += dx;
  
        if ( dy == 0 )
          ;
        else if ( dy > -256 && dy < 256 )
          dst[y_offset++] = FT_ABS( dy );
        else
        {
          pointer = dst + y_offset;
          WRITE_SHORT( pointer, dy );
          y_offset += 2;
        }
  
        last_y += dy;
      }
  
      *glyph_size = y_offset;
      return FT_Err_Ok;
    }
  
  
    static void
    compute_bbox( FT_ULong           n_points,
                  const WOFF2_Point  points,
                  FT_Byte*           dst,
                  FT_UShort*         src_x_min )
    {
      FT_Int  x_min = 0;
      FT_Int  y_min = 0;
      FT_Int  x_max = 0;
      FT_Int  y_max = 0;
  
      FT_UInt  i;
  
      FT_ULong  offset;
      FT_Byte*  pointer;
  
  
      if ( n_points > 0 )
      {
        x_min = points[0].x;
        y_min = points[0].y;
        x_max = points[0].x;
        y_max = points[0].y;
      }
  
      for ( i = 1; i < n_points; ++i )
      {
        FT_Int  x = points[i].x;
        FT_Int  y = points[i].y;
  
  
        x_min = FT_MIN( x, x_min );
        y_min = FT_MIN( y, y_min );
        x_max = FT_MAX( x, x_max );
        y_max = FT_MAX( y, y_max );
      }
  
      /* Write values to `glyf' record. */
      offset  = 2;
      pointer = dst + offset;
  
      WRITE_SHORT( pointer, x_min );
      WRITE_SHORT( pointer, y_min );
      WRITE_SHORT( pointer, x_max );
      WRITE_SHORT( pointer, y_max );
  
      *src_x_min = (FT_UShort)x_min;
    }
  
  
    static FT_Error
    compositeGlyph_size( FT_Stream  stream,
                         FT_ULong   offset,
                         FT_ULong*  size,
                         FT_Bool*   have_instructions )
    {
      FT_Error   error        = FT_Err_Ok;
      FT_ULong   start_offset = offset;
      FT_Bool    we_have_inst = FALSE;
      FT_UShort  flags        = FLAG_MORE_COMPONENTS;
  
  
      if ( FT_STREAM_SEEK( start_offset ) )
        goto Exit;
      while ( flags & FLAG_MORE_COMPONENTS )
      {
        FT_ULong  arg_size;
  
  
        if ( FT_READ_USHORT( flags ) )
          goto Exit;
        we_have_inst |= ( flags & FLAG_WE_HAVE_INSTRUCTIONS ) != 0;
        /* glyph index */
        arg_size = 2;
        if ( flags & FLAG_ARG_1_AND_2_ARE_WORDS )
          arg_size += 4;
        else
          arg_size += 2;
  
        if ( flags & FLAG_WE_HAVE_A_SCALE )
          arg_size += 2;
        else if ( flags & FLAG_WE_HAVE_AN_X_AND_Y_SCALE )
          arg_size += 4;
        else if ( flags & FLAG_WE_HAVE_A_TWO_BY_TWO )
          arg_size += 8;
  
        if ( FT_STREAM_SKIP( arg_size ) )
          goto Exit;
      }
  
      *size              = FT_STREAM_POS() - start_offset;
      *have_instructions = we_have_inst;
  
    Exit:
      return error;
    }
  
  
    /* Store loca values (provided by `reconstruct_glyf') to output stream. */
    static FT_Error
    store_loca( FT_ULong*  loca_values,
                FT_ULong   loca_values_size,
                FT_UShort  index_format,
                FT_ULong*  checksum,
                FT_Byte**  sfnt_bytes,
                FT_ULong*  sfnt_size,
                FT_ULong*  out_offset,
                FT_Memory  memory )
    {
      FT_Error  error       = FT_Err_Ok;
      FT_Byte*  sfnt        = *sfnt_bytes;
      FT_ULong  dest_offset = *out_offset;
  
      FT_Byte*  loca_buf = NULL;
      FT_Byte*  dst      = NULL;
  
      FT_UInt   i = 0;
      FT_ULong  loca_buf_size;
  
      const FT_ULong  offset_size = index_format ? 4 : 2;
  
  
      if ( ( loca_values_size << 2 ) >> 2 != loca_values_size )
        goto Fail;
  
      loca_buf_size = loca_values_size * offset_size;
      if ( FT_NEW_ARRAY( loca_buf, loca_buf_size ) )
        goto Fail;
  
      dst = loca_buf;
      for ( i = 0; i < loca_values_size; i++ )
      {
        FT_ULong  value = loca_values[i];
  
  
        if ( index_format )
          WRITE_ULONG( dst, value );
        else
          WRITE_USHORT( dst, ( value >> 1 ) );
      }
  
      *checksum = compute_ULong_sum( loca_buf, loca_buf_size );
      /* Write `loca' table to sfnt buffer. */
      if ( WRITE_SFNT_BUF( loca_buf, loca_buf_size ) )
        goto Fail;
  
      /* Set pointer `sfnt_bytes' to its correct value. */
      *sfnt_bytes = sfnt;
      *out_offset = dest_offset;
  
      FT_FREE( loca_buf );
      return error;
  
    Fail:
      if ( !error )
        error = FT_THROW( Invalid_Table );
  
      FT_FREE( loca_buf );
  
      return error;
    }
  
  
    static FT_Error
    reconstruct_glyf( FT_Stream    stream,
                      FT_ULong*    glyf_checksum,
                      FT_ULong*    loca_checksum,
                      FT_Byte**    sfnt_bytes,
                      FT_ULong*    sfnt_size,
                      FT_ULong*    out_offset,
                      WOFF2_Info   info,
                      FT_Memory    memory )
    {
      FT_Error  error = FT_Err_Ok;
      FT_Byte*  sfnt  = *sfnt_bytes;
  
      /* current position in stream */
      const FT_ULong  pos = FT_STREAM_POS();
  
      FT_UInt  num_substreams = 7;
  
      FT_UShort  num_glyphs;
      FT_UShort  index_format;
      FT_ULong   expected_loca_length;
      FT_UInt    offset;
      FT_UInt    i;
      FT_ULong   points_size;
      FT_ULong   bitmap_length;
      FT_ULong   glyph_buf_size;
      FT_ULong   bbox_bitmap_offset;
  
      const FT_ULong  glyf_start  = *out_offset;
      FT_ULong        dest_offset = *out_offset;
  
      WOFF2_Substream  substreams = NULL;
  
      FT_ULong*    loca_values  = NULL;
      FT_UShort*   n_points_arr = NULL;
      FT_Byte*     glyph_buf    = NULL;
      WOFF2_Point  points       = NULL;
  
  
      if ( FT_NEW_ARRAY( substreams, num_substreams ) )
        goto Fail;
  
      if ( FT_STREAM_SKIP( 4 ) )
        goto Fail;
      if ( FT_READ_USHORT( num_glyphs ) )
        goto Fail;
      if ( FT_READ_USHORT( index_format ) )
        goto Fail;
  
