gxvkern.c

奇趣公司比较新的qt/emd版本

/***************************************************************************/
/*                                                                         */
/*  gxvkern.c                                                              */
/*                                                                         */
/*    TrueTypeGX/AAT kern table validation (body).                         */
/*                                                                         */
/*  Copyright 2004, 2005, 2006, 2007                                       */
/*  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"

#include FT_SFNT_NAMES_H
#include FT_SERVICE_GX_VALIDATE_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_gxvkern


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

  typedef enum  GXV_kern_Version_
  {
    KERN_VERSION_CLASSIC = 0x0000,
    KERN_VERSION_NEW     = 0x0001

  } GXV_kern_Version;


  typedef enum GXV_kern_Dialect_
  {
    KERN_DIALECT_UNKNOWN = 0,
    KERN_DIALECT_MS      = FT_VALIDATE_MS,
    KERN_DIALECT_APPLE   = FT_VALIDATE_APPLE,
    KERN_DIALECT_ANY     = FT_VALIDATE_CKERN

  } GXV_kern_Dialect;


  typedef struct  GXV_kern_DataRec_
  {
    GXV_kern_Version  version;
    void             *subtable_data;
    GXV_kern_Dialect  dialect_request;

  } GXV_kern_DataRec, *GXV_kern_Data;


#define GXV_KERN_DATA( field )  GXV_TABLE_DATA( kern, field )

#define KERN_IS_CLASSIC( valid )                               \
          ( KERN_VERSION_CLASSIC == GXV_KERN_DATA( version ) )
#define KERN_IS_NEW( valid )                                   \
          ( KERN_VERSION_NEW     == GXV_KERN_DATA( version ) )

#define KERN_DIALECT( valid )              \
          GXV_KERN_DATA( dialect_request )
#define KERN_ALLOWS_MS( valid )                       \
          ( KERN_DIALECT( valid ) & KERN_DIALECT_MS )
#define KERN_ALLOWS_APPLE( valid )                       \
          ( KERN_DIALECT( valid ) & KERN_DIALECT_APPLE )

#define GXV_KERN_HEADER_SIZE           ( KERN_IS_NEW( valid ) ? 8 : 4 )
#define GXV_KERN_SUBTABLE_HEADER_SIZE  ( KERN_IS_NEW( valid ) ? 8 : 6 )


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                      SUBTABLE VALIDATORS                      *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  /* ============================= format 0 ============================== */

  static void
  gxv_kern_subtable_fmt0_pairs_validate( FT_Bytes       table,
                                         FT_Bytes       limit,
                                         FT_UShort      nPairs,
                                         GXV_Validator  valid )
  {
    FT_Bytes   p = table;
    FT_UShort  i;

    FT_UShort  last_gid_left  = 0;
    FT_UShort  last_gid_right = 0;

    FT_UNUSED( limit );


    GXV_NAME_ENTER( "kern format 0 pairs" );

    for ( i = 0; i < nPairs; i++ )
    {
      FT_UShort  gid_left;
      FT_UShort  gid_right;
      FT_Short   kernValue;


      /* left */
      gid_left  = FT_NEXT_USHORT( p );
      gxv_glyphid_validate( gid_left, valid );

      /* right */
      gid_right = FT_NEXT_USHORT( p );
      gxv_glyphid_validate( gid_right, valid );

      /* Pairs of left and right GIDs must be unique and sorted. */
      GXV_TRACE(( "left gid = %u, right gid = %u\n", gid_left, gid_right ));
      if ( gid_left == last_gid_left )
      {
        if ( last_gid_right < gid_right )
          last_gid_right = gid_right;
        else
          FT_INVALID_DATA;
      }
      else if ( last_gid_left < gid_left )
      {
        last_gid_left  = gid_left;
        last_gid_right = gid_right;
      }
      else
        FT_INVALID_DATA;

      /* skip the kern value */
      kernValue = FT_NEXT_SHORT( p );
    }

    GXV_EXIT;
  }

  static void
  gxv_kern_subtable_fmt0_validate( FT_Bytes       table,
                                   FT_Bytes       limit,
                                   GXV_Validator  valid )
  {
    FT_Bytes   p = table + GXV_KERN_SUBTABLE_HEADER_SIZE;

    FT_UShort  nPairs;
    FT_UShort  unitSize;


    GXV_NAME_ENTER( "kern subtable format 0" );

    unitSize = 2 + 2 + 2;
    nPairs   = 0;

    /* nPairs, searchRange, entrySelector, rangeShift */
    GXV_LIMIT_CHECK( 2 + 2 + 2 + 2 );
    gxv_BinSrchHeader_validate( p, limit, &unitSize, &nPairs, valid );
    p += 2 + 2 + 2 + 2;

    gxv_kern_subtable_fmt0_pairs_validate( p, limit, nPairs, valid );

