misc/libfreetype/src/truetype/ttobjs.c
author Xeli
Thu, 09 Feb 2012 14:12:50 +0100
changeset 6654 120e95c10532
parent 5172 88f2e05288ba
permissions -rw-r--r--
use the way actions are initiated the same way as koda implemented with PascalExports, using boolean values such as upKey and enterKey, this prevents the user from being able to control the AI

/***************************************************************************/
/*                                                                         */
/*  ttobjs.c                                                               */
/*                                                                         */
/*    Objects manager (body).                                              */
/*                                                                         */
/*  Copyright 1996-2011                                                    */
/*  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_STREAM_H
#include FT_TRUETYPE_TAGS_H
#include FT_INTERNAL_SFNT_H

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

#include "tterrors.h"

#ifdef TT_USE_BYTECODE_INTERPRETER
#include "ttinterp.h"
#endif

#ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING
#include FT_TRUETYPE_UNPATENTED_H
#endif

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

  /*************************************************************************/
  /*                                                                       */
  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  /* messages during execution.                                            */
  /*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_ttobjs


#ifdef TT_USE_BYTECODE_INTERPRETER

  /*************************************************************************/
  /*                                                                       */
  /*                       GLYPH ZONE FUNCTIONS                            */
  /*                                                                       */
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_glyphzone_done                                                  */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Deallocate a glyph zone.                                           */
  /*                                                                       */
  /* <Input>                                                               */
  /*    zone :: A pointer to the target glyph zone.                        */
  /*                                                                       */
  FT_LOCAL_DEF( void )
  tt_glyphzone_done( TT_GlyphZone  zone )
  {
    FT_Memory  memory = zone->memory;


    if ( memory )
    {
      FT_FREE( zone->contours );
      FT_FREE( zone->tags );
      FT_FREE( zone->cur );
      FT_FREE( zone->org );
      FT_FREE( zone->orus );

      zone->max_points   = zone->n_points   = 0;
      zone->max_contours = zone->n_contours = 0;
      zone->memory       = NULL;
    }
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_glyphzone_new                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Allocate a new glyph zone.                                         */
  /*                                                                       */
  /* <Input>                                                               */
  /*    memory      :: A handle to the current memory object.              */
  /*                                                                       */
  /*    maxPoints   :: The capacity of glyph zone in points.               */
  /*                                                                       */
  /*    maxContours :: The capacity of glyph zone in contours.             */
  /*                                                                       */
  /* <Output>                                                              */
  /*    zone        :: A pointer to the target glyph zone record.          */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_glyphzone_new( FT_Memory     memory,
                    FT_UShort     maxPoints,
                    FT_Short      maxContours,
                    TT_GlyphZone  zone )
  {
    FT_Error  error;


    FT_MEM_ZERO( zone, sizeof ( *zone ) );
    zone->memory = memory;

    if ( FT_NEW_ARRAY( zone->org,      maxPoints   ) ||
         FT_NEW_ARRAY( zone->cur,      maxPoints   ) ||
         FT_NEW_ARRAY( zone->orus,     maxPoints   ) ||
         FT_NEW_ARRAY( zone->tags,     maxPoints   ) ||
         FT_NEW_ARRAY( zone->contours, maxContours ) )
    {
      tt_glyphzone_done( zone );
    }
    else
    {
      zone->max_points   = maxPoints;
      zone->max_contours = maxContours;
    }

    return error;
  }
#endif /* TT_USE_BYTECODE_INTERPRETER */


  /* Compare the face with a list of well-known `tricky' fonts. */
  /* This list shall be expanded as we find more of them.       */

  static FT_Bool
  tt_check_trickyness_family( FT_String*  name )
  {

#define TRICK_NAMES_MAX_CHARACTERS  16
#define TRICK_NAMES_COUNT            8

    static const char trick_names[TRICK_NAMES_COUNT]
                                 [TRICK_NAMES_MAX_CHARACTERS + 1] =
    {
      "DFKaiSho-SB",     /* dfkaisb.ttf */
      "DFKaiShu",
      "DFKai-SB",        /* kaiu.ttf */
      "HuaTianKaiTi?",   /* htkt2.ttf */
      "HuaTianSongTi?",  /* htst3.ttf */
      "MingLiU",         /* mingliu.ttf & mingliu.ttc */
      "PMingLiU",        /* mingliu.ttc */
      "MingLi43",        /* mingli.ttf */
    };

