/lib_freetype/freetype/src/truetype/ttgload.c

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/***************************************************************************/
/*                                                                         */
/*  ttgload.c                                                              */
/*                                                                         */
/*    TrueType Glyph Loader (body).                                        */
/*                                                                         */
/*  Copyright 1996-2015 by                                                 */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_CALC_H
#include FT_INTERNAL_STREAM_H
#include FT_INTERNAL_SFNT_H
#include FT_TRUETYPE_TAGS_H
#include FT_OUTLINE_H
#include FT_TRUETYPE_DRIVER_H

#include "ttgload.h"
#include "ttpload.h"

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
#include "ttgxvar.h"
#endif

#include "tterrors.h"
#include "ttsubpix.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_ttgload


  /*************************************************************************/
  /*                                                                       */
  /* Composite glyph flags.                                                */
  /*                                                                       */
#define ARGS_ARE_WORDS             0x0001
#define ARGS_ARE_XY_VALUES         0x0002
#define ROUND_XY_TO_GRID           0x0004
#define WE_HAVE_A_SCALE            0x0008
/* reserved                        0x0010 */
#define MORE_COMPONENTS            0x0020
#define WE_HAVE_AN_XY_SCALE        0x0040
#define WE_HAVE_A_2X2              0x0080
#define WE_HAVE_INSTR              0x0100
#define USE_MY_METRICS             0x0200
#define OVERLAP_COMPOUND           0x0400
#define SCALED_COMPONENT_OFFSET    0x0800
#define UNSCALED_COMPONENT_OFFSET  0x1000


  /*************************************************************************/
  /*                                                                       */
  /* Return the horizontal metrics in font units for a given glyph.        */
  /*                                                                       */
  FT_LOCAL_DEF( void )
  TT_Get_HMetrics( TT_Face     face,
                   FT_UInt     idx,
                   FT_Short*   lsb,
                   FT_UShort*  aw )
  {
    ( (SFNT_Service)face->sfnt )->get_metrics( face, 0, idx, lsb, aw );

    FT_TRACE5(( "  advance width (font units): %d\n", *aw ));
    FT_TRACE5(( "  left side bearing (font units): %d\n", *lsb ));
  }


  /*************************************************************************/
  /*                                                                       */
  /* Return the vertical metrics in font units for a given glyph.          */
  /* See macro `TT_LOADER_SET_PP' below for explanations.                  */
  /*                                                                       */
  FT_LOCAL_DEF( void )
  TT_Get_VMetrics( TT_Face     face,
                   FT_UInt     idx,
                   FT_Pos      yMax,
                   FT_Short*   tsb,
                   FT_UShort*  ah )
  {
    if ( face->vertical_info )
      ( (SFNT_Service)face->sfnt )->get_metrics( face, 1, idx, tsb, ah );

    else if ( face->os2.version != 0xFFFFU )
    {
      *tsb = (FT_Short)( face->os2.sTypoAscender - yMax );
      *ah  = (FT_UShort)FT_ABS( face->os2.sTypoAscender -
                                face->os2.sTypoDescender );
    }

    else
    {
      *tsb = (FT_Short)( face->horizontal.Ascender - yMax );
      *ah  = (FT_UShort)FT_ABS( face->horizontal.Ascender -
                                face->horizontal.Descender );
    }

    FT_TRACE5(( "  advance height (font units): %d\n", *ah ));
    FT_TRACE5(( "  top side bearing (font units): %d\n", *tsb ));
  }


  static FT_Error
  tt_get_metrics( TT_Loader  loader,
                  FT_UInt    glyph_index )
  {
    TT_Face    face   = (TT_Face)loader->face;
#ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
    TT_Driver  driver = (TT_Driver)FT_FACE_DRIVER( face );
#endif

    FT_Error   error;
    FT_Stream  stream = loader->stream;

    FT_Short   left_bearing = 0, top_bearing = 0;
    FT_UShort  advance_width = 0, advance_height = 0;

    /* we must preserve the stream position          */
    /* (which gets altered by the metrics functions) */
    FT_ULong  pos = FT_STREAM_POS();


    TT_Get_HMetrics( face, glyph_index,
                     &left_bearing,
                     &advance_width );
    TT_Get_VMetrics( face, glyph_index,
                     loader->bbox.yMax,
                     &top_bearing,
                     &advance_height );

    if ( FT_STREAM_SEEK( pos ) )
      return error;

    loader->left_bearing = left_bearing;
    loader->advance      = advance_width;
    loader->top_bearing  = top_bearing;
    loader->vadvance     = advance_height;

#ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
    if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 &&
         loader->exec                                             )
    {
      loader->exec->sph_tweak_flags = 0;

      /* This may not be the right place for this, but it works...  */
      /* Note that we have to unconditionally load the tweaks since */
      /* it is possible that glyphs individually switch ClearType's */
      /* backwards compatibility mode on and off.                   */
      sph_set_tweaks( loader, glyph_index );
    }
#endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */

    if ( !loader->linear_def )
    {
      loader->linear_def = 1;
      loader->linear     = advance_width;
    }

    return FT_Err_Ok;
  }


#ifdef FT_CONFIG_OPTION_INCREMENTAL

  static void
  tt_get_metrics_incr_overrides( TT_Loader  loader,
                                 FT_UInt    glyph_index )
  {
    TT_Face  face = (TT_Face)loader->face;

    FT_Short   left_bearing = 0, top_bearing = 0;
    FT_UShort  advance_width = 0, advance_height = 0;


