Subversion Repositories Kolibri OS

/***************************************************************************/

/*                                                                         */

/*  gxvmort.c                                                              */

/*                                                                         */

/*    TrueTypeGX/AAT mort table validation (body).                         */

/*                                                                         */

/*  Copyright 2005, 2013 by suzuki toshiya, Masatake YAMATO, Red Hat K.K., */

/*  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.                                        */

/*                                                                         */

/***************************************************************************/

/***************************************************************************/

/*                                                                         */

/* gxvalid is derived from both gxlayout module and otvalid module.        */

/* Development of gxlayout is supported by the Information-technology      */

/* Promotion Agency(IPA), Japan.                                           */

/*                                                                         */

/***************************************************************************/

#include "gxvmort.h"

#include "gxvfeat.h"

  /*************************************************************************/

  /*                                                                       */

  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */

  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */

  /* messages during execution.                                            */

  /*                                                                       */

#undef  FT_COMPONENT

#define FT_COMPONENT  trace_gxvmort

  static void

  gxv_mort_feature_validate( GXV_mort_feature  f,

                             GXV_Validator     valid )

  {

    if ( f->featureType >= gxv_feat_registry_length )

    {

      GXV_TRACE(( "featureType %d is out of registered range, "

                  "setting %d is unchecked\n",

                  f->featureType, f->featureSetting ));

      GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );

    }

    else if ( !gxv_feat_registry[f->featureType].existence )

    {

      GXV_TRACE(( "featureType %d is within registered area "

                  "but undefined, setting %d is unchecked\n",

                  f->featureType, f->featureSetting ));

      GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );

    }

    else

    {

      FT_Byte  nSettings_max;

      /* nSettings in gxvfeat.c is halved for exclusive on/off settings */

      nSettings_max = gxv_feat_registry[f->featureType].nSettings;

      if ( gxv_feat_registry[f->featureType].exclusive )

        nSettings_max = (FT_Byte)( 2 * nSettings_max );

      GXV_TRACE(( "featureType %d is registered", f->featureType ));

      GXV_TRACE(( "setting %d", f->featureSetting ));

      if ( f->featureSetting > nSettings_max )

      {

        GXV_TRACE(( "out of defined range %d", nSettings_max ));

        GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );

      }

      GXV_TRACE(( "\n" ));

    }

    /* TODO: enableFlags must be unique value in specified chain?  */

  }

  /*

   * nFeatureFlags is typed to FT_ULong to accept that in

   * mort (typed FT_UShort) and morx (typed FT_ULong).

   */

  FT_LOCAL_DEF( void )

  gxv_mort_featurearray_validate( FT_Bytes       table,

                                  FT_Bytes       limit,

                                  FT_ULong       nFeatureFlags,

                                  GXV_Validator  valid )

  {

    FT_Bytes  p = table;

    FT_ULong  i;

    GXV_mort_featureRec  f = GXV_MORT_FEATURE_OFF;

    GXV_NAME_ENTER( "mort feature list" );

    for ( i = 0; i < nFeatureFlags; i++ )

    {

      GXV_LIMIT_CHECK( 2 + 2 + 4 + 4 );

      f.featureType    = FT_NEXT_USHORT( p );

      f.featureSetting = FT_NEXT_USHORT( p );

      f.enableFlags    = FT_NEXT_ULONG( p );

      f.disableFlags   = FT_NEXT_ULONG( p );

      gxv_mort_feature_validate( &f, valid );

    }

    if ( !IS_GXV_MORT_FEATURE_OFF( f ) )

      FT_INVALID_DATA;

    valid->subtable_length = p - table;

    GXV_EXIT;

  }

  FT_LOCAL_DEF( void )

  gxv_mort_coverage_validate( FT_UShort      coverage,

                              GXV_Validator  valid )

  {

    FT_UNUSED( valid );

    if ( coverage & 0x8000U )

      GXV_TRACE(( " this subtable is for vertical text only\n" ));

    else

      GXV_TRACE(( " this subtable is for horizontal text only\n" ));

    if ( coverage & 0x4000 )

      GXV_TRACE(( " this subtable is applied to glyph array "

                  "in descending order\n" ));

    else

      GXV_TRACE(( " this subtable is applied to glyph array "

                  "in ascending order\n" ));

    if ( coverage & 0x2000 )

      GXV_TRACE(( " this subtable is forcibly applied to "

                  "vertical/horizontal text\n" ));

    if ( coverage & 0x1FF8 )

      GXV_TRACE(( " coverage has non-zero bits in reserved area\n" ));