    int  nn;


    for ( nn = 0; nn < TRICK_NAMES_COUNT; nn++ )
      if ( ft_strstr( name, trick_names[nn] ) )
        return TRUE;

    return FALSE;
  }


  /* XXX: This function should be in the `sfnt' module. */

  /* Some PDF generators clear the checksums in the TrueType header table. */
  /* For example, Quartz ContextPDF clears all entries, or Bullzip PDF     */
  /* Printer clears the entries for subsetted subtables.  We thus have to  */
  /* recalculate the checksums  where necessary.                           */

  static FT_UInt32
  tt_synth_sfnt_checksum( FT_Stream  stream,
                          FT_ULong   length )
  {
    FT_Error   error;
    FT_UInt32  checksum = 0;
    int        i;


    if ( FT_FRAME_ENTER( length ) )
      return 0;

    for ( ; length > 3; length -= 4 )
      checksum += (FT_UInt32)FT_GET_ULONG();

    for ( i = 3; length > 0; length --, i-- )
      checksum += (FT_UInt32)( FT_GET_BYTE() << ( i * 8 ) );

    FT_FRAME_EXIT();

    return checksum;
  }


  /* XXX: This function should be in the `sfnt' module. */

  static FT_ULong
  tt_get_sfnt_checksum( TT_Face    face,
                        FT_UShort  i )
  {
    if ( face->dir_tables[i].CheckSum )
      return face->dir_tables[i].CheckSum;

    else if ( !face->goto_table )
      return 0;

    else if ( !face->goto_table( face,
                                 face->dir_tables[i].Tag,
                                 face->root.stream,
                                 NULL ) )
      return 0;

    return (FT_ULong)tt_synth_sfnt_checksum( face->root.stream,
                                             face->dir_tables[i].Length );
  }


  typedef struct tt_sfnt_id_rec_
  {
    FT_ULong  CheckSum;
    FT_ULong  Length;

  } tt_sfnt_id_rec;


  static FT_Bool
  tt_check_trickyness_sfnt_ids( TT_Face  face )
  {
#define TRICK_SFNT_IDS_PER_FACE   3
#define TRICK_SFNT_IDS_NUM_FACES  5

    static const tt_sfnt_id_rec sfnt_id[TRICK_SFNT_IDS_NUM_FACES]
                                       [TRICK_SFNT_IDS_PER_FACE] = {

#define TRICK_SFNT_ID_cvt   0
#define TRICK_SFNT_ID_fpgm  1
#define TRICK_SFNT_ID_prep  2

      { /* MingLiU 1995 */
        { 0x05bcf058, 0x000002e4 }, /* cvt  */
        { 0x28233bf1, 0x000087c4 }, /* fpgm */
        { 0xa344a1ea, 0x000001e1 }  /* prep */
      },
      { /* MingLiU 1996- */
        { 0x05bcf058, 0x000002e4 }, /* cvt  */
        { 0x28233bf1, 0x000087c4 }, /* fpgm */
        { 0xa344a1eb, 0x000001e1 }  /* prep */
      },
      { /* DFKaiShu */
        { 0x11e5ead4, 0x00000350 }, /* cvt  */
        { 0x5a30ca3b, 0x00009063 }, /* fpgm */
        { 0x13a42602, 0x0000007e }  /* prep */
      },
      { /* HuaTianKaiTi */
        { 0xfffbfffc, 0x00000008 }, /* cvt  */
        { 0x9c9e48b8, 0x0000bea2 }, /* fpgm */
        { 0x70020112, 0x00000008 }  /* prep */
      },
      { /* HuaTianSongTi */
        { 0xfffbfffc, 0x00000008 }, /* cvt  */
        { 0x0a5a0483, 0x00017c39 }, /* fpgm */
        { 0x70020112, 0x00000008 }  /* prep */
      }
    };

    FT_ULong  checksum;
    int       num_matched_ids[TRICK_SFNT_IDS_NUM_FACES];
    int       i, j, k;


