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Engineering LibreTexts

11.2: Source Code for Flippy

  • Page ID
    13626
  • This source code can be downloaded from http://invpy.com/flippy.py.

    The image files that Flippy uses can be downloaded from http://invpy.com/flippyimages.zip.

    # Flippy (an Othello or Reversi clone)
    # By Al Sweigart al@inventwithpython.com
    # http://inventwithpython.com/pygame
    # Released under a "Simplified BSD" license
    
    # Based on the "reversi.py" code that originally appeared in "Invent
    # Your Own Computer Games with Python", chapter 15:
    #   http://inventwithpython.com/chapter15.html
    
    import random, sys, pygame, time, copy
    from pygame.locals import *
    
    FPS = 10 # frames per second to update the screen
    WINDOWWIDTH = 640 # width of the program's window, in pixels
    WINDOWHEIGHT = 480 # height in pixels
    SPACESIZE = 50 # width & height of each space on the board, in pixels
    BOARDWIDTH = 8 # how many columns of spaces on the game board
    BOARDHEIGHT = 8 # how many rows of spaces on the game board
    WHITE_TILE = 'WHITE_TILE' # an arbitrary but unique value
    BLACK_TILE = 'BLACK_TILE' # an arbitrary but unique value
    EMPTY_SPACE = 'EMPTY_SPACE' # an arbitrary but unique value
    HINT_TILE = 'HINT_TILE' # an arbitrary but unique value
    ANIMATIONSPEED = 25 # integer from 1 to 100, higher is faster animation
    
    # Amount of space on the left & right side (XMARGIN) or above and below
    # (YMARGIN) the game board, in pixels.
    XMARGIN = int((WINDOWWIDTH - (BOARDWIDTH * SPACESIZE)) / 2)
    YMARGIN = int((WINDOWHEIGHT - (BOARDHEIGHT * SPACESIZE)) / 2)
    
    #              R    G    B
    WHITE      = (255, 255, 255)
    BLACK      = (  0,   0,   0)
    GREEN      = (  0, 155,   0)
    BRIGHTBLUE = (  0,  50, 255)
    BROWN      = (174,  94,   0)
    
    TEXTBGCOLOR1 = BRIGHTBLUE
    TEXTBGCOLOR2 = GREEN
    GRIDLINECOLOR = BLACK
    TEXTCOLOR = WHITE
    HINTCOLOR = BROWN
    
    
    def main():
        global MAINCLOCK, DISPLAYSURF, FONT, BIGFONT, BGIMAGE
    
        pygame.init()
        MAINCLOCK = pygame.time.Clock()
        DISPLAYSURF = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT))
        pygame.display.set_caption('Flippy')
        FONT = pygame.font.Font('freesansbold.ttf', 16)
        BIGFONT = pygame.font.Font('freesansbold.ttf', 32)
    
        # Set up the background image.
        boardImage = pygame.image.load('flippyboard.png')
        # Use smoothscale() to stretch the board image to fit the entire board:
        boardImage = pygame.transform.smoothscale(boardImage, (BOARDWIDTH * SPACESIZE, BOARDHEIGHT * SPACESIZE))
        boardImageRect = boardImage.get_rect()
        boardImageRect.topleft = (XMARGIN, YMARGIN)
        BGIMAGE = pygame.image.load('flippybackground.png')
        # Use smoothscale() to stretch the background image to fit the entire window:
        BGIMAGE = pygame.transform.smoothscale(BGIMAGE, (WINDOWWIDTH, WINDOWHEIGHT))
        BGIMAGE.blit(boardImage, boardImageRect)
    
        # Run the main game.
        while True:
            if runGame() == False:
                break
    
    
    def runGame():
        # Plays a single game of reversi each time this function is called.
    
        # Reset the board and game.
        mainBoard = getNewBoard()
        resetBoard(mainBoard)
        showHints = False
        turn = random.choice(['computer', 'player'])
    
        # Draw the starting board and ask the player what color they want.
        drawBoard(mainBoard)
        playerTile, computerTile = enterPlayerTile()
    
        # Make the Surface and Rect objects for the "New Game" and "Hints" buttons
        newGameSurf = FONT.render('New Game', True, TEXTCOLOR, TEXTBGCOLOR2)
        newGameRect = newGameSurf.get_rect()
        newGameRect.topright = (WINDOWWIDTH - 8, 10)
        hintsSurf = FONT.render('Hints', True, TEXTCOLOR, TEXTBGCOLOR2)
        hintsRect = hintsSurf.get_rect()
        hintsRect.topright = (WINDOWWIDTH - 8, 40)
    
        while True: # main game loop
            # Keep looping for player and computer's turns.
            if turn == 'player':
                # Player's turn:
                if getValidMoves(mainBoard, playerTile) == []:
                    # If it's the player's turn but they
                    # can't move, then end the game.
                    break
                movexy = None
                while movexy == None:
                    # Keep looping until the player clicks on a valid space.
    