      FT_TRACE4(( "num_glyphs = %u; index_format = %u\n",
                  num_glyphs, index_format ));
  
      info->num_glyphs = num_glyphs;
  
      /* Calculate expected length of loca and compare.          */
      /* See https://www.w3.org/TR/WOFF2/#conform-mustRejectLoca */
      /* index_format = 0 => Short version `loca'.               */
      /* index_format = 1 => Long version `loca'.                */
      expected_loca_length = ( index_format ? 4 : 2 ) *
                               ( (FT_ULong)num_glyphs + 1 );
      if ( info->loca_table->dst_length != expected_loca_length )
        goto Fail;
  
      offset = ( 2 + num_substreams ) * 4;
      if ( offset > info->glyf_table->TransformLength )
        goto Fail;
  
      for ( i = 0; i < num_substreams; ++i )
      {
        FT_ULong  substream_size;
  
  
        if ( FT_READ_ULONG( substream_size ) )
          goto Fail;
        if ( substream_size > info->glyf_table->TransformLength - offset )
          goto Fail;
  
        substreams[i].start  = pos + offset;
        substreams[i].offset = pos + offset;
        substreams[i].size   = substream_size;
  
        FT_TRACE5(( "  Substream %d: offset = %lu; size = %lu;\n",
                    i, substreams[i].offset, substreams[i].size ));
        offset += substream_size;
      }
  
      if ( FT_NEW_ARRAY( loca_values, num_glyphs + 1 ) )
        goto Fail;
  
      points_size        = 0;
      bbox_bitmap_offset = substreams[BBOX_STREAM].offset;
  
      /* Size of bboxBitmap = 4 * floor((numGlyphs + 31) / 32) */
      bitmap_length                   = ( ( num_glyphs + 31 ) >> 5 ) << 2;
      substreams[BBOX_STREAM].offset += bitmap_length;
  
      glyph_buf_size = WOFF2_DEFAULT_GLYPH_BUF;
      if ( FT_NEW_ARRAY( glyph_buf, glyph_buf_size ) )
        goto Fail;
  
      if ( FT_NEW_ARRAY( info->x_mins, num_glyphs ) )
        goto Fail;
  
      for ( i = 0; i < num_glyphs; ++i )
      {
        FT_ULong   glyph_size = 0;
        FT_UShort  n_contours = 0;
        FT_Bool    have_bbox  = FALSE;
        FT_Byte    bbox_bitmap;
        FT_ULong   bbox_offset;
        FT_UShort  x_min      = 0;
  
  
        /* Set `have_bbox'. */
        bbox_offset = bbox_bitmap_offset + ( i >> 3 );
        if ( FT_STREAM_SEEK( bbox_offset ) ||
             FT_READ_BYTE( bbox_bitmap )   )
          goto Fail;
        if ( bbox_bitmap & ( 0x80 >> ( i & 7 ) ) )
          have_bbox = TRUE;
  
        /* Read value from `nContourStream'. */
        if ( FT_STREAM_SEEK( substreams[N_CONTOUR_STREAM].offset ) ||
             FT_READ_USHORT( n_contours )                          )
          goto Fail;
        substreams[N_CONTOUR_STREAM].offset += 2;
  
        if ( n_contours == 0xffff )
        {
          /* composite glyph */
          FT_Bool    have_instructions = FALSE;
          FT_UShort  instruction_size  = 0;
          FT_ULong   composite_size;
          FT_ULong   size_needed;
          FT_Byte*   pointer           = NULL;
  
  
          /* Composite glyphs must have explicit bbox. */
          if ( !have_bbox )
            goto Fail;
  
          if ( compositeGlyph_size( stream,
                                    substreams[COMPOSITE_STREAM].offset,
                                    &composite_size,
                                    &have_instructions) )
            goto Fail;
  
          if ( have_instructions )
          {
            if ( FT_STREAM_SEEK( substreams[GLYPH_STREAM].offset ) ||
                 READ_255USHORT( instruction_size )                )
              goto Fail;
            substreams[GLYPH_STREAM].offset = FT_STREAM_POS();
          }
  
          size_needed = 12 + composite_size + instruction_size;
          if ( glyph_buf_size < size_needed )
          {
            if ( FT_RENEW_ARRAY( glyph_buf, glyph_buf_size, size_needed ) )
              goto Fail;
            glyph_buf_size = size_needed;
          }
  
          pointer = glyph_buf + glyph_size;
          WRITE_USHORT( pointer, n_contours );
          glyph_size += 2;
  
          /* Read x_min for current glyph. */
          if ( FT_STREAM_SEEK( substreams[BBOX_STREAM].offset ) ||
               FT_READ_USHORT( x_min )                          )
            goto Fail;
          /* No increment here because we read again. */
  
          if ( FT_STREAM_SEEK( substreams[BBOX_STREAM].offset ) ||
               FT_STREAM_READ( glyph_buf + glyph_size, 8 )      )
            goto Fail;
  
          substreams[BBOX_STREAM].offset += 8;
          glyph_size                     += 8;
  
          if ( FT_STREAM_SEEK( substreams[COMPOSITE_STREAM].offset )    ||
               FT_STREAM_READ( glyph_buf + glyph_size, composite_size ) )
            goto Fail;
  
          substreams[COMPOSITE_STREAM].offset += composite_size;
          glyph_size                          += composite_size;
  
          if ( have_instructions )
          {
            pointer = glyph_buf + glyph_size;
            WRITE_USHORT( pointer, instruction_size );
            glyph_size += 2;
  
            if ( FT_STREAM_SEEK( substreams[INSTRUCTION_STREAM].offset )    ||
                 FT_STREAM_READ( glyph_buf + glyph_size, instruction_size ) )
              goto Fail;
  
            substreams[INSTRUCTION_STREAM].offset += instruction_size;
            glyph_size                            += instruction_size;
          }
        }
        else if ( n_contours > 0 )
        {
          /* simple glyph */
          FT_ULong   total_n_points = 0;
          FT_UShort  n_points_contour;
          FT_UInt    j;
          FT_ULong   flag_size;
          FT_ULong   triplet_size;
          FT_ULong   triplet_bytes_used;
          FT_Byte*   flags_buf   = NULL;
          FT_Byte*   triplet_buf = NULL;
          FT_UShort  instruction_size;
          FT_ULong   size_needed;
          FT_Int     end_point;
          FT_UInt    contour_ix;
  