    GXV_EXIT;
  }


  /* ============================= format 1 ============================== */


  typedef struct  GXV_kern_fmt1_StateOptRec_
  {
    FT_UShort  valueTable;
    FT_UShort  valueTable_length;

  } GXV_kern_fmt1_StateOptRec, *GXV_kern_fmt1_StateOptRecData;


  static void
  gxv_kern_subtable_fmt1_valueTable_load( FT_Bytes       table,
                                          FT_Bytes       limit,
                                          GXV_Validator  valid )
  {
    FT_Bytes                       p = table;
    GXV_kern_fmt1_StateOptRecData  optdata =
      (GXV_kern_fmt1_StateOptRecData)valid->statetable.optdata;


    GXV_LIMIT_CHECK( 2 );
    optdata->valueTable = FT_NEXT_USHORT( p );
  }


  /*
   * passed tables_size covers whole StateTable, including kern fmt1 header
   */
  static void
  gxv_kern_subtable_fmt1_subtable_setup( FT_UShort      table_size,
                                         FT_UShort      classTable,
                                         FT_UShort      stateArray,
                                         FT_UShort      entryTable,
                                         FT_UShort*     classTable_length_p,
                                         FT_UShort*     stateArray_length_p,
                                         FT_UShort*     entryTable_length_p,
                                         GXV_Validator  valid )
  {
    FT_UShort  o[4];
    FT_UShort  *l[4];
    FT_UShort  buff[5];

    GXV_kern_fmt1_StateOptRecData  optdata =
      (GXV_kern_fmt1_StateOptRecData)valid->statetable.optdata;


    o[0] = classTable;
    o[1] = stateArray;
    o[2] = entryTable;
    o[3] = optdata->valueTable;
    l[0] = classTable_length_p;
    l[1] = stateArray_length_p;
    l[2] = entryTable_length_p;
    l[3] = &(optdata->valueTable_length);

    gxv_set_length_by_ushort_offset( o, l, buff, 4, table_size, valid );
  }


  /*
   * passed table & limit are of whole StateTable, not including subtables
   */
  static void
  gxv_kern_subtable_fmt1_entry_validate(
    FT_Byte                         state,
    FT_UShort                       flags,
    GXV_StateTable_GlyphOffsetDesc  glyphOffset,
    FT_Bytes                        table,
    FT_Bytes                        limit,
    GXV_Validator                   valid )
  {
    FT_UShort  push;
    FT_UShort  dontAdvance;
    FT_UShort  valueOffset;
    FT_UShort  kernAction;
    FT_UShort  kernValue;

    FT_UNUSED( state );
    FT_UNUSED( glyphOffset );


    push        = (FT_UShort)( ( flags >> 15 ) & 1      );
    dontAdvance = (FT_UShort)( ( flags >> 14 ) & 1      );
    valueOffset = (FT_UShort)(   flags         & 0x3FFF );

    {
      GXV_kern_fmt1_StateOptRecData  vt_rec =
        (GXV_kern_fmt1_StateOptRecData)valid->statetable.optdata;
      FT_Bytes  p;


      if ( valueOffset < vt_rec->valueTable )
        FT_INVALID_OFFSET;

      p     = table + valueOffset;
      limit = table + vt_rec->valueTable + vt_rec->valueTable_length;

      GXV_LIMIT_CHECK( 2 + 2 );
      kernAction = FT_NEXT_USHORT( p );
      kernValue  = FT_NEXT_USHORT( p );
    }
  }


  static void
  gxv_kern_subtable_fmt1_validate( FT_Bytes       table,
                                   FT_Bytes       limit,
                                   GXV_Validator  valid )
  {
    FT_Bytes                   p = table;
    GXV_kern_fmt1_StateOptRec  vt_rec;


    GXV_NAME_ENTER( "kern subtable format 1" );

    valid->statetable.optdata =
      &vt_rec;
    valid->statetable.optdata_load_func =
      gxv_kern_subtable_fmt1_valueTable_load;
    valid->statetable.subtable_setup_func =
      gxv_kern_subtable_fmt1_subtable_setup;
    valid->statetable.entry_glyphoffset_fmt =
      GXV_GLYPHOFFSET_NONE;
    valid->statetable.entry_validate_func =
      gxv_kern_subtable_fmt1_entry_validate;

    gxv_StateTable_validate( p, limit, valid );

    GXV_EXIT;
  }


  /* ================ Data for Class-Based Subtables 2, 3 ================ */

  typedef enum  GXV_kern_ClassSpec_
  {
    GXV_KERN_CLS_L = 0,
    GXV_KERN_CLS_R

  } GXV_kern_ClassSpec;