    /* If this is an incrementally loaded font check whether there are */
    /* overriding metrics for this glyph.                              */
    if ( face->root.internal->incremental_interface                           &&
         face->root.internal->incremental_interface->funcs->get_glyph_metrics )
    {
      FT_Incremental_MetricsRec  metrics;
      FT_Error                   error;


      metrics.bearing_x = loader->left_bearing;
      metrics.bearing_y = 0;
      metrics.advance   = loader->advance;
      metrics.advance_v = 0;

      error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
                face->root.internal->incremental_interface->object,
                glyph_index, FALSE, &metrics );
      if ( error )
        goto Exit;

      left_bearing  = (FT_Short)metrics.bearing_x;
      advance_width = (FT_UShort)metrics.advance;

#if 0

      /* GWW: Do I do the same for vertical metrics? */
      metrics.bearing_x = 0;
      metrics.bearing_y = loader->top_bearing;
      metrics.advance   = loader->vadvance;

      error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
                face->root.internal->incremental_interface->object,
                glyph_index, TRUE, &metrics );
      if ( error )
        goto Exit;

      top_bearing    = (FT_Short)metrics.bearing_y;
      advance_height = (FT_UShort)metrics.advance;

#endif /* 0 */

      loader->left_bearing = left_bearing;
      loader->advance      = advance_width;
      loader->top_bearing  = top_bearing;
      loader->vadvance     = advance_height;

      if ( !loader->linear_def )
      {
        loader->linear_def = 1;
        loader->linear     = advance_width;
      }
    }

  Exit:
    return;
  }

#endif /* FT_CONFIG_OPTION_INCREMENTAL */


  /*************************************************************************/
  /*                                                                       */
  /* Translates an array of coordinates.                                   */
  /*                                                                       */
  static void
  translate_array( FT_UInt     n,
                   FT_Vector*  coords,
                   FT_Pos      delta_x,
                   FT_Pos      delta_y )
  {
    FT_UInt  k;


    if ( delta_x )
      for ( k = 0; k < n; k++ )
        coords[k].x += delta_x;

    if ( delta_y )
      for ( k = 0; k < n; k++ )
        coords[k].y += delta_y;
  }


  /*************************************************************************/
  /*                                                                       */
  /* The following functions are used by default with TrueType fonts.      */
  /* However, they can be replaced by alternatives if we need to support   */
  /* TrueType-compressed formats (like MicroType) in the future.           */
  /*                                                                       */
  /*************************************************************************/

  FT_CALLBACK_DEF( FT_Error )
  TT_Access_Glyph_Frame( TT_Loader  loader,
                         FT_UInt    glyph_index,
                         FT_ULong   offset,
                         FT_UInt    byte_count )
  {
    FT_Error   error;
    FT_Stream  stream = loader->stream;

    /* for non-debug mode */
    FT_UNUSED( glyph_index );


    FT_TRACE4(( "Glyph %ld\n", glyph_index ));

    /* the following line sets the `error' variable through macros! */
    if ( FT_STREAM_SEEK( offset ) || FT_FRAME_ENTER( byte_count ) )
      return error;

    loader->cursor = stream->cursor;
    loader->limit  = stream->limit;

    return FT_Err_Ok;
  }


  FT_CALLBACK_DEF( void )
  TT_Forget_Glyph_Frame( TT_Loader  loader )
  {
    FT_Stream  stream = loader->stream;


    FT_FRAME_EXIT();
  }


  FT_CALLBACK_DEF( FT_Error )
  TT_Load_Glyph_Header( TT_Loader  loader )
  {
    FT_Byte*  p     = loader->cursor;
    FT_Byte*  limit = loader->limit;


    if ( p + 10 > limit )
      return FT_THROW( Invalid_Outline );

    loader->n_contours = FT_NEXT_SHORT( p );

    loader->bbox.xMin = FT_NEXT_SHORT( p );
    loader->bbox.yMin = FT_NEXT_SHORT( p );
    loader->bbox.xMax = FT_NEXT_SHORT( p );
    loader->bbox.yMax = FT_NEXT_SHORT( p );

    FT_TRACE5(( "  # of contours: %d\n", loader->n_contours ));
    FT_TRACE5(( "  xMin: %4d  xMax: %4d\n", loader->bbox.xMin,
                                            loader->bbox.xMax ));
    FT_TRACE5(( "  yMin: %4d  yMax: %4d\n", loader->bbox.yMin,
                                            loader->bbox.yMax ));
    loader->cursor = p;

    return FT_Err_Ok;
  }


  FT_CALLBACK_DEF( FT_Error )
  TT_Load_Simple_Glyph( TT_Loader  load )
  {
    FT_Error        error;
    FT_Byte*        p          = load->cursor;
    FT_Byte*        limit      = load->limit;
    FT_GlyphLoader  gloader    = load->gloader;
    FT_Int          n_contours = load->n_contours;
    FT_Outline*     outline;
    FT_UShort       n_ins;
    FT_Int          n_points;
    FT_ULong        tmp;

    FT_Byte         *flag, *flag_limit;
    FT_Byte         c, count;
    FT_Vector       *vec, *vec_limit;
    FT_Pos          x;
    FT_Short        *cont, *cont_limit, prev_cont;
    FT_Int          xy_size = 0;


    /* check that we can add the contours to the glyph */
    error = FT_GLYPHLOADER_CHECK_POINTS( gloader, 0, n_contours );
    if ( error )
      goto Fail;

    /* reading the contours' endpoints & number of points */
    cont       = gloader->current.outline.contours;
    cont_limit = cont + n_contours;

    /* check space for contours array + instructions count */
    if ( n_contours >= 0xFFF || p + ( n_contours + 1 ) * 2 > limit )
      goto Invalid_Outline;

    prev_cont = FT_NEXT_SHORT( p );

    if ( n_contours > 0 )
      cont[0] = prev_cont;

    if ( prev_cont < 0 )
      goto Invalid_Outline;

    for ( cont++; cont < cont_limit; cont++ )
    {
      cont[0] = FT_NEXT_SHORT( p );
      if ( cont[0] <= prev_cont )
      {
        /* unordered contours: this is invalid */
        goto Invalid_Outline;
      }
      prev_cont = cont[0];
    }

    n_points = 0;
    if ( n_contours > 0 )
    {
      n_points = cont[-1] + 1;
      if ( n_points < 0 )
        goto Invalid_Outline;
    }