    FT_MEM_SET( num_matched_ids, 0,
                sizeof( int ) * TRICK_SFNT_IDS_NUM_FACES );

    for ( i = 0; i < face->num_tables; i++ )
    {
      checksum = 0;

      switch( face->dir_tables[i].Tag )
      {
      case TTAG_cvt:
        k = TRICK_SFNT_ID_cvt;
        break;

      case TTAG_fpgm:
        k = TRICK_SFNT_ID_fpgm;
        break;

      case TTAG_prep:
        k = TRICK_SFNT_ID_prep;
        break;

      default:
        continue;
      }

      for ( j = 0; j < TRICK_SFNT_IDS_NUM_FACES; j++ )
        if ( face->dir_tables[i].Length == sfnt_id[j][k].Length )
        {
          if ( !checksum )
            checksum = tt_get_sfnt_checksum( face, i );

          if ( sfnt_id[j][k].CheckSum == checksum )
            num_matched_ids[j]++;

          if ( num_matched_ids[j] == TRICK_SFNT_IDS_PER_FACE )
            return TRUE;
        }
    }

    return FALSE;
  }


  static FT_Bool
  tt_check_trickyness( FT_Face  face )
  {
    if ( !face )
      return FALSE;

    /* First, check the face name. */
    if ( face->family_name )
    {
      if ( tt_check_trickyness_family( face->family_name ) )
        return TRUE;
      else
        return FALSE;
    }

    /* Type42 fonts may lack `name' tables, we thus try to identify */
    /* tricky fonts by checking the checksums of Type42-persistent  */
    /* sfnt tables (`cvt', `fpgm', and `prep').                     */
    if ( tt_check_trickyness_sfnt_ids( (TT_Face)face ) )
      return TRUE;

    return FALSE;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_face_init                                                       */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Initialize a given TrueType face object.                           */
  /*                                                                       */
  /* <Input>                                                               */
  /*    stream     :: The source font stream.                              */
  /*                                                                       */
  /*    face_index :: The index of the font face in the resource.          */
  /*                                                                       */
  /*    num_params :: Number of additional generic parameters.  Ignored.   */
  /*                                                                       */
  /*    params     :: Additional generic parameters.  Ignored.             */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    face       :: The newly built face object.                         */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_face_init( FT_Stream      stream,
                FT_Face        ttface,      /* TT_Face */
                FT_Int         face_index,
                FT_Int         num_params,
                FT_Parameter*  params )
  {
    FT_Error      error;
    FT_Library    library;
    SFNT_Service  sfnt;
    TT_Face       face = (TT_Face)ttface;


    library = ttface->driver->root.library;
    sfnt    = (SFNT_Service)FT_Get_Module_Interface( library, "sfnt" );
    if ( !sfnt )
      goto Bad_Format;

    /* create input stream from resource */
    if ( FT_STREAM_SEEK( 0 ) )
      goto Exit;

    /* check that we have a valid TrueType file */
    error = sfnt->init_face( stream, face, face_index, num_params, params );
    if ( error )
      goto Exit;

    /* We must also be able to accept Mac/GX fonts, as well as OT ones. */
    /* The 0x00020000 tag is completely undocumented; some fonts from   */
    /* Arphic made for Chinese Windows 3.1 have this.                   */
    if ( face->format_tag != 0x00010000L &&    /* MS fonts  */
         face->format_tag != 0x00020000L &&    /* CJK fonts for Win 3.1 */
         face->format_tag != TTAG_true   )     /* Mac fonts */
    {
      FT_TRACE2(( "[not a valid TTF font]\n" ));
      goto Bad_Format;
    }

#ifdef TT_USE_BYTECODE_INTERPRETER
    ttface->face_flags |= FT_FACE_FLAG_HINTER;
#endif

    /* If we are performing a simple font format check, exit immediately. */
    if ( face_index < 0 )
      return TT_Err_Ok;

    /* Load font directory */
    error = sfnt->load_face( stream, face, face_index, num_params, params );
    if ( error )
      goto Exit;

    if ( tt_check_trickyness( ttface ) )
      ttface->face_flags |= FT_FACE_FLAG_TRICKY;

    error = tt_face_load_hdmx( face, stream );
    if ( error )
      goto Exit;

    if ( FT_IS_SCALABLE( ttface ) )
    {

#ifdef FT_CONFIG_OPTION_INCREMENTAL

      if ( !ttface->internal->incremental_interface )
        error = tt_face_load_loca( face, stream );
      if ( !error )
        error = tt_face_load_cvt( face, stream );
      if ( !error )
        error = tt_face_load_fpgm( face, stream );
      if ( !error )
        error = tt_face_load_prep( face, stream );

#else

      if ( !error )
        error = tt_face_load_loca( face, stream );
      if ( !error )
        error = tt_face_load_cvt( face, stream );
      if ( !error )
        error = tt_face_load_fpgm( face, stream );
      if ( !error )
        error = tt_face_load_prep( face, stream );

