Android Open Source - android-chess Move

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License

The source code is released under:

MIT License

Java Source Code

package jwtc.chess;
/*w  ww.j av  a2  s. com*/
// Move. Wrapper class for the integer representation of a move
// The positional values "from" and "to" are shifted into the integer.
// Also en-passant, castling, hit, first pawn move, promotion and promotion piece
// are part of the move.

public class Move
{
  // mask for a position [0-63], 6 bits.
  private static final int MASK_POS = 0x3F;
  // mask for a boolean [false=0, true=1], 1 bit
  private static final int MASK_BOOL = 1;
  
  // shift values
  private static final int SHIFT_TO = 6;
  private static final int SHIFT_EP = 13;
  // short castling OO
  private static final int SHIFT_OO = 14;
  // long castling OOO
  private static final int SHIFT_OOO = 15;
  private static final int SHIFT_HIT = 16;
  // is the first 2 step move of a pawn
  private static final int SHIFT_FIRSTPAWN = 17;
  // with this move the opponent king is checked
  private static final int SHIFT_CHECK = 18;
  // a pawn is promoted with this move
  private static final int SHIFT_PROMOTION = 19;
  // the piece the pawn is promoted to
  private static final int SHIFT_PROMOTIONPIECE = 20;
  
  // returns the integer representation of the simpelest move, from
  // position @from to position @to
  public static final int makeMove(final int from, final int to)
  {
    return from | (to << SHIFT_TO);
  }
  public static final int makeMoveFirstPawn(final int from, final int to)
  {
    return from | (to << SHIFT_TO) | (1 << SHIFT_FIRSTPAWN);
  }
  public static final int makeMoveHit(final int from, final int to)
  {
    //co.pl("makeMovehit " + from + "-" + to);
    return from | (to << SHIFT_TO) | (1 << SHIFT_HIT);
  }
  public static final int makeMoveEP(final int from, final int to)
  {
    return from | (to << SHIFT_TO) | (1 << SHIFT_HIT) | (1 << SHIFT_EP);
  }
  public static final int makeMoveOO(final int from, final int to)
  {
    return from | (to << SHIFT_TO) | (1 << SHIFT_OO);
  }
  public static final int makeMoveOOO(final int from, final int to)
  {
    return from | (to << SHIFT_TO) | (1 << SHIFT_OOO);
  }
  public static final int makeMovePromotion(final int from, final int to, final int piece, boolean bHit)
  {
    return from | (to << SHIFT_TO) | (1 << SHIFT_PROMOTION) | (piece << SHIFT_PROMOTIONPIECE) | (bHit == true ? (1 << SHIFT_HIT) : 0);
  }
  public static final int setCheck(final int move)
  {
    return move | (1 << SHIFT_CHECK);
  }
  // returns true when "from" and "to" are equal in both arguments
  public static final boolean equalPositions(final int m, final int m2)
  {
    return (m & MASK_POS) == (m2 & MASK_POS) && ((m >> SHIFT_TO) & MASK_POS) == ((m2 >> SHIFT_TO) & MASK_POS);
  }
  // return true when "to" in both arguments are equal
  public static final boolean equalTos(int m, int m2)
  {
    return ((m >> SHIFT_TO) & MASK_POS) == ((m2 >> SHIFT_TO) & MASK_POS);
  }

  // returns "from" of the move
  public static final int getFrom(final int move)
  {
    return move & MASK_POS;
  }
  public static final int getTo(final int move)
  {
    return (move >> SHIFT_TO) & MASK_POS;
  }
  public static final boolean isEP(final int move)
  {
    return ((move >> SHIFT_EP) & MASK_BOOL) == MASK_BOOL;
  }
  public static final boolean isOO(final int move)
  {
    return ((move >> SHIFT_OO) & MASK_BOOL) == MASK_BOOL;
  }
  public static final boolean isOOO(final int move)
  {
    return ((move >> SHIFT_OOO) & MASK_BOOL) == MASK_BOOL;
  }
  public static final boolean isHIT(final int move)
  {
    return ((move >> SHIFT_HIT) & MASK_BOOL) == MASK_BOOL;
  }
  public static final boolean isCheck(final int move)
  {
    return ((move >> SHIFT_CHECK) & MASK_BOOL) == MASK_BOOL;
  }
  public static final boolean isFirstPawnMove(final int move)
  {
    return ((move >> SHIFT_FIRSTPAWN) & MASK_BOOL) == MASK_BOOL;
  }
  public static final boolean isPromotionMove(final int move)
  {
    return ((move >> SHIFT_PROMOTION) & MASK_BOOL) == MASK_BOOL;
  }
  public static final int getPromotionPiece(final int move)
  {
    return move >> SHIFT_PROMOTIONPIECE;
  }

  // returns pgn alike string representation of the move - not full pgn format because then more information is needed
  public static final String toDbgString(final int move)
  {
    if(Move.isOO(move))
      return "O-O";
    if(Move.isOOO(move))
      return "O-O-O";
    return "[" + Pos.toString(Move.getFrom(move)) + (Move.isHIT(move) ? "x" : "-") + Pos.toString(Move.getTo(move)) + (Move.isCheck(move) ? "+" : "") + (Move.isEP(move) ? " ep" : "") + "]";
  }
  
}

Java Source Code List

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