    /* note that we will add four phantom points later */
    error = FT_GLYPHLOADER_CHECK_POINTS( gloader, n_points + 4, 0 );
    if ( error )
      goto Fail;

    /* reading the bytecode instructions */
    load->glyph->control_len  = 0;
    load->glyph->control_data = NULL;

    if ( p + 2 > limit )
      goto Invalid_Outline;

    n_ins = FT_NEXT_USHORT( p );

    FT_TRACE5(( "  Instructions size: %u\n", n_ins ));

    /* check it */
    if ( ( limit - p ) < n_ins )
    {
      FT_TRACE0(( "TT_Load_Simple_Glyph: instruction count mismatch\n" ));
      error = FT_THROW( Too_Many_Hints );
      goto Fail;
    }

#ifdef TT_USE_BYTECODE_INTERPRETER

    if ( IS_HINTED( load->load_flags ) )
    {
      /* we don't trust `maxSizeOfInstructions' in the `maxp' table */
      /* and thus update the bytecode array size by ourselves       */

      tmp   = load->exec->glyphSize;
      error = Update_Max( load->exec->memory,
                          &tmp,
                          sizeof ( FT_Byte ),
                          (void*)&load->exec->glyphIns,
                          n_ins );

      load->exec->glyphSize = (FT_UShort)tmp;
      if ( error )
        return error;

      load->glyph->control_len  = n_ins;
      load->glyph->control_data = load->exec->glyphIns;

      FT_MEM_COPY( load->exec->glyphIns, p, (FT_Long)n_ins );
    }

#endif /* TT_USE_BYTECODE_INTERPRETER */

    p += n_ins;

    outline = &gloader->current.outline;

    /* reading the point tags */
    flag       = (FT_Byte*)outline->tags;
    flag_limit = flag + n_points;

    FT_ASSERT( flag != NULL );

    while ( flag < flag_limit )
    {
      if ( p + 1 > limit )
        goto Invalid_Outline;

      *flag++ = c = FT_NEXT_BYTE( p );
      if ( c & 8 )
      {
        if ( p + 1 > limit )
          goto Invalid_Outline;

        count = FT_NEXT_BYTE( p );
        if ( flag + (FT_Int)count > flag_limit )
          goto Invalid_Outline;

        for ( ; count > 0; count-- )
          *flag++ = c;
      }
    }

    /* reading the X coordinates */

    vec       = outline->points;
    vec_limit = vec + n_points;
    flag      = (FT_Byte*)outline->tags;
    x         = 0;

    if ( p + xy_size > limit )
      goto Invalid_Outline;

    for ( ; vec < vec_limit; vec++, flag++ )
    {
      FT_Pos   y = 0;
      FT_Byte  f = *flag;


      if ( f & 2 )
      {
        if ( p + 1 > limit )
          goto Invalid_Outline;

        y = (FT_Pos)FT_NEXT_BYTE( p );
        if ( ( f & 16 ) == 0 )
          y = -y;
      }
      else if ( ( f & 16 ) == 0 )
      {
        if ( p + 2 > limit )
          goto Invalid_Outline;

        y = (FT_Pos)FT_NEXT_SHORT( p );
      }

      x     += y;
      vec->x = x;
      /* the cast is for stupid compilers */
      *flag  = (FT_Byte)( f & ~( 2 | 16 ) );
    }

    /* reading the Y coordinates */

    vec       = gloader->current.outline.points;
    vec_limit = vec + n_points;
    flag      = (FT_Byte*)outline->tags;
    x         = 0;

    for ( ; vec < vec_limit; vec++, flag++ )
    {
      FT_Pos   y = 0;
      FT_Byte  f = *flag;


      if ( f & 4 )
      {
        if ( p + 1 > limit )
          goto Invalid_Outline;

        y = (FT_Pos)FT_NEXT_BYTE( p );
        if ( ( f & 32 ) == 0 )
          y = -y;
      }
      else if ( ( f & 32 ) == 0 )
      {
        if ( p + 2 > limit )
          goto Invalid_Outline;

        y = (FT_Pos)FT_NEXT_SHORT( p );
      }

      x     += y;
      vec->y = x;
      /* the cast is for stupid compilers */
      *flag  = (FT_Byte)( f & FT_CURVE_TAG_ON );
    }

    outline->n_points   = (FT_Short)n_points;
    outline->n_contours = (FT_Short)n_contours;

    load->cursor = p;

  Fail:
    return error;

  Invalid_Outline:
    error = FT_THROW( Invalid_Outline );
    goto Fail;
  }


  FT_CALLBACK_DEF( FT_Error )
  TT_Load_Composite_Glyph( TT_Loader  loader )
  {
    FT_Error        error;
    FT_Byte*        p       = loader->cursor;
    FT_Byte*        limit   = loader->limit;
    FT_GlyphLoader  gloader = loader->gloader;
    FT_SubGlyph     subglyph;
    FT_UInt         num_subglyphs;


    num_subglyphs = 0;

    do
    {
      FT_Fixed  xx, xy, yy, yx;
      FT_UInt   count;


      /* check that we can load a new subglyph */
      error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs + 1 );
      if ( error )
        goto Fail;

      /* check space */
      if ( p + 4 > limit )
        goto Invalid_Composite;

      subglyph = gloader->current.subglyphs + num_subglyphs;

      subglyph->arg1 = subglyph->arg2 = 0;

      subglyph->flags = FT_NEXT_USHORT( p );
      subglyph->index = FT_NEXT_USHORT( p );