#endif

    }

#if defined( TT_CONFIG_OPTION_UNPATENTED_HINTING    ) && \
    !defined( TT_CONFIG_OPTION_BYTECODE_INTERPRETER )

    {
      FT_Bool  unpatented_hinting;
      int      i;


      /* Determine whether unpatented hinting is to be used for this face. */
      unpatented_hinting = FT_BOOL
        ( library->debug_hooks[FT_DEBUG_HOOK_UNPATENTED_HINTING] != NULL );

      for ( i = 0; i < num_params && !face->unpatented_hinting; i++ )
        if ( params[i].tag == FT_PARAM_TAG_UNPATENTED_HINTING )
          unpatented_hinting = TRUE;

      if ( !unpatented_hinting )
        ttface->internal->ignore_unpatented_hinter = TRUE;
    }

#endif /* TT_CONFIG_OPTION_UNPATENTED_HINTING &&
          !TT_CONFIG_OPTION_BYTECODE_INTERPRETER */

    /* initialize standard glyph loading routines */
    TT_Init_Glyph_Loading( face );

  Exit:
    return error;

  Bad_Format:
    error = TT_Err_Unknown_File_Format;
    goto Exit;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_face_done                                                       */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Finalize a given face object.                                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face :: A pointer to the face object to destroy.                   */
  /*                                                                       */
  FT_LOCAL_DEF( void )
  tt_face_done( FT_Face  ttface )           /* TT_Face */
  {
    TT_Face       face = (TT_Face)ttface;
    FT_Memory     memory;
    FT_Stream     stream;
    SFNT_Service  sfnt;


    if ( !face )
      return;

    memory = ttface->memory;
    stream = ttface->stream;
    sfnt   = (SFNT_Service)face->sfnt;

    /* for `extended TrueType formats' (i.e. compressed versions) */
    if ( face->extra.finalizer )
      face->extra.finalizer( face->extra.data );

    if ( sfnt )
      sfnt->done_face( face );

    /* freeing the locations table */
    tt_face_done_loca( face );

    tt_face_free_hdmx( face );

    /* freeing the CVT */
    FT_FREE( face->cvt );
    face->cvt_size = 0;

    /* freeing the programs */
    FT_FRAME_RELEASE( face->font_program );
    FT_FRAME_RELEASE( face->cvt_program );
    face->font_program_size = 0;
    face->cvt_program_size  = 0;

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    tt_done_blend( memory, face->blend );
    face->blend = NULL;
#endif
  }


  /*************************************************************************/
  /*                                                                       */
  /*                           SIZE  FUNCTIONS                             */
  /*                                                                       */
  /*************************************************************************/

#ifdef TT_USE_BYTECODE_INTERPRETER

  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_size_run_fpgm                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Run the font program.                                              */
  /*                                                                       */
  /* <Input>                                                               */
  /*    size     :: A handle to the size object.                           */
  /*                                                                       */
  /*    pedantic :: Set if bytecode execution should be pedantic.          */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_size_run_fpgm( TT_Size  size,
                    FT_Bool  pedantic )
  {
    TT_Face         face = (TT_Face)size->root.face;
    TT_ExecContext  exec;
    FT_Error        error;


    /* debugging instances have their own context */
    if ( size->debug )
      exec = size->context;
    else
      exec = ( (TT_Driver)FT_FACE_DRIVER( face ) )->context;

    if ( !exec )
      return TT_Err_Could_Not_Find_Context;

    TT_Load_Context( exec, face, size );

    exec->callTop = 0;
    exec->top     = 0;

    exec->period    = 64;
    exec->phase     = 0;
    exec->threshold = 0;

    exec->instruction_trap = FALSE;
    exec->F_dot_P          = 0x10000L;

    exec->pedantic_hinting = pedantic;

    {
      FT_Size_Metrics*  metrics    = &exec->metrics;
      TT_Size_Metrics*  tt_metrics = &exec->tt_metrics;


      metrics->x_ppem   = 0;
      metrics->y_ppem   = 0;
      metrics->x_scale  = 0;
      metrics->y_scale  = 0;

      tt_metrics->ppem  = 0;
      tt_metrics->scale = 0;
      tt_metrics->ratio = 0x10000L;
    }

