ttgxvar.c 55.0 KB
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/***************************************************************************/
/*                                                                         */
/*  ttgxvar.c                                                              */
/*                                                                         */
/*    TrueType GX Font Variation loader                                    */
/*                                                                         */
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/*  Copyright 2004-2014 by                                                 */
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/*  David Turner, Robert Wilhelm, Werner Lemberg, and George Williams.     */
/*                                                                         */
/*  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.                                        */
/*                                                                         */
/***************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* Apple documents the `fvar', `gvar', `cvar', and `avar' tables at      */
  /*                                                                       */
  /*   http://developer.apple.com/fonts/TTRefMan/RM06/Chap6[fgca]var.html  */
  /*                                                                       */
  /* The documentation for `fvar' is inconsistent.  At one point it says   */
  /* that `countSizePairs' should be 3, at another point 2.  It should     */
  /* be 2.                                                                 */
  /*                                                                       */
  /* The documentation for `gvar' is not intelligible; `cvar' refers you   */
  /* to `gvar' and is thus also incomprehensible.                          */
  /*                                                                       */
  /* The documentation for `avar' appears correct, but Apple has no fonts  */
  /* with an `avar' table, so it is hard to test.                          */
  /*                                                                       */
  /* Many thanks to John Jenkins (at Apple) in figuring this out.          */
  /*                                                                       */
  /*                                                                       */
  /* Apple's `kern' table has some references to tuple indices, but as     */
  /* there is no indication where these indices are defined, nor how to    */
  /* interpolate the kerning values (different tuples have different       */
  /* classes) this issue is ignored.                                       */
  /*                                                                       */
  /*************************************************************************/


#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_CONFIG_CONFIG_H
#include FT_INTERNAL_STREAM_H
#include FT_INTERNAL_SFNT_H
#include FT_TRUETYPE_TAGS_H
#include FT_MULTIPLE_MASTERS_H

#include "ttpload.h"
#include "ttgxvar.h"

#include "tterrors.h"


#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT


#define FT_Stream_FTell( stream )  \
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          (FT_ULong)( (stream)->cursor - (stream)->base )
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#define FT_Stream_SeekSet( stream, off ) \
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          ( (stream)->cursor = (stream)->base + (off) )
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  /*************************************************************************/
  /*                                                                       */
  /* 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_ttgxvar


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       Internal Routines                       *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* The macro ALL_POINTS is used in `ft_var_readpackedpoints'.  It        */
  /* indicates that there is a delta for every point without needing to    */
  /* enumerate all of them.                                                */
  /*                                                                       */
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  /* ensure that value `0' has the same width as a pointer */
#define ALL_POINTS  (FT_UShort*)~(FT_PtrDist)0
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#define GX_PT_POINTS_ARE_WORDS      0x80
#define GX_PT_POINT_RUN_COUNT_MASK  0x7F


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_readpackedpoints                                            */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Read a set of points to which the following deltas will apply.     */
  /*    Points are packed with a run length encoding.                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    stream    :: The data stream.                                      */
  /*                                                                       */
  /* <Output>                                                              */
  /*    point_cnt :: The number of points read.  A zero value means that   */
  /*                 all points in the glyph will be affected, without     */
  /*                 enumerating them individually.                        */
  /*                                                                       */
  /* <Return>                                                              */
  /*    An array of FT_UShort containing the affected points or the        */
  /*    special value ALL_POINTS.                                          */
  /*                                                                       */
  static FT_UShort*
  ft_var_readpackedpoints( FT_Stream  stream,
                           FT_UInt   *point_cnt )
  {
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    FT_UShort *points = NULL;
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    FT_Int     n;
    FT_Int     runcnt;
    FT_Int     i;
    FT_Int     j;
    FT_Int     first;
    FT_Memory  memory = stream->memory;
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    FT_Error   error  = FT_Err_Ok;
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    FT_UNUSED( error );


    *point_cnt = n = FT_GET_BYTE();
    if ( n == 0 )
      return ALL_POINTS;

    if ( n & GX_PT_POINTS_ARE_WORDS )
      n = FT_GET_BYTE() | ( ( n & GX_PT_POINT_RUN_COUNT_MASK ) << 8 );

    if ( FT_NEW_ARRAY( points, n ) )
      return NULL;

    i = 0;
    while ( i < n )
    {
      runcnt = FT_GET_BYTE();
      if ( runcnt & GX_PT_POINTS_ARE_WORDS )
      {
        runcnt = runcnt & GX_PT_POINT_RUN_COUNT_MASK;
        first  = points[i++] = FT_GET_USHORT();

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        if ( runcnt < 1 || i + runcnt >= n )
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          goto Exit;

        /* first point not included in runcount */
        for ( j = 0; j < runcnt; ++j )
          points[i++] = (FT_UShort)( first += FT_GET_USHORT() );
      }
      else
      {
        first = points[i++] = FT_GET_BYTE();

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        if ( runcnt < 1 || i + runcnt >= n )
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          goto Exit;

        for ( j = 0; j < runcnt; ++j )
          points[i++] = (FT_UShort)( first += FT_GET_BYTE() );
      }
    }

  Exit:
    return points;
  }


  enum
  {
    GX_DT_DELTAS_ARE_ZERO      = 0x80,
    GX_DT_DELTAS_ARE_WORDS     = 0x40,
    GX_DT_DELTA_RUN_COUNT_MASK = 0x3F
  };


