Python国际象棋程序

Question

I'm attempting to make a fairly simple chess game for my a coding project, hoping to implement a computer opponent at some point too, a bit stuck on how to add move limits and functions to detect the game ending at this point. The body was designed by @sloth and I've added to it.

I've done the fairly simple stuff, load all the pieces and change the board colour but I'm not too sure on what to do at this point. Any help would be appreciated!

import pygame

TILESIZE = 75
BOARD_POS = (10, 10)

def create_board_surf():
    board_surf = pygame.Surface((TILESIZE*8, TILESIZE*8))
    dark = False
    for y in range(8):
        for x in range(8):
            rect = pygame.Rect(x*TILESIZE, y*TILESIZE, TILESIZE, TILESIZE)
            pygame.draw.rect(board_surf, pygame.Color('darkgreen' if dark else 'beige'), rect)
            dark = not dark
        dark = not dark
    return board_surf

def get_square_under_mouse(board):
    mouse_pos = pygame.Vector2(pygame.mouse.get_pos()) - BOARD_POS
    x, y = [int(v // TILESIZE) for v in mouse_pos]
    try:
        if x >= 0 and y >= 0: return (board[y][x], x, y)
    except IndexError: pass
    return None, None, None

def create_board():
    board = []
    for y in range(8):
        board.append([])
        for x in range(8):
            board[y].append(None)

    ## BLACK PIECES ##

    for x in range(0, 8):
        board[1][x] = ('black', 'pawn')
    for x in range(0, 1):
        board[0][x] = ('black', 'rook')
    for x in range(0, 8):
        board[0][x] = ('black', 'rook')
    for x in range(1, 2):
        board[0][x] = ('black', 'horse')
    for x in range(6, 7):
        board[0][x] = ('black', 'horse')
    for x in range(2, 3):
        board[0][x] = ('black', 'bishop')
    for x in range(5, 6):
        board[0][x] = ('black', 'bishop')
    for x in range(3, 4):
        board[0][x] = ('black', 'queen')
    for x in range(4, 5):
        board[0][x] = ('black', 'king')

    ## WHITE PIECES ##

    for x in range(0, 8):
        board[6][x] = ('white', 'pawn')
    for x in range(0, 1):
        board[7][x] = ('white', 'rook')
    for x in range(7, 8):
        board[7][x] = ('white', 'rook')
    for x in range(1, 2):
        board[7][x] = ('white', 'horse')
    for x in range(6, 7):
        board[7][x] = ('white', 'horse')
    for x in range(2, 3):
        board[7][x] = ('white', 'bishop')
    for x in range(5, 6):
        board[7][x] = ('white', 'bishop')
    for x in range(3, 4):
        board[7][x] = ('white', 'queen')
    for x in range(4, 5):
        board[7][x] = ('white', 'king')



    return board

def draw_pieces(screen, board, font, selected_piece):
    sx, sy = None, None
    if selected_piece:
        piece, sx, sy = selected_piece

    for y in range(8):
        for x in range(8):
            piece = board[y][x]
            if piece:
                selected = x == sx and y == sy
                color, type = piece
                s1 = font.render(type[0], True, pygame.Color('red' if selected else color))
                s2 = font.render(type[0], True, pygame.Color('darkgrey'))
                pos = pygame.Rect(BOARD_POS[0] + x * TILESIZE+1, BOARD_POS[1] + y * TILESIZE + 1, TILESIZE, TILESIZE)
                screen.blit(s2, s2.get_rect(center=pos.center).move(1, 1))
                screen.blit(s1, s1.get_rect(center=pos.center))

def draw_selector(screen, piece, x, y):
    if piece != None:
        rect = (BOARD_POS[0] + x * TILESIZE, BOARD_POS[1] + y * TILESIZE, TILESIZE, TILESIZE)
        pygame.draw.rect(screen, (255, 0, 0, 50), rect, 2)

def draw_drag(screen, board, selected_piece, font):
    if selected_piece:
        piece, x, y = get_square_under_mouse(board)
        if x != None:
            rect = (BOARD_POS[0] + x * TILESIZE, BOARD_POS[1] + y * TILESIZE, TILESIZE, TILESIZE)
            pygame.draw.rect(screen, (0, 255, 0, 50), rect, 2)

        color, type = selected_piece[0]
        s1 = font.render(type[0], True, pygame.Color(color))
        s2 = font.render(type[0], True, pygame.Color('darkgrey'))
        pos = pygame.Vector2(pygame.mouse.get_pos())
        screen.blit(s2, s2.get_rect(center=pos + (1, 1)))
        screen.blit(s1, s1.get_rect(center=pos))
        selected_rect = pygame.Rect(BOARD_POS[0] + selected_piece[1] * TILESIZE, BOARD_POS[1] + selected_piece[2] * TILESIZE, TILESIZE, TILESIZE)
        pygame.draw.line(screen, pygame.Color('red'), selected_rect.center, pos)
        return (x, y)

def main():
    pygame.init()
    font = pygame.font.SysFont('', 64)
    screen = pygame.display.set_mode((620, 620))
    board = create_board()
    board_surf = create_board_surf()
    clock = pygame.time.Clock()
    selected_piece = None
    drop_pos = None
    while True:
        piece, x, y = get_square_under_mouse(board)
        events = pygame.event.get()
        for e in events:
            if e.type == pygame.QUIT:
                return
            if e.type == pygame.MOUSEBUTTONDOWN:
                if piece != None:
                    selected_piece = piece, x, y
            if e.type == pygame.MOUSEBUTTONUP:
                if drop_pos:
                    piece, old_x, old_y = selected_piece
                    board[old_y][old_x] = 0
                    new_x, new_y = drop_pos
                    board[new_y][new_x] = piece
                selected_piece = None
                drop_pos = None

        screen.fill(pygame.Color('grey'))
        screen.blit(board_surf, BOARD_POS)
        draw_pieces(screen, board, font, selected_piece)
        draw_selector(screen, piece, x, y)
        drop_pos = draw_drag(screen, board, selected_piece, font)

        pygame.display.flip()
        clock.tick(60)

if __name__ == '__main__':
    main()

Answer 1

First of all you would be better of using python-chess library if you just want to get things done. Otherwise to check for the end of a game in chess you need to see if few of possible conditions are true:

• is it checkmate (ie king is in check and cannot move to any adjacent square or otherwise get out of check)
• is it stalemate (ie no legal move)
• is it threefold repetition (ie the position repeated three times in a game)
• 50 move rule (ie if no captures or pawn moves were made in 50 moves)
• is it draw because of insufficient material to mate

So it is quite complicated just because of the rules of the game.

Now if you want to pick legal moves read about 0x88 method of representing the board. It represents the position as two boards, with one containing pieces and the other illegal territory. This provides easy check on legal moves since you just AND the board with generated moves to check legality. Take caution when implementing sliding pieces, king and en passant.