[sfnt] Clean up bitmap code.

* src/sfnt/ttsbit.c: Deleted.
* src/sfnt/ttsbit0.c: Renamed to `ttsbit.c'.
* rules.mk (SFNT_DRV_H): Updated.

4 files changed, 990 insertions, 1019 deletions

diff --git a/ChangeLog b/ChangeLog
index b2b435a66..efe4b2cc9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2013-05-10  Werner Lemberg  <wl@gnu.org>
 
+	[sfnt] Clean up bitmap code.
+
+	* src/sfnt/ttsbit.c: Deleted.
+	* src/sfnt/ttsbit0.c: Renamed to `ttsbit.c'. 
+	* rules.mk (SFNT_DRV_H): Updated.
+
+2013-05-10  Werner Lemberg  <wl@gnu.org>
+
 	*/* [FT_CONFIG_OPTION_OLD_INTERNALS]: Remove macro and guarded code.
 
 2013-05-08  Werner Lemberg  <wl@gnu.org>
diff --git a/src/sfnt/rules.mk b/src/sfnt/rules.mk
index 02cee585d..65dd1479c 100644
--- a/src/sfnt/rules.mk
+++ b/src/sfnt/rules.mk
@@ -3,7 +3,7 @@
 #
 
 
-# Copyright 1996-2000, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2011 by
+# Copyright 1996-2000, 2002-2007, 2009, 2011, 2013 by
 # David Turner, Robert Wilhelm, and Werner Lemberg.
 #
 # This file is part of the FreeType project, and may only be used, modified,
@@ -38,11 +38,8 @@ SFNT_DRV_SRC := $(SFNT_DIR)/ttload.c   \
 
 # SFNT driver headers
 #
-# Note that ttsbit0.c gets #included by ttsbit.c.
-#
 SFNT_DRV_H := $(SFNT_DRV_SRC:%c=%h)  \
-              $(SFNT_DIR)/sferrors.h \
-              $(SFNT_DIR)/ttsbit0.c
+              $(SFNT_DIR)/sferrors.h
 
 
 # SFNT driver object(s)
diff --git a/src/sfnt/ttsbit.c b/src/sfnt/ttsbit.c
index 4cc64b23e..05d7be920 100644
--- a/src/sfnt/ttsbit.c
+++ b/src/sfnt/ttsbit.c
@@ -4,7 +4,7 @@
 /*                                                                         */
 /*    TrueType and OpenType embedded bitmap support (body).                */
 /*                                                                         */
-/*  Copyright 1996-2010, 2013 by                                           */
+/*  Copyright 2005-2009, 2013 by                                           */
 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
 /*                                                                         */
 /*  This file is part of the FreeType project, and may only be used,       */
@@ -15,16 +15,991 @@
 /*                                                                         */
 /***************************************************************************/
 
+
 #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 = FT_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 = FT_THROW( 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 = FT_THROW( 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 FT_THROW( 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 FT_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 = FT_THROW( 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 = FT_THROW( 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 = FT_Err_Ok;
+    FT_UInt     width, height;
+    FT_Bitmap*  map = decoder->bitmap;
+    FT_Long     size;
+
+
+    if ( !decoder->metrics_loaded )
+    {
+      error = FT_THROW( 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 = FT_THROW( 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 FT_Err_Ok;
+
+  Fail:
+    return FT_THROW( 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 = FT_Err_Ok;
+    FT_Byte*    line;
+    FT_Int      bit_height, bit_width, pitch, width, height, line_bits, 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;
+
+    line_bits = width * decoder->bit_depth;
+
+    if ( x_pos < 0 || x_pos + width > bit_width   ||
+         y_pos < 0 || y_pos + height > bit_height )
+    {
+      error = FT_THROW( Invalid_File_Format );
+      goto Exit;
+    }
+
+    if ( p + ( ( line_bits + 7 ) >> 3 ) * height > limit )
+    {
+      error = FT_THROW( 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 = line_bits; 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 = line_bits; 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;
+  }
+
 
   /*
-   *  Alas, the memory-optimized sbit loader can't be used when implementing
-   *  the `old internals' hack
+   * 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
+   *
    */
-#include "ttsbit0.c"
 