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_readpackeddeltas                                            */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Read a set of deltas.  These are packed slightly differently than  */
  /*    points.  In particular there is no overall count.                  */
  /*                                                                       */
  /* <Input>                                                               */
  /*    stream    :: The data stream.                                      */
  /*                                                                       */
  /*    delta_cnt :: The number of to be read.                             */
  /*                                                                       */
  /* <Return>                                                              */
  /*    An array of FT_Short containing the deltas for the affected        */
  /*    points.  (This only gets the deltas for one dimension.  It will    */
  /*    generally be called twice, once for x, once for y.  When used in   */
  /*    cvt table, it will only be called once.)                           */
  /*                                                                       */
  static FT_Short*
  ft_var_readpackeddeltas( FT_Stream  stream,
                           FT_Offset  delta_cnt )
  {
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    FT_Short  *deltas = NULL;
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    FT_UInt    runcnt;
    FT_Offset  i;
    FT_UInt    j;
    FT_Memory  memory = stream->memory;
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    FT_Error   error  = FT_Err_Ok;
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    FT_UNUSED( error );


    if ( FT_NEW_ARRAY( deltas, delta_cnt ) )
      return NULL;

    i = 0;
    while ( i < delta_cnt )
    {
      runcnt = FT_GET_BYTE();
      if ( runcnt & GX_DT_DELTAS_ARE_ZERO )
      {
        /* runcnt zeroes get added */
        for ( j = 0;
              j <= ( runcnt & GX_DT_DELTA_RUN_COUNT_MASK ) && i < delta_cnt;
              ++j )
          deltas[i++] = 0;
      }
      else if ( runcnt & GX_DT_DELTAS_ARE_WORDS )
      {
        /* runcnt shorts from the stack */
        for ( j = 0;
              j <= ( runcnt & GX_DT_DELTA_RUN_COUNT_MASK ) && i < delta_cnt;
              ++j )
          deltas[i++] = FT_GET_SHORT();
      }
      else
      {
        /* runcnt signed bytes from the stack */
        for ( j = 0;
              j <= ( runcnt & GX_DT_DELTA_RUN_COUNT_MASK ) && i < delta_cnt;
              ++j )
          deltas[i++] = FT_GET_CHAR();
      }

      if ( j <= ( runcnt & GX_DT_DELTA_RUN_COUNT_MASK ) )
      {
        /* Bad format */
        FT_FREE( deltas );
        return NULL;
      }
    }

    return deltas;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_load_avar                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Parse the `avar' table if present.  It need not be, so we return   */
  /*    nothing.                                                           */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face :: The font face.                                             */
  /*                                                                       */
  static void
  ft_var_load_avar( TT_Face  face )
  {
    FT_Stream       stream = FT_FACE_STREAM(face);
    FT_Memory       memory = stream->memory;
    GX_Blend        blend  = face->blend;
    GX_AVarSegment  segment;
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    FT_Error        error = FT_Err_Ok;
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    FT_ULong        version;
    FT_Long         axisCount;
    FT_Int          i, j;
    FT_ULong        table_len;

    FT_UNUSED( error );


    blend->avar_checked = TRUE;
    if ( (error = face->goto_table( face, TTAG_avar, stream, &table_len )) != 0 )
      return;

    if ( FT_FRAME_ENTER( table_len ) )
      return;

    version   = FT_GET_LONG();
    axisCount = FT_GET_LONG();

    if ( version != 0x00010000L                       ||
         axisCount != (FT_Long)blend->mmvar->num_axis )
      goto Exit;

    if ( FT_NEW_ARRAY( blend->avar_segment, axisCount ) )
      goto Exit;

    segment = &blend->avar_segment[0];
    for ( i = 0; i < axisCount; ++i, ++segment )
    {
      segment->pairCount = FT_GET_USHORT();
      if ( FT_NEW_ARRAY( segment->correspondence, segment->pairCount ) )
      {
        /* Failure.  Free everything we have done so far.  We must do */
        /* it right now since loading the `avar' table is optional.   */

        for ( j = i - 1; j >= 0; --j )
          FT_FREE( blend->avar_segment[j].correspondence );

        FT_FREE( blend->avar_segment );
        blend->avar_segment = NULL;
        goto Exit;
      }

      for ( j = 0; j < segment->pairCount; ++j )
      {
        segment->correspondence[j].fromCoord =
          FT_GET_SHORT() << 2;    /* convert to Fixed */
        segment->correspondence[j].toCoord =
          FT_GET_SHORT()<<2;    /* convert to Fixed */
      }
    }

  Exit:
    FT_FRAME_EXIT();
  }


  typedef struct  GX_GVar_Head_
  {
    FT_Long    version;
    FT_UShort  axisCount;
    FT_UShort  globalCoordCount;
    FT_ULong   offsetToCoord;
    FT_UShort  glyphCount;
    FT_UShort  flags;
    FT_ULong   offsetToData;

  } GX_GVar_Head;


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_load_gvar                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Parses the `gvar' table if present.  If `fvar' is there, `gvar'    */
  /*    had better be there too.                                           */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face :: The font face.                                             */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  static FT_Error
  ft_var_load_gvar( TT_Face  face )
  {
    FT_Stream     stream = FT_FACE_STREAM(face);
    FT_Memory     memory = stream->memory;
    GX_Blend      blend  = face->blend;
    FT_Error      error;
    FT_UInt       i, j;
    FT_ULong      table_len;
    FT_ULong      gvar_start;
    FT_ULong      offsetToData;
    GX_GVar_Head  gvar_head;

    static const FT_Frame_Field  gvar_fields[] =
    {

#undef  FT_STRUCTURE
#define FT_STRUCTURE  GX_GVar_Head

      FT_FRAME_START( 20 ),
        FT_FRAME_LONG  ( version ),
        FT_FRAME_USHORT( axisCount ),
        FT_FRAME_USHORT( globalCoordCount ),
        FT_FRAME_ULONG ( offsetToCoord ),
        FT_FRAME_USHORT( glyphCount ),
        FT_FRAME_USHORT( flags ),
        FT_FRAME_ULONG ( offsetToData ),
      FT_FRAME_END
    };

    if ( (error = face->goto_table( face, TTAG_gvar, stream, &table_len )) != 0 )
      goto Exit;

    gvar_start = FT_STREAM_POS( );
    if ( FT_STREAM_READ_FIELDS( gvar_fields, &gvar_head ) )
      goto Exit;

    blend->tuplecount  = gvar_head.globalCoordCount;
    blend->gv_glyphcnt = gvar_head.glyphCount;
    offsetToData       = gvar_start + gvar_head.offsetToData;

    if ( gvar_head.version   != (FT_Long)0x00010000L              ||
         gvar_head.axisCount != (FT_UShort)blend->mmvar->num_axis )
    {
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      error = FT_THROW( Invalid_Table );
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      goto Exit;
    }

    if ( FT_NEW_ARRAY( blend->glyphoffsets, blend->gv_glyphcnt + 1 ) )
      goto Exit;

    if ( gvar_head.flags & 1 )
    {
      /* long offsets (one more offset than glyphs, to mark size of last) */
      if ( FT_FRAME_ENTER( ( blend->gv_glyphcnt + 1 ) * 4L ) )
        goto Exit;

      for ( i = 0; i <= blend->gv_glyphcnt; ++i )
        blend->glyphoffsets[i] = offsetToData + FT_GET_LONG();