          FT_Byte*   pointer = NULL;
  
  
          if ( FT_NEW_ARRAY( n_points_arr, n_contours ) )
            goto Fail;
  
          if ( FT_STREAM_SEEK( substreams[N_POINTS_STREAM].offset ) )
            goto Fail;
  
          for ( j = 0; j < n_contours; ++j )
          {
            if ( READ_255USHORT( n_points_contour ) )
              goto Fail;
            n_points_arr[j] = n_points_contour;
            /* Prevent negative/overflow. */
            if ( total_n_points + n_points_contour < total_n_points )
              goto Fail;
            total_n_points += n_points_contour;
          }
          substreams[N_POINTS_STREAM].offset = FT_STREAM_POS();
  
          flag_size = total_n_points;
          if ( flag_size > substreams[FLAG_STREAM].size )
            goto Fail;
  
          flags_buf   = stream->base + substreams[FLAG_STREAM].offset;
          triplet_buf = stream->base + substreams[GLYPH_STREAM].offset;
  
          if ( substreams[GLYPH_STREAM].size <
                 ( substreams[GLYPH_STREAM].offset -
                   substreams[GLYPH_STREAM].start ) )
            goto Fail;
  
          triplet_size       = substreams[GLYPH_STREAM].size -
                                 ( substreams[GLYPH_STREAM].offset -
                                   substreams[GLYPH_STREAM].start );
          triplet_bytes_used = 0;
  
          /* Create array to store point information. */
          points_size = total_n_points;
          if ( FT_NEW_ARRAY( points, points_size ) )
            goto Fail;
  
          if ( triplet_decode( flags_buf,
                               triplet_buf,
                               triplet_size,
                               total_n_points,
                               points,
                               &triplet_bytes_used ) )
            goto Fail;
  
          substreams[FLAG_STREAM].offset  += flag_size;
          substreams[GLYPH_STREAM].offset += triplet_bytes_used;
  
          if ( FT_STREAM_SEEK( substreams[GLYPH_STREAM].offset ) ||
               READ_255USHORT( instruction_size )                )
            goto Fail;
  
          substreams[GLYPH_STREAM].offset = FT_STREAM_POS();
  
          if ( total_n_points >= ( 1 << 27 ) )
            goto Fail;
  
          size_needed = 12 +
                        ( 2 * n_contours ) +
                        ( 5 * total_n_points ) +
                        instruction_size;
          if ( glyph_buf_size < size_needed )
          {
            if ( FT_RENEW_ARRAY( glyph_buf, glyph_buf_size, size_needed ) )
              goto Fail;
            glyph_buf_size = size_needed;
          }
  
          pointer = glyph_buf + glyph_size;
          WRITE_USHORT( pointer, n_contours );
          glyph_size += 2;
  
          if ( have_bbox )
          {
            /* Read x_min for current glyph. */
            if ( FT_STREAM_SEEK( substreams[BBOX_STREAM].offset ) ||
                 FT_READ_USHORT( x_min )                          )
              goto Fail;
            /* No increment here because we read again. */
  
            if ( FT_STREAM_SEEK( substreams[BBOX_STREAM].offset ) ||
                 FT_STREAM_READ( glyph_buf + glyph_size, 8 )      )
              goto Fail;
            substreams[BBOX_STREAM].offset += 8;
          }
          else
            compute_bbox( total_n_points, points, glyph_buf, &x_min );
  
          glyph_size = CONTOUR_OFFSET_END_POINT;
  
          pointer   = glyph_buf + glyph_size;
          end_point = -1;
  
          for ( contour_ix = 0; contour_ix < n_contours; ++contour_ix )
          {
            end_point += n_points_arr[contour_ix];
            if ( end_point >= 65536 )
              goto Fail;
  
            WRITE_SHORT( pointer, end_point );
            glyph_size += 2;
          }
  
          WRITE_USHORT( pointer, instruction_size );
          glyph_size += 2;
  
          if ( FT_STREAM_SEEK( substreams[INSTRUCTION_STREAM].offset )    ||
               FT_STREAM_READ( glyph_buf + glyph_size, instruction_size ) )
            goto Fail;
  
          substreams[INSTRUCTION_STREAM].offset += instruction_size;
          glyph_size                            += instruction_size;
  
          if ( store_points( total_n_points,
                             points,
                             n_contours,
                             instruction_size,
                             glyph_buf,
                             glyph_buf_size,
                             &glyph_size ) )
            goto Fail;
  
          FT_FREE( points );
          FT_FREE( n_points_arr );
        }
        else
        {
          /* Empty glyph.          */
          /* Must not have a bbox. */
          if ( have_bbox )
          {
            FT_ERROR(( "Empty glyph has a bbox.\n" ));
            goto Fail;
          }
        }
  
        loca_values[i] = dest_offset - glyf_start;
  
        if ( WRITE_SFNT_BUF( glyph_buf, glyph_size ) )
          goto Fail;
  
        if ( pad4( &sfnt, sfnt_size, &dest_offset, memory ) )
          goto Fail;
  
        *glyf_checksum += compute_ULong_sum( glyph_buf, glyph_size );
  
        /* Store x_mins, may be required to reconstruct `hmtx'. */
        if ( n_contours > 0 )
          info->x_mins[i] = x_min;
      }
  
      info->glyf_table->dst_length = dest_offset - info->glyf_table->dst_offset;
      info->loca_table->dst_offset = dest_offset;
  
      /* `loca[n]' will be equal to the length of the `glyf' table. */
      loca_values[num_glyphs] = info->glyf_table->dst_length;
  
      if ( store_loca( loca_values,
                       num_glyphs + 1,
                       index_format,
                       loca_checksum,
                       &sfnt,
                       sfnt_size,
                       &dest_offset,
                       memory ) )
        goto Fail;
  
      info->loca_table->dst_length = dest_offset - info->loca_table->dst_offset;
  
      FT_TRACE4(( "  loca table info:\n" ));
      FT_TRACE4(( "    dst_offset = %lu\n", info->loca_table->dst_offset ));
      FT_TRACE4(( "    dst_length = %lu\n", info->loca_table->dst_length ));
      FT_TRACE4(( "    checksum = %09x\n", *loca_checksum ));
  
      /* Set pointer `sfnt_bytes' to its correct value. */
      *sfnt_bytes = sfnt;
      *out_offset = dest_offset;
  
      FT_FREE( substreams );
      FT_FREE( loca_values );
      FT_FREE( n_points_arr );
      FT_FREE( glyph_buf );
      FT_FREE( points );
  
      return error;
  
    Fail:
      if ( !error )
        error = FT_THROW( Invalid_Table );
  
      /* Set pointer `sfnt_bytes' to its correct value. */
      *sfnt_bytes = sfnt;
  
      FT_FREE( substreams );
      FT_FREE( loca_values );
      FT_FREE( n_points_arr );
      FT_FREE( glyph_buf );
      FT_FREE( points );
  
      return error;
    }
  
  
    /* Get `x_mins' for untransformed `glyf' table. */
    static FT_Error
    get_x_mins( FT_Stream     stream,
                WOFF2_Table*  tables,
                FT_UShort     num_tables,
                WOFF2_Info    info,
                FT_Memory     memory )
    {
      FT_UShort  num_glyphs;
      FT_UShort  index_format;
      FT_ULong   glyf_offset;
      FT_UShort  glyf_offset_short;
      FT_ULong   loca_offset;
      FT_Int     i;
      FT_Error   error = FT_Err_Ok;
      FT_ULong   offset_size;
  
