misc/libfreetype/src/sfnt/ttsbit0.c
changeset 9372 915436ff64ab
parent 9371 f3840de881bd
child 9373 b769a8e38cbd
--- a/misc/libfreetype/src/sfnt/ttsbit0.c	Thu Jul 25 23:16:06 2013 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1011 +0,0 @@
-/***************************************************************************/
-/*                                                                         */
-/*  ttsbit0.c                                                              */
-/*                                                                         */
-/*    TrueType and OpenType embedded bitmap support (body).                */
-/*    This is a heap-optimized version.                                    */
-/*                                                                         */
-/*  Copyright 2005, 2006, 2007, 2008, 2009 by                              */
-/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
-/*                                                                         */
-/*  This file is part of the FreeType project, and may only be used,       */
-/*  modified, and distributed under the terms of the FreeType project      */
-/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
-/*  this file you indicate that you have read the license and              */
-/*  understand and accept it fully.                                        */
-/*                                                                         */
-/***************************************************************************/
-
-
-/* This file is included by ttsbit.c */
-
-
-#include <ft2build.h>
-#include FT_INTERNAL_DEBUG_H
-#include FT_INTERNAL_STREAM_H
-#include FT_TRUETYPE_TAGS_H
-#include "ttsbit.h"
-
-#include "sferrors.h"
-
-
-  /*************************************************************************/
-  /*                                                                       */
-  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
-  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
-  /* messages during execution.                                            */
-  /*                                                                       */
-#undef  FT_COMPONENT
-#define FT_COMPONENT  trace_ttsbit
-
-
-  FT_LOCAL_DEF( FT_Error )
-  tt_face_load_eblc( TT_Face    face,
-                     FT_Stream  stream )
-  {
-    FT_Error  error = SFNT_Err_Ok;
-    FT_Fixed  version;
-    FT_ULong  num_strikes, table_size;
-    FT_Byte*  p;
-    FT_Byte*  p_limit;
-    FT_UInt   count;
-
-
-    face->sbit_num_strikes = 0;
-
-    /* this table is optional */
-    error = face->goto_table( face, TTAG_EBLC, stream, &table_size );
-    if ( error )
-      error = face->goto_table( face, TTAG_bloc, stream, &table_size );
-    if ( error )
-      goto Exit;
-
-    if ( table_size < 8 )
-    {
-      FT_ERROR(( "tt_face_load_sbit_strikes: table too short\n" ));
-      error = SFNT_Err_Invalid_File_Format;
-      goto Exit;
-    }
-
-    if ( FT_FRAME_EXTRACT( table_size, face->sbit_table ) )
-      goto Exit;
-
-    face->sbit_table_size = table_size;
-
-    p       = face->sbit_table;
-    p_limit = p + table_size;
-
-    version     = FT_NEXT_ULONG( p );
-    num_strikes = FT_NEXT_ULONG( p );
-
-    if ( version != 0x00020000UL || num_strikes >= 0x10000UL )
-    {
-      FT_ERROR(( "tt_face_load_sbit_strikes: invalid table version\n" ));
-      error = SFNT_Err_Invalid_File_Format;
-      goto Fail;
-    }
-
-    /*
-     *  Count the number of strikes available in the table.  We are a bit
-     *  paranoid there and don't trust the data.
