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

/*                                                                         */

/*  gxvprop.c                                                              */

/*                                                                         */

/*    TrueTypeGX/AAT prop 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_gxvprop

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

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

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

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

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

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

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

#define GXV_PROP_HEADER_SIZE  ( 4 + 2 + 2 )

#define GXV_PROP_SIZE_MIN     GXV_PROP_HEADER_SIZE

  typedef struct  GXV_prop_DataRec_

  {

    FT_Fixed  version;

  } GXV_prop_DataRec, *GXV_prop_Data;

#define GXV_PROP_DATA( field )  GXV_TABLE_DATA( prop, field )

#define GXV_PROP_FLOATER                      0x8000U

#define GXV_PROP_USE_COMPLEMENTARY_BRACKET    0x1000U

#define GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET 0x0F00U

#define GXV_PROP_ATTACHING_TO_RIGHT           0x0080U

#define GXV_PROP_RESERVED                     0x0060U

#define GXV_PROP_DIRECTIONALITY_CLASS         0x001FU

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

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

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

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

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

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

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

  static void

  gxv_prop_zero_advance_validate( FT_UShort      gid,

                                  GXV_Validator  valid )

  {

    FT_Face       face;

    FT_Error      error;

    FT_GlyphSlot  glyph;

    GXV_NAME_ENTER( "zero advance" );

    face = valid->face;

    error = FT_Load_Glyph( face,

                           gid,

                           FT_LOAD_IGNORE_TRANSFORM );

    if ( error )

      FT_INVALID_GLYPH_ID;

    glyph = face->glyph;

    if ( glyph->advance.x != (FT_Pos)0 ||

         glyph->advance.y != (FT_Pos)0 )

      FT_INVALID_DATA;

    GXV_EXIT;

  }

  /* Pass 0 as GLYPH to check the default property */

  static void

  gxv_prop_property_validate( FT_UShort      property,

                              FT_UShort      glyph,

                              GXV_Validator  valid )

  {

    if ( glyph != 0 && ( property & GXV_PROP_FLOATER ) )

      gxv_prop_zero_advance_validate( glyph, valid );

    if ( property & GXV_PROP_USE_COMPLEMENTARY_BRACKET )

    {

      FT_UShort  offset;

      char       complement;

      offset = (FT_UShort)( property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET );

      if ( offset == 0 )

        FT_INVALID_DATA;

      complement = (char)( offset >> 8 );

      if ( complement & 0x08 )

      {

        /* Top bit is set: negative */

        /* Calculate the absolute offset */

        complement = (char)( ( complement & 0x07 ) + 1 );

        /* The gid for complement must be greater than 0 */

        if ( glyph <= complement )

          FT_INVALID_DATA;

      }

      else

      {

        /* The gid for complement must be the face. */

        gxv_glyphid_validate( (FT_UShort)( glyph + complement ), valid );

      }

    }

    else

    {

      if ( property & GXV_PROP_COMPLEMENTARY_BRACKET_OFFSET )

        GXV_TRACE(( "glyph %d cannot have complementary bracketing\n",

                    glyph ));

    }

    /* this is introduced in version 2.0 */

    if ( property & GXV_PROP_ATTACHING_TO_RIGHT )

    {

      if ( GXV_PROP_DATA( version ) == 0x00010000UL )

        FT_INVALID_DATA;

    }

    if ( property & GXV_PROP_RESERVED )

      FT_INVALID_DATA;

    if ( ( property & GXV_PROP_DIRECTIONALITY_CLASS ) > 11 )

    {

      /* TODO: Too restricted. Use the validation level. */

      if ( GXV_PROP_DATA( version ) == 0x00010000UL ||

           GXV_PROP_DATA( version ) == 0x00020000UL )

        FT_INVALID_DATA;

    }

  }

  static void

  gxv_prop_LookupValue_validate( FT_UShort            glyph,

                                 GXV_LookupValueCPtr  value_p,

                                 GXV_Validator        valid )

  {

    gxv_prop_property_validate( value_p->u, glyph, valid );

  }

  /*

    +===============+ --------+

    | lookup header |         |

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

    | BinSrchHeader |         |

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

    | lastGlyph[0]  |         |

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

    | firstGlyph[0] |         |    head of lookup table

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

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

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

    | lastGlyph[1]  |         | (glyphID - firstGlyph) * 2 [byte]

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

    | firstGlyph[1] |         |

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

    | offset[1]     |         |

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

                              |

     ...                      |

                              |

    16bit value array         |

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

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

    ...

  */

  static GXV_LookupValueDesc

  gxv_prop_LookupFmt4_transit( FT_UShort            relative_gindex,

                               GXV_LookupValueCPtr  base_value_p,

                               FT_Bytes             lookuptbl_limit,

                               GXV_Validator        valid )

  {

    FT_Bytes             p;

    FT_Bytes             limit;

    FT_UShort            offset;

    GXV_LookupValueDesc  value;

    /* XXX: check range? */

    offset = (FT_UShort)( base_value_p->u +

                          relative_gindex * sizeof( FT_UShort ) );

    p      = valid->lookuptbl_head + offset;

    limit  = lookuptbl_limit;

    GXV_LIMIT_CHECK ( 2 );

    value.u = FT_NEXT_USHORT( p );

    return value;

  }

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

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

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

  /*****                         prop TABLE                            *****/

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

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

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

  FT_LOCAL_DEF( void )

  gxv_prop_validate( FT_Bytes      table,

                     FT_Face       face,

                     FT_Validator  ftvalid )

  {

    FT_Bytes          p     = table;

    FT_Bytes          limit = 0;

    GXV_ValidatorRec  validrec;

    GXV_Validator     valid = &validrec;

    GXV_prop_DataRec  proprec;

    GXV_prop_Data     prop = &proprec;

    FT_Fixed          version;

    FT_UShort         format;

    FT_UShort         defaultProp;

    valid->root       = ftvalid;

    valid->table_data = prop;

    valid->face       = face;

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

    GXV_INIT;

    GXV_LIMIT_CHECK( 4 + 2 + 2 );

    version     = FT_NEXT_ULONG( p );

    format      = FT_NEXT_USHORT( p );

    defaultProp = FT_NEXT_USHORT( p );

    /* only versions 1.0, 2.0, 3.0 are defined (1996) */

    if ( version != 0x00010000UL &&

         version != 0x00020000UL &&

         version != 0x00030000UL )

      FT_INVALID_FORMAT;

    /* only formats 0x0000, 0x0001 are defined (1996) */

    if ( format > 1 )

      FT_INVALID_FORMAT;

    gxv_prop_property_validate( defaultProp, 0, valid );

    if ( format == 0 )

    {

      FT_TRACE3(( "(format 0, no per-glyph properties, "

                  "remaining %d bytes are skipped)", limit - p ));

      goto Exit;

    }

    /* format == 1 */

    GXV_PROP_DATA( version ) = version;

    valid->lookupval_sign   = GXV_LOOKUPVALUE_UNSIGNED;

    valid->lookupval_func   = gxv_prop_LookupValue_validate;

    valid->lookupfmt4_trans = gxv_prop_LookupFmt4_transit;

    gxv_LookupTable_validate( p, limit, valid );

  Exit:

    FT_TRACE4(( "\n" ));

  }

/* END */