  }

  static void

  gxv_mort_subtables_validate( FT_Bytes       table,

                               FT_Bytes       limit,

                               FT_UShort      nSubtables,

                               GXV_Validator  valid )

  {

    FT_Bytes  p = table;

    GXV_Validate_Func fmt_funcs_table[] =

    {

      gxv_mort_subtable_type0_validate, /* 0 */

      gxv_mort_subtable_type1_validate, /* 1 */

      gxv_mort_subtable_type2_validate, /* 2 */

      NULL,                             /* 3 */

      gxv_mort_subtable_type4_validate, /* 4 */

      gxv_mort_subtable_type5_validate, /* 5 */

    };

    FT_UShort  i;

    GXV_NAME_ENTER( "subtables in a chain" );

    for ( i = 0; i < nSubtables; i++ )

    {

      GXV_Validate_Func  func;

      FT_UShort  length;

      FT_UShort  coverage;

#ifdef GXV_LOAD_UNUSED_VARS

      FT_ULong   subFeatureFlags;

#endif

      FT_UInt    type;

      FT_UInt    rest;

      GXV_LIMIT_CHECK( 2 + 2 + 4 );

      length          = FT_NEXT_USHORT( p );

      coverage        = FT_NEXT_USHORT( p );

#ifdef GXV_LOAD_UNUSED_VARS

      subFeatureFlags = FT_NEXT_ULONG( p );

#else

      p += 4;

#endif

      GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n",

                  i + 1, nSubtables, length ));

      type = coverage & 0x0007;

      rest = length - ( 2 + 2 + 4 );

      GXV_LIMIT_CHECK( rest );

      gxv_mort_coverage_validate( coverage, valid );

      if ( type > 5 )

        FT_INVALID_FORMAT;

      func = fmt_funcs_table[type];

      if ( func == NULL )

        GXV_TRACE(( "morx type %d is reserved\n", type ));

      func( p, p + rest, valid );

      p += rest;

      /* TODO: validate subFeatureFlags */

    }

    valid->subtable_length = p - table;

    GXV_EXIT;

  }

  static void

  gxv_mort_chain_validate( FT_Bytes       table,

                           FT_Bytes       limit,

                           GXV_Validator  valid )

  {

    FT_Bytes   p = table;

#ifdef GXV_LOAD_UNUSED_VARS

    FT_ULong   defaultFlags;

#endif

    FT_ULong   chainLength;

    FT_UShort  nFeatureFlags;

    FT_UShort  nSubtables;

    GXV_NAME_ENTER( "mort chain header" );

    GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 );

#ifdef GXV_LOAD_UNUSED_VARS

    defaultFlags  = FT_NEXT_ULONG( p );

#else

    p += 4;

#endif

    chainLength   = FT_NEXT_ULONG( p );

    nFeatureFlags = FT_NEXT_USHORT( p );

    nSubtables    = FT_NEXT_USHORT( p );

    gxv_mort_featurearray_validate( p, table + chainLength,

                                    nFeatureFlags, valid );

    p += valid->subtable_length;

    gxv_mort_subtables_validate( p, table + chainLength, nSubtables, valid );

    valid->subtable_length = chainLength;

    /* TODO: validate defaultFlags */

    GXV_EXIT;

  }

  FT_LOCAL_DEF( void )

  gxv_mort_validate( FT_Bytes      table,

                     FT_Face       face,

                     FT_Validator  ftvalid )

  {

    GXV_ValidatorRec  validrec;

    GXV_Validator     valid = &validrec;

    FT_Bytes          p     = table;

    FT_Bytes          limit = 0;

    FT_ULong          version;

    FT_ULong          nChains;

    FT_ULong          i;

    valid->root = ftvalid;

    valid->face = face;

    limit       = valid->root->limit;

    FT_TRACE3(( "validating `mort' table\n" ));

    GXV_INIT;

    GXV_LIMIT_CHECK( 4 + 4 );

    version = FT_NEXT_ULONG( p );

    nChains = FT_NEXT_ULONG( p );

    if (version != 0x00010000UL)

      FT_INVALID_FORMAT;

    for ( i = 0; i < nChains; i++ )

    {

      GXV_TRACE(( "validating chain %d/%d\n", i + 1, nChains ));

      GXV_32BIT_ALIGNMENT_VALIDATE( p - table );

      gxv_mort_chain_validate( p, limit, valid );

      p += valid->subtable_length;

    }

    FT_TRACE4(( "\n" ));

  }

/* END */