      FT_FRAME_EXIT();
    }
    else
    {
      /* short offsets (one more offset than glyphs, to mark size of last) */
      if ( FT_FRAME_ENTER( ( blend->gv_glyphcnt + 1 ) * 2L ) )
        goto Exit;

      for ( i = 0; i <= blend->gv_glyphcnt; ++i )
        blend->glyphoffsets[i] = offsetToData + FT_GET_USHORT() * 2;
                                              /* XXX: Undocumented: `*2'! */

      FT_FRAME_EXIT();
    }

    if ( blend->tuplecount != 0 )
    {
      if ( FT_NEW_ARRAY( blend->tuplecoords,
                         gvar_head.axisCount * blend->tuplecount ) )
        goto Exit;

      if ( FT_STREAM_SEEK( gvar_start + gvar_head.offsetToCoord )       ||
           FT_FRAME_ENTER( blend->tuplecount * gvar_head.axisCount * 2L )                   )
        goto Exit;

      for ( i = 0; i < blend->tuplecount; ++i )
        for ( j = 0 ; j < (FT_UInt)gvar_head.axisCount; ++j )
          blend->tuplecoords[i * gvar_head.axisCount + j] =
            FT_GET_SHORT() << 2;                /* convert to FT_Fixed */

      FT_FRAME_EXIT();
    }

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    ft_var_apply_tuple                                                 */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Figure out whether a given tuple (design) applies to the current   */
  /*    blend, and if so, what is the scaling factor.                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    blend           :: The current blend of the font.                  */
  /*                                                                       */
  /*    tupleIndex      :: A flag saying whether this is an intermediate   */
  /*                       tuple or not.                                   */
  /*                                                                       */
  /*    tuple_coords    :: The coordinates of the tuple in normalized axis */
  /*                       units.                                          */
  /*                                                                       */
  /*    im_start_coords :: The initial coordinates where this tuple starts */
  /*                       to apply (for intermediate coordinates).        */
  /*                                                                       */
  /*    im_end_coords   :: The final coordinates after which this tuple no */
  /*                       longer applies (for intermediate coordinates).  */
  /*                                                                       */
  /* <Return>                                                              */
  /*    An FT_Fixed value containing the scaling factor.                   */
  /*                                                                       */
  static FT_Fixed
  ft_var_apply_tuple( GX_Blend   blend,
                      FT_UShort  tupleIndex,
                      FT_Fixed*  tuple_coords,
                      FT_Fixed*  im_start_coords,
                      FT_Fixed*  im_end_coords )
  {
    FT_UInt   i;
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    FT_Fixed  apply = 0x10000L;
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    for ( i = 0; i < blend->num_axis; ++i )
    {
      if ( tuple_coords[i] == 0 )
        /* It's not clear why (for intermediate tuples) we don't need     */
        /* to check against start/end -- the documentation says we don't. */
        /* Similarly, it's unclear why we don't need to scale along the   */
        /* axis.                                                          */
        continue;

      else if ( blend->normalizedcoords[i] == 0                           ||
                ( blend->normalizedcoords[i] < 0 && tuple_coords[i] > 0 ) ||
                ( blend->normalizedcoords[i] > 0 && tuple_coords[i] < 0 ) )
      {
        apply = 0;
        break;
      }

      else if ( !( tupleIndex & GX_TI_INTERMEDIATE_TUPLE ) )
        /* not an intermediate tuple */
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        apply = FT_MulFix( apply,
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                           blend->normalizedcoords[i] > 0
                             ? blend->normalizedcoords[i]
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                             : -blend->normalizedcoords[i] );
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      else if ( blend->normalizedcoords[i] <= im_start_coords[i] ||
                blend->normalizedcoords[i] >= im_end_coords[i]   )
      {
        apply = 0;
        break;
      }

      else if ( blend->normalizedcoords[i] < tuple_coords[i] )
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        apply = FT_MulDiv( apply,
                           blend->normalizedcoords[i] - im_start_coords[i],
                           tuple_coords[i] - im_start_coords[i] );
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      else
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        apply = FT_MulDiv( apply,
                           im_end_coords[i] - blend->normalizedcoords[i],
                           im_end_coords[i] - tuple_coords[i] );
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    }

    return apply;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****               MULTIPLE MASTERS SERVICE FUNCTIONS              *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  typedef struct  GX_FVar_Head_
  {
    FT_Long    version;
    FT_UShort  offsetToData;
    FT_UShort  countSizePairs;
    FT_UShort  axisCount;
    FT_UShort  axisSize;
    FT_UShort  instanceCount;
    FT_UShort  instanceSize;

  } GX_FVar_Head;


  typedef struct  fvar_axis_
  {
    FT_ULong   axisTag;
    FT_ULong   minValue;
    FT_ULong   defaultValue;
    FT_ULong   maxValue;
    FT_UShort  flags;
    FT_UShort  nameID;

  } GX_FVar_Axis;