  /* ============================= format 2 ============================== */

  /* ---------------------- format 2 specific data ----------------------- */

  typedef struct  GXV_kern_subtable_fmt2_DataRec_
  {
    FT_UShort         rowWidth;
    FT_UShort         array;
    FT_UShort         offset_min[2];
    FT_UShort         offset_max[2];
    const FT_String*  class_tag[2];
    GXV_odtect_Range  odtect;

  } GXV_kern_subtable_fmt2_DataRec, *GXV_kern_subtable_fmt2_Data;


#define GXV_KERN_FMT2_DATA( field )                         \
        ( ( (GXV_kern_subtable_fmt2_DataRec *)              \
              ( GXV_KERN_DATA( subtable_data ) ) )->field )


  /* -------------------------- utility functions ----------------------- */

  static void
  gxv_kern_subtable_fmt2_clstbl_validate( FT_Bytes            table,
                                          FT_Bytes            limit,
                                          GXV_kern_ClassSpec  spec,
                                          GXV_Validator       valid )
  {
    const FT_String*  tag    = GXV_KERN_FMT2_DATA( class_tag[spec] );
    GXV_odtect_Range  odtect = GXV_KERN_FMT2_DATA( odtect );

    FT_Bytes   p = table;
    FT_UShort  firstGlyph;
    FT_UShort  nGlyphs;


    GXV_NAME_ENTER( "kern format 2 classTable" );

    GXV_LIMIT_CHECK( 2 + 2 );
    firstGlyph = FT_NEXT_USHORT( p );
    nGlyphs    = FT_NEXT_USHORT( p );
    GXV_TRACE(( " %s firstGlyph=%d, nGlyphs=%d\n",
                tag, firstGlyph, nGlyphs ));

    gxv_glyphid_validate( firstGlyph, valid );
    gxv_glyphid_validate( (FT_UShort)( firstGlyph + nGlyphs - 1 ), valid );

    gxv_array_getlimits_ushort( p, p + ( 2 * nGlyphs ),
                                &( GXV_KERN_FMT2_DATA( offset_min[spec] ) ),
                                &( GXV_KERN_FMT2_DATA( offset_max[spec] ) ),
                                valid );

    gxv_odtect_add_range( table, 2 * nGlyphs, tag, odtect );

    GXV_EXIT;
  }


  static void
  gxv_kern_subtable_fmt2_validate( FT_Bytes       table,
                                   FT_Bytes       limit,
                                   GXV_Validator  valid )
  {
    GXV_ODTECT( 3, odtect );
    GXV_kern_subtable_fmt2_DataRec  fmt2_rec =
      { 0, 0, { 0, 0 }, { 0, 0 }, { "leftClass", "rightClass" }, NULL };

    FT_Bytes   p = table + GXV_KERN_SUBTABLE_HEADER_SIZE;
    FT_UShort  leftOffsetTable;
    FT_UShort  rightOffsetTable;


    GXV_NAME_ENTER( "kern subtable format 2" );

    GXV_ODTECT_INIT( odtect );
    fmt2_rec.odtect = odtect;
    GXV_KERN_DATA( subtable_data ) = &fmt2_rec;

    GXV_LIMIT_CHECK( 2 + 2 + 2 + 2 );
    GXV_KERN_FMT2_DATA( rowWidth ) = FT_NEXT_USHORT( p );
    leftOffsetTable                = FT_NEXT_USHORT( p );
    rightOffsetTable               = FT_NEXT_USHORT( p );
    GXV_KERN_FMT2_DATA( array )    = FT_NEXT_USHORT( p );

    GXV_TRACE(( "rowWidth = %d\n", GXV_KERN_FMT2_DATA( rowWidth ) ));


    GXV_LIMIT_CHECK( leftOffsetTable );
    GXV_LIMIT_CHECK( rightOffsetTable );
    GXV_LIMIT_CHECK( GXV_KERN_FMT2_DATA( array ) );

    gxv_kern_subtable_fmt2_clstbl_validate( table + leftOffsetTable, limit,
                                            GXV_KERN_CLS_L, valid );

    gxv_kern_subtable_fmt2_clstbl_validate( table + rightOffsetTable, limit,
                                            GXV_KERN_CLS_R, valid );

    if ( GXV_KERN_FMT2_DATA( offset_min[GXV_KERN_CLS_L] ) +
           GXV_KERN_FMT2_DATA( offset_min[GXV_KERN_CLS_R] )
         < GXV_KERN_FMT2_DATA( array )                      )
      FT_INVALID_OFFSET;

    gxv_odtect_add_range( table + GXV_KERN_FMT2_DATA( array ),
                          GXV_KERN_FMT2_DATA( offset_max[GXV_KERN_CLS_L] )