+  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 = FT_Err_Ok;
+    FT_Byte*    line;
+    FT_Int      bit_height, bit_width, pitch, width, height, line_bits, 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;
+
+    line_bits = width * decoder->bit_depth;
+
+    if ( x_pos < 0 || x_pos + width  > bit_width  ||
+         y_pos < 0 || y_pos + height > bit_height )
+    {
+      error = FT_THROW( Invalid_File_Format );
+      goto Exit;
+    }
+
+    if ( p + ( ( line_bits * height + 7 ) >> 3 ) > limit )
+    {
+      error = FT_THROW( 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     = line_bits;
+
+
+      /* handle initial byte (in target bitmap) specially if necessary */
+      if ( x_pos )
+      {
+        w = ( line_bits < 8 - x_pos ) ? line_bits : 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 = line_bits - 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 = FT_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 = FT_THROW( 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 = FT_THROW( 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 = FT_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 */
+    p = decoder->eblc_base + decoder->strike_index_array;
+    if ( image_offset > (FT_ULong)( p_limit - p ) )
+      goto Failure;
+
+    p += 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 for p + ( num_glyphs + 1 ) * 4 */
+        if ( num_glyphs > (FT_ULong)( ( ( p_limit - p ) >> 2 ) - 1 ) )
+          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 for p + 2 * num_glyphs */
+        if ( num_glyphs > (FT_ULong)( ( p_limit - p ) >> 1 ) )
+          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 FT_THROW( Invalid_Table );
+
+  NoBitmap:
+    return FT_THROW( 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;
+  }
 
-/* END */
+/* EOF */
diff --git a/src/sfnt/ttsbit0.c b/src/sfnt/ttsbit0.c
deleted file mode 100644
index 1abca8952..000000000
--- a/src/sfnt/ttsbit0.c
+++ /dev/null
@@ -1,1009 +0,0 @@
-/***************************************************************************/
-/*                                                                         */
-/*  ttsbit0.c                                                              */
-/*                                                                         */
-/*    TrueType and OpenType embedded bitmap support (body).                */
-/*    This is a heap-optimized version.                                    */
-/*                                                                         */
-/*  Copyright 2005-2009, 2013 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 = FT_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 = FT_THROW( 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 = FT_THROW( 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 FT_THROW( 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 FT_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 = FT_THROW( 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 = FT_THROW( 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 = FT_Err_Ok;
-    FT_UInt     width, height;
-    FT_Bitmap*  map = decoder->bitmap;
-    FT_Long     size;
-
-
-    if ( !decoder->metrics_loaded )
-    {
-      error = FT_THROW( 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 = FT_THROW( 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 FT_Err_Ok;
-
-  Fail:
-    return FT_THROW( 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 = FT_Err_Ok;
-    FT_Byte*    line;
-    FT_Int      bit_height, bit_width, pitch, width, height, line_bits, 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;
-
-    line_bits = width * decoder->bit_depth;
-
-    if ( x_pos < 0 || x_pos + width > bit_width   ||
-         y_pos < 0 || y_pos + height > bit_height )
-    {
-      error = FT_THROW( Invalid_File_Format );
-      goto Exit;
-    }
-
-    if ( p + ( ( line_bits + 7 ) >> 3 ) * height > limit )
-    {
-      error = FT_THROW( 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 = line_bits; 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 = line_bits; 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 = FT_Err_Ok;
-    FT_Byte*    line;
-    FT_Int      bit_height, bit_width, pitch, width, height, line_bits, 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;
-
-    line_bits = width * decoder->bit_depth;
-
-    if ( x_pos < 0 || x_pos + width  > bit_width  ||
-         y_pos < 0 || y_pos + height > bit_height )
-    {
-      error = FT_THROW( Invalid_File_Format );
-      goto Exit;
-    }
-
-    if ( p + ( ( line_bits * height + 7 ) >> 3 ) > limit )
-    {
-      error = FT_THROW( 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     = line_bits;
-
-
-      /* handle initial byte (in target bitmap) specially if necessary */
-      if ( x_pos )
-      {
-        w = ( line_bits < 8 - x_pos ) ? line_bits : 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 = line_bits - 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 = FT_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 = FT_THROW( 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 = FT_THROW( 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 = FT_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 */
-    p = decoder->eblc_base + decoder->strike_index_array;
-    if ( image_offset > (FT_ULong)( p_limit - p ) )
-      goto Failure;
-
-    p += 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 for p + ( num_glyphs + 1 ) * 4 */
-        if ( num_glyphs > (FT_ULong)( ( ( p_limit - p ) >> 2 ) - 1 ) )
-          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 for p + 2 * num_glyphs */
-        if ( num_glyphs > (FT_ULong)( ( p_limit - p ) >> 1 ) )
-          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 FT_THROW( Invalid_Table );
-
-  NoBitmap:
-    return FT_THROW( 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 */