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Get_MM_Var                                                      */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Check that the font's `fvar' table is valid, parse it, and return  */
  /*    those data.                                                        */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face   :: The font face.                                           */
  /*              TT_Get_MM_Var initializes the blend structure.           */
  /*                                                                       */
  /* <Output>                                                              */
  /*    master :: The `fvar' data (must be freed by caller).               */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  TT_Get_MM_Var( TT_Face      face,
                 FT_MM_Var*  *master )
  {
    FT_Stream            stream = face->root.stream;
    FT_Memory            memory = face->root.memory;
    FT_ULong             table_len;
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    FT_Error             error  = FT_Err_Ok;
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    FT_ULong             fvar_start;
    FT_Int               i, j;
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    FT_MM_Var*           mmvar = NULL;
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    FT_Fixed*            next_coords;
    FT_String*           next_name;
    FT_Var_Axis*         a;
    FT_Var_Named_Style*  ns;
    GX_FVar_Head         fvar_head;

    static const FT_Frame_Field  fvar_fields[] =
    {

#undef  FT_STRUCTURE
#define FT_STRUCTURE  GX_FVar_Head

      FT_FRAME_START( 16 ),
        FT_FRAME_LONG  ( version ),
        FT_FRAME_USHORT( offsetToData ),
        FT_FRAME_USHORT( countSizePairs ),
        FT_FRAME_USHORT( axisCount ),
        FT_FRAME_USHORT( axisSize ),
        FT_FRAME_USHORT( instanceCount ),
        FT_FRAME_USHORT( instanceSize ),
      FT_FRAME_END
    };

    static const FT_Frame_Field  fvaraxis_fields[] =
    {

#undef  FT_STRUCTURE
#define FT_STRUCTURE  GX_FVar_Axis

      FT_FRAME_START( 20 ),
        FT_FRAME_ULONG ( axisTag ),
        FT_FRAME_ULONG ( minValue ),
        FT_FRAME_ULONG ( defaultValue ),
        FT_FRAME_ULONG ( maxValue ),
        FT_FRAME_USHORT( flags ),
        FT_FRAME_USHORT( nameID ),
      FT_FRAME_END
    };


    if ( face->blend == NULL )
    {
      /* both `fvar' and `gvar' must be present */
      if ( (error = face->goto_table( face, TTAG_gvar,
                                      stream, &table_len )) != 0 )
        goto Exit;

      if ( (error = face->goto_table( face, TTAG_fvar,
                                      stream, &table_len )) != 0 )
        goto Exit;

      fvar_start = FT_STREAM_POS( );

      if ( FT_STREAM_READ_FIELDS( fvar_fields, &fvar_head ) )
        goto Exit;

      if ( fvar_head.version != (FT_Long)0x00010000L                      ||
           fvar_head.countSizePairs != 2                                  ||
           fvar_head.axisSize != 20                                       ||
G
Grissiom 已提交
678 679
           /* axisCount limit implied by 16-bit instanceSize */
           fvar_head.axisCount > 0x3FFE                                   ||
M
Ming, Bai 已提交
680
           fvar_head.instanceSize != 4 + 4 * fvar_head.axisCount          ||
G
Grissiom 已提交
681 682
           /* instanceCount limit implied by limited range of name IDs */
           fvar_head.instanceCount > 0x7EFF                               ||
M
Ming, Bai 已提交
683 684 685
           fvar_head.offsetToData + fvar_head.axisCount * 20U +
             fvar_head.instanceCount * fvar_head.instanceSize > table_len )
      {
G
Grissiom 已提交
686
        error = FT_THROW( Invalid_Table );
M
Ming, Bai 已提交
687 688 689 690 691 692
        goto Exit;
      }

      if ( FT_NEW( face->blend ) )
        goto Exit;

G
Grissiom 已提交
693
      /* cannot overflow 32-bit arithmetic because of limits above */
M
Ming, Bai 已提交
694 695 696 697 698 699 700 701 702 703 704 705 706 707
      face->blend->mmvar_len =
        sizeof ( FT_MM_Var ) +
        fvar_head.axisCount * sizeof ( FT_Var_Axis ) +
        fvar_head.instanceCount * sizeof ( FT_Var_Named_Style ) +
        fvar_head.instanceCount * fvar_head.axisCount * sizeof ( FT_Fixed ) +
        5 * fvar_head.axisCount;

      if ( FT_ALLOC( mmvar, face->blend->mmvar_len ) )
        goto Exit;
      face->blend->mmvar = mmvar;

      mmvar->num_axis =
        fvar_head.axisCount;
      mmvar->num_designs =
G
Grissiom 已提交
708
        ~0U;                   /* meaningless in this context; each glyph */
M
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709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851
                               /* may have a different number of designs  */
                               /* (or tuples, as called by Apple)         */
      mmvar->num_namedstyles =
        fvar_head.instanceCount;
      mmvar->axis =
        (FT_Var_Axis*)&(mmvar[1]);
      mmvar->namedstyle =
        (FT_Var_Named_Style*)&(mmvar->axis[fvar_head.axisCount]);

      next_coords =
        (FT_Fixed*)&(mmvar->namedstyle[fvar_head.instanceCount]);
      for ( i = 0; i < fvar_head.instanceCount; ++i )
      {
        mmvar->namedstyle[i].coords  = next_coords;
        next_coords                 += fvar_head.axisCount;
      }

      next_name = (FT_String*)next_coords;
      for ( i = 0; i < fvar_head.axisCount; ++i )
      {
        mmvar->axis[i].name  = next_name;
        next_name           += 5;
      }

      if ( FT_STREAM_SEEK( fvar_start + fvar_head.offsetToData ) )
        goto Exit;

      a = mmvar->axis;
      for ( i = 0; i < fvar_head.axisCount; ++i )
      {
        GX_FVar_Axis  axis_rec;


        if ( FT_STREAM_READ_FIELDS( fvaraxis_fields, &axis_rec ) )
          goto Exit;
        a->tag     = axis_rec.axisTag;
        a->minimum = axis_rec.minValue;     /* A Fixed */
        a->def     = axis_rec.defaultValue; /* A Fixed */
        a->maximum = axis_rec.maxValue;     /* A Fixed */
        a->strid   = axis_rec.nameID;

        a->name[0] = (FT_String)(   a->tag >> 24 );
        a->name[1] = (FT_String)( ( a->tag >> 16 ) & 0xFF );
        a->name[2] = (FT_String)( ( a->tag >>  8 ) & 0xFF );
        a->name[3] = (FT_String)( ( a->tag       ) & 0xFF );
        a->name[4] = 0;