      /* check space */
      count = 2;
      if ( subglyph->flags & ARGS_ARE_WORDS )
        count += 2;
      if ( subglyph->flags & WE_HAVE_A_SCALE )
        count += 2;
      else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
        count += 4;
      else if ( subglyph->flags & WE_HAVE_A_2X2 )
        count += 8;

      if ( p + count > limit )
        goto Invalid_Composite;

      /* read arguments */
      if ( subglyph->flags & ARGS_ARE_XY_VALUES )
      {
        if ( subglyph->flags & ARGS_ARE_WORDS )
        {
          subglyph->arg1 = FT_NEXT_SHORT( p );
          subglyph->arg2 = FT_NEXT_SHORT( p );
        }
        else
        {
          subglyph->arg1 = FT_NEXT_CHAR( p );
          subglyph->arg2 = FT_NEXT_CHAR( p );
        }
      }
      else
      {
        if ( subglyph->flags & ARGS_ARE_WORDS )
        {
          subglyph->arg1 = (FT_Int)FT_NEXT_USHORT( p );
          subglyph->arg2 = (FT_Int)FT_NEXT_USHORT( p );
        }
        else
        {
          subglyph->arg1 = (FT_Int)FT_NEXT_BYTE( p );
          subglyph->arg2 = (FT_Int)FT_NEXT_BYTE( p );
        }
      }

      /* read transform */
      xx = yy = 0x10000L;
      xy = yx = 0;

      if ( subglyph->flags & WE_HAVE_A_SCALE )
      {
        xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
        yy = xx;
      }
      else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
      {
        xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
        yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
      }
      else if ( subglyph->flags & WE_HAVE_A_2X2 )
      {
        xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
        yx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
        xy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
        yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
      }

      subglyph->transform.xx = xx;
      subglyph->transform.xy = xy;
      subglyph->transform.yx = yx;
      subglyph->transform.yy = yy;

      num_subglyphs++;

    } while ( subglyph->flags & MORE_COMPONENTS );

    gloader->current.num_subglyphs = num_subglyphs;

#ifdef TT_USE_BYTECODE_INTERPRETER

    {
      FT_Stream  stream = loader->stream;


      /* we must undo the FT_FRAME_ENTER in order to point */
      /* to the composite instructions, if we find some.   */
      /* We will process them later.                       */
      /*                                                   */
      loader->ins_pos = (FT_ULong)( FT_STREAM_POS() +
                                    p - limit );
    }

#endif

    loader->cursor = p;

  Fail:
    return error;

  Invalid_Composite:
    error = FT_THROW( Invalid_Composite );
    goto Fail;
  }


  FT_LOCAL_DEF( void )
  TT_Init_Glyph_Loading( TT_Face  face )
  {
    face->access_glyph_frame   = TT_Access_Glyph_Frame;
    face->read_glyph_header    = TT_Load_Glyph_Header;
    face->read_simple_glyph    = TT_Load_Simple_Glyph;
    face->read_composite_glyph = TT_Load_Composite_Glyph;
    face->forget_glyph_frame   = TT_Forget_Glyph_Frame;
  }


  static void
  tt_prepare_zone( TT_GlyphZone  zone,
                   FT_GlyphLoad  load,
                   FT_UInt       start_point,
                   FT_UInt       start_contour )
  {
    zone->n_points    = (FT_UShort)load->outline.n_points -
                          (FT_UShort)start_point;
    zone->n_contours  = load->outline.n_contours -
                          (FT_Short)start_contour;
    zone->org         = load->extra_points + start_point;
    zone->cur         = load->outline.points + start_point;
    zone->orus        = load->extra_points2 + start_point;
    zone->tags        = (FT_Byte*)load->outline.tags + start_point;
    zone->contours    = (FT_UShort*)load->outline.contours + start_contour;
    zone->first_point = (FT_UShort)start_point;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Hint_Glyph                                                      */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Hint the glyph using the zone prepared by the caller.  Note that   */
  /*    the zone is supposed to include four phantom points.               */
  /*                                                                       */
  static FT_Error
  TT_Hint_Glyph( TT_Loader  loader,
                 FT_Bool    is_composite )
  {
#ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
    TT_Face    face   = (TT_Face)loader->face;
    TT_Driver  driver = (TT_Driver)FT_FACE_DRIVER( face );
#endif

    TT_GlyphZone  zone = &loader->zone;

#ifdef TT_USE_BYTECODE_INTERPRETER
    FT_Long       n_ins;
#else
    FT_UNUSED( is_composite );
#endif


#ifdef TT_USE_BYTECODE_INTERPRETER
    if ( loader->glyph->control_len > 0xFFFFL )
    {
      FT_TRACE1(( "TT_Hint_Glyph: too long instructions" ));
      FT_TRACE1(( " (0x%lx byte) is truncated\n",
                 loader->glyph->control_len ));
    }
    n_ins = loader->glyph->control_len;

    /* save original point position in org */
    if ( n_ins > 0 )
      FT_ARRAY_COPY( zone->org, zone->cur, zone->n_points );

    /* Reset graphics state. */
    loader->exec->GS = ((TT_Size)loader->size)->GS;

    /* XXX: UNDOCUMENTED! Hinting instructions of a composite glyph */
    /*      completely refer to the (already) hinted subglyphs.     */
    if ( is_composite )
    {
      loader->exec->metrics.x_scale = 1 << 16;
      loader->exec->metrics.y_scale = 1 << 16;

      FT_ARRAY_COPY( zone->orus, zone->cur, zone->n_points );
    }
    else
    {
      loader->exec->metrics.x_scale =
        ((TT_Size)loader->size)->metrics.x_scale;
      loader->exec->metrics.y_scale =
        ((TT_Size)loader->size)->metrics.y_scale;
    }
#endif