                    # Determine which board data structure to use for display.
                    if showHints:
                        boardToDraw = getBoardWithValidMoves(mainBoard, playerTile)
                    else:
                        boardToDraw = mainBoard
    
                    checkForQuit()
                    for event in pygame.event.get(): # event handling loop
                        if event.type == MOUSEBUTTONUP:
                            # Handle mouse click events
                            mousex, mousey = event.pos
                            if newGameRect.collidepoint( (mousex, mousey) ):
                                # Start a new game
                                return True
                            elif hintsRect.collidepoint( (mousex, mousey) ):
                                # Toggle hints mode
                                showHints = not showHints
                            # movexy is set to a two-item tuple XY coordinate, or None value
                            movexy = getSpaceClicked(mousex, mousey)
                            if movexy != None and not isValidMove(mainBoard, playerTile, movexy[0], movexy[1]):
                                movexy = None
    
                    # Draw the game board.
                    drawBoard(boardToDraw)
                    drawInfo(boardToDraw, playerTile, computerTile, turn)
    
                    # Draw the "New Game" and "Hints" buttons.
                    DISPLAYSURF.blit(newGameSurf, newGameRect)
                    DISPLAYSURF.blit(hintsSurf, hintsRect)
    
                    MAINCLOCK.tick(FPS)
                    pygame.display.update()
    
                # Make the move and end the turn.
                makeMove(mainBoard, playerTile, movexy[0], movexy[1], True)
                if getValidMoves(mainBoard, computerTile) != []:
                    # Only set for the computer's turn if it can make a move.
                    turn = 'computer'
    
            else:
                # Computer's turn:
                if getValidMoves(mainBoard, computerTile) == []:
                    # If it was set to be the computer's turn but
                    # they can't move, then end the game.
                    break
    
                # Draw the board.
                drawBoard(mainBoard)
                drawInfo(mainBoard, playerTile, computerTile, turn)
    
                # Draw the "New Game" and "Hints" buttons.
                DISPLAYSURF.blit(newGameSurf, newGameRect)
                DISPLAYSURF.blit(hintsSurf, hintsRect)
    
                # Make it look like the computer is thinking by pausing a bit.
                pauseUntil = time.time() + random.randint(5, 15) * 0.1
                while time.time() < pauseUntil:
                    pygame.display.update()
    
                # Make the move and end the turn.
                x, y = getComputerMove(mainBoard, computerTile)
                makeMove(mainBoard, computerTile, x, y, True)
                if getValidMoves(mainBoard, playerTile) != []:
                    # Only set for the player's turn if they can make a move.
                    turn = 'player'
    
        # Display the final score.
        drawBoard(mainBoard)
        scores = getScoreOfBoard(mainBoard)
    
        # Determine the text of the message to display.
        if scores[playerTile] > scores[computerTile]:
            text = 'You beat the computer by %s points! Congratulations!' % \
                   (scores[playerTile] - scores[computerTile])
        elif scores[playerTile] < scores[computerTile]:
            text = 'You lost. The computer beat you by %s points.' % \
                   (scores[computerTile] - scores[playerTile])
        else:
            text = 'The game was a tie!'
    
        textSurf = FONT.render(text, True, TEXTCOLOR, TEXTBGCOLOR1)
        textRect = textSurf.get_rect()
        textRect.center = (int(WINDOWWIDTH / 2), int(WINDOWHEIGHT / 2))
        DISPLAYSURF.blit(textSurf, textRect)
    
        # Display the "Play again?" text with Yes and No buttons.
        text2Surf = BIGFONT.render('Play again?', True, TEXTCOLOR, TEXTBGCOLOR1)
        text2Rect = text2Surf.get_rect()
        text2Rect.center = (int(WINDOWWIDTH / 2), int(WINDOWHEIGHT / 2) + 50)
    
