pieces.py

#coding=utf8
"""
Created on Nov 10, 2011

@author: CVi
"""

class piece(object):
    """
    Superclass for all the pieces also doubles as the "no piece" piece.
    """
    def __init__(self, board, player):
        """
        @param board: The board to play with
        @param player: The player the piece belongs to
        """
        self.board = board
        self.player = player
        self.check = False

    def LegalMove(self, start, stop):
        """
        Checks if the move is legal
        @param start: coordinate (y,x)
        @param stop: coordinate (y,x)
        """
        return False

    def __str__(self):
        return "   "

    def postMove(self, stop):
        """
        Action to perform after a move has been completed 
        @param stop: Ending position for the piece
        """

    def possibleMoves(self, pos):
        """
        Gets all the legal moves for this piece
        @param pos: coordinate (y,x)
        """
        return []

class pawn(piece):
    """
    Pawn piece
    """
    def __str__(self):
        return "PAW" if self.player == 0 else "paw"
    def LegalMove(self, start, stop):
        if start[1] == stop[1]:
            if stop[0] == start[0] + (1 if self.player == 0 else -1) and\
                self.board.grid[stop[0]][stop[1]].player == None:
                return True
            elif start[0] == (1 if self.player == 0 else 6) and\
                stop[0] == (3 if self.player == 0 else 4) and\
                self.board.grid[stop[0]][stop[1]].player == None and\
                self.board.grid[stop[0]][(start[0] + 1 if self.player == 0 else start[0] - 1)].player == None:
                return True
        elif start[1] == stop[1] + 1 or start[1] == stop[1] - 1:
            if stop[0] == (start[0] + (1 if self.player == 0 else -1)) and\
                self.board.grid[stop[0]][stop[1]].player == (1 if self.player == 0 else 0):
                return True
        return False

    def postMove(self, stop):
        """
        Transforms the piece to a Queed if the piece reaches the other end of the board
        @param stop: coordianate (y,x)
        """
        if stop[0] == (7 if self.player == 0 else 7):
            self.board.grid[stop[0]][stop[1]] = queen(self.board, self.player)

    def possibleMoves(self, pos):
        moves = []
        options = []
        if self.player == 0 and pos[0] <= 6:
            options.append((pos[0] + 1, pos[1]))
            if pos[1] < 7: options.append((pos[0] + 1, pos[1] + 1))
            if pos[1] > 0: options.append((pos[0] + 1, pos[1] - 1))
            if pos[0] == 1:
                options.append((pos[0] + 2, pos[1]))
        elif self.player == 1 and pos[0] >= 1:
            options.append((pos[0] - 1, pos[1]))
            if pos[1] < 7: options.append((pos[0] - 1, pos[1] + 1))
            if pos[1] > 0: options.append((pos[0] - 1, pos[1] - 1))
            if pos[0] == 6:
                options.append((pos[0] - 2, pos[1]))
        for move in options:
            if self.LegalMove(pos, move):
                moves.append(move)
        return moves

class king(piece):
    """
    King piece
    """
    def __str__(self):
        return ("KIN" if self.player == 0 else "kin")
    def LegalMove(self, start, stop):
        return abs(stop[0] - start[0]) <= 1 and abs(stop[1] - start[1]) <= 1 and\
            self.board.grid[stop[0]][stop[1]].player != self.player

    def possibleMoves(self, pos):
        moves = []
        for x in [1, 0, -1]:
            for y in [1, 0, -1]:
                if (pos[0] + y) >= 0 and (pos[0] + y) <= 7 and\
                (pos[1] + x) >= 0 and (pos[1] + x) <= 7 and\
                self.LegalMove(pos, (pos[0] + y, pos[1] + x)):
                    moves.append((pos[0] + y, pos[1] + x))
        return moves

class queen(piece):
    """
    Queen Piece
    """
    def __str__(self):
        return "QUE" if self.player == 0 else "que"
    def LegalMove(self, start, stop):
        if start[0] == stop[0]:
            if start[1] - stop[1] > 0:
                begin = stop[1]
                end = start[1]
            elif start[1] - stop[1] < 0:
                begin = start[1]
                end = stop[1]
            else:
                return False
            for i in range(begin + 1, end):
                if self.board.grid[stop[0]][i].player != None:
                    return False
            return self.board.grid[stop[0]][stop[1]].player != self.player

        elif start[1] == stop[1]:
            if start[0] - stop[0] > 0:
                begin = stop[0]
                end = start[0]
            elif start[0] - stop[0] < 0:
                begin = start[0]
                end = stop[0]
            else:
                return False
            for i in range(begin + 1, end):
                if self.board.grid[i][stop[1]].player != None:
                    return False
            return self.board.grid[stop[0]][stop[1]].player != self.player