      /* At this point of time those tables might not have been read yet. */
      const WOFF2_Table  maxp_table = find_table( tables, num_tables,
                                                  TTAG_maxp );
      const WOFF2_Table  head_table = find_table( tables, num_tables,
                                                  TTAG_head );
  
  
      if ( !maxp_table )
      {
        FT_ERROR(( "`maxp' table is missing.\n" ));
        return FT_THROW( Invalid_Table );
      }
  
      if ( !head_table )
      {
        FT_ERROR(( "`head' table is missing.\n" ));
        return FT_THROW( Invalid_Table );
      }
  
      /* Read `numGlyphs' field from `maxp' table. */
      if ( FT_STREAM_SEEK( maxp_table->src_offset ) || FT_STREAM_SKIP( 8 ) )
        return error;
  
      if ( FT_READ_USHORT( num_glyphs ) )
        return error;
  
      info->num_glyphs = num_glyphs;
  
      /* Read `indexToLocFormat' field from `head' table. */
      if ( FT_STREAM_SEEK( head_table->src_offset ) ||
           FT_STREAM_SKIP( 50 )                     )
        return error;
  
      if ( FT_READ_USHORT( index_format ) )
        return error;
  
      offset_size = index_format ? 4 : 2;
  
      /* Create `x_mins' array. */
      if ( FT_NEW_ARRAY( info->x_mins, num_glyphs ) )
        return error;
  
      loca_offset = info->loca_table->src_offset;
  
      for ( i = 0; i < num_glyphs; ++i )
      {
        if ( FT_STREAM_SEEK( loca_offset ) )
          return error;
  
        loca_offset += offset_size;
  
        if ( index_format )
        {
          if ( FT_READ_ULONG( glyf_offset ) )
            return error;
        }
        else
        {
          if ( FT_READ_USHORT( glyf_offset_short ) )
            return error;
  
          glyf_offset = (FT_ULong)( glyf_offset_short );
          glyf_offset = glyf_offset << 1;
        }
  
        glyf_offset += info->glyf_table->src_offset;
  
        if ( FT_STREAM_SEEK( glyf_offset ) || FT_STREAM_SKIP( 2 ) )
          return error;
  
        if ( FT_READ_USHORT( info->x_mins[i] ) )
          return error;
      }
  
      return error;
    }
  
  
    static FT_Error
    reconstruct_hmtx( FT_Stream  stream,
                      FT_UShort  num_glyphs,
                      FT_UShort  num_hmetrics,
                      FT_Short*  x_mins,
                      FT_ULong*  checksum,
                      FT_Byte**  sfnt_bytes,
                      FT_ULong*  sfnt_size,
                      FT_ULong*  out_offset,
                      FT_Memory  memory )
    {
      FT_Error  error       = FT_Err_Ok;
      FT_Byte*  sfnt        = *sfnt_bytes;
      FT_ULong  dest_offset = *out_offset;
  
      FT_Byte   hmtx_flags;
      FT_Bool   has_proportional_lsbs, has_monospace_lsbs;
      FT_ULong  hmtx_table_size;
      FT_Int    i;
  
      FT_UShort*  advance_widths = NULL;
      FT_Short*   lsbs           = NULL;
      FT_Byte*    hmtx_table     = NULL;
      FT_Byte*    dst            = NULL;
  
  
      if ( FT_READ_BYTE( hmtx_flags ) )
        goto Fail;
  
      has_proportional_lsbs = ( hmtx_flags & 1 ) == 0;
      has_monospace_lsbs    = ( hmtx_flags & 2 ) == 0;
  
      /* Bits 2-7 are reserved and MUST be zero. */
      if ( ( hmtx_flags & 0xFC ) != 0 )
        goto Fail;
  
      /* Are you REALLY transformed? */
      if ( has_proportional_lsbs && has_monospace_lsbs )
        goto Fail;
  
      /* Cannot have a transformed `hmtx' without `glyf'. */
      if ( ( num_hmetrics > num_glyphs ) ||
           ( num_hmetrics < 1 )          )
        goto Fail;
  
      /* Must have at least one entry. */
      if ( num_hmetrics < 1 )
        goto Fail;
  
      if ( FT_NEW_ARRAY( advance_widths, num_hmetrics ) ||
           FT_NEW_ARRAY( lsbs, num_glyphs )             )
        goto Fail;
  
      /* Read `advanceWidth' stream.  Always present. */
      for ( i = 0; i < num_hmetrics; i++ )
      {
        FT_UShort  advance_width;
  
  
        if ( FT_READ_USHORT( advance_width ) )
          goto Fail;
  
        advance_widths[i] = advance_width;
      }
  
      /* lsb values for proportional glyphs. */
      for ( i = 0; i < num_hmetrics; i++ )
      {
        FT_Short  lsb;
  
  
        if ( has_proportional_lsbs )
        {
          if ( FT_READ_SHORT( lsb ) )
            goto Fail;
        }
        else
          lsb = x_mins[i];
  
        lsbs[i] = lsb;
      }
  
      /* lsb values for monospaced glyphs. */
      for ( i = num_hmetrics; i < num_glyphs; i++ )
      {
        FT_Short  lsb;
  
  
        if ( has_monospace_lsbs )
        {
          if ( FT_READ_SHORT( lsb ) )
            goto Fail;
        }
        else
          lsb = x_mins[i];
  
        lsbs[i] = lsb;
      }
  
      /* Build the hmtx table. */
      hmtx_table_size = 2 * num_hmetrics + 2 * num_glyphs;
      if ( FT_NEW_ARRAY( hmtx_table, hmtx_table_size ) )
        goto Fail;
  
      dst = hmtx_table;
      FT_TRACE6(( "hmtx values: \n" ));
      for ( i = 0; i < num_glyphs; i++ )
      {
        if ( i < num_hmetrics )
        {
          WRITE_SHORT( dst, advance_widths[i] );
          FT_TRACE6(( "%d ", advance_widths[i] ));
        }
  
        WRITE_SHORT( dst, lsbs[i] );
        FT_TRACE6(( "%d ", lsbs[i] ));
      }
      FT_TRACE6(( "\n" ));
  
      *checksum = compute_ULong_sum( hmtx_table, hmtx_table_size );
      /* Write `hmtx' table to sfnt buffer. */
      if ( WRITE_SFNT_BUF( hmtx_table, hmtx_table_size ) )
        goto Fail;
  
      /* Set pointer `sfnt_bytes' to its correct value. */
      *sfnt_bytes = sfnt;
      *out_offset = dest_offset;
  
      FT_FREE( advance_widths );
      FT_FREE( lsbs );
      FT_FREE( hmtx_table );
  
      return error;
  
    Fail:
      FT_FREE( advance_widths );
      FT_FREE( lsbs );
      FT_FREE( hmtx_table );
  
      if ( !error )
        error = FT_THROW( Invalid_Table );
  
      return error;
    }
  
  
    static FT_Error
    reconstruct_font( FT_Byte*      transformed_buf,
                      FT_ULong      transformed_buf_size,
                      WOFF2_Table*  indices,
                      WOFF2_Header  woff2,
                      WOFF2_Info    info,
                      FT_Byte**     sfnt_bytes,
                      FT_ULong*     sfnt_size,
                      FT_Memory     memory )
    {
      /* Memory management of `transformed_buf' is handled by the caller. */
  