-     */
-    count = (FT_UInt)num_strikes;
-    if ( 8 + 48UL * count > table_size )
-      count = (FT_UInt)( ( p_limit - p ) / 48 );
-
-    face->sbit_num_strikes = count;
-
-    FT_TRACE3(( "sbit_num_strikes: %u\n", count ));
-  Exit:
-    return error;
-
-  Fail:
-    FT_FRAME_RELEASE( face->sbit_table );
-    face->sbit_table_size = 0;
-    goto Exit;
-  }
-
-
-  FT_LOCAL_DEF( void )
-  tt_face_free_eblc( TT_Face  face )
-  {
-    FT_Stream  stream = face->root.stream;
-
-
-    FT_FRAME_RELEASE( face->sbit_table );
-    face->sbit_table_size  = 0;
-    face->sbit_num_strikes = 0;
-  }
-
-
-  FT_LOCAL_DEF( FT_Error )
-  tt_face_set_sbit_strike( TT_Face          face,
-                           FT_Size_Request  req,
-                           FT_ULong*        astrike_index )
-  {
-    return FT_Match_Size( (FT_Face)face, req, 0, astrike_index );
-  }
-
-
-  FT_LOCAL_DEF( FT_Error )
-  tt_face_load_strike_metrics( TT_Face           face,
-                               FT_ULong          strike_index,
-                               FT_Size_Metrics*  metrics )
-  {
-    FT_Byte*  strike;
-
-
-    if ( strike_index >= (FT_ULong)face->sbit_num_strikes )
-      return SFNT_Err_Invalid_Argument;
-
-    strike = face->sbit_table + 8 + strike_index * 48;
-
-    metrics->x_ppem = (FT_UShort)strike[44];
-    metrics->y_ppem = (FT_UShort)strike[45];
-
-    metrics->ascender  = (FT_Char)strike[16] << 6;  /* hori.ascender  */
-    metrics->descender = (FT_Char)strike[17] << 6;  /* hori.descender */
-    metrics->height    = metrics->ascender - metrics->descender;
-
-    /* XXX: Is this correct? */
-    metrics->max_advance = ( (FT_Char)strike[22] + /* min_origin_SB  */
-                                      strike[18] + /* max_width      */
-                             (FT_Char)strike[23]   /* min_advance_SB */
-                                                 ) << 6;
-
-    return SFNT_Err_Ok;
-  }
-
-
-  typedef struct  TT_SBitDecoderRec_
-  {
-    TT_Face          face;
-    FT_Stream        stream;
-    FT_Bitmap*       bitmap;
-    TT_SBit_Metrics  metrics;
-    FT_Bool          metrics_loaded;
-    FT_Bool          bitmap_allocated;
-    FT_Byte          bit_depth;
-
-    FT_ULong         ebdt_start;
-    FT_ULong         ebdt_size;
-
-    FT_ULong         strike_index_array;
-    FT_ULong         strike_index_count;
-    FT_Byte*         eblc_base;
-    FT_Byte*         eblc_limit;
-
-  } TT_SBitDecoderRec, *TT_SBitDecoder;
-
-
-  static FT_Error
-  tt_sbit_decoder_init( TT_SBitDecoder       decoder,
-                        TT_Face              face,
-                        FT_ULong             strike_index,
-                        TT_SBit_MetricsRec*  metrics )
-  {
-    FT_Error   error;
-    FT_Stream  stream = face->root.stream;
-    FT_ULong   ebdt_size;
-
-
-    error = face->goto_table( face, TTAG_EBDT, stream, &ebdt_size );
-    if ( error )
-      error = face->goto_table( face, TTAG_bdat, stream, &ebdt_size );
-    if ( error )
-      goto Exit;
-
-    decoder->face    = face;
-    decoder->stream  = stream;
-    decoder->bitmap  = &face->root.glyph->bitmap;
-    decoder->metrics = metrics;
-
-    decoder->metrics_loaded   = 0;
-    decoder->bitmap_allocated = 0;
-
-    decoder->ebdt_start = FT_STREAM_POS();
-    decoder->ebdt_size  = ebdt_size;
-
-    decoder->eblc_base  = face->sbit_table;
-    decoder->eblc_limit = face->sbit_table + face->sbit_table_size;
-
-    /* now find the strike corresponding to the index */
