ttinterp.c

神龙卡开发原代码

    /*  MDRP[23]  */  PACK( 1, 0 ),
    /*  MDRP[24]  */  PACK( 1, 0 ),
    /*  MDRP[25]  */  PACK( 1, 0 ),
    /*  MDRP[26]  */  PACK( 1, 0 ),
    /*  MDRP[27]  */  PACK( 1, 0 ),
    /*  MDRP[28]  */  PACK( 1, 0 ),
    /*  MDRP[29]  */  PACK( 1, 0 ),
    /*  MDRP[30]  */  PACK( 1, 0 ),
    /*  MDRP[31]  */  PACK( 1, 0 ),

    /*  MIRP[00]  */  PACK( 2, 0 ),
    /*  MIRP[01]  */  PACK( 2, 0 ),
    /*  MIRP[02]  */  PACK( 2, 0 ),
    /*  MIRP[03]  */  PACK( 2, 0 ),
    /*  MIRP[04]  */  PACK( 2, 0 ),
    /*  MIRP[05]  */  PACK( 2, 0 ),
    /*  MIRP[06]  */  PACK( 2, 0 ),
    /*  MIRP[07]  */  PACK( 2, 0 ),
    /*  MIRP[08]  */  PACK( 2, 0 ),
    /*  MIRP[09]  */  PACK( 2, 0 ),
    /*  MIRP[10]  */  PACK( 2, 0 ),
    /*  MIRP[11]  */  PACK( 2, 0 ),
    /*  MIRP[12]  */  PACK( 2, 0 ),
    /*  MIRP[13]  */  PACK( 2, 0 ),
    /*  MIRP[14]  */  PACK( 2, 0 ),
    /*  MIRP[15]  */  PACK( 2, 0 ),

    /*  MIRP[16]  */  PACK( 2, 0 ),
    /*  MIRP[17]  */  PACK( 2, 0 ),
    /*  MIRP[18]  */  PACK( 2, 0 ),
    /*  MIRP[19]  */  PACK( 2, 0 ),
    /*  MIRP[20]  */  PACK( 2, 0 ),
    /*  MIRP[21]  */  PACK( 2, 0 ),
    /*  MIRP[22]  */  PACK( 2, 0 ),
    /*  MIRP[23]  */  PACK( 2, 0 ),
    /*  MIRP[24]  */  PACK( 2, 0 ),
    /*  MIRP[25]  */  PACK( 2, 0 ),
    /*  MIRP[26]  */  PACK( 2, 0 ),
    /*  MIRP[27]  */  PACK( 2, 0 ),
    /*  MIRP[28]  */  PACK( 2, 0 ),
    /*  MIRP[29]  */  PACK( 2, 0 ),
    /*  MIRP[30]  */  PACK( 2, 0 ),
    /*  MIRP[31]  */  PACK( 2, 0 )
  };

  static  const  TT_Vector  Null_Vector = {0,0};

#undef  NULL_Vector
#define NULL_Vector (TT_Vector*)&Null_Vector

/*******************************************************************
 *
 *  Function    :  Norm
 *
 *  Description :  Returns the norm (length) of a vector.
 *
 *  Input  :  X, Y   vector
 *
 *  Output :  Returns length in F26dot6.
 *
 *****************************************************************/

  static TT_F26Dot6  Norm( TT_F26Dot6  X, TT_F26Dot6  Y )
  {
    TT_Int64       T1, T2;


    MUL_64( X, X, T1 );
    MUL_64( Y, Y, T2 );

    ADD_64( T1, T2, T1 );

    return (TT_F26Dot6)SQRT_64( T1 );
  }


/*******************************************************************
 *
 *  Function    :  FUnits_To_Pixels
 *
 *  Description :  Scale a distance in FUnits to pixel coordinates.
 *
 *  Input  :  Distance in FUnits
 *
 *  Output :  Distance in 26.6 format.
 *
 *****************************************************************/

  static TT_F26Dot6  FUnits_To_Pixels( EXEC_OPS Short  distance )
  {
    return TT_MulDiv( distance,
                      CUR.metrics.scale1,
                      CUR.metrics.scale2 );
  }


