ttinterp.c

奇趣公司比较新的qt/emd版本

  static FT_Long
  Current_Ppem( EXEC_OP )
  {
    return TT_MULFIX( CUR.tt_metrics.ppem, CURRENT_Ratio() );
  }


  /*************************************************************************/
  /*                                                                       */
  /* Functions related to the control value table (CVT).                   */
  /*                                                                       */
  /*************************************************************************/


  FT_CALLBACK_DEF( FT_F26Dot6 )
  Read_CVT( EXEC_OP_ FT_ULong  idx )
  {
    return CUR.cvt[idx];
  }


  FT_CALLBACK_DEF( FT_F26Dot6 )
  Read_CVT_Stretched( EXEC_OP_ FT_ULong  idx )
  {
    return TT_MULFIX( CUR.cvt[idx], CURRENT_Ratio() );
  }


  FT_CALLBACK_DEF( void )
  Write_CVT( EXEC_OP_ FT_ULong    idx,
                      FT_F26Dot6  value )
  {
    CUR.cvt[idx] = value;
  }


  FT_CALLBACK_DEF( void )
  Write_CVT_Stretched( EXEC_OP_ FT_ULong    idx,
                                FT_F26Dot6  value )
  {
    CUR.cvt[idx] = FT_DivFix( value, CURRENT_Ratio() );
  }


  FT_CALLBACK_DEF( void )
  Move_CVT( EXEC_OP_ FT_ULong    idx,
                     FT_F26Dot6  value )
  {
    CUR.cvt[idx] += value;
  }


  FT_CALLBACK_DEF( void )
  Move_CVT_Stretched( EXEC_OP_ FT_ULong    idx,
                               FT_F26Dot6  value )
  {
    CUR.cvt[idx] += FT_DivFix( value, CURRENT_Ratio() );
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    GetShortIns                                                        */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Returns a short integer taken from the instruction stream at       */
  /*    address IP.                                                        */
  /*                                                                       */
  /* <Return>                                                              */
  /*    Short read at code[IP].                                            */
  /*                                                                       */
  /* <Note>                                                                */
  /*    This one could become a macro.                                     */
  /*                                                                       */
  static FT_Short
  GetShortIns( EXEC_OP )
  {
    /* Reading a byte stream so there is no endianess (DaveP) */
    CUR.IP += 2;
    return (FT_Short)( ( CUR.code[CUR.IP - 2] << 8 ) +
                         CUR.code[CUR.IP - 1]      );
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    Ins_Goto_CodeRange                                                 */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Goes to a certain code range in the instruction stream.            */
  /*                                                                       */
  /* <Input>                                                               */
  /*    aRange :: The index of the code range.                             */
  /*                                                                       */
  /*    aIP    :: The new IP address in the code range.                    */
  /*                                                                       */
  /* <Return>                                                              */
  /*    SUCCESS or FAILURE.                                                */
  /*                                                                       */
  static FT_Bool
  Ins_Goto_CodeRange( EXEC_OP_ FT_Int    aRange,
                               FT_ULong  aIP )
  {
    TT_CodeRange*  range;


    if ( aRange < 1 || aRange > 3 )
    {
      CUR.error = TT_Err_Bad_Argument;
      return FAILURE;
    }

    range = &CUR.codeRangeTable[aRange - 1];

    if ( range->base == NULL )     /* invalid coderange */
    {
      CUR.error = TT_Err_Invalid_CodeRange;
      return FAILURE;
    }

    /* NOTE: Because the last instruction of a program may be a CALL */
    /*       which will return to the first byte *after* the code    */
    /*       range, we test for AIP <= Size, instead of AIP < Size.  */

    if ( aIP > range->size )
    {
      CUR.error = TT_Err_Code_Overflow;
      return FAILURE;
    }

    CUR.code     = range->base;
    CUR.codeSize = range->size;
    CUR.IP       = aIP;
    CUR.curRange = aRange;

    return SUCCESS;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    Direct_Move                                                        */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Moves a point by a given distance along the freedom vector.  The   */
  /*    point will be `touched'.                                           */
  /*                                                                       */
  /* <Input>                                                               */
  /*    point    :: The index of the point to move.                        */
  /*                                                                       */
  /*    distance :: The distance to apply.                                 */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    zone     :: The affected glyph zone.                               */
  /*                                                                       */
  static void
  Direct_Move( EXEC_OP_ TT_GlyphZone  zone,
                        FT_UShort     point,
                        FT_F26Dot6    distance )
  {
    FT_F26Dot6  v;


#ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING
    FT_ASSERT( !CUR.face->unpatented_hinting );
#endif

    v = CUR.GS.freeVector.x;

    if ( v != 0 )
    {
      zone->cur[point].x += TT_MULDIV( distance,
                                       v * 0x10000L,
                                       CUR.F_dot_P );

      zone->tags[point] |= FT_CURVE_TAG_TOUCH_X;
    }

    v = CUR.GS.freeVector.y;

    if ( v != 0 )
    {
      zone->cur[point].y += TT_MULDIV( distance,
                                       v * 0x10000L,
                                       CUR.F_dot_P );

      zone->tags[point] |= FT_CURVE_TAG_TOUCH_Y;
    }
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    Direct_Move_Orig                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Moves the *original* position of a point by a given distance along */
  /*    the freedom vector.  Obviously, the point will not be `touched'.   */
  /*                                                                       */
  /* <Input>                                                               */
  /*    point    :: The index of the point to move.                        */
  /*                                                                       */
  /*    distance :: The distance to apply.                                 */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    zone     :: The affected glyph zone.                               */
  /*                                                                       */
  static void
  Direct_Move_Orig( EXEC_OP_ TT_GlyphZone  zone,
                             FT_UShort     point,
                             FT_F26Dot6    distance )
  {
    FT_F26Dot6  v;


#ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING
    FT_ASSERT( !CUR.face->unpatented_hinting );
#endif

    v = CUR.GS.freeVector.x;

    if ( v != 0 )
      zone->org[point].x += TT_MULDIV( distance,
                                       v * 0x10000L,
                                       CUR.F_dot_P );

    v = CUR.GS.freeVector.y;

    if ( v != 0 )
      zone->org[point].y += TT_MULDIV( distance,
                                       v * 0x10000L,
                                       CUR.F_dot_P );
  }


  /*************************************************************************/
  /*                                                                       */
  /* Special versions of Direct_Move()                                     */
  /*                                                                       */
  /*   The following versions are used whenever both vectors are both      */
  /*   along one of the coordinate unit vectors, i.e. in 90% of the cases. */
  /*                                                                       */
  /*************************************************************************/


  static void
  Direct_Move_X( EXEC_OP_ TT_GlyphZone  zone,
                          FT_UShort     point,
                          FT_F26Dot6    distance )
  {
    FT_UNUSED_EXEC;

    zone->cur[point].x += distance;
    zone->tags[point]  |= FT_CURVE_TAG_TOUCH_X;
  }


  static void
  Direct_Move_Y( EXEC_OP_ TT_GlyphZone  zone,
                          FT_UShort     point,
                          FT_F26Dot6    distance )
  {
    FT_UNUSED_EXEC;

    zone->cur[point].y += distance;
    zone->tags[point]  |= FT_CURVE_TAG_TOUCH_Y;
  }


  /*************************************************************************/
  /*                                                                       */
  /* Special versions of Direct_Move_Orig()                                */
  /*                                                                       */
  /*   The following versions are used whenever both vectors are both      */
  /*   along one of the coordinate unit vectors, i.e. in 90% of the cases. */
  /*                                                                       */
  /*************************************************************************/


  static void
  Direct_Move_Orig_X( EXEC_OP_ TT_GlyphZone  zone,
                               FT_UShort     point,
                               FT_F26Dot6    distance )
  {
    FT_UNUSED_EXEC;

    zone->org[point].x += distance;
  }


  static void
  Direct_Move_Orig_Y( EXEC_OP_ TT_GlyphZone  zone,
                               FT_UShort     point,
                               FT_F26Dot6    distance )
  {
    FT_UNUSED_EXEC;

    zone->org[point].y += distance;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    Round_None                                                         */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Does not round, but adds engine compensation.                      */
  /*                                                                       */
  /* <Input>                                                               */
  /*    distance     :: The distance (not) to round.                       */
  /*                                                                       */
  /*    compensation :: The engine compensation.                           */
  /*                                                                       */
  /* <Return>                                                              */
  /*    The compensated distance.                                          */
  /*                                                                       */
  /* <Note>                                                                */
  /*    The TrueType specification says very few about the relationship    */
  /*    between rounding and engine compensation.  However, it seems from  */
  /*    the description of super round that we should add the compensation */
  /*    before rounding.                                                   */
  /*                                                                       */
  static FT_F26Dot6
  Round_None( EXEC_OP_ FT_F26Dot6  distance,
                       FT_F26Dot6  compensation )
  {
    FT_F26Dot6  val;

    FT_UNUSED_EXEC;


    if ( distance >= 0 )
    {
      val = distance + compensation;
      if ( distance && val < 0 )
        val = 0;
    }
    else {
      val = distance