        # Make "Yes" button.
        yesSurf = BIGFONT.render('Yes', True, TEXTCOLOR, TEXTBGCOLOR1)
        yesRect = yesSurf.get_rect()
        yesRect.center = (int(WINDOWWIDTH / 2) - 60, int(WINDOWHEIGHT / 2) + 90)
    
        # Make "No" button.
        noSurf = BIGFONT.render('No', True, TEXTCOLOR, TEXTBGCOLOR1)
        noRect = noSurf.get_rect()
        noRect.center = (int(WINDOWWIDTH / 2) + 60, int(WINDOWHEIGHT / 2) + 90)
    
        while True:
            # Process events until the user clicks on Yes or No.
            checkForQuit()
            for event in pygame.event.get(): # event handling loop
                if event.type == MOUSEBUTTONUP:
                    mousex, mousey = event.pos
                    if yesRect.collidepoint( (mousex, mousey) ):
                        return True
                    elif noRect.collidepoint( (mousex, mousey) ):
                        return False
            DISPLAYSURF.blit(textSurf, textRect)
            DISPLAYSURF.blit(text2Surf, text2Rect)
            DISPLAYSURF.blit(yesSurf, yesRect)
            DISPLAYSURF.blit(noSurf, noRect)
            pygame.display.update()
            MAINCLOCK.tick(FPS)
    
    
    def translateBoardToPixelCoord(x, y):
        return XMARGIN + x * SPACESIZE + int(SPACESIZE / 2), YMARGIN + y * SPACESIZE + int(SPACESIZE / 2)
    
    
    def animateTileChange(tilesToFlip, tileColor, additionalTile):
        # Draw the additional tile that was just laid down. (Otherwise we'd
        # have to completely redraw the board & the board info.)
        if tileColor == WHITE_TILE:
            additionalTileColor = WHITE
        else:
            additionalTileColor = BLACK
        additionalTileX, additionalTileY = translateBoardToPixelCoord(additionalTile[0], additionalTile[1])
        pygame.draw.circle(DISPLAYSURF, additionalTileColor, (additionalTileX, additionalTileY), int(SPACESIZE / 2) - 4)
        pygame.display.update()
    
        for rgbValues in range(0, 255, int(ANIMATIONSPEED * 2.55)):
            if rgbValues > 255:
                rgbValues = 255
            elif rgbValues < 0:
                rgbValues = 0
    
            if tileColor == WHITE_TILE:
                color = tuple([rgbValues] * 3) # rgbValues goes from 0 to 255
            elif tileColor == BLACK_TILE:
                color = tuple([255 - rgbValues] * 3) # rgbValues goes from 255 to 0
    
            for x, y in tilesToFlip:
                centerx, centery = translateBoardToPixelCoord(x, y)
                pygame.draw.circle(DISPLAYSURF, color, (centerx, centery), int(SPACESIZE / 2) - 4)
            pygame.display.update()
            MAINCLOCK.tick(FPS)
            checkForQuit()
    
    
    def drawBoard(board):
        # Draw background of board.
        DISPLAYSURF.blit(BGIMAGE, BGIMAGE.get_rect())
    
        # Draw grid lines of the board.
        for x in range(BOARDWIDTH + 1):
            # Draw the horizontal lines.
            startx = (x * SPACESIZE) + XMARGIN
            starty = YMARGIN
            endx = (x * SPACESIZE) + XMARGIN
            endy = YMARGIN + (BOARDHEIGHT * SPACESIZE)
            pygame.draw.line(DISPLAYSURF, GRIDLINECOLOR, (startx, starty), (endx, endy))
        for y in range(BOARDHEIGHT + 1):
            # Draw the vertical lines.
            startx = XMARGIN
            starty = (y * SPACESIZE) + YMARGIN
            endx = XMARGIN + (BOARDWIDTH * SPACESIZE)
            endy = (y * SPACESIZE) + YMARGIN
            pygame.draw.line(DISPLAYSURF, GRIDLINECOLOR, (startx, starty), (endx, endy))
    
