gameloader.java

chess 一个beguanyu国际象棋的一个Java源码

/*
  GameLoader - A class to follow a chess game, while it is loaded
               from a PGN file.

  Copyright (C) 2003 The Java-Chess team <[e-mail]>

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version 2
  of the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/   

package de.java_chess.javaChess.pgn;

import de.java_chess.javaChess.bitboard.*;
import de.java_chess.javaChess.board.*;
import de.java_chess.javaChess.engine.*;
import de.java_chess.javaChess.engine.hashtable.*;
import de.java_chess.javaChess.game.*;
import de.java_chess.javaChess.notation.*;
import de.java_chess.javaChess.piece.*;
import de.java_chess.javaChess.ply.*;
import de.java_chess.javaChess.position.*;


/**
 * This class follows a chess game, while it is loaded from a PGN file.
 */
public class GameLoader {

    // Instance variables

    /**
     * A game for the generator.
     */
    Game _game;

    /**
     * The current board of the game.
     */
    Board _board;

    /**
     * A ply generator to check for valid moves.
     */
    PlyGenerator _plyGenerator;

    /**
     * The analyzer, that is required by the ply generator.
     */
    BitBoardAnalyzer _analyzer;

    /**
     * Flag to indicate, what color moves.
     */
    boolean _whiteMoves = true;


    // Constructors

    /**
     * Create a new game loader instance.
     */
    public GameLoader() {

        // Create a new game.
        _game = new GameImpl();

        // Create a new board.
        _board = new BitBoardImpl();
	
        // Create the ply generator.
        _plyGenerator = new PlyGenerator( _game, (BitBoard)_board, new PlyHashtableImpl( 10));

        // And the analyzer.
        _analyzer = new BitBoardAnalyzerImpl( _game, _plyGenerator);
	
        _plyGenerator.setAnalyzer( _analyzer);

        // Set the pieces on their initial positions.
        _board.initialPosition();               
    }


    // Methods

    /**
     * Turn a loaded ply fragment from a PGN file into a notated ply.
     *
     * @param plyFragment The info from the PGN file.
     *
     * @return The notation for the ply, if we could recognize the ply, or null.
     */
    public final PlyNotation completePly( PGNPlyFragment plyFragment) {

	// Create a ply from the ply fragment.
	Ply ply = null;
	PlyNotation notation = null;

	// If the origin of the move is missing, compute it from the destination
	// ...not necessary yet...

	if( plyFragment.isCastling()) {
	    ply = new CastlingPlyImpl( new PositionImpl( _whiteMoves ? 4 : 60), plyFragment.isLeftCastling());
	    notation = new PlyNotationImpl( ply, _board.getPiece( ply.getSource()));
	} else {

	    // Check, how complete our fragment is so far.
	    if( plyFragment.getOrigin() == null) {  // If there was no origin given, try to figure it from the currently available moves

		// Compute all the available moves for this board.
		Ply [] plies = _plyGenerator.getPliesForColor( _whiteMoves);    

		for( int i=0; i < plies.length; i++) {
		    if( ( plies[i].getDestination() == plyFragment.getDestination())
                        && ( _board.getPiece( plies[i].getSource()).getType() == plyFragment.getPieceType())) {

			// Found the right ply!
			plyFragment.setOrigin( plies[i].getSource());
			
			break;  // Stop the search for the ply origin.
		    }
		}
	    }

	    if( plyFragment.isPawnPromotion()) {
		ply = new TransformationPlyImpl( plyFragment.getOrigin(), plyFragment.getDestination(), plyFragment.getNewPieceType(), _board.getPiece( plyFragment.getDestination()) == null);
		notation = new PlyNotationImpl( ply, _board.getPiece( ply.getSource()));
	    } else {
		ply = new PlyImpl( plyFragment.getOrigin(), plyFragment.getDestination(), _board.getPiece( plyFragment.getDestination()) == null);
		notation = new PlyNotationImpl( ply, _board.getPiece( ply.getSource()));
	    }

	    // Verifiy, if the notation doesn't show a capture on an empty sqare.
	    if( plyFragment.isCapture() && _board.getPiece( plyFragment.getDestination()) == null) {
		return null;
	    }
	}

	// No perform the ply on our simulated board.
	doPly( ply);

	// And return the notation for the ply.
	return notation;
    }

    /**
     * Perform a ply, when it is completely loaded.
     *
     * param ply The ply to perform.
     */
    private final void doPly( Ply ply) {
	_game.doPly( ply);
        _board.doPly( ply);

	// The other color is about to move now.
	_whiteMoves = ! _whiteMoves;
    }
}