俄羅斯方塊

俄羅斯方塊是由俄羅斯程式設計師Alexey Pajitnov在1985年設計和程式設計的。

在這個遊戲中，我們有七種不同的形狀：S形，Z形，T形，L形，線形，鏡面L形，和一個方形。每一個形狀都是由四個小正方形組成的。這些形狀都是從棋盤上掉下來的。俄羅斯方塊遊戲的目的是移動和旋轉這些形狀，使它們儘可能地適合。如果我們成功地形成一排，這一排就會被銷燬，我們就會得分。我們玩俄羅斯方塊遊戲，直到我們達到頂點。

wxPython 是一個用於建立應用程式的工具包。還有一些其他的庫比如pygame是針對建立電腦遊戲的，但wxPython也可以用來建立遊戲。

開發過程

我們的俄羅斯方塊遊戲沒有影像，我們使用wxPython中提供的繪圖API繪製俄羅斯方塊。每一個電腦遊戲的背後，都有一個數學模型。俄羅斯方塊中也是如此。

遊戲背後的一些基礎想法。

• 用wx.Timer來建立一個遊戲迴圈。

• 畫出不同形狀

• 形狀以方塊為單位移動（而不是以畫素為單位）。

• 在數學上，棋盤是一個簡單的數字列表。

#tetris_game.py

import wx
import random

class Tetris(wx.Frame):

    def __init__(self, parent):
        wx.Frame.__init__(self, parent, size=(180, 380),
            style=wx.DEFAULT_FRAME_STYLE ^ wx.RESIZE_BORDER ^ wx.MAXIMIZE_BOX)

        self.initFrame()

    def initFrame(self):

        #狀態列 顯示分數
        self.statusbar = self.CreateStatusBar()
        self.statusbar.SetStatusText('0')
        #主board
        self.board = Board(self)
        self.board.SetFocus()
        self.board.start()

        self.SetTitle("俄羅斯方塊")
        self.Centre()


class Board(wx.Panel):

    BoardWidth = 10
    BoardHeight = 22
    Speed = 300
    ID_TIMER = 1

    def __init__(self, *args, **kw):

        super(Board, self).__init__(*args, **kw)

        self.initBoard()

    def initBoard(self):

        self.timer = wx.Timer(self, Board.ID_TIMER)
        self.isWaitingAfterLine = False
        self.curPiece = Shape()
        self.nextPiece = Shape()
        self.curX = 0
        self.curY = 0
        self.numLinesRemoved = 0
        self.board = []

        self.isStarted = False
        self.isPaused = False

        self.Bind(wx.EVT_PAINT, self.OnPaint)
        self.Bind(wx.EVT_KEY_DOWN, self.OnKeyDown)
        self.Bind(wx.EVT_TIMER, self.OnTimer, id=Board.ID_TIMER)

        self.clearBoard()

    def shapeAt(self, x, y):

        return self.board[(y * Board.BoardWidth) + x]

    def setShapeAt(self, x, y, shape):

        self.board[(y * Board.BoardWidth) + x] = shape

    def squareWidth(self):

        return self.GetClientSize().GetWidth() // Board.BoardWidth

    def squareHeight(self):

        return self.GetClientSize().GetHeight() // Board.BoardHeight

    def start(self):

        if self.isPaused:
            return

        self.isStarted = True
        self.isWaitingAfterLine = False
        self.numLinesRemoved = 0
        self.clearBoard()

        self.newPiece()
        self.timer.Start(Board.Speed)

    def pause(self):

        if not self.isStarted:
            return

        self.isPaused = not self.isPaused
        statusbar = self.GetParent().statusbar

        if self.isPaused:
            self.timer.Stop()
            statusbar.SetStatusText('paused')
        else:
            self.timer.Start(Board.Speed)
            statusbar.SetStatusText(str(self.numLinesRemoved))

        self.Refresh()

    def clearBoard(self):

        for i in range(Board.BoardHeight * Board.BoardWidth):
            self.board.append(Tetrominoes.NoShape)

    def OnPaint(self, event):

        dc = wx.PaintDC(self)

        size = self.GetClientSize()
        boardTop = size.GetHeight() - Board.BoardHeight * self.squareHeight()

        for i in range(Board.BoardHeight):
            for j in range(Board.BoardWidth):

                shape = self.shapeAt(j, Board.BoardHeight - i - 1)

                if shape != Tetrominoes.NoShape:
                    self.drawSquare(dc,
                        0 + j * self.squareWidth(),
                        boardTop + i * self.squareHeight(), shape)