      FT_Error   error       = FT_Err_Ok;
      FT_Stream  stream      = NULL;
      FT_Byte*   buf_cursor  = NULL;
      FT_Byte*   table_entry = NULL;
  
      /* We are reallocating memory for `sfnt', so its pointer may change. */
      FT_Byte*   sfnt = *sfnt_bytes;
  
      FT_UShort  num_tables  = woff2->num_tables;
      FT_ULong   dest_offset = 12 + num_tables * 16UL;
  
      FT_ULong   checksum      = 0;
      FT_ULong   loca_checksum = 0;
      FT_Int     nn            = 0;
      FT_UShort  num_hmetrics  = 0;
      FT_ULong   font_checksum = info->header_checksum;
      FT_Bool    is_glyf_xform = FALSE;
  
      FT_ULong  table_entry_offset = 12;
  
  
      /* A few table checks before reconstruction. */
      /* `glyf' must be present with `loca'.       */
      info->glyf_table = find_table( indices, num_tables, TTAG_glyf );
      info->loca_table = find_table( indices, num_tables, TTAG_loca );
  
      if ( ( info->glyf_table == NULL ) ^ ( info->loca_table == NULL ) )
      {
        FT_ERROR(( "One of `glyf'/`loca' tables missing.\n" ));
        return FT_THROW( Invalid_Table );
      }
  
      /* Both `glyf' and `loca' must have same transformation. */
      if ( info->glyf_table != NULL )
      {
        if ( ( info->glyf_table->flags & WOFF2_FLAGS_TRANSFORM ) !=
             ( info->loca_table->flags & WOFF2_FLAGS_TRANSFORM ) )
        {
          FT_ERROR(( "Transformation mismatch"
                     " between `glyf' and `loca' table." ));
          return FT_THROW( Invalid_Table );
        }
      }
  
      /* Create buffer for table entries. */
      if ( FT_NEW_ARRAY( table_entry, 16 ) )
        goto Fail;
  
      /* Create a stream for the uncompressed buffer. */
      if ( FT_NEW( stream ) )
        goto Fail;
      FT_Stream_OpenMemory( stream, transformed_buf, transformed_buf_size );
  
      FT_ASSERT( FT_STREAM_POS() == 0 );
  
      /* Reconstruct/copy tables to output stream. */
      for ( nn = 0; nn < num_tables; nn++ )
      {
        WOFF2_TableRec  table = *( indices[nn] );
  
  
        FT_TRACE3(( "Seeking to %d with table size %d.\n",
                    table.src_offset, table.src_length ));
        FT_TRACE3(( "Table tag: %c%c%c%c.\n",
                    (FT_Char)( table.Tag >> 24 ),
                    (FT_Char)( table.Tag >> 16 ),
                    (FT_Char)( table.Tag >> 8  ),
                    (FT_Char)( table.Tag       ) ));
  
        if ( FT_STREAM_SEEK( table.src_offset ) )
          goto Fail;
  
        if ( table.src_offset + table.src_length > transformed_buf_size )
          goto Fail;
  
        /* Get stream size for fields of `hmtx' table. */
        if ( table.Tag == TTAG_hhea )
        {
          if ( read_num_hmetrics( stream, &num_hmetrics ) )
            goto Fail;
        }
  
        info->num_hmetrics = num_hmetrics;
  
        checksum = 0;
        if ( ( table.flags & WOFF2_FLAGS_TRANSFORM ) != WOFF2_FLAGS_TRANSFORM )
        {
          /* Check whether `head' is at least 12 bytes. */
          if ( table.Tag == TTAG_head )
          {
            if ( table.src_length < 12 )
              goto Fail;
  
            buf_cursor = transformed_buf + table.src_offset + 8;
            /* Set checkSumAdjustment = 0 */
            WRITE_ULONG( buf_cursor, 0 );
          }
  
          table.dst_offset = dest_offset;
  
          checksum = compute_ULong_sum( transformed_buf + table.src_offset,
                                        table.src_length );
          FT_TRACE4(( "Checksum = %09x.\n", checksum ));
  
          if ( WRITE_SFNT_BUF( transformed_buf + table.src_offset,
                               table.src_length ) )
            goto Fail;
        }
        else
        {
          FT_TRACE3(( "This table is transformed.\n" ));
  
          if ( table.Tag == TTAG_glyf )
          {
            is_glyf_xform    = TRUE;
            table.dst_offset = dest_offset;
  
            if ( reconstruct_glyf( stream,
                                   &checksum,
                                   &loca_checksum,
                                   &sfnt,
                                   sfnt_size,
                                   &dest_offset,
                                   info,
                                   memory ) )
              goto Fail;
  
            FT_TRACE4(( "Checksum = %09x.\n", checksum ));
          }
  
          else if ( table.Tag == TTAG_loca )
            checksum = loca_checksum;
  
          else if ( table.Tag == TTAG_hmtx )
          {
            /* If glyf is not transformed and hmtx is, handle separately. */
            if ( !is_glyf_xform )
            {
              if ( get_x_mins( stream, indices, num_tables, info, memory ) )
                goto Fail;
            }
  
            table.dst_offset = dest_offset;
  
            if ( reconstruct_hmtx( stream,
                                   info->num_glyphs,
                                   info->num_hmetrics,
                                   info->x_mins,
                                   &checksum,
                                   &sfnt,
                                   sfnt_size,
                                   &dest_offset,
                                   memory ) )
              goto Fail;
          }
          else
          {
            /* Unknown transform. */
            FT_ERROR(( "Unknown table transform.\n" ));
            goto Fail;
          }
        }
  
        font_checksum += checksum;
  
        buf_cursor = &table_entry[0];
        WRITE_ULONG( buf_cursor, table.Tag );
        WRITE_ULONG( buf_cursor, checksum );
        WRITE_ULONG( buf_cursor, table.dst_offset );
        WRITE_ULONG( buf_cursor, table.dst_length );
  
        WRITE_SFNT_BUF_AT( table_entry_offset, table_entry, 16 );
  
        /* Update checksum. */
        font_checksum += compute_ULong_sum( table_entry, 16 );
  
        if ( pad4( &sfnt, sfnt_size, &dest_offset, memory ) )
          goto Fail;
  
        /* Sanity check. */
        if ( (FT_ULong)( table.dst_offset + table.dst_length ) > dest_offset )
        {
          FT_ERROR(( "Table was partially written.\n" ));
          goto Fail;
        }
      }
  
      /* Update `head' checkSumAdjustment. */
      info->head_table = find_table( indices, num_tables, TTAG_head );
      if ( !info->head_table )
      {
        FT_ERROR(( "`head' table is missing.\n" ));
        goto Fail;
      }
  
      if ( info->head_table->dst_length < 12 )
        goto Fail;
  
      buf_cursor    = sfnt + info->head_table->dst_offset + 8;
      font_checksum = 0xB1B0AFBA - font_checksum;
  