        elif abs(start[0] - stop[0]) == abs(start[1] - stop[1]) and abs(start[1] - stop[1]) > 0:
            ym = (stop[0] - start[0]) / abs(start[0] - stop[0])
            xm = (stop[1] - start[1]) / abs(start[1] - stop[1])
            for i in range(1, abs(start[1] - stop[1])):
                s = abs(start[1] - stop[1])
                dbg = self.board.grid[start[0] + (ym * i)][start[1] + (xm * i)].player
                if self.board.grid[start[0] + (ym * i)][start[1] + (xm * i)].player != None:
                    return False
            return self.board.grid[stop[0]][stop[1]].player != self.player
        else:
            return False
    def possibleMoves(self, pos):
        moves = []
        for x in [1, 0, -1]:
            for y in [1, 0, -1]:
                i = 1
                while pos[0] + (y * i) >= 0 and pos[0] + (y * i) <= 7 and\
                pos[1] + (x * i) >= 0 and pos[1] + (x * i) <= 7 and\
                self.LegalMove(pos, (pos[0] + (y * i), pos[1] + (x * i))):
                    moves.append((pos[0] + (y * i), pos[1] + (x * i)))
                    i += 1
        return moves

class bishop(piece):
    """
    Bishop piece
    """
    def __str__(self):
        return "BIS" if self.player == 0 else "bis"
    def LegalMove(self, start, stop):
        if abs(start[0] - stop[0]) == abs(start[1] - stop[1]) and abs(start[1] - stop[1]) > 0:
            ym = (stop[0] - start[0]) / abs(start[0] - stop[0])
            xm = (stop[1] - start[1]) / abs(start[1] - stop[1])
            for i in range(1, abs(start[1] - stop[1])):
                if self.board.grid[start[0] + (ym * i)][start[1] + (xm * i)].player != None:
                    return False

            return self.board.grid[stop[0]][stop[1]].player != self.player
        else:
            return False

    def possibleMoves(self, pos):
        moves = []
        for x in [1, -1]:
            for y in [1, -1]:
                i = 1
                while (pos[0] + (y * i)) >= 0 and (pos[0] + (y * i)) <= 7 and\
                (pos[1] + (x * i)) >= 0 and (pos[1] + (x * i)) <= 7 and\
                self.LegalMove(pos, (pos[0] + (y * i), pos[1] + (x * i))):
                    moves.append((pos[0] + (y * i), pos[1] + (x * i)))
                    i += 1
        return moves

class rook(piece):
    """
    Rook Piece
    """
    def __str__(self):
        return "ROO" if self.player == 0 else "roo"
    def LegalMove(self, start, stop):
        if start[0] == stop[0]:
            if start[1] - stop[1] > 0:
                begin = stop[1]
                end = start[1]
            elif start[1] - stop[1] < 0:
                begin = start[1]
                end = stop[1]
            else:
                return False
            for i in range(begin + 1, end):
                if self.board.grid[stop[0]][i].player != None:
                    return False
            return self.board.grid[stop[0]][stop[1]].player != self.player

        elif start[1] == stop[1]:
            if start[0] - stop[0] > 0:
                begin = stop[0]
                end = start[0]
            elif start[0] - stop[0] < 0:
                begin = start[0]
                end = stop[0]
            else:
                return False
            for i in range(begin + 1, end):
                if self.board.grid[i][stop[1]].player != None:
                    return False
            return self.board.grid[stop[0]][stop[1]].player != self.player
        else:
            return False

    def possibleMoves(self, pos):
        moves = []
        for (x, y) in [(0, 1), (0, -1), (1, 0), (-1, 0)]:
            i = 1
            while pos[0] + (y * i) >= 0 and pos[0] + (y * i) <= 7 and\
                pos[1] + (x * i) >= 0 and pos[1] + (x * i) <= 7 and\
                self.LegalMove(pos, (pos[0] + (y * i), pos[1] + (x * i))):
                    moves.append((pos[0] + (y * i), pos[1] + (x * i)))
                    i += 1
        return moves

class knight(piece):
    """
    Knight piece
    """
    def __str__(self):
        return "KNI" if self.player == 0 else "kni"
    def LegalMove(self, start, stop):
        if (abs(start[0] - stop[0]) == 2 and abs(start[1] - stop[1]) == 1) or\
        (abs(start[0] - stop[0]) == 1 and abs(start[1] - stop[1]) == 2):
            return self.board.grid[stop[0]][stop[1]].player != self.player
        return False

    def possibleMoves(self, pos):
        moves = []
        for (x, y) in [(2, 1), (2, -1), (-2, 1), (-2, -1), (1, 2), (1, -2), (-1, 2), (-1, -2)]:
            if (pos[0] + y >= 0 and pos[0] + y <= 7) and (pos[1] + x >= 0 and pos[1] + x <= 7) and\
            self.LegalMove(pos, (pos[0] + y, pos[1] + x)):
                moves.append((pos[0] + y, pos[1] + x))
        return moves