misc/libfreetype/src/otvalid/otvmath.c
author belphegorr <szabibibi@gmail.com>
Mon, 23 Jul 2012 19:15:59 +0300
changeset 7263 644eabbc9218
parent 5172 88f2e05288ba
permissions -rw-r--r--
Added a new function: AddNewEvent, which only adds an event to the list if it doesn't already exist. Kept the old one as it might me useful to be able to add an event more than once.

/***************************************************************************/
/*                                                                         */
/*  otvmath.c                                                              */
/*                                                                         */
/*    OpenType MATH table validation (body).                               */
/*                                                                         */
/*  Copyright 2007, 2008 by                                                */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  Written by 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.                                        */
/*                                                                         */
/***************************************************************************/


#include "otvalid.h"
#include "otvcommn.h"
#include "otvgpos.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_otvmath



  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                  MATH TYPOGRAPHIC CONSTANTS                   *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static void
  otv_MathConstants_validate( FT_Bytes       table,
                              OTV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_UInt   i;
    FT_UInt   table_size;

    OTV_OPTIONAL_TABLE( DeviceTableOffset );


    OTV_NAME_ENTER( "MathConstants" );

    /* 56 constants, 51 have device tables */
    OTV_LIMIT_CHECK( 2 * ( 56 + 51 ) );
    table_size = 2 * ( 56 + 51 );

    p += 4 * 2;                 /* First 4 constants have no device tables */
    for ( i = 0; i < 51; ++i )
    {
      p += 2;                                            /* skip the value */
      OTV_OPTIONAL_OFFSET( DeviceTableOffset );
      OTV_SIZE_CHECK( DeviceTableOffset );
      if ( DeviceTableOffset )
        otv_Device_validate( table + DeviceTableOffset, valid );
    }

    OTV_EXIT;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                   MATH ITALICS CORRECTION                     *****/
  /*****                 MATH TOP ACCENT ATTACHMENT                    *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static void
  otv_MathItalicsCorrectionInfo_validate( FT_Bytes       table,
                                          OTV_Validator  valid,
                                          FT_Int         isItalic )
  {
    FT_Bytes  p = table;
    FT_UInt   i, cnt, table_size ;

    OTV_OPTIONAL_TABLE( Coverage );
    OTV_OPTIONAL_TABLE( DeviceTableOffset );

    FT_UNUSED( isItalic );  /* only used if tracing is active */


    OTV_NAME_ENTER( isItalic ? "MathItalicsCorrectionInfo"
                             : "MathTopAccentAttachment" );

    OTV_LIMIT_CHECK( 4 );

    OTV_OPTIONAL_OFFSET( Coverage );
    cnt = FT_NEXT_USHORT( p );

    OTV_LIMIT_CHECK( 4 * cnt );
    table_size = 4 + 4 * cnt;

    OTV_SIZE_CHECK( Coverage );
    otv_Coverage_validate( table + Coverage, valid, cnt );

    for ( i = 0; i < cnt; ++i )
    {
      p += 2;                                            /* Skip the value */
      OTV_OPTIONAL_OFFSET( DeviceTableOffset );
      OTV_SIZE_CHECK( DeviceTableOffset );
      if ( DeviceTableOffset )
        otv_Device_validate( table + DeviceTableOffset, valid );
    }

    OTV_EXIT;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                           MATH KERNING                        *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static void
  otv_MathKern_validate( FT_Bytes       table,
                         OTV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_UInt   i, cnt, table_size;

    OTV_OPTIONAL_TABLE( DeviceTableOffset );


    /* OTV_NAME_ENTER( "MathKern" );*/

    OTV_LIMIT_CHECK( 2 );

    cnt = FT_NEXT_USHORT( p );

    OTV_LIMIT_CHECK( 4 * cnt + 2 );
    table_size = 4 + 4 * cnt;

    /* Heights */
    for ( i = 0; i < cnt; ++i )
    {
      p += 2;                                            /* Skip the value */
      OTV_OPTIONAL_OFFSET( DeviceTableOffset );
      OTV_SIZE_CHECK( DeviceTableOffset );
      if ( DeviceTableOffset )
        otv_Device_validate( table + DeviceTableOffset, valid );
    }