        # Draw the black & white tiles or hint spots.
        for x in range(BOARDWIDTH):
            for y in range(BOARDHEIGHT):
                centerx, centery = translateBoardToPixelCoord(x, y)
                if board[x][y] == WHITE_TILE or board[x][y] == BLACK_TILE:
                    if board[x][y] == WHITE_TILE:
                        tileColor = WHITE
                    else:
                        tileColor = BLACK
                    pygame.draw.circle(DISPLAYSURF, tileColor, (centerx, centery), int(SPACESIZE / 2) - 4)
                if board[x][y] == HINT_TILE:
                    pygame.draw.rect(DISPLAYSURF, HINTCOLOR, (centerx - 4, centery - 4, 8, 8))
    
    
    def getSpaceClicked(mousex, mousey):
        # Return a tuple of two integers of the board space coordinates where
        # the mouse was clicked. (Or returns None not in any space.)
        for x in range(BOARDWIDTH):
            for y in range(BOARDHEIGHT):
                if mousex > x * SPACESIZE + XMARGIN and \
                   mousex < (x + 1) * SPACESIZE + XMARGIN and \
                   mousey > y * SPACESIZE + YMARGIN and \
                   mousey < (y + 1) * SPACESIZE + YMARGIN:
                    return (x, y)
        return None
    
    
    def drawInfo(board, playerTile, computerTile, turn):
        # Draws scores and whose turn it is at the bottom of the screen.
        scores = getScoreOfBoard(board)
        scoreSurf = FONT.render("Player Score: %s    Computer Score: %s    %s's Turn" % (str(scores[playerTile]), str(scores[computerTile]), turn.title()), True, TEXTCOLOR)
        scoreRect = scoreSurf.get_rect()
        scoreRect.bottomleft = (10, WINDOWHEIGHT - 5)
        DISPLAYSURF.blit(scoreSurf, scoreRect)
    
    
    def resetBoard(board):
        # Blanks out the board it is passed, and sets up starting tiles.
        for x in range(BOARDWIDTH):
            for y in range(BOARDHEIGHT):
                board[x][y] = EMPTY_SPACE
    
        # Add starting pieces to the center
        board[3][3] = WHITE_TILE
        board[3][4] = BLACK_TILE
        board[4][3] = BLACK_TILE
        board[4][4] = WHITE_TILE
    
    
    def getNewBoard():
        # Creates a brand new, empty board data structure.
        board = []
        for i in range(BOARDWIDTH):
            board.append([EMPTY_SPACE] * BOARDHEIGHT)
    
        return board
    
    
    def isValidMove(board, tile, xstart, ystart):
        # Returns False if the player's move is invalid. If it is a valid
        # move, returns a list of spaces of the captured pieces.
        if board[xstart][ystart] != EMPTY_SPACE or not isOnBoard(xstart, ystart):
            return False
    
        board[xstart][ystart] = tile # temporarily set the tile on the board.
    
        if tile == WHITE_TILE:
            otherTile = BLACK_TILE
        else:
            otherTile = WHITE_TILE
    
        tilesToFlip = []
        # check each of the eight directions:
        for xdirection, ydirection in [[0, 1], [1, 1], [1, 0], [1, -1], [0, -1], [-1, -1], [-1, 0], [-1, 1]]:
            x, y = xstart, ystart
            x += xdirection
            y += ydirection
            if isOnBoard(x, y) and board[x][y] == otherTile:
                # The piece belongs to the other player next to our piece.
                x += xdirection
                y += ydirection
                if not isOnBoard(x, y):
                    continue
                while board[x][y] == otherTile:
                    x += xdirection
                    y += ydirection
                    if not isOnBoard(x, y):
                        break # break out of while loop, continue in for loop
                if not isOnBoard(x, y):
                    continue
                if board[x][y] == tile:
                    # There are pieces to flip over. Go in the reverse
                    # direction until we reach the original space, noting all
                    # the tiles along the way.
                    while True:
                        x -= xdirection
                        y -= ydirection
                        if x == xstart and y == ystart:
                            break
                        tilesToFlip.append([x, y])
    
        board[xstart][ystart] = EMPTY_SPACE # make space empty
        if len(tilesToFlip) == 0: # If no tiles flipped, this move is invalid
            return False
        return tilesToFlip
    
    
    def isOnBoard(x, y):
        # Returns True if the coordinates are located on the board.
        return x >= 0 and x < BOARDWIDTH and y >= 0 and y < BOARDHEIGHT
    
    
    def getBoardWithValidMoves(board, tile):
        # Returns a new board with hint markings.
        dupeBoard = copy.deepcopy(board)
    
        for x, y in getValidMoves(dupeBoard, tile):
            dupeBoard[x][y] = HINT_TILE
        return dupeBoard
    
    
    def getValidMoves(board, tile):
        # Returns a list of (x,y) tuples of all valid moves.
        validMoves = []
    