        if self.curPiece.shape() != Tetrominoes.NoShape:

            for i in range(4):

                x = self.curX + self.curPiece.x(i)
                y = self.curY - self.curPiece.y(i)

                self.drawSquare(dc, 0 + x * self.squareWidth(),
                    boardTop + (Board.BoardHeight - y - 1) * self.squareHeight(),
                    self.curPiece.shape())


    def OnKeyDown(self, event):

        if not self.isStarted or self.curPiece.shape() == Tetrominoes.NoShape:
            event.Skip()
            return

        keycode = event.GetKeyCode()

        if keycode == ord('P') or keycode == ord('p'):
            self.pause()
            return

        if self.isPaused:
            return

        elif keycode == wx.WXK_LEFT:
            self.tryMove(self.curPiece, self.curX - 1, self.curY)

        elif keycode == wx.WXK_RIGHT:
            self.tryMove(self.curPiece, self.curX + 1, self.curY)

        elif keycode == wx.WXK_DOWN:
            self.tryMove(self.curPiece.rotatedRight(), self.curX, self.curY)

        elif keycode == wx.WXK_UP:
            self.tryMove(self.curPiece.rotatedLeft(), self.curX, self.curY)

        elif keycode == wx.WXK_SPACE:
            self.dropDown()

        elif keycode == ord('D') or keycode == ord('d'):
            self.oneLineDown()

        else:
            event.Skip()


    def OnTimer(self, event):

        if event.GetId() == Board.ID_TIMER:

            if self.isWaitingAfterLine:
                self.isWaitingAfterLine = False
                self.newPiece()
            else:
                self.oneLineDown()
        else:
            event.Skip()


    def dropDown(self):

        newY = self.curY

        while newY > 0:
            if not self.tryMove(self.curPiece, self.curX, newY - 1):
                break
            newY -= 1

        self.pieceDropped()

    def oneLineDown(self):

        if not self.tryMove(self.curPiece, self.curX, self.curY - 1):
            self.pieceDropped()


    def pieceDropped(self):

        for i in range(4):

            x = self.curX + self.curPiece.x(i)
            y = self.curY - self.curPiece.y(i)
            self.setShapeAt(x, y, self.curPiece.shape())

        self.removeFullLines()

        if not self.isWaitingAfterLine:
            self.newPiece()


    def removeFullLines(self):

        numFullLines = 0

        statusbar = self.GetParent().statusbar

        rowsToRemove = []

        for i in range(Board.BoardHeight):
            n = 0
            for j in range(Board.BoardWidth):
                if not self.shapeAt(j, i) == Tetrominoes.NoShape:
                    n = n + 1

            if n == 10:
                rowsToRemove.append(i)

        rowsToRemove.reverse()

        for m in rowsToRemove:
            for k in range(m, Board.BoardHeight):
                for l in range(Board.BoardWidth):
                        self.setShapeAt(l, k, self.shapeAt(l, k + 1))

            numFullLines = numFullLines + len(rowsToRemove)

            if numFullLines > 0:

                self.numLinesRemoved = self.numLinesRemoved + numFullLines
                statusbar.SetStatusText(str(self.numLinesRemoved))
                self.isWaitingAfterLine = True
                self.curPiece.setShape(Tetrominoes.NoShape)
                self.Refresh()


    def newPiece(self):

        self.curPiece = self.nextPiece
        statusbar = self.GetParent().statusbar
        self.nextPiece.setRandomShape()

        self.curX = Board.BoardWidth // 2 + 1
        self.curY = Board.BoardHeight - 1 + self.curPiece.minY()

        if not self.tryMove(self.curPiece, self.curX, self.curY):

            self.curPiece.setShape(Tetrominoes.NoShape)
            self.timer.Stop()
            self.isStarted = False
            statusbar.SetStatusText('Game over')


    def tryMove(self, newPiece, newX, newY):

        for i in range(4):

            x = newX + newPiece.x(i)
            y = newY - newPiece.y(i)

            if x < 0 or x >= Board.BoardWidth or y < 0 or y >= Board.BoardHeight:
                return False

            if self.shapeAt(x, y) != Tetrominoes.NoShape:
                return False

        self.curPiece = newPiece
        self.curX = newX
        self.curY = newY
        self.Refresh()

        return True


    def drawSquare(self, dc, x, y, shape):

        colors = ['#000000', '#CC6666', '#66CC66', '#6666CC',
                  '#CCCC66', '#CC66CC', '#66CCCC', '#DAAA00']