-    {
-      FT_Byte*  p;
-
-
-      if ( 8 + 48 * strike_index + 3 * 4 + 34 + 1 > face->sbit_table_size )
-      {
-        error = SFNT_Err_Invalid_File_Format;
-        goto Exit;
-      }
-
-      p = decoder->eblc_base + 8 + 48 * strike_index;
-
-      decoder->strike_index_array = FT_NEXT_ULONG( p );
-      p                          += 4;
-      decoder->strike_index_count = FT_NEXT_ULONG( p );
-      p                          += 34;
-      decoder->bit_depth          = *p;
-
-      if ( decoder->strike_index_array > face->sbit_table_size             ||
-           decoder->strike_index_array + 8 * decoder->strike_index_count >
-             face->sbit_table_size                                         )
-        error = SFNT_Err_Invalid_File_Format;
-    }
-
-  Exit:
-    return error;
-  }
-
-
-  static void
-  tt_sbit_decoder_done( TT_SBitDecoder  decoder )
-  {
-    FT_UNUSED( decoder );
-  }
-
-
-  static FT_Error
-  tt_sbit_decoder_alloc_bitmap( TT_SBitDecoder  decoder )
-  {
-    FT_Error    error = SFNT_Err_Ok;
-    FT_UInt     width, height;
-    FT_Bitmap*  map = decoder->bitmap;
-    FT_Long     size;
-
-
-    if ( !decoder->metrics_loaded )
-    {
-      error = SFNT_Err_Invalid_Argument;
-      goto Exit;
-    }
-
-    width  = decoder->metrics->width;
-    height = decoder->metrics->height;
-
-    map->width = (int)width;
-    map->rows  = (int)height;
-
-    switch ( decoder->bit_depth )
-    {
-    case 1:
-      map->pixel_mode = FT_PIXEL_MODE_MONO;
-      map->pitch      = ( map->width + 7 ) >> 3;
-      break;
-
-    case 2:
-      map->pixel_mode = FT_PIXEL_MODE_GRAY2;
-      map->pitch      = ( map->width + 3 ) >> 2;
-      break;
-
-    case 4:
-      map->pixel_mode = FT_PIXEL_MODE_GRAY4;
-      map->pitch      = ( map->width + 1 ) >> 1;
-      break;
-
-    case 8:
-      map->pixel_mode = FT_PIXEL_MODE_GRAY;
-      map->pitch      = map->width;
-      break;
-
-    default:
-      error = SFNT_Err_Invalid_File_Format;
-      goto Exit;
-    }
-
-    size = map->rows * map->pitch;
-
-    /* check that there is no empty image */
-    if ( size == 0 )
-      goto Exit;     /* exit successfully! */
-
-    error = ft_glyphslot_alloc_bitmap( decoder->face->root.glyph, size );
-    if ( error )
-      goto Exit;
-
-    decoder->bitmap_allocated = 1;
-
-  Exit:
-    return error;
-  }
-
-
-  static FT_Error
-  tt_sbit_decoder_load_metrics( TT_SBitDecoder  decoder,
-                                FT_Byte*       *pp,
-                                FT_Byte*        limit,
-                                FT_Bool         big )
-  {
-    FT_Byte*         p       = *pp;
-    TT_SBit_Metrics  metrics = decoder->metrics;
-
-
-    if ( p + 5 > limit )
-      goto Fail;
-
-    metrics->height       = p[0];
-    metrics->width        = p[1];
-    metrics->horiBearingX = (FT_Char)p[2];
-    metrics->horiBearingY = (FT_Char)p[3];
-    metrics->horiAdvance  = p[4];
-
-    p += 5;
-    if ( big )
-    {
-      if ( p + 3 > limit )
-        goto Fail;
-
-      metrics->vertBearingX = (FT_Char)p[0];
-      metrics->vertBearingY = (FT_Char)p[1];
-      metrics->vertAdvance  = p[2];
-
-      p += 3;
-    }
-
-    decoder->metrics_loaded = 1;
-    *pp = p;
-    return SFNT_Err_Ok;
-
-  Fail:
-    return SFNT_Err_Invalid_Argument;
-  }
-
-
-  /* forward declaration */
-  static FT_Error
-  tt_sbit_decoder_load_image( TT_SBitDecoder  decoder,
-                              FT_UInt         glyph_index,
-                              FT_Int          x_pos,