        for x in range(BOARDWIDTH):
            for y in range(BOARDHEIGHT):
                if isValidMove(board, tile, x, y) != False:
                    validMoves.append((x, y))
        return validMoves
    
    
    def getScoreOfBoard(board):
        # Determine the score by counting the tiles.
        xscore = 0
        oscore = 0
        for x in range(BOARDWIDTH):
            for y in range(BOARDHEIGHT):
                if board[x][y] == WHITE_TILE:
                    xscore += 1
                if board[x][y] == BLACK_TILE:
                    oscore += 1
        return {WHITE_TILE:xscore, BLACK_TILE:oscore}
    
    
    def enterPlayerTile():
        # Draws the text and handles the mouse click events for letting
        # the player choose which color they want to be.  Returns
        # [WHITE_TILE, BLACK_TILE] if the player chooses to be White,
        # [BLACK_TILE, WHITE_TILE] if Black.
    
        # Create the text.
        textSurf = FONT.render('Do you want to be white or black?', True, TEXTCOLOR, TEXTBGCOLOR1)
        textRect = textSurf.get_rect()
        textRect.center = (int(WINDOWWIDTH / 2), int(WINDOWHEIGHT / 2))
    
        xSurf = BIGFONT.render('White', True, TEXTCOLOR, TEXTBGCOLOR1)
        xRect = xSurf.get_rect()
        xRect.center = (int(WINDOWWIDTH / 2) - 60, int(WINDOWHEIGHT / 2) + 40)
    
        oSurf = BIGFONT.render('Black', True, TEXTCOLOR, TEXTBGCOLOR1)
        oRect = oSurf.get_rect()
        oRect.center = (int(WINDOWWIDTH / 2) + 60, int(WINDOWHEIGHT / 2) + 40)
    
        while True:
            # Keep looping until the player has clicked on a color.
            checkForQuit()
            for event in pygame.event.get(): # event handling loop
                if event.type == MOUSEBUTTONUP:
                    mousex, mousey = event.pos
                    if xRect.collidepoint( (mousex, mousey) ):
                        return [WHITE_TILE, BLACK_TILE]
                    elif oRect.collidepoint( (mousex, mousey) ):
                        return [BLACK_TILE, WHITE_TILE]
    
            # Draw the screen.
            DISPLAYSURF.blit(textSurf, textRect)
            DISPLAYSURF.blit(xSurf, xRect)
            DISPLAYSURF.blit(oSurf, oRect)
            pygame.display.update()
            MAINCLOCK.tick(FPS)
    
    
    def makeMove(board, tile, xstart, ystart, realMove=False):
        # Place the tile on the board at xstart, ystart, and flip tiles
        # Returns False if this is an invalid move, True if it is valid.
        tilesToFlip = isValidMove(board, tile, xstart, ystart)
    
        if tilesToFlip == False:
            return False
    
        board[xstart][ystart] = tile
    
        if realMove:
            animateTileChange(tilesToFlip, tile, (xstart, ystart))
    
        for x, y in tilesToFlip:
            board[x][y] = tile
        return True
    
    
    def isOnCorner(x, y):
        # Returns True if the position is in one of the four corners.
        return (x == 0 and y == 0) or \
               (x == BOARDWIDTH and y == 0) or \
               (x == 0 and y == BOARDHEIGHT) or \
               (x == BOARDWIDTH and y == BOARDHEIGHT)
    
    
    def getComputerMove(board, computerTile):
        # Given a board and the computer's tile, determine where to
        # move and return that move as a [x, y] list.
        possibleMoves = getValidMoves(board, computerTile)
    
        # randomize the order of the possible moves
        random.shuffle(possibleMoves)
    
        # always go for a corner if available.
        for x, y in possibleMoves:
            if isOnCorner(x, y):
                return [x, y]
    
        # Go through all possible moves and remember the best scoring move
        bestScore = -1
        for x, y in possibleMoves:
            dupeBoard = copy.deepcopy(board)
            makeMove(dupeBoard, computerTile, x, y)
            score = getScoreOfBoard(dupeBoard)[computerTile]
            if score > bestScore:
                bestMove = [x, y]
                bestScore = score
        return bestMove
    
    
    def checkForQuit():
        for event in pygame.event.get((QUIT, KEYUP)): # event handling loop
            if event.type == QUIT or (event.type == KEYUP and event.key == K_ESCAPE):
                pygame.quit()
                sys.exit()
    
    
    if __name__ == '__main__':
        main()