      WRITE_ULONG( buf_cursor, font_checksum );
  
      FT_TRACE2(( "Final checksum = %09x.\n", font_checksum ));
  
      woff2->actual_sfnt_size = dest_offset;
  
      /* Set pointer of sfnt stream to its correct value. */
      *sfnt_bytes = sfnt;
  
      FT_FREE( table_entry );
      FT_Stream_Close( stream );
      FT_FREE( stream );
  
      return error;
  
    Fail:
      if ( !error )
        error = FT_THROW( Invalid_Table );
  
      /* Set pointer of sfnt stream to its correct value. */
      *sfnt_bytes = sfnt;
  
      FT_FREE( table_entry );
      FT_Stream_Close( stream );
      FT_FREE( stream );
  
      return error;
    }
  
  
    /* Replace `face->root.stream' with a stream containing the extracted */
    /* SFNT of a WOFF2 font.                                              */
  
    FT_LOCAL_DEF( FT_Error )
    woff2_open_font( FT_Stream  stream,
                     TT_Face    face,
                     FT_Int*    face_instance_index,
                     FT_Long*   num_faces )
    {
      FT_Memory  memory = stream->memory;
      FT_Error   error  = FT_Err_Ok;
      FT_Int     face_index;
  
      WOFF2_HeaderRec  woff2;
      WOFF2_InfoRec    info         = { 0, 0, 0, NULL, NULL, NULL, NULL };
      WOFF2_Table      tables       = NULL;
      WOFF2_Table*     indices      = NULL;
      WOFF2_Table*     temp_indices = NULL;
      WOFF2_Table      last_table;
  
      FT_Int     nn;
      FT_ULong   j;
      FT_ULong   flags;
      FT_UShort  xform_version;
      FT_ULong   src_offset = 0;
  
      FT_UInt    glyf_index;
      FT_UInt    loca_index;
      FT_UInt32  file_offset;
  
      FT_Byte*   sfnt        = NULL;
      FT_Stream  sfnt_stream = NULL;
      FT_Byte*   sfnt_header;
      FT_ULong   sfnt_size;
  
      FT_Byte*  uncompressed_buf = NULL;
  
      static const FT_Frame_Field  woff2_header_fields[] =
      {
  #undef  FT_STRUCTURE
  #define FT_STRUCTURE  WOFF2_HeaderRec
  
        FT_FRAME_START( 48 ),
          FT_FRAME_ULONG     ( signature ),
          FT_FRAME_ULONG     ( flavor ),
          FT_FRAME_ULONG     ( length ),
          FT_FRAME_USHORT    ( num_tables ),
          FT_FRAME_SKIP_BYTES( 2 ),
          FT_FRAME_ULONG     ( totalSfntSize ),
          FT_FRAME_ULONG     ( totalCompressedSize ),
          FT_FRAME_SKIP_BYTES( 2 * 2 ),
          FT_FRAME_ULONG     ( metaOffset ),
          FT_FRAME_ULONG     ( metaLength ),
          FT_FRAME_ULONG     ( metaOrigLength ),
          FT_FRAME_ULONG     ( privOffset ),
          FT_FRAME_ULONG     ( privLength ),
        FT_FRAME_END
      };
  
  
      FT_ASSERT( stream == face->root.stream );
      FT_ASSERT( FT_STREAM_POS() == 0 );
  
      face_index = FT_ABS( *face_instance_index ) & 0xFFFF;
  
      /* Read WOFF2 Header. */
      if ( FT_STREAM_READ_FIELDS( woff2_header_fields, &woff2 ) )
        return error;
  
      FT_TRACE4(( "signature     -> 0x%X\n", woff2.signature ));
      FT_TRACE2(( "flavor        -> 0x%08lx\n", woff2.flavor ));
      FT_TRACE4(( "length        -> %lu\n", woff2.length ));
      FT_TRACE2(( "num_tables    -> %hu\n", woff2.num_tables ));
      FT_TRACE4(( "totalSfntSize -> %lu\n", woff2.totalSfntSize ));
      FT_TRACE4(( "metaOffset    -> %hu\n", woff2.metaOffset ));
      FT_TRACE4(( "metaLength    -> %hu\n", woff2.metaLength ));
      FT_TRACE4(( "privOffset    -> %hu\n", woff2.privOffset ));
      FT_TRACE4(( "privLength    -> %hu\n", woff2.privLength ));
  
      /* Make sure we don't recurse back here. */
      if ( woff2.flavor == TTAG_wOF2 )
        return FT_THROW( Invalid_Table );
  
      /* Miscellaneous checks. */
      if ( woff2.length != stream->size                               ||
           woff2.num_tables == 0                                      ||
           48 + woff2.num_tables * 20UL >= woff2.length               ||
           ( woff2.metaOffset == 0 && ( woff2.metaLength != 0     ||
                                        woff2.metaOrigLength != 0 ) ) ||
           ( woff2.metaLength != 0 && woff2.metaOrigLength == 0 )     ||
           ( woff2.metaOffset >= woff2.length )                       ||
           ( woff2.length - woff2.metaOffset < woff2.metaLength )     ||
           ( woff2.privOffset == 0 && woff2.privLength != 0 )         ||
           ( woff2.privOffset >= woff2.length )                       ||
           ( woff2.length - woff2.privOffset < woff2.privLength )     )
      {
        FT_ERROR(( "woff2_open_font: invalid WOFF2 header\n" ));
        return FT_THROW( Invalid_Table );
      }
  
      FT_TRACE2(( "woff2_open_font: WOFF2 Header is valid.\n" ));
  
      woff2.ttc_fonts = NULL;
  
      /* Read table directory. */
      if ( FT_NEW_ARRAY( tables, woff2.num_tables )  ||
           FT_NEW_ARRAY( indices, woff2.num_tables ) )
        goto Exit;
  
      FT_TRACE2(( "\n"
                  "  tag    flags    transform   origLen   transformLen\n"
                  "  --------------------------------------------------\n" ));
  
      for ( nn = 0; nn < woff2.num_tables; nn++ )
      {
        WOFF2_Table  table = tables + nn;
  
  
        if ( FT_READ_BYTE( table->FlagByte ) )
          goto Exit;
  
        if ( ( table->FlagByte & 0x3f ) == 0x3f )
        {
          if ( FT_READ_ULONG( table->Tag ) )
            goto Exit;
        }
        else
        {
          table->Tag = woff2_known_tags( table->FlagByte & 0x3f );
          if ( !table->Tag )
          {
            FT_ERROR(( "woff2_open_font: Unknown table tag." ));
            error = FT_THROW( Invalid_Table );
            goto Exit;
          }
        }
  
        flags = 0;
        xform_version = ( table->FlagByte >> 6 ) & 0x03;
  