-                              FT_Int          y_pos );
-
-  typedef FT_Error  (*TT_SBitDecoder_LoadFunc)( TT_SBitDecoder  decoder,
-                                                FT_Byte*        p,
-                                                FT_Byte*        plimit,
-                                                FT_Int          x_pos,
-                                                FT_Int          y_pos );
-
-
-  static FT_Error
-  tt_sbit_decoder_load_byte_aligned( TT_SBitDecoder  decoder,
-                                     FT_Byte*        p,
-                                     FT_Byte*        limit,
-                                     FT_Int          x_pos,
-                                     FT_Int          y_pos )
-  {
-    FT_Error    error = SFNT_Err_Ok;
-    FT_Byte*    line;
-    FT_Int      bit_height, bit_width, pitch, width, height, h;
-    FT_Bitmap*  bitmap;
-
-
-    if ( !decoder->bitmap_allocated )
-    {
-      error = tt_sbit_decoder_alloc_bitmap( decoder );
-      if ( error )
-        goto Exit;
-    }
-
-    /* check that we can write the glyph into the bitmap */
-    bitmap     = decoder->bitmap;
-    bit_width  = bitmap->width;
-    bit_height = bitmap->rows;
-    pitch      = bitmap->pitch;
-    line       = bitmap->buffer;
-
-    width  = decoder->metrics->width;
-    height = decoder->metrics->height;
-
-    if ( x_pos < 0 || x_pos + width > bit_width   ||
-         y_pos < 0 || y_pos + height > bit_height )
-    {
-      error = SFNT_Err_Invalid_File_Format;
-      goto Exit;
-    }
-
-    if ( p + ( ( width + 7 ) >> 3 ) * height > limit )
-    {
-      error = SFNT_Err_Invalid_File_Format;
-      goto Exit;
-    }
-
-    /* now do the blit */
-    line  += y_pos * pitch + ( x_pos >> 3 );
-    x_pos &= 7;
-
-    if ( x_pos == 0 )  /* the easy one */
-    {
-      for ( h = height; h > 0; h--, line += pitch )
-      {
-        FT_Byte*  write = line;
-        FT_Int    w;
-
-
-        for ( w = width; w >= 8; w -= 8 )
-        {
-          write[0] = (FT_Byte)( write[0] | *p++ );
-          write   += 1;
-        }
-
-        if ( w > 0 )
-          write[0] = (FT_Byte)( write[0] | ( *p++ & ( 0xFF00U >> w ) ) );
-      }
-    }
-    else  /* x_pos > 0 */
-    {
-      for ( h = height; h > 0; h--, line += pitch )
-      {
-        FT_Byte*  write = line;
-        FT_Int    w;
-        FT_UInt   wval = 0;
-
-
-        for ( w = width; w >= 8; w -= 8 )
-        {
-          wval      = (FT_UInt)( wval | *p++ );
-          write[0]  = (FT_Byte)( write[0] | ( wval >> x_pos ) );
-          write    += 1;
-          wval    <<= 8;
-        }
-
-        if ( w > 0 )
-          wval = (FT_UInt)( wval | ( *p++ & ( 0xFF00U >> w ) ) );
-
-        /* all bits read and there are `x_pos + w' bits to be written */
-
-        write[0] = (FT_Byte)( write[0] | ( wval >> x_pos ) );
-
-        if ( x_pos + w > 8 )
-        {
-          write++;
-          wval   <<= 8;
-          write[0] = (FT_Byte)( write[0] | ( wval >> x_pos ) );
-        }
-      }
-    }
-
-  Exit:
-    return error;
-  }
-
-
-  /*
-   * Load a bit-aligned bitmap (with pointer `p') into a line-aligned bitmap
-   * (with pointer `write').  In the example below, the width is 3 pixel,
-   * and `x_pos' is 1 pixel.
-   *
-   *       p                               p+1
-   *     |                               |                               |
-   *     | 7   6   5   4   3   2   1   0 | 7   6   5   4   3   2   1   0 |...