    /* One more Kerning value */
    for ( i = 0; i < cnt + 1; ++i )
    {
      p += 2;                                            /* Skip the value */
      OTV_OPTIONAL_OFFSET( DeviceTableOffset );
      OTV_SIZE_CHECK( DeviceTableOffset );
      if ( DeviceTableOffset )
        otv_Device_validate( table + DeviceTableOffset, valid );
    }

    OTV_EXIT;
  }


  static void
  otv_MathKernInfo_validate( FT_Bytes       table,
                             OTV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_UInt   i, j, cnt, table_size;

    OTV_OPTIONAL_TABLE( Coverage );
    OTV_OPTIONAL_TABLE( MKRecordOffset );


    OTV_NAME_ENTER( "MathKernInfo" );

    OTV_LIMIT_CHECK( 4 );

    OTV_OPTIONAL_OFFSET( Coverage );
    cnt = FT_NEXT_USHORT( p );

    OTV_LIMIT_CHECK( 8 * cnt );
    table_size = 4 + 8 * cnt;

    OTV_SIZE_CHECK( Coverage );
    otv_Coverage_validate( table + Coverage, valid, cnt );

    for ( i = 0; i < cnt; ++i )
    {
      for ( j = 0; j < 4; ++j )
      {
        OTV_OPTIONAL_OFFSET( MKRecordOffset );
        OTV_SIZE_CHECK( MKRecordOffset );
        if ( MKRecordOffset )
          otv_MathKern_validate( table + MKRecordOffset, valid );
      }
    }

    OTV_EXIT;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                         MATH GLYPH INFO                       *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static void
  otv_MathGlyphInfo_validate( FT_Bytes       table,
                              OTV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_UInt   MathItalicsCorrectionInfo, MathTopAccentAttachment;
    FT_UInt   ExtendedShapeCoverage, MathKernInfo;


    OTV_NAME_ENTER( "MathGlyphInfo" );

    OTV_LIMIT_CHECK( 8 );

    MathItalicsCorrectionInfo = FT_NEXT_USHORT( p );
    MathTopAccentAttachment   = FT_NEXT_USHORT( p );
    ExtendedShapeCoverage     = FT_NEXT_USHORT( p );
    MathKernInfo              = FT_NEXT_USHORT( p );

    if ( MathItalicsCorrectionInfo )
      otv_MathItalicsCorrectionInfo_validate(
        table + MathItalicsCorrectionInfo, valid, TRUE );

    /* Italic correction and Top Accent Attachment have the same format */
    if ( MathTopAccentAttachment )
      otv_MathItalicsCorrectionInfo_validate(
        table + MathTopAccentAttachment, valid, FALSE );

    if ( ExtendedShapeCoverage )
    {
      OTV_NAME_ENTER( "ExtendedShapeCoverage" );
      otv_Coverage_validate( table + ExtendedShapeCoverage, valid, -1 );
      OTV_EXIT;
    }

    if ( MathKernInfo )
      otv_MathKernInfo_validate( table + MathKernInfo, valid );

    OTV_EXIT;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                    MATH GLYPH CONSTRUCTION                    *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static void
  otv_GlyphAssembly_validate( FT_Bytes       table,
                              OTV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_UInt   pcnt, table_size;
    FT_UInt   i;

    OTV_OPTIONAL_TABLE( DeviceTableOffset );


    /* OTV_NAME_ENTER( "GlyphAssembly" ); */

    OTV_LIMIT_CHECK( 6 );

    p += 2;                           /* Skip the Italics Correction value */
    OTV_OPTIONAL_OFFSET( DeviceTableOffset );
    pcnt = FT_NEXT_USHORT( p );

    OTV_LIMIT_CHECK( 8 * pcnt );
    table_size = 6 + 8 * pcnt;

    OTV_SIZE_CHECK( DeviceTableOffset );
    if ( DeviceTableOffset )
      otv_Device_validate( table + DeviceTableOffset, valid );

    for ( i = 0; i < pcnt; ++i )
    {
      FT_UInt  gid;


      gid = FT_NEXT_USHORT( p );
      if ( gid >= valid->glyph_count )
        FT_INVALID_GLYPH_ID;
      p += 2*4;             /* skip the Start, End, Full, and Flags fields */
    }