    /* round phantom points */
    zone->cur[zone->n_points - 4].x =
      FT_PIX_ROUND( zone->cur[zone->n_points - 4].x );
    zone->cur[zone->n_points - 3].x =
      FT_PIX_ROUND( zone->cur[zone->n_points - 3].x );
    zone->cur[zone->n_points - 2].y =
      FT_PIX_ROUND( zone->cur[zone->n_points - 2].y );
    zone->cur[zone->n_points - 1].y =
      FT_PIX_ROUND( zone->cur[zone->n_points - 1].y );

#ifdef TT_USE_BYTECODE_INTERPRETER

    if ( n_ins > 0 )
    {
      FT_Error  error;

      FT_GlyphLoader  gloader         = loader->gloader;
      FT_Outline      current_outline = gloader->current.outline;


      TT_Set_CodeRange( loader->exec, tt_coderange_glyph,
                        loader->exec->glyphIns, n_ins );

      loader->exec->is_composite = is_composite;
      loader->exec->pts          = *zone;

      error = TT_Run_Context( loader->exec );
      if ( error && loader->exec->pedantic_hinting )
        return error;

      /* store drop-out mode in bits 5-7; set bit 2 also as a marker */
      current_outline.tags[0] |=
        ( loader->exec->GS.scan_type << 5 ) | FT_CURVE_TAG_HAS_SCANMODE;
    }

#endif

    /* save glyph phantom points */
    loader->pp1 = zone->cur[zone->n_points - 4];
    loader->pp2 = zone->cur[zone->n_points - 3];
    loader->pp3 = zone->cur[zone->n_points - 2];
    loader->pp4 = zone->cur[zone->n_points - 1];

#ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
    if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
    {
      if ( loader->exec->sph_tweak_flags & SPH_TWEAK_DEEMBOLDEN )
        FT_Outline_EmboldenXY( &loader->gloader->current.outline, -24, 0 );

      else if ( loader->exec->sph_tweak_flags & SPH_TWEAK_EMBOLDEN )
        FT_Outline_EmboldenXY( &loader->gloader->current.outline, 24, 0 );
    }
#endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */

    return FT_Err_Ok;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Process_Simple_Glyph                                            */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Once a simple glyph has been loaded, it needs to be processed.     */
  /*    Usually, this means scaling and hinting through bytecode           */
  /*    interpretation.                                                    */
  /*                                                                       */
  static FT_Error
  TT_Process_Simple_Glyph( TT_Loader  loader )
  {
    FT_GlyphLoader  gloader = loader->gloader;
    FT_Error        error   = FT_Err_Ok;
    FT_Outline*     outline;
    FT_Int          n_points;


    outline  = &gloader->current.outline;
    n_points = outline->n_points;

    /* set phantom points */

    outline->points[n_points    ] = loader->pp1;
    outline->points[n_points + 1] = loader->pp2;
    outline->points[n_points + 2] = loader->pp3;
    outline->points[n_points + 3] = loader->pp4;

    outline->tags[n_points    ] = 0;
    outline->tags[n_points + 1] = 0;
    outline->tags[n_points + 2] = 0;
    outline->tags[n_points + 3] = 0;

    n_points += 4;

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT

    if ( ((TT_Face)loader->face)->doblend )
    {
      /* Deltas apply to the unscaled data. */
      error = TT_Vary_Apply_Glyph_Deltas( (TT_Face)(loader->face),
                                           loader->glyph_index,
                                           outline,
                                           (FT_UInt)n_points );
      if ( error )
        return error;
    }

#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */

    if ( IS_HINTED( loader->load_flags ) )
    {
      tt_prepare_zone( &loader->zone, &gloader->current, 0, 0 );

      FT_ARRAY_COPY( loader->zone.orus, loader->zone.cur,
                     loader->zone.n_points + 4 );
    }

    {
#ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
      TT_Face    face   = (TT_Face)loader->face;
      TT_Driver  driver = (TT_Driver)FT_FACE_DRIVER( face );

      FT_String*  family         = face->root.family_name;
      FT_UInt     ppem           = loader->size->metrics.x_ppem;
      FT_String*  style          = face->root.style_name;
      FT_UInt     x_scale_factor = 1000;
#endif

      FT_Vector*  vec   = outline->points;
      FT_Vector*  limit = outline->points + n_points;

      FT_Fixed  x_scale = 0; /* pacify compiler */
      FT_Fixed  y_scale = 0;

      FT_Bool  do_scale = FALSE;


#ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING

      if ( driver->interpreter_version == TT_INTERPRETER_VERSION_38 )
      {
        /* scale, but only if enabled and only if TT hinting is being used */
        if ( IS_HINTED( loader->load_flags ) )
          x_scale_factor = sph_test_tweak_x_scaling( face,
                                                     family,
                                                     ppem,
                                                     style,
                                                     loader->glyph_index );
        /* scale the glyph */
        if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 ||
             x_scale_factor != 1000                         )
        {
          x_scale = FT_MulDiv( ((TT_Size)loader->size)->metrics.x_scale,
                               (FT_Long)x_scale_factor, 1000 );
          y_scale = ((TT_Size)loader->size)->metrics.y_scale;

          /* compensate for any scaling by de/emboldening; */
          /* the amount was determined via experimentation */
          if ( x_scale_factor != 1000 && ppem > 11 )
            FT_Outline_EmboldenXY( outline,
                                   FT_MulFix( 1280 * ppem,
                                              1000 - x_scale_factor ),
                                   0 );
          do_scale = TRUE;
        }
      }
      else

#endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */

      {
        /* scale the glyph */
        if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
        {
          x_scale = ((TT_Size)loader->size)->metrics.x_scale;
          y_scale = ((TT_Size)loader->size)->metrics.y_scale;

          do_scale = TRUE;
        }
      }

      if ( do_scale )
      {
        for ( ; vec < limit; vec++ )
        {
          vec->x = FT_MulFix( vec->x, x_scale );
          vec->y = FT_MulFix( vec->y, y_scale );
        }

        loader->pp1 = outline->points[n_points - 4];
        loader->pp2 = outline->points[n_points - 3];
        loader->pp3 = outline->points[n_points - 2];
        loader->pp4 = outline->points[n_points - 1];
      }
    }

    if ( IS_HINTED( loader->load_flags ) )
    {
      loader->zone.n_points += 4;

      error = TT_Hint_Glyph( loader, 0 );
    }

    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Process_Composite_Component                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Once a composite component has been loaded, it needs to be         */
  /*    processed.  Usually, this means transforming and translating.      */
  /*                                                                       */
  static FT_Error
  TT_Process_Composite_Component( TT_Loader    loader,
                                  FT_SubGlyph  subglyph,
                                  FT_UInt      start_point,
                                  FT_UInt      num_base_points )
  {
    FT_GlyphLoader  gloader    = loader->gloader;
    FT_Vector*      base_vec   = gloader->base.outline.points;
    FT_UInt         num_points = (FT_UInt)gloader->base.outline.n_points;
    FT_Bool         have_scale;
    FT_Pos          x, y;


    have_scale = FT_BOOL( subglyph->flags & ( WE_HAVE_A_SCALE     |
                                              WE_HAVE_AN_XY_SCALE |
                                              WE_HAVE_A_2X2       ) );

    /* perform the transform required for this subglyph */
    if ( have_scale )
    {
      FT_UInt  i;


      for ( i = num_base_points; i < num_points; i++ )
        FT_Vector_Transform( base_vec + i, &subglyph->transform );
    }

    /* get offset */
    if ( !( subglyph->flags & ARGS_ARE_XY_VALUES ) )
    {
      FT_UInt     k = (FT_UInt)subglyph->arg1;
      FT_UInt     l = (FT_UInt)subglyph->arg2;
      FT_Vector*  p1;
      FT_Vector*  p2;


      /* match l-th point of the newly loaded component to the k-th point */
      /* of the previously loaded components.                             */

      /* change to the point numbers used by our outline */
      k += start_point;
      l += num_base_points;
      if ( k >= num_base_points ||
           l >= num_points      )
        return FT_THROW( Invalid_Composite );

      p1 = gloader->base.outline.points + k;
      p2 = gloader->base.outline.points + l;

      x = p1->x - p2->x;
      y = p1->y - p2->y;
    }
    else
    {
      x = subglyph->arg1;
      y = subglyph->arg2;

      if ( !x && !y )
        return FT_Err_Ok;

      /* Use a default value dependent on                                  */
      /* TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED.  This is useful for old */
      /* TT fonts which don't set the xxx_COMPONENT_OFFSET bit.            */

      if ( have_scale &&
#ifdef TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED
           !( subglyph->flags & UNSCALED_COMPONENT_OFFSET ) )
#else
            ( subglyph->flags & SCALED_COMPONENT_OFFSET ) )
#endif
      {

#if 0

        /*******************************************************************/
        /*                                                                 */
        /* This algorithm is what Apple documents.  But it doesn't work.   */
        /*                                                                 */
        int  a = subglyph->transform.xx > 0 ?  subglyph->transform.xx
                                            : -subglyph->transform.xx;
        int  b = subglyph->transform.yx > 0 ?  subglyph->transform.yx
                                            : -subglyph->transform.yx;
        int  c = subglyph->transform.xy > 0 ?  subglyph->transform.xy
                                            : -subglyph->transform.xy;
        int  d = subglyph->transform.yy > 0 ? subglyph->transform.yy
                                            : -subglyph->transform.yy;
        int  m = a > b ? a : b;
        int  n = c > d ? c : d;


        if ( a - b <= 33 && a - b >= -33 )
          m *= 2;
        if ( c - d <= 33 && c - d >= -33 )
          n *= 2;
        x = FT_MulFix( x, m );
        y = FT_MulFix( y, n );

#else /* 1 */

        /*******************************************************************/
        /*                                                                 */
        /* This algorithm is a guess and works much better than the above. */
        /*                                                                 */
        FT_Fixed  mac_xscale = FT_Hypot( subglyph->transform.xx,
                                         subglyph->transform.xy );
        FT_Fixed  mac_yscale = FT_Hypot( subglyph->transform.yy,
                                         subglyph->transform.yx );


        x = FT_MulFix( x, mac_xscale );
        y = FT_MulFix( y, mac_yscale );

#endif /* 1 */

      }

      if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
      {
        FT_Fixed  x_scale = ((TT_Size)loader->size)->metrics.x_scale;
        FT_Fixed  y_scale = ((TT_Size)loader->size)->metrics.y_scale;


        x = FT_MulFix( x, x_scale );
        y = FT_MulFix( y, y_scale );

        if ( subglyph->flags & ROUND_XY_TO_GRID )
        {
          x = FT_PIX_ROUND( x );
          y = FT_PIX_ROUND( y );
        }
      }
    }

    if ( x || y )
      translate_array( num_points - num_base_points,
                       base_vec + num_base_points,
                       x, y );

    return FT_Err_Ok;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Process_Composite_Glyph                                         */
  /*                                                                       */
  /* <Description>                                                         */
  /*    This is slightly different from TT_Process_Simple_Glyph, in that   */
  /*    its sole purpose is to hint the glyph.  Thus this function is      */
  /*    only available when bytecode interpreter is enabled.               */
  /*                                                                       */
  static FT_Error
  TT_Process_Composite_Glyph( TT_Loader  loader,
                              FT_UInt    start_point,
                              FT_UInt    start_contour )
  {
    FT_Error     error;
    FT_Outline*  outline;
    FT_UInt      i;


    outline = &loader->gloader->base.outline;