-   *     |                               |                               |
-   *       +-------+   +-------+   +-------+ ...
-   *           .           .           .
-   *           .           .           .
-   *           v           .           .
-   *       +-------+       .           .
-   * |                               | .
-   * | 7   6   5   4   3   2   1   0 | .
-   * |                               | .
-   *   write               .           .
-   *                       .           .
-   *                       v           .
-   *                   +-------+       .
-   *             |                               |
-   *             | 7   6   5   4   3   2   1   0 |
-   *             |                               |
-   *               write+1             .
-   *                                   .
-   *                                   v
-   *                               +-------+
-   *                         |                               |
-   *                         | 7   6   5   4   3   2   1   0 |
-   *                         |                               |
-   *                           write+2
-   *
-   */
-
-  static FT_Error
-  tt_sbit_decoder_load_bit_aligned( TT_SBitDecoder  decoder,
-                                    FT_Byte*        p,
-                                    FT_Byte*        limit,
-                                    FT_Int          x_pos,
-                                    FT_Int          y_pos )
-  {
-    FT_Error    error = SFNT_Err_Ok;
-    FT_Byte*    line;
-    FT_Int      bit_height, bit_width, pitch, width, height, h, nbits;
-    FT_Bitmap*  bitmap;
-    FT_UShort   rval;
-
-
-    if ( !decoder->bitmap_allocated )
-    {
-      error = tt_sbit_decoder_alloc_bitmap( decoder );
-      if ( error )
-        goto Exit;
-    }
-
-    /* check that we can write the glyph into the bitmap */
-    bitmap     = decoder->bitmap;
-    bit_width  = bitmap->width;
-    bit_height = bitmap->rows;
-    pitch      = bitmap->pitch;
-    line       = bitmap->buffer;
-
-    width  = decoder->metrics->width;
-    height = decoder->metrics->height;
-
-    if ( x_pos < 0 || x_pos + width  > bit_width  ||
-         y_pos < 0 || y_pos + height > bit_height )
-    {
-      error = SFNT_Err_Invalid_File_Format;
-      goto Exit;
-    }
-
-    if ( p + ( ( width * height + 7 ) >> 3 ) > limit )
-    {
-      error = SFNT_Err_Invalid_File_Format;
-      goto Exit;
-    }
-
-    /* now do the blit */
-
-    /* adjust `line' to point to the first byte of the bitmap */
-    line  += y_pos * pitch + ( x_pos >> 3 );
-    x_pos &= 7;
-
-    /* the higher byte of `rval' is used as a buffer */
-    rval  = 0;
-    nbits = 0;
-
-    for ( h = height; h > 0; h--, line += pitch )
-    {
-      FT_Byte*  write = line;
-      FT_Int    w     = width;
-
-
-      /* handle initial byte (in target bitmap) specially if necessary */
-      if ( x_pos )
-      {
-        w = ( width < 8 - x_pos ) ? width : 8 - x_pos;
-
-        if ( h == height )
-        {
-          rval  = *p++;
-          nbits = x_pos;
-        }
-        else if ( nbits < w )
-        {
-          if ( p < limit )
-            rval |= *p++;
-          nbits += 8 - w;
-        }
-        else
-        {
-          rval  >>= 8;
-          nbits  -= w;
-        }
-
-        *write++ |= ( ( rval >> nbits ) & 0xFF ) &
-                    ( ~( 0xFF << w ) << ( 8 - w - x_pos ) );
-        rval    <<= 8;
-
-        w = width - w;
-      }
-
-      /* handle medial bytes */