/*******************************************************************
 *
 *  Function    :  Current_Ratio
 *
 *  Description :  Return the current aspect ratio scaling factor
 *                 depending on the projection vector's state and
 *                 device resolutions.
 *
 *  Input  :  None
 *
 *  Output :  Aspect ratio in 16.16 format, always <= 1.0 .
 *
 *****************************************************************/

  static Long  Current_Ratio( EXEC_OP )
  {
    if ( CUR.metrics.ratio )
      return CUR.metrics.ratio;

    if ( CUR.GS.projVector.y == 0 )
      CUR.metrics.ratio = CUR.metrics.x_ratio;

    else if ( CUR.GS.projVector.x == 0 )
      CUR.metrics.ratio = CUR.metrics.y_ratio;

    else
    {
      Long  x, y;


      x = TT_MulDiv( CUR.GS.projVector.x, CUR.metrics.x_ratio, 0x4000 );
      y = TT_MulDiv( CUR.GS.projVector.y, CUR.metrics.y_ratio, 0x4000 );
      CUR.metrics.ratio = Norm( x, y );
    }

    return CUR.metrics.ratio;
  }


  static Long  Current_Ppem( EXEC_OP )
  {
    return TT_MulFix( CUR.metrics.ppem, CURRENT_Ratio() );
  }


  static TT_F26Dot6  Read_CVT( EXEC_OPS ULong  index )
  {
    return CUR.cvt[index];
  }


  static TT_F26Dot6  Read_CVT_Stretched( EXEC_OPS ULong  index )
  {
    return TT_MulFix( CUR.cvt[index], CURRENT_Ratio() );
  }


  static void  Write_CVT( EXEC_OPS ULong  index, TT_F26Dot6  value )
  {
    CUR.cvt[index] = value;
  }

  static void  Write_CVT_Stretched( EXEC_OPS ULong  index, TT_F26Dot6  value )
  {
    CUR.cvt[index] = TT_MulDiv( value, 0x10000, CURRENT_Ratio() );
  }


  static void  Move_CVT( EXEC_OPS ULong  index, TT_F26Dot6  value )
  {
    CUR.cvt[index] += value;
  }

  static void  Move_CVT_Stretched( EXEC_OPS ULong  index, TT_F26Dot6  value )
  {
    CUR.cvt[index] += TT_MulDiv( value, 0x10000, CURRENT_Ratio() );
  }


/******************************************************************
 *
 *  Function    :  Calc_Length
 *
 *  Description :  Computes the length in bytes of current opcode.
 *
 *****************************************************************/

  static Bool  Calc_Length( EXEC_OP )
  {
    CUR.opcode = CUR.code[CUR.IP];

    switch ( CUR.opcode )
    {
    case 0x40:
      if ( CUR.IP + 1 >= CUR.codeSize )
        return FAILURE;

      CUR.length = CUR.code[CUR.IP + 1] + 2;
      break;

    case 0x41:
      if ( CUR.IP + 1 >= CUR.codeSize )
        return FAILURE;

      CUR.length = CUR.code[CUR.IP + 1] * 2 + 2;
      break;

    case 0xB0:
    case 0xB1:
    case 0xB2:
    case 0xB3:
    case 0xB4:
    case 0xB5:
    case 0xB6:
    case 0xB7:
      CUR.length = CUR.opcode - 0xB0 + 2;
      break;

    case 0xB8:
    case 0xB9:
    case 0xBA:
    case 0xBB:
    case 0xBC:
    case 0xBD:
    case 0xBE:
    case 0xBF:
      CUR.length = (CUR.opcode - 0xB8) * 2 + 3;
      break;