        /* 0 means xform for glyph/loca, non-0 for others. */
        if ( table->Tag == TTAG_glyf || table->Tag == TTAG_loca )
        {
          if ( xform_version == 0 )
            flags |= WOFF2_FLAGS_TRANSFORM;
        }
        else if ( xform_version != 0 )
          flags |= WOFF2_FLAGS_TRANSFORM;
  
        flags |= xform_version;
  
        if ( READ_BASE128( table->dst_length ) )
          goto Exit;
  
        table->TransformLength = table->dst_length;
  
        if ( ( flags & WOFF2_FLAGS_TRANSFORM ) != 0 )
        {
          if ( READ_BASE128( table->TransformLength ) )
            goto Exit;
  
          if ( table->Tag == TTAG_loca && table->TransformLength )
          {
            FT_ERROR(( "woff2_open_font: Invalid loca `transformLength'.\n" ));
            error = FT_THROW( Invalid_Table );
            goto Exit;
          }
        }
  
        if ( src_offset + table->TransformLength < src_offset )
        {
          FT_ERROR(( "woff2_open_font: invalid WOFF2 table directory.\n" ));
          error = FT_THROW( Invalid_Table );
          goto Exit;
        }
  
        table->src_offset = src_offset;
        table->src_length = table->TransformLength;
        src_offset       += table->TransformLength;
        table->flags      = flags;
  
        FT_TRACE2(( "  %c%c%c%c  %08d  %08d    %08ld  %08ld\n",
                    (FT_Char)( table->Tag >> 24 ),
                    (FT_Char)( table->Tag >> 16 ),
                    (FT_Char)( table->Tag >> 8  ),
                    (FT_Char)( table->Tag       ),
                    table->FlagByte & 0x3f,
                    ( table->FlagByte >> 6 ) & 0x03,
                    table->dst_length,
                    table->TransformLength,
                    table->src_length,
                    table->src_offset ));
  
        indices[nn] = table;
      }
  
      /* End of last table is uncompressed size. */
      last_table = indices[woff2.num_tables - 1];
  
      woff2.uncompressed_size = last_table->src_offset +
                                last_table->src_length;
      if ( woff2.uncompressed_size < last_table->src_offset )
      {
        error = FT_THROW( Invalid_Table );
        goto Exit;
      }
  
      FT_TRACE2(( "Table directory parsed.\n" ));
  
      /* Check for and read collection directory. */
      woff2.num_fonts      = 1;
      woff2.header_version = 0;
  
      if ( woff2.flavor == TTAG_ttcf )
      {
        FT_TRACE2(( "Font is a TTC, reading collection directory.\n" ));
  
        if ( FT_READ_ULONG( woff2.header_version ) )
          goto Exit;
  
        if ( woff2.header_version != 0x00010000 &&
             woff2.header_version != 0x00020000 )
        {
          error = FT_THROW( Invalid_Table );
          goto Exit;
        }
  
        if ( READ_255USHORT( woff2.num_fonts ) )
          goto Exit;
  
        if ( !woff2.num_fonts )
        {
          error = FT_THROW( Invalid_Table );
          goto Exit;
        }
  
        FT_TRACE4(( "Number of fonts in TTC: %ld\n", woff2.num_fonts ));
  
        if ( FT_NEW_ARRAY( woff2.ttc_fonts, woff2.num_fonts ) )
          goto Exit;
  
        for ( nn = 0; nn < woff2.num_fonts; nn++ )
        {
          WOFF2_TtcFont  ttc_font = woff2.ttc_fonts + nn;
  
  
          if ( READ_255USHORT( ttc_font->num_tables ) )
            goto Exit;
          if ( FT_READ_ULONG( ttc_font->flavor ) )
            goto Exit;
  
          if ( FT_NEW_ARRAY( ttc_font->table_indices, ttc_font->num_tables ) )
            goto Exit;
  
          FT_TRACE5(( "Number of tables in font %d: %ld\n",
                      nn, ttc_font->num_tables ));
  
  #ifdef FT_DEBUG_LEVEL_TRACE
          if ( ttc_font->num_tables )
            FT_TRACE6(( "  Indices: " ));
  #endif
  
          glyf_index = 0;
          loca_index = 0;
  
          for ( j = 0; j < ttc_font->num_tables; j++ )
          {
            FT_UShort    table_index;
            WOFF2_Table  table;
  
  
            if ( READ_255USHORT( table_index ) )
              goto Exit;
  
            FT_TRACE6(( "%hu ", table_index ));
            if ( table_index >= woff2.num_tables )
            {
              FT_ERROR(( "woff2_open_font: invalid table index\n" ));
              error = FT_THROW( Invalid_Table );
              goto Exit;
            }
  
            ttc_font->table_indices[j] = table_index;
  
            table = indices[table_index];
            if ( table->Tag == TTAG_loca )
              loca_index = table_index;
            if ( table->Tag == TTAG_glyf )
              glyf_index = table_index;
          }
  
  #ifdef FT_DEBUG_LEVEL_TRACE
          if ( ttc_font->num_tables )
            FT_TRACE6(( "\n" ));
  #endif
  
          /* glyf and loca must be consecutive */
          if ( glyf_index > 0 || loca_index > 0 )
          {
            if ( glyf_index > loca_index      ||
                 loca_index - glyf_index != 1 )
            {
              error = FT_THROW( Invalid_Table );
              goto Exit;
            }
          }
        }
  
        /* Collection directory reading complete. */
        FT_TRACE2(( "WOFF2 collection directory is valid.\n" ));
      }
      else
        woff2.ttc_fonts = NULL;
  
      woff2.compressed_offset = FT_STREAM_POS();
      file_offset             = ROUND4( woff2.compressed_offset +
                                        woff2.totalCompressedSize );
  
      /* Some more checks before we start reading the tables. */
      if ( file_offset > woff2.length )
      {
        error = FT_THROW( Invalid_Table );
        goto Exit;
      }
  
      if ( woff2.metaOffset )
      {
        if ( file_offset != woff2.metaOffset )
        {
          error = FT_THROW( Invalid_Table );
          goto Exit;
        }
        file_offset = ROUND4(woff2.metaOffset + woff2.metaLength);
      }
  
      if ( woff2.privOffset )
      {
        if ( file_offset != woff2.privOffset )
        {
          error = FT_THROW( Invalid_Table );
          goto Exit;
        }
        file_offset = ROUND4(woff2.privOffset + woff2.privLength);
      }
  
      if ( file_offset != ( ROUND4( woff2.length ) ) )
      {
        error = FT_THROW( Invalid_Table );
        goto Exit;
      }
  
      /* Validate requested face index. */
      *num_faces = woff2.num_fonts;
      /* value -(N+1) requests information on index N */
      if ( *face_instance_index < 0 )
        face_index--;
  
      if ( face_index >= woff2.num_fonts )
      {
        if ( *face_instance_index >= 0 )
        {
          error = FT_THROW( Invalid_Argument );
          goto Exit;
        }
        else
          face_index = 0;
      }
  
      /* Only retain tables of the requested face in a TTC. */
      if ( woff2.header_version )
      {
        WOFF2_TtcFont  ttc_font = woff2.ttc_fonts + face_index;
  