-      for ( ; w >= 8; w -= 8 )
-      {
-        rval     |= *p++;
-        *write++ |= ( rval >> nbits ) & 0xFF;
-
-        rval <<= 8;
-      }
-
-      /* handle final byte if necessary */
-      if ( w > 0 )
-      {
-        if ( nbits < w )
-        {
-          if ( p < limit )
-            rval |= *p++;
-          *write |= ( ( rval >> nbits ) & 0xFF ) & ( 0xFF00U >> w );
-          nbits  += 8 - w;
-
-          rval <<= 8;
-        }
-        else
-        {
-          *write |= ( ( rval >> nbits ) & 0xFF ) & ( 0xFF00U >> w );
-          nbits  -= w;
-        }
-      }
-    }
-
-  Exit:
-    return error;
-  }
-
-
-  static FT_Error
-  tt_sbit_decoder_load_compound( TT_SBitDecoder  decoder,
-                                 FT_Byte*        p,
-                                 FT_Byte*        limit,
-                                 FT_Int          x_pos,
-                                 FT_Int          y_pos )
-  {
-    FT_Error  error = SFNT_Err_Ok;
-    FT_UInt   num_components, nn;
-
-    FT_Char  horiBearingX = decoder->metrics->horiBearingX;
-    FT_Char  horiBearingY = decoder->metrics->horiBearingY;
-    FT_Byte  horiAdvance  = decoder->metrics->horiAdvance;
-    FT_Char  vertBearingX = decoder->metrics->vertBearingX;
-    FT_Char  vertBearingY = decoder->metrics->vertBearingY;
-    FT_Byte  vertAdvance  = decoder->metrics->vertAdvance;
-
-
-    if ( p + 2 > limit )
-      goto Fail;
-
-    num_components = FT_NEXT_USHORT( p );
-    if ( p + 4 * num_components > limit )
-      goto Fail;
-
-    if ( !decoder->bitmap_allocated )
-    {
-      error = tt_sbit_decoder_alloc_bitmap( decoder );
-      if ( error )
-        goto Exit;
-    }
-
-    for ( nn = 0; nn < num_components; nn++ )
-    {
-      FT_UInt  gindex = FT_NEXT_USHORT( p );
-      FT_Byte  dx     = FT_NEXT_BYTE( p );
-      FT_Byte  dy     = FT_NEXT_BYTE( p );
-
-
-      /* NB: a recursive call */
-      error = tt_sbit_decoder_load_image( decoder, gindex,
-                                          x_pos + dx, y_pos + dy );
-      if ( error )
-        break;
-    }
-
-    decoder->metrics->horiBearingX = horiBearingX;
-    decoder->metrics->horiBearingY = horiBearingY;
-    decoder->metrics->horiAdvance  = horiAdvance;
-    decoder->metrics->vertBearingX = vertBearingX;
-    decoder->metrics->vertBearingY = vertBearingY;
-    decoder->metrics->vertAdvance  = vertAdvance;
-    decoder->metrics->width        = (FT_UInt)decoder->bitmap->width;
-    decoder->metrics->height       = (FT_UInt)decoder->bitmap->rows;
-
-  Exit:
-    return error;
-
-  Fail:
-    error = SFNT_Err_Invalid_File_Format;
-    goto Exit;
-  }
-
-
-  static FT_Error
-  tt_sbit_decoder_load_bitmap( TT_SBitDecoder  decoder,
-                               FT_UInt         glyph_format,
-                               FT_ULong        glyph_start,
-                               FT_ULong        glyph_size,
-                               FT_Int          x_pos,
-                               FT_Int          y_pos )
-  {
-    FT_Error   error;
-    FT_Stream  stream = decoder->stream;
-    FT_Byte*   p;
-    FT_Byte*   p_limit;
-    FT_Byte*   data;
-
-
-    /* seek into the EBDT table now */
-    if ( glyph_start + glyph_size > decoder->ebdt_size )
-    {
-      error = SFNT_Err_Invalid_Argument;
-      goto Exit;
-    }
-
-    if ( FT_STREAM_SEEK( decoder->ebdt_start + glyph_start ) ||
-         FT_FRAME_EXTRACT( glyph_size, data )                )
-      goto Exit;
-
-    p       = data;
-    p_limit = p + glyph_size;
-