    /* allow font program execution */
    TT_Set_CodeRange( exec,
                      tt_coderange_font,
                      face->font_program,
                      face->font_program_size );

    /* disable CVT and glyph programs coderange */
    TT_Clear_CodeRange( exec, tt_coderange_cvt );
    TT_Clear_CodeRange( exec, tt_coderange_glyph );

    if ( face->font_program_size > 0 )
    {
      error = TT_Goto_CodeRange( exec, tt_coderange_font, 0 );

      if ( !error )
      {
        FT_TRACE4(( "Executing `fpgm' table.\n" ));

        error = face->interpreter( exec );
      }
    }
    else
      error = TT_Err_Ok;

    if ( !error )
      TT_Save_Context( exec, size );

    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_size_run_prep                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Run the control value program.                                     */
  /*                                                                       */
  /* <Input>                                                               */
  /*    size     :: A handle to the size object.                           */
  /*                                                                       */
  /*    pedantic :: Set if bytecode execution should be pedantic.          */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_size_run_prep( TT_Size  size,
                    FT_Bool  pedantic )
  {
    TT_Face         face = (TT_Face)size->root.face;
    TT_ExecContext  exec;
    FT_Error        error;


    /* debugging instances have their own context */
    if ( size->debug )
      exec = size->context;
    else
      exec = ( (TT_Driver)FT_FACE_DRIVER( face ) )->context;

    if ( !exec )
      return TT_Err_Could_Not_Find_Context;

    TT_Load_Context( exec, face, size );

    exec->callTop = 0;
    exec->top     = 0;

    exec->instruction_trap = FALSE;

    exec->pedantic_hinting = pedantic;

    TT_Set_CodeRange( exec,
                      tt_coderange_cvt,
                      face->cvt_program,
                      face->cvt_program_size );

    TT_Clear_CodeRange( exec, tt_coderange_glyph );

    if ( face->cvt_program_size > 0 )
    {
      error = TT_Goto_CodeRange( exec, tt_coderange_cvt, 0 );

      if ( !error && !size->debug )
      {
        FT_TRACE4(( "Executing `prep' table.\n" ));

        error = face->interpreter( exec );
      }
    }
    else
      error = TT_Err_Ok;

    /* save as default graphics state */
    size->GS = exec->GS;

    TT_Save_Context( exec, size );

    return error;
  }

#endif /* TT_USE_BYTECODE_INTERPRETER */


#ifdef TT_USE_BYTECODE_INTERPRETER

  static void
  tt_size_done_bytecode( FT_Size  ftsize )
  {
    TT_Size    size   = (TT_Size)ftsize;
    TT_Face    face   = (TT_Face)ftsize->face;
    FT_Memory  memory = face->root.memory;


    if ( size->debug )
    {
      /* the debug context must be deleted by the debugger itself */
      size->context = NULL;
      size->debug   = FALSE;
    }

    FT_FREE( size->cvt );
    size->cvt_size = 0;

    /* free storage area */
    FT_FREE( size->storage );
    size->storage_size = 0;

    /* twilight zone */
    tt_glyphzone_done( &size->twilight );

    FT_FREE( size->function_defs );
    FT_FREE( size->instruction_defs );

    size->num_function_defs    = 0;
    size->max_function_defs    = 0;
    size->num_instruction_defs = 0;
    size->max_instruction_defs = 0;

    size->max_func = 0;
    size->max_ins  = 0;

    size->bytecode_ready = 0;
    size->cvt_ready      = 0;
  }


  /* Initialize bytecode-related fields in the size object.       */
  /* We do this only if bytecode interpretation is really needed. */
  static FT_Error
  tt_size_init_bytecode( FT_Size  ftsize,
                         FT_Bool  pedantic )
  {
    FT_Error   error;
    TT_Size    size = (TT_Size)ftsize;
    TT_Face    face = (TT_Face)ftsize->face;
    FT_Memory  memory = face->root.memory;
    FT_Int     i;

    FT_UShort       n_twilight;
    TT_MaxProfile*  maxp = &face->max_profile;


    size->bytecode_ready = 1;
    size->cvt_ready      = 0;

    size->max_function_defs    = maxp->maxFunctionDefs;
    size->max_instruction_defs = maxp->maxInstructionDefs;

    size->num_function_defs    = 0;
    size->num_instruction_defs = 0;

    size->max_func = 0;
    size->max_ins  = 0;

    size->cvt_size     = face->cvt_size;
    size->storage_size = maxp->maxStorage;

