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

/*                                                                         */

/*  gxvopbd.c                                                              */

/*                                                                         */

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

/*                                                                         */

/*  Copyright 2004, 2005 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 "gxvalid.h"

#include "gxvcommn.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_gxvopbd

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

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

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

  /*****                      Data and Types                           *****/

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

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

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

  typedef struct  GXV_opbd_DataRec_

  {

    FT_UShort  format;

    FT_UShort  valueOffset_min;

  } GXV_opbd_DataRec, *GXV_opbd_Data;

#define GXV_OPBD_DATA( FIELD )  GXV_TABLE_DATA( opbd, FIELD )

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

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

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

  /*****                      UTILITY FUNCTIONS                        *****/

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

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

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

  static void

  gxv_opbd_LookupValue_validate( FT_UShort            glyph,

                                 GXV_LookupValueCPtr  value_p,

                                 GXV_Validator        valid )

  {

    /* offset in LookupTable is measured from the head of opbd table */

    FT_Bytes   p     = valid->root->base + value_p->u;

    FT_Bytes   limit = valid->root->limit;

    FT_Short   delta_value;

    int        i;

    if ( value_p->u < GXV_OPBD_DATA( valueOffset_min ) )

      GXV_OPBD_DATA( valueOffset_min ) = value_p->u;

    for ( i = 0; i < 4; i++ )

    {

      GXV_LIMIT_CHECK( 2 );

      delta_value = FT_NEXT_SHORT( p );

      if ( GXV_OPBD_DATA( format ) )    /* format 1, value is ctrl pt. */

      {

        if ( delta_value == -1 )

          continue;

        gxv_ctlPoint_validate( glyph, delta_value, valid );

      }

      else                              /* format 0, value is distance */

        continue;

    }

  }

  /*

    opbd ---------------------+

                              |

    +===============+         |

    | lookup header |         |

    +===============+         |

    | BinSrchHeader |         |

    +===============+         |

    | lastGlyph[0]  |         |

    +---------------+         |

    | firstGlyph[0] |         |  head of opbd sfnt table

    +---------------+         |             +

    | offset[0]     |    ->   |          offset            [byte]

    +===============+         |             +

    | lastGlyph[1]  |         | (glyphID - firstGlyph) * 4 * sizeof(FT_Short) [byte]

    +---------------+         |

    | firstGlyph[1] |         |

    +---------------+         |

    | offset[1]     |         |

    +===============+         |

                              |

     ....                     |

                              |

    48bit value array         |

    +===============+         |

    |     value     | <-------+

    |               |

    |               |

    |               |

    +---------------+

    .... */

  static GXV_LookupValueDesc

  gxv_opbd_LookupFmt4_transit( FT_UShort            relative_gindex,

                               GXV_LookupValueCPtr  base_value_p,

                               FT_Bytes             lookuptbl_limit,

                               GXV_Validator        valid )

  {

    GXV_LookupValueDesc  value;

    FT_UNUSED( lookuptbl_limit );

    FT_UNUSED( valid );

    /* XXX: check range? */

    value.u = (FT_UShort)( base_value_p->u +

                           relative_gindex * 4 * sizeof ( FT_Short ) );

    return value;

  }

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

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

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

  /*****                         opbd TABLE                            *****/

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

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

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

  FT_LOCAL_DEF( void )

  gxv_opbd_validate( FT_Bytes      table,

                     FT_Face       face,

                     FT_Validator  ftvalid )

  {

    GXV_ValidatorRec  validrec;

    GXV_Validator     valid = &validrec;

    GXV_opbd_DataRec  opbdrec;

    GXV_opbd_Data     opbd  = &opbdrec;

    FT_Bytes          p     = table;

    FT_Bytes          limit = 0;

    FT_ULong  version;

    valid->root       = ftvalid;

    valid->table_data = opbd;

    valid->face       = face;

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

    GXV_INIT;

    GXV_OPBD_DATA( valueOffset_min ) = 0xFFFFU;

    GXV_LIMIT_CHECK( 4 + 2 );

    version                 = FT_NEXT_ULONG( p );

    GXV_OPBD_DATA( format ) = FT_NEXT_USHORT( p );

    /* only 0x00010000 is defined (1996) */

    GXV_TRACE(( "(version=0x%08x)\n", version ));

    if ( 0x00010000UL != version )

      FT_INVALID_FORMAT;

    /* only values 0 and 1 are defined (1996) */

    GXV_TRACE(( "(format=0x%04x)\n", GXV_OPBD_DATA( format ) ));

    if ( 0x0001 < GXV_OPBD_DATA( format ) )

      FT_INVALID_FORMAT;

    valid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;

    valid->lookupval_func   = gxv_opbd_LookupValue_validate;

    valid->lookupfmt4_trans = gxv_opbd_LookupFmt4_transit;

    gxv_LookupTable_validate( p, limit, valid );

    p += valid->subtable_length;

    if ( p > table + GXV_OPBD_DATA( valueOffset_min ) )

    {

      GXV_TRACE((

        "found overlap between LookupTable and opbd_value array\n" ));

      FT_INVALID_OFFSET;

    }

    FT_TRACE4(( "\n" ));

  }

/* END */