-    /* read the data, depending on the glyph format */
-    switch ( glyph_format )
-    {
-    case 1:
-    case 2:
-    case 8:
-      error = tt_sbit_decoder_load_metrics( decoder, &p, p_limit, 0 );
-      break;
-
-    case 6:
-    case 7:
-    case 9:
-      error = tt_sbit_decoder_load_metrics( decoder, &p, p_limit, 1 );
-      break;
-
-    default:
-      error = SFNT_Err_Ok;
-    }
-
-    if ( error )
-      goto Fail;
-
-    {
-      TT_SBitDecoder_LoadFunc  loader;
-
-
-      switch ( glyph_format )
-      {
-      case 1:
-      case 6:
-        loader = tt_sbit_decoder_load_byte_aligned;
-        break;
-
-      case 2:
-      case 5:
-      case 7:
-        loader = tt_sbit_decoder_load_bit_aligned;
-        break;
-
-      case 8:
-        if ( p + 1 > p_limit )
-          goto Fail;
-
-        p += 1;  /* skip padding */
-        /* fall-through */
-
-      case 9:
-        loader = tt_sbit_decoder_load_compound;
-        break;
-
-      default:
-        goto Fail;
-      }
-
-      error = loader( decoder, p, p_limit, x_pos, y_pos );
-    }
-
-  Fail:
-    FT_FRAME_RELEASE( data );
-
-  Exit:
-    return error;
-  }
-
-
-  static FT_Error
-  tt_sbit_decoder_load_image( TT_SBitDecoder  decoder,
-                              FT_UInt         glyph_index,
-                              FT_Int          x_pos,
-                              FT_Int          y_pos )
-  {
-    /*
-     *  First, we find the correct strike range that applies to this
-     *  glyph index.
-     */
-
-    FT_Byte*  p          = decoder->eblc_base + decoder->strike_index_array;
-    FT_Byte*  p_limit    = decoder->eblc_limit;
-    FT_ULong  num_ranges = decoder->strike_index_count;
-    FT_UInt   start, end, index_format, image_format;
-    FT_ULong  image_start = 0, image_end = 0, image_offset;
-
-
-    for ( ; num_ranges > 0; num_ranges-- )
-    {
-      start = FT_NEXT_USHORT( p );
-      end   = FT_NEXT_USHORT( p );
-
-      if ( glyph_index >= start && glyph_index <= end )
-        goto FoundRange;
-
-      p += 4;  /* ignore index offset */
-    }
-    goto NoBitmap;
-
-  FoundRange:
-    image_offset = FT_NEXT_ULONG( p );
-
-    /* overflow check */
-    if ( decoder->eblc_base + decoder->strike_index_array + image_offset <
-           decoder->eblc_base )
-      goto Failure;
-
-    p = decoder->eblc_base + decoder->strike_index_array + image_offset;
-    if ( p + 8 > p_limit )
-      goto NoBitmap;
-
-    /* now find the glyph's location and extend within the ebdt table */
-    index_format = FT_NEXT_USHORT( p );
-    image_format = FT_NEXT_USHORT( p );
-    image_offset = FT_NEXT_ULONG ( p );
-
-    switch ( index_format )
-    {
-    case 1: /* 4-byte offsets relative to `image_offset' */
-      {
-        p += 4 * ( glyph_index - start );
-        if ( p + 8 > p_limit )
-          goto NoBitmap;
-
-        image_start = FT_NEXT_ULONG( p );
-        image_end   = FT_NEXT_ULONG( p );
-
-        if ( image_start == image_end )  /* missing glyph */
-          goto NoBitmap;
-      }
-      break;
-
-    case 2: /* big metrics, constant image size */
-      {
-        FT_ULong  image_size;
-
-
-        if ( p + 12 > p_limit )
-          goto NoBitmap;
-
-        image_size = FT_NEXT_ULONG( p );
-
-        if ( tt_sbit_decoder_load_metrics( decoder, &p, p_limit, 1 ) )
-          goto NoBitmap;
-
-        image_start = image_size * ( glyph_index - start );
-        image_end   = image_start + image_size;
-      }
-      break;
-
-    case 3: /* 2-byte offsets relative to 'image_offset' */