        ++a;
      }

      ns = mmvar->namedstyle;
      for ( i = 0; i < fvar_head.instanceCount; ++i, ++ns )
      {
        if ( FT_FRAME_ENTER( 4L + 4L * fvar_head.axisCount ) )
          goto Exit;

        ns->strid       =    FT_GET_USHORT();
        (void) /* flags = */ FT_GET_USHORT();

        for ( j = 0; j < fvar_head.axisCount; ++j )
          ns->coords[j] = FT_GET_ULONG();     /* A Fixed */

        FT_FRAME_EXIT();
      }
    }

    if ( master != NULL )
    {
      FT_UInt  n;


      if ( FT_ALLOC( mmvar, face->blend->mmvar_len ) )
        goto Exit;
      FT_MEM_COPY( mmvar, face->blend->mmvar, face->blend->mmvar_len );

      mmvar->axis =
        (FT_Var_Axis*)&(mmvar[1]);
      mmvar->namedstyle =
        (FT_Var_Named_Style*)&(mmvar->axis[mmvar->num_axis]);
      next_coords =
        (FT_Fixed*)&(mmvar->namedstyle[mmvar->num_namedstyles]);

      for ( n = 0; n < mmvar->num_namedstyles; ++n )
      {
        mmvar->namedstyle[n].coords  = next_coords;
        next_coords                 += mmvar->num_axis;
      }

      a = mmvar->axis;
      next_name = (FT_String*)next_coords;
      for ( n = 0; n < mmvar->num_axis; ++n )
      {
        a->name = next_name;

        /* standard PostScript names for some standard apple tags */
        if ( a->tag == TTAG_wght )
          a->name = (char *)"Weight";
        else if ( a->tag == TTAG_wdth )
          a->name = (char *)"Width";
        else if ( a->tag == TTAG_opsz )
          a->name = (char *)"OpticalSize";
        else if ( a->tag == TTAG_slnt )
          a->name = (char *)"Slant";

        next_name += 5;
        ++a;
      }

      *master = mmvar;
    }

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Set_MM_Blend                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Set the blend (normalized) coordinates for this instance of the    */
  /*    font.  Check that the `gvar' table is reasonable and does some     */
  /*    initial preparation.                                               */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face       :: The font.                                            */
  /*                  Initialize the blend structure with `gvar' data.     */
  /*                                                                       */
  /* <Input>                                                               */
  /*    num_coords :: Must be the axis count of the font.                  */
  /*                                                                       */
  /*    coords     :: An array of num_coords, each between [-1,1].         */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  TT_Set_MM_Blend( TT_Face    face,
                   FT_UInt    num_coords,
                   FT_Fixed*  coords )
  {
G
Grissiom 已提交
852
    FT_Error    error = FT_Err_Ok;
M
Ming, Bai 已提交
853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879
    GX_Blend    blend;
    FT_MM_Var*  mmvar;
    FT_UInt     i;
    FT_Memory   memory = face->root.memory;

    enum
    {
      mcvt_retain,
      mcvt_modify,
      mcvt_load

    } manageCvt;


    face->doblend = FALSE;

    if ( face->blend == NULL )
    {
      if ( (error = TT_Get_MM_Var( face, NULL)) != 0 )
        goto Exit;
    }

    blend = face->blend;
    mmvar = blend->mmvar;

    if ( num_coords != mmvar->num_axis )
    {
G
Grissiom 已提交
880
      error = FT_THROW( Invalid_Argument );
M
Ming, Bai 已提交
881 882 883 884 885 886
      goto Exit;
    }

    for ( i = 0; i < num_coords; ++i )
      if ( coords[i] < -0x00010000L || coords[i] > 0x00010000L )
      {
G
Grissiom 已提交
887
        error = FT_THROW( Invalid_Argument );
M
Ming, Bai 已提交
888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940
        goto Exit;
      }

    if ( blend->glyphoffsets == NULL )
      if ( (error = ft_var_load_gvar( face )) != 0 )
        goto Exit;

    if ( blend->normalizedcoords == NULL )
    {
      if ( FT_NEW_ARRAY( blend->normalizedcoords, num_coords ) )
        goto Exit;

      manageCvt = mcvt_modify;

      /* If we have not set the blend coordinates before this, then the  */
      /* cvt table will still be what we read from the `cvt ' table and  */
      /* we don't need to reload it.  We may need to change it though... */
    }
    else
    {
      manageCvt = mcvt_retain;
      for ( i = 0; i < num_coords; ++i )
      {
        if ( blend->normalizedcoords[i] != coords[i] )
        {
          manageCvt = mcvt_load;
          break;
        }
      }

      /* If we don't change the blend coords then we don't need to do  */
      /* anything to the cvt table.  It will be correct.  Otherwise we */
      /* no longer have the original cvt (it was modified when we set  */
      /* the blend last time), so we must reload and then modify it.   */
    }

    blend->num_axis = num_coords;
    FT_MEM_COPY( blend->normalizedcoords,
                 coords,
                 num_coords * sizeof ( FT_Fixed ) );

    face->doblend = TRUE;

    if ( face->cvt != NULL )
    {
      switch ( manageCvt )
      {
      case mcvt_load:
        /* The cvt table has been loaded already; every time we change the */
        /* blend we may need to reload and remodify the cvt table.         */
        FT_FREE( face->cvt );
        face->cvt = NULL;

G
Grissiom 已提交
941
        error = tt_face_load_cvt( face, face->root.stream );
M
Ming, Bai 已提交
942 943 944 945 946
        break;

      case mcvt_modify:
        /* The original cvt table is in memory.  All we need to do is */
        /* apply the `cvar' table (if any).                           */
G
Grissiom 已提交
947
        error = tt_face_vary_cvt( face, face->root.stream );
M
Ming, Bai 已提交
948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987
        break;

      case mcvt_retain:
        /* The cvt table is correct for this set of coordinates. */
        break;
      }
    }