    /* Set default metrics */
    {
      TT_Size_Metrics*  metrics = &size->ttmetrics;


      metrics->rotated   = FALSE;
      metrics->stretched = FALSE;

      /* set default compensation (all 0) */
      for ( i = 0; i < 4; i++ )
        metrics->compensations[i] = 0;
    }

    /* allocate function defs, instruction defs, cvt, and storage area */
    if ( FT_NEW_ARRAY( size->function_defs,    size->max_function_defs    ) ||
         FT_NEW_ARRAY( size->instruction_defs, size->max_instruction_defs ) ||
         FT_NEW_ARRAY( size->cvt,              size->cvt_size             ) ||
         FT_NEW_ARRAY( size->storage,          size->storage_size         ) )
      goto Exit;

    /* reserve twilight zone */
    n_twilight = maxp->maxTwilightPoints;

    /* there are 4 phantom points (do we need this?) */
    n_twilight += 4;

    error = tt_glyphzone_new( memory, n_twilight, 0, &size->twilight );
    if ( error )
      goto Exit;

    size->twilight.n_points = n_twilight;

    size->GS = tt_default_graphics_state;

    /* set `face->interpreter' according to the debug hook present */
    {
      FT_Library  library = face->root.driver->root.library;


      face->interpreter = (TT_Interpreter)
                            library->debug_hooks[FT_DEBUG_HOOK_TRUETYPE];
      if ( !face->interpreter )
        face->interpreter = (TT_Interpreter)TT_RunIns;
    }

    /* Fine, now run the font program! */
    error = tt_size_run_fpgm( size, pedantic );

  Exit:
    if ( error )
      tt_size_done_bytecode( ftsize );

    return error;
  }


  FT_LOCAL_DEF( FT_Error )
  tt_size_ready_bytecode( TT_Size  size,
                          FT_Bool  pedantic )
  {
    FT_Error  error = TT_Err_Ok;


    if ( !size->bytecode_ready )
    {
      error = tt_size_init_bytecode( (FT_Size)size, pedantic );
      if ( error )
        goto Exit;
    }

    /* rescale CVT when needed */
    if ( !size->cvt_ready )
    {
      FT_UInt  i;
      TT_Face  face = (TT_Face)size->root.face;


      /* Scale the cvt values to the new ppem.          */
      /* We use by default the y ppem to scale the CVT. */
      for ( i = 0; i < size->cvt_size; i++ )
        size->cvt[i] = FT_MulFix( face->cvt[i], size->ttmetrics.scale );

      /* all twilight points are originally zero */
      for ( i = 0; i < (FT_UInt)size->twilight.n_points; i++ )
      {
        size->twilight.org[i].x = 0;
        size->twilight.org[i].y = 0;
        size->twilight.cur[i].x = 0;
        size->twilight.cur[i].y = 0;
      }

      /* clear storage area */
      for ( i = 0; i < (FT_UInt)size->storage_size; i++ )
        size->storage[i] = 0;

      size->GS = tt_default_graphics_state;

      error = tt_size_run_prep( size, pedantic );
      if ( !error )
        size->cvt_ready = 1;
    }

  Exit:
    return error;
  }

#endif /* TT_USE_BYTECODE_INTERPRETER */


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_size_init                                                       */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Initialize a new TrueType size object.                             */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    size :: A handle to the size object.                               */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_size_init( FT_Size  ttsize )           /* TT_Size */
  {
    TT_Size   size  = (TT_Size)ttsize;
    FT_Error  error = TT_Err_Ok;

#ifdef TT_USE_BYTECODE_INTERPRETER
    size->bytecode_ready = 0;
    size->cvt_ready      = 0;
#endif

    size->ttmetrics.valid = FALSE;
    size->strike_index    = 0xFFFFFFFFUL;

    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_size_done                                                       */
  /*                                                                       */
  /* <Description>                                                         */
  /*    The TrueType size object finalizer.                                */
  /*                                                                       */
  /* <Input>                                                               */
  /*    size :: A handle to the target size object.                        */
  /*                                                                       */
  FT_LOCAL_DEF( void )
  tt_size_done( FT_Size  ttsize )           /* TT_Size */
  {
    TT_Size  size = (TT_Size)ttsize;