    /* OTV_EXIT; */
  }


  static void
  otv_MathGlyphConstruction_validate( FT_Bytes       table,
                                      OTV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_UInt   vcnt, table_size;
    FT_UInt   i;

    OTV_OPTIONAL_TABLE( GlyphAssembly );


    /* OTV_NAME_ENTER( "MathGlyphConstruction" ); */

    OTV_LIMIT_CHECK( 4 );

    OTV_OPTIONAL_OFFSET( GlyphAssembly );
    vcnt = FT_NEXT_USHORT( p );

    OTV_LIMIT_CHECK( 4 * vcnt );
    table_size = 4 + 4 * vcnt;

    for ( i = 0; i < vcnt; ++i )
    {
      FT_UInt  gid;


      gid = FT_NEXT_USHORT( p );
      if ( gid >= valid->glyph_count )
        FT_INVALID_GLYPH_ID;
      p += 2;                          /* skip the size */
    }

    OTV_SIZE_CHECK( GlyphAssembly );
    if ( GlyphAssembly )
      otv_GlyphAssembly_validate( table+GlyphAssembly, valid );

    /* OTV_EXIT; */
  }


  static void
  otv_MathVariants_validate( FT_Bytes       table,
                             OTV_Validator  valid )
  {
    FT_Bytes  p = table;
    FT_UInt   vcnt, hcnt, i, table_size;

    OTV_OPTIONAL_TABLE( VCoverage );
    OTV_OPTIONAL_TABLE( HCoverage );
    OTV_OPTIONAL_TABLE( Offset );


    OTV_NAME_ENTER( "MathVariants" );

    OTV_LIMIT_CHECK( 10 );

    p += 2;                       /* Skip the MinConnectorOverlap constant */
    OTV_OPTIONAL_OFFSET( VCoverage );
    OTV_OPTIONAL_OFFSET( HCoverage );
    vcnt = FT_NEXT_USHORT( p );
    hcnt = FT_NEXT_USHORT( p );

    OTV_LIMIT_CHECK( 2 * vcnt + 2 * hcnt );
    table_size = 10 + 2 * vcnt + 2 * hcnt;

    OTV_SIZE_CHECK( VCoverage );
    if ( VCoverage )
      otv_Coverage_validate( table + VCoverage, valid, vcnt );

    OTV_SIZE_CHECK( HCoverage );
    if ( HCoverage )
      otv_Coverage_validate( table + HCoverage, valid, hcnt );

    for ( i = 0; i < vcnt; ++i )
    {
      OTV_OPTIONAL_OFFSET( Offset );
      OTV_SIZE_CHECK( Offset );
      otv_MathGlyphConstruction_validate( table + Offset, valid );
    }

    for ( i = 0; i < hcnt; ++i )
    {
      OTV_OPTIONAL_OFFSET( Offset );
      OTV_SIZE_CHECK( Offset );
      otv_MathGlyphConstruction_validate( table + Offset, valid );
    }

    OTV_EXIT;
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                          MATH TABLE                           *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  /* sets valid->glyph_count */

  FT_LOCAL_DEF( void )
  otv_MATH_validate( FT_Bytes      table,
                     FT_UInt       glyph_count,
                     FT_Validator  ftvalid )
  {
    OTV_ValidatorRec  validrec;
    OTV_Validator     valid = &validrec;
    FT_Bytes          p     = table;
    FT_UInt           MathConstants, MathGlyphInfo, MathVariants;


    valid->root = ftvalid;

    FT_TRACE3(( "validating MATH table\n" ));
    OTV_INIT;

    OTV_LIMIT_CHECK( 10 );

    if ( FT_NEXT_ULONG( p ) != 0x10000UL )      /* Version */
      FT_INVALID_FORMAT;

    MathConstants = FT_NEXT_USHORT( p );
    MathGlyphInfo = FT_NEXT_USHORT( p );
    MathVariants  = FT_NEXT_USHORT( p );

    valid->glyph_count = glyph_count;

    otv_MathConstants_validate( table + MathConstants,
                                valid );
    otv_MathGlyphInfo_validate( table + MathGlyphInfo,
                                valid );
    otv_MathVariants_validate ( table + MathVariants,
                                valid );

    FT_TRACE4(( "\n" ));
  }


/* END */