        light = ['#000000', '#F89FAB', '#79FC79', '#7979FC',
                 '#FCFC79', '#FC79FC', '#79FCFC', '#FCC600']

        dark = ['#000000', '#803C3B', '#3B803B', '#3B3B80',
                 '#80803B', '#803B80', '#3B8080', '#806200']

        pen = wx.Pen(light[shape])
        pen.SetCap(wx.CAP_PROJECTING)
        dc.SetPen(pen)

        dc.DrawLine(x, y + self.squareHeight() - 1, x, y)
        dc.DrawLine(x, y, x + self.squareWidth() - 1, y)

        darkpen = wx.Pen(dark[shape])
        darkpen.SetCap(wx.CAP_PROJECTING)
        dc.SetPen(darkpen)

        dc.DrawLine(x + 1, y + self.squareHeight() - 1,
            x + self.squareWidth() - 1, y + self.squareHeight() - 1)
        dc.DrawLine(x + self.squareWidth() - 1,
        y + self.squareHeight() - 1, x + self.squareWidth() - 1, y + 1)

        dc.SetPen(wx.TRANSPARENT_PEN)
        dc.SetBrush(wx.Brush(colors[shape]))
        dc.DrawRectangle(x + 1, y + 1, self.squareWidth() - 2,
        self.squareHeight() - 2)


class Tetrominoes(object):

    NoShape = 0
    ZShape = 1
    SShape = 2
    LineShape = 3
    TShape = 4
    SquareShape = 5
    LShape = 6
    MirroredLShape = 7


class Shape(object):

    coordsTable = (
        ((0, 0),     (0, 0),     (0, 0),     (0, 0)),
        ((0, -1),    (0, 0),     (-1, 0),    (-1, 1)),
        ((0, -1),    (0, 0),     (1, 0),     (1, 1)),
        ((0, -1),    (0, 0),     (0, 1),     (0, 2)),
        ((-1, 0),    (0, 0),     (1, 0),     (0, 1)),
        ((0, 0),     (1, 0),     (0, 1),     (1, 1)),
        ((-1, -1),   (0, -1),    (0, 0),     (0, 1)),
        ((1, -1),    (0, -1),    (0, 0),     (0, 1))
    )

    def __init__(self):

        self.coords = [[0,0] for i in range(4)]
        self.pieceShape = Tetrominoes.NoShape

        self.setShape(Tetrominoes.NoShape)

    def shape(self):

        return self.pieceShape

    def setShape(self, shape):

        table = Shape.coordsTable[shape]
        for i in range(4):
            for j in range(2):
                self.coords[i][j] = table[i][j]

        self.pieceShape = shape

    def setRandomShape(self):

        self.setShape(random.randint(1, 7))

    def x(self, index):

        return self.coords[index][0]

    def y(self, index):

        return self.coords[index][1]

    def setX(self, index, x):

        self.coords[index][0] = x

    def setY(self, index, y):

        self.coords[index][1] = y

    def minX(self):

        m = self.coords[0][0]
        for i in range(4):
            m = min(m, self.coords[i][0])

        return m

    def maxX(self):

        m = self.coords[0][0]
        for i in range(4):
            m = max(m, self.coords[i][0])

        return m

    def minY(self):

        m = self.coords[0][1]
        for i in range(4):
            m = min(m, self.coords[i][1])

        return m

    def maxY(self):

        m = self.coords[0][1]

        for i in range(4):
            m = max(m, self.coords[i][1])

        return m

    def rotatedLeft(self):

        if self.pieceShape == Tetrominoes.SquareShape:
            return self

        result = Shape()
        result.pieceShape = self.pieceShape

        for i in range(4):
            result.setX(i, self.y(i))
            result.setY(i, -self.x(i))

        return result

    def rotatedRight(self):

        if self.pieceShape == Tetrominoes.SquareShape:
            return self

        result = Shape()
        result.pieceShape = self.pieceShape

        for i in range(4):
            result.setX(i, -self.y(i))
            result.setY(i, self.x(i))

        return result


def main():

    app = wx.App()
    ex = Tetris(None)
    ex.Show()
    app.MainLoop()


if __name__ == '__main__':
    main()

應用程式啟動後，立即開始。我們可以通過按p鍵來暫停遊戲。空格鍵會將掉落的俄羅斯方塊立即掉到底部。d鍵則會使棋子加速下落。方向下鍵會旋轉形狀。遊戲以恆定的速度進行,分數是我們刪除的排數。

...
self.curX = 0
self.curY = 0
self.numLinesRemoved = 0
self.board = []
...