#ifdef TT_USE_BYTECODE_INTERPRETER
    if ( size->bytecode_ready )
      tt_size_done_bytecode( ttsize );
#endif

    size->ttmetrics.valid = FALSE;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_size_reset                                                      */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Reset a TrueType size when resolutions and character dimensions    */
  /*    have been changed.                                                 */
  /*                                                                       */
  /* <Input>                                                               */
  /*    size :: A handle to the target size object.                        */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_size_reset( TT_Size  size )
  {
    TT_Face           face;
    FT_Error          error = TT_Err_Ok;
    FT_Size_Metrics*  metrics;


    size->ttmetrics.valid = FALSE;

    face = (TT_Face)size->root.face;

    metrics = &size->metrics;

    /* copy the result from base layer */
    *metrics = size->root.metrics;

    if ( metrics->x_ppem < 1 || metrics->y_ppem < 1 )
      return TT_Err_Invalid_PPem;

    /* This bit flag, if set, indicates that the ppems must be       */
    /* rounded to integers.  Nearly all TrueType fonts have this bit */
    /* set, as hinting won't work really well otherwise.             */
    /*                                                               */
    if ( face->header.Flags & 8 )
    {
      metrics->x_scale = FT_DivFix( metrics->x_ppem << 6,
                                    face->root.units_per_EM );
      metrics->y_scale = FT_DivFix( metrics->y_ppem << 6,
                                    face->root.units_per_EM );

      metrics->ascender =
        FT_PIX_ROUND( FT_MulFix( face->root.ascender, metrics->y_scale ) );
      metrics->descender =
        FT_PIX_ROUND( FT_MulFix( face->root.descender, metrics->y_scale ) );
      metrics->height =
        FT_PIX_ROUND( FT_MulFix( face->root.height, metrics->y_scale ) );
      metrics->max_advance =
        FT_PIX_ROUND( FT_MulFix( face->root.max_advance_width,
                                 metrics->x_scale ) );
    }

    /* compute new transformation */
    if ( metrics->x_ppem >= metrics->y_ppem )
    {
      size->ttmetrics.scale   = metrics->x_scale;
      size->ttmetrics.ppem    = metrics->x_ppem;
      size->ttmetrics.x_ratio = 0x10000L;
      size->ttmetrics.y_ratio = FT_MulDiv( metrics->y_ppem,
                                           0x10000L,
                                           metrics->x_ppem );
    }
    else
    {
      size->ttmetrics.scale   = metrics->y_scale;
      size->ttmetrics.ppem    = metrics->y_ppem;
      size->ttmetrics.x_ratio = FT_MulDiv( metrics->x_ppem,
                                           0x10000L,
                                           metrics->y_ppem );
      size->ttmetrics.y_ratio = 0x10000L;
    }

#ifdef TT_USE_BYTECODE_INTERPRETER
    size->cvt_ready = 0;
#endif /* TT_USE_BYTECODE_INTERPRETER */

    if ( !error )
      size->ttmetrics.valid = TRUE;

    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_driver_init                                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Initialize a given TrueType driver object.                         */
  /*                                                                       */
  /* <Input>                                                               */
  /*    driver :: A handle to the target driver object.                    */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_driver_init( FT_Module  ttdriver )     /* TT_Driver */
  {

#ifdef TT_USE_BYTECODE_INTERPRETER

    TT_Driver  driver = (TT_Driver)ttdriver;


    if ( !TT_New_Context( driver ) )
      return TT_Err_Could_Not_Find_Context;

#else

    FT_UNUSED( ttdriver );

#endif

    return TT_Err_Ok;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_driver_done                                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Finalize a given TrueType driver.                                  */
  /*                                                                       */
  /* <Input>                                                               */
  /*    driver :: A handle to the target TrueType driver.                  */
  /*                                                                       */
  FT_LOCAL_DEF( void )
  tt_driver_done( FT_Module  ttdriver )     /* TT_Driver */
  {
#ifdef TT_USE_BYTECODE_INTERPRETER
    TT_Driver  driver = (TT_Driver)ttdriver;


    /* destroy the execution context */
    if ( driver->context )
    {
      TT_Done_Context( driver->context );
      driver->context = NULL;
    }
#else
    FT_UNUSED( ttdriver );
#endif

  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_slot_init                                                       */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Initialize a new slot object.                                      */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    slot :: A handle to the slot object.                               */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_slot_init( FT_GlyphSlot  slot )
  {
    return FT_GlyphLoader_CreateExtra( slot->internal->loader );
  }


/* END */