  
        /* Create a temporary array. */
        if ( FT_NEW_ARRAY( temp_indices,
                           ttc_font->num_tables ) )
          goto Exit;
  
        FT_TRACE4(( "Storing tables for TTC face index %d.\n", face_index ));
        for ( nn = 0; nn < ttc_font->num_tables; nn++ )
          temp_indices[nn] = indices[ttc_font->table_indices[nn]];
  
        /* Resize array to required size. */
        if ( FT_RENEW_ARRAY( indices,
                             woff2.num_tables,
                             ttc_font->num_tables ) )
          goto Exit;
  
        for ( nn = 0; nn < ttc_font->num_tables; nn++ )
          indices[nn] = temp_indices[nn];
  
        FT_FREE( temp_indices );
  
        /* Change header values. */
        woff2.flavor     = ttc_font->flavor;
        woff2.num_tables = ttc_font->num_tables;
      }
  
      /* We need to allocate this much at the minimum. */
      sfnt_size = 12 + woff2.num_tables * 16UL;
      /* This is what we normally expect.                              */
      /* Initially trust `totalSfntSize' and change later as required. */
      if ( woff2.totalSfntSize > sfnt_size )
      {
        /* However, adjust the value to something reasonable. */
  
        /* Factor 64 is heuristic. */
        if ( ( woff2.totalSfntSize >> 6 ) > woff2.length )
          sfnt_size = woff2.length << 6;
        else
          sfnt_size = woff2.totalSfntSize;
  
        /* Value 1<<26 = 67108864 is heuristic. */
        if (sfnt_size >= (1 << 26))
          sfnt_size = 1 << 26;
  
  #ifdef FT_DEBUG_LEVEL_TRACE
        if ( sfnt_size != woff2.totalSfntSize )
          FT_TRACE4(( "adjusting estimate of uncompressed font size"
                      " to %lu bytes\n",
                      sfnt_size ));
  #endif
      }
  
      /* Write sfnt header. */
      if ( FT_ALLOC( sfnt, sfnt_size ) ||
           FT_NEW( sfnt_stream )       )
        goto Exit;
  
      sfnt_header = sfnt;
  
      WRITE_ULONG( sfnt_header, woff2.flavor );
  
      if ( woff2.num_tables )
      {
        FT_UInt  searchRange, entrySelector, rangeShift, x;
  
  
        x             = woff2.num_tables;
        entrySelector = 0;
        while ( x )
        {
          x            >>= 1;
          entrySelector += 1;
        }
        entrySelector--;
  
        searchRange = ( 1 << entrySelector ) * 16;
        rangeShift  = ( woff2.num_tables * 16 ) - searchRange;
  
        WRITE_USHORT( sfnt_header, woff2.num_tables );
        WRITE_USHORT( sfnt_header, searchRange );
        WRITE_USHORT( sfnt_header, entrySelector );
        WRITE_USHORT( sfnt_header, rangeShift );
      }
  
      info.header_checksum = compute_ULong_sum( sfnt, 12 );
  
      /* Sort tables by tag. */
      ft_qsort( indices,
                woff2.num_tables,
                sizeof ( WOFF2_Table ),
                compare_tags );
  
      if ( woff2.uncompressed_size < 1 )
      {
        error = FT_THROW( Invalid_Table );
        goto Exit;
      }
  
      if ( woff2.uncompressed_size > sfnt_size )
      {
        FT_ERROR(( "woff2_open_font: SFNT table lengths are too large.\n" ));
        error = FT_THROW( Invalid_Table );
        goto Exit;
      }
  
      /* Allocate memory for uncompressed table data. */
      if ( FT_ALLOC( uncompressed_buf, woff2.uncompressed_size ) ||
           FT_FRAME_ENTER( woff2.totalCompressedSize )           )
        goto Exit;
  
      /* Uncompress the stream. */
      error = woff2_decompress( uncompressed_buf,
                                woff2.uncompressed_size,
                                stream->cursor,
                                woff2.totalCompressedSize );
  
      FT_FRAME_EXIT();
  
      if ( error )
        goto Exit;
  
      error = reconstruct_font( uncompressed_buf,
                                woff2.uncompressed_size,
                                indices,
                                &woff2,
                                &info,
                                &sfnt,
                                &sfnt_size,
                                memory );
  
      if ( error )
        goto Exit;
  
      /* Resize `sfnt' to actual size of sfnt stream. */
      if ( woff2.actual_sfnt_size < sfnt_size )
      {
        FT_TRACE5(( "Trimming sfnt stream from %lu to %lu.\n",
                    sfnt_size, woff2.actual_sfnt_size ));
        if ( FT_REALLOC( sfnt,
                         (FT_ULong)( sfnt_size ),
                         (FT_ULong)( woff2.actual_sfnt_size ) ) )
          goto Exit;
      }
  
      /* `reconstruct_font' has done all the work. */
      /* Swap out stream and return.               */
      FT_Stream_OpenMemory( sfnt_stream, sfnt, woff2.actual_sfnt_size );
      sfnt_stream->memory = stream->memory;
      sfnt_stream->close  = stream_close;
  
      FT_Stream_Free(
        face->root.stream,
        ( face->root.face_flags & FT_FACE_FLAG_EXTERNAL_STREAM ) != 0 );
  
      face->root.stream      = sfnt_stream;
      face->root.face_flags &= ~FT_FACE_FLAG_EXTERNAL_STREAM;
  
      /* Set face_index to 0 or -1. */
      if ( *face_instance_index >= 0 )
        *face_instance_index = 0;
      else
        *face_instance_index = -1;
  
      FT_TRACE2(( "woff2_open_font: SFNT synthesized.\n" ));
  
    Exit:
      FT_FREE( tables );
      FT_FREE( indices );
      FT_FREE( uncompressed_buf );
      FT_FREE( info.x_mins );
  
      if ( woff2.ttc_fonts )
      {
        WOFF2_TtcFont  ttc_font = woff2.ttc_fonts;
  
  
        for ( nn = 0; nn < woff2.num_fonts; nn++ )
        {
          FT_FREE( ttc_font->table_indices );
          ttc_font++;
        }
  
        FT_FREE( woff2.ttc_fonts );
      }
  
      if ( error )
      {
        FT_FREE( sfnt );
        if ( sfnt_stream )
        {
          FT_Stream_Close( sfnt_stream );
          FT_FREE( sfnt_stream );
        }
      }
  
      return error;
    }
  
  
  #undef READ_255USHORT
  #undef READ_BASE128
  #undef ROUND4
  #undef WRITE_USHORT
  #undef WRITE_ULONG
  #undef WRITE_SHORT
  #undef WRITE_SFNT_BUF
  #undef WRITE_SFNT_BUF_AT
  
  #undef N_CONTOUR_STREAM
  #undef N_POINTS_STREAM
  #undef FLAG_STREAM
  #undef GLYPH_STREAM
  #undef COMPOSITE_STREAM
  #undef BBOX_STREAM
  #undef INSTRUCTION_STREAM
  
  
  /* END */
  

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