    default:
      CUR.length = 1;
      break;
    }

    /* make sure result is in range */

    if ( CUR.IP + CUR.length > CUR.codeSize )
      return FAILURE;

    return SUCCESS;
  }


/*******************************************************************
 *
 *  Function    :  GetShortIns
 *
 *  Description :  Returns a short integer taken from the instruction
 *                 stream at address IP.
 *
 *  Input  :  None
 *
 *  Output :  Short read at Code^[IP..IP+1]
 *
 *  Notes  :  This one could become a Macro in the C version.
 *
 *****************************************************************/

  static Short  GetShortIns( EXEC_OP )
  {
    /* Reading a byte stream so there is no endianess (DaveP) */
    CUR.IP += 2;
    return (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
 *            aIP
 *
 *  Output :  SUCCESS or FAILURE.
 *
 *****************************************************************/

  static Bool  Ins_Goto_CodeRange( EXEC_OPS Int  aRange, ULong  aIP )
  {
    TCodeRange*  WITH;


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

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

    if ( WITH->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 > WITH->Size )
    {
      CUR.error = TT_Err_Code_Overflow;
      return FAILURE;
    }

    CUR.code     = WITH->Base;
    CUR.codeSize = WITH->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       index of point to move
 *           distance    distance to apply
 *           zone        affected glyph zone
 *
 *  Output :  None
 *
 *****************************************************************/

  static void  Direct_Move( EXEC_OPS PGlyph_Zone zone,
                                     UShort      point,
                                     TT_F26Dot6  distance )
  {
    TT_F26Dot6 v;


    v = CUR.GS.freeVector.x;

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

      zone->touch[point] |= TT_Flag_Touched_X;
    }

    v = CUR.GS.freeVector.y;

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

      zone->touch[point] |= TT_Flag_Touched_Y;
    }
  }


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

/*******************************************************************
 * Direct_Move_X
 *
 *******************************************************************/

  static void  Direct_Move_X( EXEC_OPS PGlyph_Zone  zone,
                                       UShort       point,
                                       TT_F26Dot6   distance )
  {
    zone->cur[point].x += distance;
    zone->touch[point] |= TT_Flag_Touched_X;
  }


/*******************************************************************
 * Direct_Move_Y
 *
 *******************************************************************/

  static void  Direct_Move_Y( EXEC_OPS PGlyph_Zone  zone,
                                       UShort       point,
                                       TT_F26Dot6   distance )
  {
    zone->cur[point].y += distance;
    zone->touch[point] |= TT_Flag_Touched_Y;
  }


/*******************************************************************
 *
 *  Function    :  Round_None
 *
 *  Description :  Does not round, but adds engine compensation.
 *
 *  Input  :  distance      : distance to round
 *            compensation  : engine compensation
 *
 *  Output :  rounded distance.
 *
 *  NOTE : The spec says very few about the relationship between
 *         rounding and engine compensation.  However, it seems
 *         from the description of super round that we should
 *         should add the compensation before rounding.
 *
 ******************************************************************/

  static TT_F26Dot6  Round_None( EXEC_OPS TT_F26Dot6  distance,
                                          TT_F26Dot6  compensation )
  {
    TT_F26Dot6  val;


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

    return val;
  }


/*******************************************************************
 *
 *  Function    :  Round_To_Grid
 *
 *  Description :  Rounds value to grid after adding engine
 *                 compensation
 *
 *  Input  :  distance      : distance to round
 *            compensation  : engine compensation
 *
 *  Output :  Rounded distance.
 *
 *****************************************************************/

  static TT_F26Dot6  Round_To_Grid( EXEC_OPS TT_F26Dot6  distance,
                                             TT_F26Dot6  compensation )
  {
    TT_F26Dot6  val;


    if ( distance >= 0 )
    {
      val = distance + compensation + 32;
      if ( val > 0 )
        val &= ~63;
      else
        val = 0;
    }