在開始遊戲迴圈之前，我們先初始化一些重要的變數。self.board變數是一個從0到7的數字列表。它代表各種形狀的位置和形狀在棋盤上的遺蹟。

for i in range(Board.BoardHeight):
    for j in range(Board.BoardWidth):

        shape = self.shapeAt(j, Board.BoardHeight - i - 1)

        if shape != Tetrominoes.NoShape:
            self.drawSquare(dc,
                0 + j * self.squareWidth(),
                boardTop + i * self.squareHeight(), shape)

遊戲的繪畫分為兩個步驟。第一步，我們畫出所有的形狀，或者是掉到棋盤底部的形狀。所有的方塊都被儲存在self.board列表變數中。我們使用shapeAt()方法訪問它。

if self.curPiece.shape() != Tetrominoes.NoShape:

    for i in range(4):

        x = self.curX + self.curPiece.x(i)
        y = self.curY - self.curPiece.y(i)

        self.drawSquare(dc, 0 + x * self.squareWidth(),
            boardTop + (Board.BoardHeight - y - 1) * self.squareHeight(),
            self.curPiece.shape())

下一步是畫出落下的實際作品。

elif keycode == wx.WXK_LEFT:
    self.tryMove(self.curPiece, self.curX - 1, self.curY)

在OnKeyDown()方法中，我們檢查是否有按鍵被按下。如果按了左邊的方向鍵，就會嘗試將棋子向左移動。tryMove是因為棋子可能無法移動(邊界上)。

def tryMove(self, newPiece, newX, newY):

    for i in range(4):
        x = newX + newPiece.x(i)
        y = newY - newPiece.y(i)
        if x < 0 or x >= Board.BoardWidth or y < 0 or y >= Board.BoardHeight:
            return False
        if self.shapeAt(x, y) != Tetrominoes.NoShape:
            return False

    self.curPiece = newPiece
    self.curX = newX
    self.curY = newY
    self.Refresh()

    return True

在tryMove()方法中，我們嘗試移動我們的形狀。如果形狀在棋盤的邊緣或與其他棋子相鄰，我們返回 "False"；否則我們將當前下落的棋子放置到新的位置並返回 "True"。

def OnTimer(self, event):

    if event.GetId() == Board.ID_TIMER:
        if self.isWaitingAfterLine:
            self.isWaitingAfterLine = False
            self.newPiece()
        else:
            self.oneLineDown()
    else:
        event.Skip()

在OnTimer()方法中，我們要麼在前一個棋子落到底部後，建立一個新的棋子，要麼將落下的棋子向下移動一行。

def removeFullLines(self):

    numFullLines = 0

    rowsToRemove = []

    for i in range(Board.BoardHeight):
        n = 0
        for j in range(Board.BoardWidth):
            if not self.shapeAt(j, i) == Tetrominoes.NoShape:
                n = n + 1

        if n == 10:
            rowsToRemove.append(i)

    rowsToRemove.reverse()

    for m in rowsToRemove:
        for k in range(m, Board.BoardHeight):
            for l in range(Board.BoardWidth):
                self.setShapeAt(l, k, self.shapeAt(l, k + 1))
...

如果形狀到達底部，就呼叫removeFullLines()方法。首先我們找出所有的滿行，並將其刪除。我們的做法是將當前要刪除的滿行之上的所有行向下移動一行。

def newPiece(self):

    self.curPiece = self.nextPiece
    statusbar = self.GetParent().statusbar
    self.nextPiece.setRandomShape()
    self.curX = Board.BoardWidth / 2 + 1
    self.curY = Board.BoardHeight - 1 + self.curPiece.minY()

    if not self.tryMove(self.curPiece, self.curX, self.curY):

        self.curPiece.setShape(Tetrominoes.NoShape)
        self.timer.Stop()
        self.isStarted = False
        statusbar.SetStatusText('Game over')

newPiece()方法隨機建立一個新的俄羅斯方塊。如果這個棋子不能進入它的初始位置，遊戲就結束了。

Shape類儲存了俄羅斯方塊的資訊。

self.coords = [[0,0] for i in range(4)]

建立後我們建立一個空的座標列表。該列表將儲存俄羅斯方塊片的座標。例如，元組(0，-1)，(0，0)，(-1，0)，(-1，-1)代表一個旋轉的S形。下圖說明了這個形狀。

當畫出當前落下的棋子時，我們在self.curX和self.curY位置畫出它。然後我們看座標表，把四個方塊都畫出來。