-      {
-        p += 2 * ( glyph_index - start );
-        if ( p + 4 > p_limit )
-          goto NoBitmap;
-
-        image_start = FT_NEXT_USHORT( p );
-        image_end   = FT_NEXT_USHORT( p );
-
-        if ( image_start == image_end )  /* missing glyph */
-          goto NoBitmap;
-      }
-      break;
-
-    case 4: /* sparse glyph array with (glyph,offset) pairs */
-      {
-        FT_ULong  mm, num_glyphs;
-
-
-        if ( p + 4 > p_limit )
-          goto NoBitmap;
-
-        num_glyphs = FT_NEXT_ULONG( p );
-
-        /* overflow check */
-        if ( p + ( num_glyphs + 1 ) * 4 < p )
-          goto Failure;
-
-        if ( p + ( num_glyphs + 1 ) * 4 > p_limit )
-          goto NoBitmap;
-
-        for ( mm = 0; mm < num_glyphs; mm++ )
-        {
-          FT_UInt  gindex = FT_NEXT_USHORT( p );
-
-
-          if ( gindex == glyph_index )
-          {
-            image_start = FT_NEXT_USHORT( p );
-            p          += 2;
-            image_end   = FT_PEEK_USHORT( p );
-            break;
-          }
-          p += 2;
-        }
-
-        if ( mm >= num_glyphs )
-          goto NoBitmap;
-      }
-      break;
-
-    case 5: /* constant metrics with sparse glyph codes */
-      {
-        FT_ULong  image_size, mm, num_glyphs;
-
-
-        if ( p + 16 > p_limit )
-          goto NoBitmap;
-
-        image_size = FT_NEXT_ULONG( p );
-
-        if ( tt_sbit_decoder_load_metrics( decoder, &p, p_limit, 1 ) )
-          goto NoBitmap;
-
-        num_glyphs = FT_NEXT_ULONG( p );
-
-        /* overflow check */
-        if ( p + 2 * num_glyphs < p )
-          goto Failure;
-
-        if ( p + 2 * num_glyphs > p_limit )
-          goto NoBitmap;
-
-        for ( mm = 0; mm < num_glyphs; mm++ )
-        {
-          FT_UInt  gindex = FT_NEXT_USHORT( p );
-
-
-          if ( gindex == glyph_index )
-            break;
-        }
-
-        if ( mm >= num_glyphs )
-          goto NoBitmap;
-
-        image_start = image_size * mm;
-        image_end   = image_start + image_size;
-      }
-      break;
-
-    default:
-      goto NoBitmap;
-    }
-
-    if ( image_start > image_end )
-      goto NoBitmap;
-
-    image_end  -= image_start;
-    image_start = image_offset + image_start;
-
-    return tt_sbit_decoder_load_bitmap( decoder,
-                                        image_format,
-                                        image_start,
-                                        image_end,
-                                        x_pos,
-                                        y_pos );
-
-  Failure:
-    return SFNT_Err_Invalid_Table;
-
-  NoBitmap:
-    return SFNT_Err_Invalid_Argument;
-  }
-
-
-  FT_LOCAL( FT_Error )
-  tt_face_load_sbit_image( TT_Face              face,
-                           FT_ULong             strike_index,
-                           FT_UInt              glyph_index,
-                           FT_UInt              load_flags,
-                           FT_Stream            stream,
-                           FT_Bitmap           *map,
-                           TT_SBit_MetricsRec  *metrics )
-  {
-    TT_SBitDecoderRec  decoder[1];
-    FT_Error           error;
-
-    FT_UNUSED( load_flags );
-    FT_UNUSED( stream );
-    FT_UNUSED( map );
-
-
-    error = tt_sbit_decoder_init( decoder, face, strike_index, metrics );
-    if ( !error )
-    {
-      error = tt_sbit_decoder_load_image( decoder, glyph_index, 0, 0 );
-      tt_sbit_decoder_done( decoder );
-    }
-
-    return error;
-  }
-
-/* EOF */