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Set_Var_Design                                                  */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Set the coordinates for the instance, measured in the user         */
  /*    coordinate system.  Parse the `avar' table (if present) to convert */
  /*    from user to normalized coordinates.                               */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face       :: The font face.                                       */
  /*                  Initialize the blend struct with `gvar' data.        */
  /*                                                                       */
  /* <Input>                                                               */
  /*    num_coords :: This must be the axis count of the font.             */
  /*                                                                       */
  /*    coords     :: A coordinate array with `num_coords' elements.       */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  TT_Set_Var_Design( TT_Face    face,
                     FT_UInt    num_coords,
                     FT_Fixed*  coords )
  {
G
Grissiom 已提交
988
    FT_Error        error      = FT_Err_Ok;
M
Ming, Bai 已提交
989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008
    FT_Fixed*       normalized = NULL;
    GX_Blend        blend;
    FT_MM_Var*      mmvar;
    FT_UInt         i, j;
    FT_Var_Axis*    a;
    GX_AVarSegment  av;
    FT_Memory       memory = face->root.memory;


    if ( face->blend == NULL )
    {
      if ( (error = TT_Get_MM_Var( face, NULL )) != 0 )
        goto Exit;
    }

    blend = face->blend;
    mmvar = blend->mmvar;

    if ( num_coords != mmvar->num_axis )
    {
G
Grissiom 已提交
1009
      error = FT_THROW( Invalid_Argument );
M
Ming, Bai 已提交
1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024
      goto Exit;
    }

    /* Axis normalization is a two stage process.  First we normalize */
    /* based on the [min,def,max] values for the axis to be [-1,0,1]. */
    /* Then, if there's an `avar' table, we renormalize this range.   */

    if ( FT_NEW_ARRAY( normalized, mmvar->num_axis ) )
      goto Exit;

    a = mmvar->axis;
    for ( i = 0; i < mmvar->num_axis; ++i, ++a )
    {
      if ( coords[i] > a->maximum || coords[i] < a->minimum )
      {
G
Grissiom 已提交
1025
        error = FT_THROW( Invalid_Argument );
M
Ming, Bai 已提交
1026 1027 1028 1029
        goto Exit;
      }

      if ( coords[i] < a->def )
G
Grissiom 已提交
1030
        normalized[i] = -FT_DivFix( coords[i] - a->def, a->minimum - a->def );
M
Ming, Bai 已提交
1031 1032 1033
      else if ( a->maximum == a->def )
        normalized[i] = 0;
      else
G
Grissiom 已提交
1034
        normalized[i] = FT_DivFix( coords[i] - a->def, a->maximum - a->def );
M
Ming, Bai 已提交
1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048
    }

    if ( !blend->avar_checked )
      ft_var_load_avar( face );

    if ( blend->avar_segment != NULL )
    {
      av = blend->avar_segment;
      for ( i = 0; i < mmvar->num_axis; ++i, ++av )
      {
        for ( j = 1; j < (FT_UInt)av->pairCount; ++j )
          if ( normalized[i] < av->correspondence[j].fromCoord )
          {
            normalized[i] =
G
Grissiom 已提交
1049 1050 1051 1052 1053
              FT_MulDiv( normalized[i] - av->correspondence[j - 1].fromCoord,
                         av->correspondence[j].toCoord -
                           av->correspondence[j - 1].toCoord,
                         av->correspondence[j].fromCoord -
                           av->correspondence[j - 1].fromCoord ) +
M
Ming, Bai 已提交
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124
              av->correspondence[j - 1].toCoord;
            break;
          }
      }
    }

    error = TT_Set_MM_Blend( face, num_coords, normalized );

  Exit:
    FT_FREE( normalized );
    return error;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                     GX VAR PARSING ROUTINES                   *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_face_vary_cvt                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Modify the loaded cvt table according to the `cvar' table and the  */
  /*    font's blend.                                                      */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face   :: A handle to the target face object.                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    stream :: A handle to the input stream.                            */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  /*    Most errors are ignored.  It is perfectly valid not to have a      */
  /*    `cvar' table even if there is a `gvar' and `fvar' table.           */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_face_vary_cvt( TT_Face    face,
                    FT_Stream  stream )
  {
    FT_Error    error;
    FT_Memory   memory = stream->memory;
    FT_ULong    table_start;
    FT_ULong    table_len;
    FT_UInt     tupleCount;
    FT_ULong    offsetToData;
    FT_ULong    here;
    FT_UInt     i, j;
    FT_Fixed*   tuple_coords    = NULL;
    FT_Fixed*   im_start_coords = NULL;
    FT_Fixed*   im_end_coords   = NULL;
    GX_Blend    blend           = face->blend;
    FT_UInt     point_count;
    FT_UShort*  localpoints;
    FT_Short*   deltas;


    FT_TRACE2(( "CVAR " ));

    if ( blend == NULL )
    {
      FT_TRACE2(( "tt_face_vary_cvt: no blend specified\n" ));

G
Grissiom 已提交
1125
      error = FT_Err_Ok;
M
Ming, Bai 已提交
1126 1127 1128 1129 1130 1131 1132
      goto Exit;
    }

    if ( face->cvt == NULL )
    {
      FT_TRACE2(( "tt_face_vary_cvt: no `cvt ' table\n" ));

G
Grissiom 已提交
1133
      error = FT_Err_Ok;
M
Ming, Bai 已提交
1134 1135 1136 1137 1138 1139 1140 1141
      goto Exit;
    }

    error = face->goto_table( face, TTAG_cvar, stream, &table_len );
    if ( error )
    {
      FT_TRACE2(( "is missing\n" ));