    /* make room for phantom points */
    error = FT_GLYPHLOADER_CHECK_POINTS( loader->gloader,
                                         outline->n_points + 4,
                                         0 );
    if ( error )
      return error;

    outline->points[outline->n_points    ] = loader->pp1;
    outline->points[outline->n_points + 1] = loader->pp2;
    outline->points[outline->n_points + 2] = loader->pp3;
    outline->points[outline->n_points + 3] = loader->pp4;

    outline->tags[outline->n_points    ] = 0;
    outline->tags[outline->n_points + 1] = 0;
    outline->tags[outline->n_points + 2] = 0;
    outline->tags[outline->n_points + 3] = 0;

#ifdef TT_USE_BYTECODE_INTERPRETER

    {
      FT_Stream  stream = loader->stream;
      FT_UShort  n_ins, max_ins;
      FT_ULong   tmp;


      /* TT_Load_Composite_Glyph only gives us the offset of instructions */
      /* so we read them here                                             */
      if ( FT_STREAM_SEEK( loader->ins_pos ) ||
           FT_READ_USHORT( n_ins )           )
        return error;

      FT_TRACE5(( "  Instructions size = %d\n", n_ins ));

      /* check it */
      max_ins = ((TT_Face)loader->face)->max_profile.maxSizeOfInstructions;
      if ( n_ins > max_ins )
      {
        /* don't trust `maxSizeOfInstructions'; */
        /* only do a rough safety check         */
        if ( (FT_Int)n_ins > loader->byte_len )
        {
          FT_TRACE1(( "TT_Process_Composite_Glyph:"
                      " too many instructions (%d) for glyph with length %d\n",
                      n_ins, loader->byte_len ));
          return FT_THROW( Too_Many_Hints );
        }

        tmp   = loader->exec->glyphSize;
        error = Update_Max( loader->exec->memory,
                            &tmp,
                            sizeof ( FT_Byte ),
                            (void*)&loader->exec->glyphIns,
                            n_ins );

        loader->exec->glyphSize = (FT_UShort)tmp;
        if ( error )
          return error;
      }
      else if ( n_ins == 0 )
        return FT_Err_Ok;

      if ( FT_STREAM_READ( loader->exec->glyphIns, n_ins ) )
        return error;

      loader->glyph->control_data = loader->exec->glyphIns;
      loader->glyph->control_len  = n_ins;
    }

#endif

    tt_prepare_zone( &loader->zone, &loader->gloader->base,
                     start_point, start_contour );

    /* Some points are likely touched during execution of  */
    /* instructions on components.  So let's untouch them. */
    for ( i = 0; i < loader->zone.n_points; i++ )
      loader->zone.tags[i] &= ~FT_CURVE_TAG_TOUCH_BOTH;

    loader->zone.n_points += 4;

    return TT_Hint_Glyph( loader, 1 );
  }


  /*
   * Calculate the phantom points
   *
   * Defining the right side bearing (rsb) as
   *
   *   rsb = aw - (lsb + xmax - xmin)
   *
   * (with `aw' the advance width, `lsb' the left side bearing, and `xmin'
   * and `xmax' the glyph's minimum and maximum x value), the OpenType
   * specification defines the initial position of horizontal phantom points
   * as
   *
   *   pp1 = (round(xmin - lsb), 0)      ,
   *   pp2 = (round(pp1 + aw), 0)        .
   *
   * Note that the rounding to the grid (in the device space) is not
   * documented currently in the specification.
   *
   * However, the specification lacks the precise definition of vertical
   * phantom points.  Greg Hitchcock provided the following explanation.
   *
   * - a `vmtx' table is present
   *
   *   For any glyph, the minimum and maximum y values (`ymin' and `ymax')
   *   are given in the `glyf' table, the top side bearing (tsb) and advance
   *   height (ah) are given in the `vmtx' table.  The bottom side bearing
   *   (bsb) is then calculated as
   *
   *     bsb = ah - (tsb + ymax - ymin)       ,
   *
   *   and the initial position of vertical phantom points is
   *
   *     pp3 = (x, round(ymax + tsb))       ,
   *     pp4 = (x, round(pp3 - ah))         .
   *
   *   See below for value `x'.
   *
   * - no `vmtx' table in the font
   *
   *   If there is an `OS/2' table, we set
   *
   *     DefaultAscender = sTypoAscender       ,
   *     DefaultDescender = sTypoDescender     ,
   *
   *   otherwise we use data from the `hhea' table:
   *
   *     DefaultAscender = Ascender         ,
   *     DefaultDescender = Descender       .
   *
   *   With these two variables we can now set
   *
   *     ah = DefaultAscender - sDefaultDescender    ,
   *     tsb = DefaultAscender - yMax                ,
   *
   *   and proceed as if a `vmtx' table was present.
   *
   * Usually we have
   *
   *   x = aw / 2      ,                                                (1)
   *
   * but there is one compatibility case where it can be set to
   *
   *   x = -DefaultDescender -
   *         ((DefaultAscender - DefaultDescender - aw) / 2)     .      (2)
   *
   * and another one with
   *
   *   x = 0     .                                                      (3)
   *
   * In Windows, the history of those values is quite complicated,
   * depending on the hinting engine (that is, the graphics framework).
   *
   *   framework        from                 to       formula
   *  ----------------------------------------------------------
   *    GDI       Windows 98               current      (1)
   *              (Windows 2000 for NT)
   *    GDI+      Windows XP               Windows 7    (2)
   *    GDI+      Windows 8                current      (3)
   *    DWrite    Windows 7                current      (3)
   *
   * For simplicity, FreeType uses (1) for grayscale subpixel hinting and
   * (3) for everything else.
   *
   */
#ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING

#define TT_LOADER_SET_PP( loader )                                          \
          do                                                                \
          {                                                                 \
            FT_Bool  subpixel_hinting_ = loader->exec                       \
                                           ? loader->exec->subpixel_hinting \
                                           : 0;                             \
            FT_Bool  grayscale_        = loader->exec                       \
                                           ? loader->exec->grayscale        \
                                           : 0;                             \
            FT_Bool  use_aw_2_         = (FT_Bool)( subpixel_hinting_ &&    \
                                                    grayscale_        );    \
                                                                            \
                                                                            \
            (loader)->pp1.x = (loader)->bbox.xMin - (loader)->left_bearing; \
            (loader)->pp1.y = 0;                                            \
            (loader)->pp2.x = (loader)->pp1.x + (loader)->advance;          \
            (loader)->pp2.y = 0;                                            \
                                                                            \
            (loader)->pp3.x = use_aw_2_ ? (loader)->advance / 2 : 0;        \
            (loader)->pp3.y = (loader)->bbox.yMax + (loader)->top_bearing;  \
            (loader)->pp4.x = use_aw_2_ ? (loader)->advance / 2 : 0;        \
            (loader)->pp4.y = (loader)->pp3.y - (loader)->vadvance;         \
          } while ( 0 )

#else /* !TT_CONFIG_OPTION_SUBPIXEL_HINTING */

#define TT_LOADER_SET_PP( loader )                                          \
          do                                                                \
          {                                                                 \
            (loader)->pp1.x = (loader)->bbox.xMin - (loader)->left_bearing; \
            (loader)->pp1.y = 0;                                            \
            (loader)->pp2.x = (loader)->pp1.x + (loader)->advance;          \
            (loader)->pp2.y = 0;                                            \
                                                                            \
            (loader)->pp3.x = 0;                                            \
            (loader)->pp3.y = (loader)->bbox.yMax + (loader)->top_bearing;  \
            (loader)->pp4.x = 0;                                            \
            (loader)->pp4.y = (loader)->pp3.y - (loader)->vadvance;         \
          } while ( 0 )

#endif /* !TT_CONFIG_OPTION_SUBPIXEL_HINTING */


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    load_truetype_glyph                                                */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Loads a given truetype glyph.  Handles composites and uses a       */
  /*    TT_Loader object.                                                  */
  /*                                                                       */
  static FT_Error
  load_truetype_glyph( TT_Loader  loader,
                       FT_UInt    glyph_index,
                       FT_UInt    recurse_count,
                       FT_Bool    header_only )
  {
    FT_Error        error        = FT_Err_Ok;
    FT_Fixed        x_scale, y_scale;
    FT_ULong        offset;
    TT_Face         face         = (TT_Face)loader->face;
    FT_GlyphLoader  gloader      = loader->gloader;
    FT_Bool         opened_frame = 0;

#ifdef FT_CONFIG_OPTION_INCREMENTAL
    FT_StreamRec    inc_stream;
    FT_Data         glyph_data;
    FT_Bool         glyph_data_loaded = 0;
#endif


    /* some fonts have an incorrect value of `maxComponentDepth', */
    /* thus we allow depth 1 to catch the majority of them        */
    if ( recurse_count > 1                                   &&
         recurse_count > face->max_profile.maxComponentDepth )
    {
      error = FT_THROW( Invalid_Composite );
      goto Exit;
    }

#ifndef FT_CONFIG_OPTION_INCREMENTAL
    /* check glyph index */
    if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
    {
      error = FT_THROW( Invalid_Glyph_Index );
      goto Exit;
    }
#endif

    loader->glyph_index = glyph_index;

    if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
    {
      x_scale = ((TT_Size)loader->size)->metrics.x_scale;
      y_scale = ((TT_Size)loader->size)->metrics.y_scale;
    }
    else
    {
      x_scale = 0x10000L;
      y_scale = 0x10000L;
    }

    /* Set `offset' to the start of the glyph relative to the start of */
    /* the `glyf' table, and `byte_len' to the length of the glyph in  */
    /* bytes.                                                          */

#ifdef FT_CONFIG_OPTION_INCREMENTAL

    /* If we are loading glyph data via the incremental interface, set */
    /* the loader stream to a memory stream reading the data returned  */
    /* by the interface.                                               */
    if ( face->root.internal->incremental_interface )
    {
      error = face->root.internal->incremental_interface->funcs->get_glyph_data(
                face->root.internal->incremental_interface->object,
                glyph_index, &glyph_data );
      if ( error )
        goto Exit;

      glyph_data_loaded = 1;
      offset            = 0;
      loader->byte_len  = glyph_data.length;

      FT_MEM_ZERO( &inc_stream, sizeof ( inc_stream ) );
      FT_Stream_OpenMemory( &inc_stream,
                            glyph_data.pointer,
                            (FT_ULong)glyph_data.length );

      loader->stream = &inc_stream;
    }
    else

#endif /* FT_CONFIG_OPTION_INCREMENTAL */

      offset = tt_face_get_location( face, glyph_index,
                                     (FT_UInt*)&loader->byte_len );

    if ( loader->byte_len > 0 )
    {
#ifdef FT_CONFIG_OPTION_INCREMENTAL
      /* for the incremental interface, `glyf_offset' is always zero */
      if ( !loader->glyf_offset                        &&
           !face->root.internal->incremental_interface )
#else
      if ( !loader->glyf_offset )
#endif /* FT_CONFIG_OPTION_INCREMENTAL */
      {
        FT_TRACE2(( "no `glyf' table but non-zero `loca' entry\n" ));
        error = FT_THROW( Invalid_Table );
        goto Exit;
      }

      error = face->access_glyph_frame( loader, glyph_index,
                                        loader->glyf_offset + offset,
                                        (FT_UInt)loader->…