G
Grissiom 已提交
1142
      error = FT_Err_Ok;
M
Ming, Bai 已提交
1143 1144 1145 1146 1147
      goto Exit;
    }

    if ( FT_FRAME_ENTER( table_len ) )
    {
G
Grissiom 已提交
1148
      error = FT_Err_Ok;
M
Ming, Bai 已提交
1149 1150 1151 1152 1153 1154 1155 1156
      goto Exit;
    }

    table_start = FT_Stream_FTell( stream );
    if ( FT_GET_LONG() != 0x00010000L )
    {
      FT_TRACE2(( "bad table version\n" ));

G
Grissiom 已提交
1157
      error = FT_Err_Ok;
M
Ming, Bai 已提交
1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308
      goto FExit;
    }

    if ( FT_NEW_ARRAY( tuple_coords, blend->num_axis )    ||
         FT_NEW_ARRAY( im_start_coords, blend->num_axis ) ||
         FT_NEW_ARRAY( im_end_coords, blend->num_axis )   )
      goto FExit;

    tupleCount   = FT_GET_USHORT();
    offsetToData = table_start + FT_GET_USHORT();

    /* The documentation implies there are flags packed into the        */
    /* tuplecount, but John Jenkins says that shared points don't apply */
    /* to `cvar', and no other flags are defined.                       */

    for ( i = 0; i < ( tupleCount & 0xFFF ); ++i )
    {
      FT_UInt   tupleDataSize;
      FT_UInt   tupleIndex;
      FT_Fixed  apply;


      tupleDataSize = FT_GET_USHORT();
      tupleIndex    = FT_GET_USHORT();

      /* There is no provision here for a global tuple coordinate section, */
      /* so John says.  There are no tuple indices, just embedded tuples.  */

      if ( tupleIndex & GX_TI_EMBEDDED_TUPLE_COORD )
      {
        for ( j = 0; j < blend->num_axis; ++j )
          tuple_coords[j] = FT_GET_SHORT() << 2; /* convert from        */
                                                 /* short frac to fixed */
      }
      else
      {
        /* skip this tuple; it makes no sense */

        if ( tupleIndex & GX_TI_INTERMEDIATE_TUPLE )
          for ( j = 0; j < 2 * blend->num_axis; ++j )
            (void)FT_GET_SHORT();

        offsetToData += tupleDataSize;
        continue;
      }

      if ( tupleIndex & GX_TI_INTERMEDIATE_TUPLE )
      {
        for ( j = 0; j < blend->num_axis; ++j )
          im_start_coords[j] = FT_GET_SHORT() << 2;
        for ( j = 0; j < blend->num_axis; ++j )
          im_end_coords[j] = FT_GET_SHORT() << 2;
      }

      apply = ft_var_apply_tuple( blend,
                                  (FT_UShort)tupleIndex,
                                  tuple_coords,
                                  im_start_coords,
                                  im_end_coords );
      if ( /* tuple isn't active for our blend */
           apply == 0                                    ||
           /* global points not allowed,           */
           /* if they aren't local, makes no sense */
           !( tupleIndex & GX_TI_PRIVATE_POINT_NUMBERS ) )
      {
        offsetToData += tupleDataSize;
        continue;
      }

      here = FT_Stream_FTell( stream );

      FT_Stream_SeekSet( stream, offsetToData );

      localpoints = ft_var_readpackedpoints( stream, &point_count );
      deltas      = ft_var_readpackeddeltas( stream,
                                             point_count == 0 ? face->cvt_size
                                                              : point_count );
      if ( localpoints == NULL || deltas == NULL )
        /* failure, ignore it */;

      else if ( localpoints == ALL_POINTS )
      {
        /* this means that there are deltas for every entry in cvt */
        for ( j = 0; j < face->cvt_size; ++j )
          face->cvt[j] = (FT_Short)( face->cvt[j] +
                                     FT_MulFix( deltas[j], apply ) );
      }

      else
      {
        for ( j = 0; j < point_count; ++j )
        {
          int  pindex = localpoints[j];

          face->cvt[pindex] = (FT_Short)( face->cvt[pindex] +
                                          FT_MulFix( deltas[j], apply ) );
        }
      }

      if ( localpoints != ALL_POINTS )
        FT_FREE( localpoints );
      FT_FREE( deltas );

      offsetToData += tupleDataSize;

      FT_Stream_SeekSet( stream, here );
    }

  FExit:
    FT_FRAME_EXIT();

  Exit:
    FT_FREE( tuple_coords );
    FT_FREE( im_start_coords );
    FT_FREE( im_end_coords );

    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    TT_Vary_Get_Glyph_Deltas                                           */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Load the appropriate deltas for the current glyph.                 */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face        :: A handle to the target face object.                 */
  /*                                                                       */
  /*    glyph_index :: The index of the glyph being modified.              */
  /*                                                                       */
  /*    n_points    :: The number of the points in the glyph, including    */
  /*                   phantom points.                                     */
  /*                                                                       */
  /* <Output>                                                              */
  /*    deltas      :: The array of points to change.                      */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  TT_Vary_Get_Glyph_Deltas( TT_Face      face,
                            FT_UInt      glyph_index,
                            FT_Vector*  *deltas,
                            FT_UInt      n_points )
  {
    FT_Stream   stream = face->root.stream;
    FT_Memory   memory = stream->memory;
    GX_Blend    blend  = face->blend;
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    FT_Vector*  delta_xy = NULL;
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    FT_Error    error;
    FT_ULong    glyph_start;
    FT_UInt     tupleCount;
    FT_ULong    offsetToData;
    FT_ULong    here;
    FT_UInt     i, j;
    FT_Fixed*   tuple_coords    = NULL;
    FT_Fixed*   im_start_coords = NULL;
    FT_Fixed*   im_end_coords   = NULL;
    FT_UInt     point_count, spoint_count = 0;
    FT_UShort*  sharedpoints = NULL;
    FT_UShort*  localpoints  = NULL;
    FT_UShort*  points;
    FT_Short    *deltas_x, *deltas_y;


    if ( !face->doblend || blend == NULL )
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      return FT_THROW( Invalid_Argument );
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    /* to be freed by the caller */
    if ( FT_NEW_ARRAY( delta_xy, n_points ) )
      goto Exit;
    *deltas = delta_xy;

    if ( glyph_index >= blend->gv_glyphcnt      ||
         blend->glyphoffsets[glyph_index] ==
           blend->glyphoffsets[glyph_index + 1] )
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      return FT_Err_Ok;               /* no variation data for this glyph */
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    if ( FT_STREAM_SEEK( blend->glyphoffsets[glyph_index] )   ||
         FT_FRAME_ENTER( blend->glyphoffsets[glyph_index + 1] -
                           blend->glyphoffsets[glyph_index] ) )
      goto Fail1;

    glyph_start = FT_Stream_FTell( stream );

    /* each set of glyph variation data is formatted similarly to `cvar' */
    /* (except we get shared points and global tuples)                   */

    if ( FT_NEW_ARRAY( tuple_coords, blend->num_axis )    ||
         FT_NEW_ARRAY( im_start_coords, blend->num_axis ) ||
         FT_NEW_ARRAY( im_end_coords, blend->num_axis )   )
      goto Fail2;

    tupleCount   = FT_GET_USHORT();
    offsetToData = glyph_start + FT_GET_USHORT();

    if ( tupleCount & GX_TC_TUPLES_SHARE_POINT_NUMBERS )
    {
      here = FT_Stream_FTell( stream );

      FT_Stream_SeekSet( stream, offsetToData );

      sharedpoints = ft_var_readpackedpoints( stream, &spoint_count );
      offsetToData = FT_Stream_FTell( stream );

      FT_Stream_SeekSet( stream, here );
    }

    for ( i = 0; i < ( tupleCount & GX_TC_TUPLE_COUNT_MASK ); ++i )
    {
      FT_UInt   tupleDataSize;
      FT_UInt   tupleIndex;
      FT_Fixed  apply;


      tupleDataSize = FT_GET_USHORT();
      tupleIndex    = FT_GET_USHORT();

      if ( tupleIndex & GX_TI_EMBEDDED_TUPLE_COORD )
      {
        for ( j = 0; j < blend->num_axis; ++j )
          tuple_coords[j] = FT_GET_SHORT() << 2;  /* convert from        */
                                                  /* short frac to fixed */
      }
      else if ( ( tupleIndex & GX_TI_TUPLE_INDEX_MASK ) >= blend->tuplecount )
      {
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        error = FT_THROW( Invalid_Table );
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        goto Fail3;
      }
      else
      {
        FT_MEM_COPY(
          tuple_coords,
          &blend->tuplecoords[(tupleIndex & 0xFFF) * blend->num_axis],
          blend->num_axis * sizeof ( FT_Fixed ) );
      }

      if ( tupleIndex & GX_TI_INTERMEDIATE_TUPLE )
      {
        for ( j = 0; j < blend->num_axis; ++j )
          im_start_coords[j] = FT_GET_SHORT() << 2;
        for ( j = 0; j < blend->num_axis; ++j )
          im_end_coords[j] = FT_GET_SHORT() << 2;
      }

      apply = ft_var_apply_tuple( blend,
                                  (FT_UShort)tupleIndex,
                                  tuple_coords,
                                  im_start_coords,
                                  im_end_coords );

      if ( apply == 0 )              /* tuple isn't active for our blend */
      {
        offsetToData += tupleDataSize;
        continue;
      }

      here = FT_Stream_FTell( stream );

      if ( tupleIndex & GX_TI_PRIVATE_POINT_NUMBERS )
      {
        FT_Stream_SeekSet( stream, offsetToData );

        localpoints = ft_var_readpackedpoints( stream, &point_count );
        points      = localpoints;
      }
      else
      {
        points      = sharedpoints;
        point_count = spoint_count;
      }

      deltas_x = ft_var_readpackeddeltas( stream,
                                          point_count == 0 ? n_points
                                                           : point_count );
      deltas_y = ft_var_readpackeddeltas( stream,
                                          point_count == 0 ? n_points
                                                           : point_count );

      if ( points == NULL || deltas_y == NULL || deltas_x == NULL )
        ; /* failure, ignore it */

      else if ( points == ALL_POINTS )
      {
        /* this means that there are deltas for every point in the glyph */
        for ( j = 0; j < n_points; ++j )
        {
          delta_xy[j].x += FT_MulFix( deltas_x[j], apply );
          delta_xy[j].y += FT_MulFix( deltas_y[j], apply );
        }
      }

      else
      {
        for ( j = 0; j < point_count; ++j )
        {
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          if ( localpoints[j] >= n_points )
            continue;

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          delta_xy[localpoints[j]].x += FT_MulFix( deltas_x[j], apply );
          delta_xy[localpoints[j]].y += FT_MulFix( deltas_y[j], apply );
        }
      }

      if ( localpoints != ALL_POINTS )
        FT_FREE( localpoints );
      FT_FREE( deltas_x );
      FT_FREE( deltas_y );

      offsetToData += tupleDataSize;

      FT_Stream_SeekSet( stream, here );
    }

  Fail3:
    FT_FREE( tuple_coords );
    FT_FREE( im_start_coords );
    FT_FREE( im_end_coords );

  Fail2:
    FT_FRAME_EXIT();

  Fail1:
    if ( error )
    {
      FT_FREE( delta_xy );
      *deltas = NULL;
    }

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_done_blend                                                      */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Frees the blend internal data structure.                           */
  /*                                                                       */
  FT_LOCAL_DEF( void )
  tt_done_blend( FT_Memory  memory,
                 GX_Blend   blend )
  {
    if ( blend != NULL )
    {
      FT_UInt  i;


      FT_FREE( blend->normalizedcoords );
      FT_FREE( blend->mmvar );

      if ( blend->avar_segment != NULL )
      {
        for ( i = 0; i < blend->num_axis; ++i )
          FT_FREE( blend->avar_segment[i].correspondence );
        FT_FREE( blend->avar_segment );
      }

      FT_FREE( blend->tuplecoords );
      FT_FREE( blend->glyphoffsets );
      FT_FREE( blend );
    }
  }

#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */


/* END */