蛇年到,贪吃蛇还是要出马下的,不准备写完整的程序,就让蛇跑起来,尾巴的长起来吧,蛇头有点动画得了。
先讲讲一些原理,蛇的脑袋使用键盘控制,因此重写他的 蛇身能够增长,运动,原来我计划是蛇身的每一块的坐标都会移动,可看见一个老哥说每次只要把尾巴移动的蛇脑袋那里,蛇脑袋再往前跑跑,蛇就动了,想想也是。蛇身是一块块组成的,很对的块形成一个组,变成蛇的身子,每次蛇要长长,只要在这个组里增加新的块即可。 因为使用了大量的图形,因此使用PyQt里面的带Graphics的那一堆类,重写 想使用动画Animation,看了看里面需要 下面是完整的代码,先贴上: View Code
资源文件: View Code
开始讲解:蛇的身体:1 class Segment(QGraphicsObject): 2 width = 50 3 def __init__(self,pos,parent=None): 4 super(Segment,self).__init__(parent) 5 self.setPixmap(QPixmap(":/img/book.jpg")) 6 self.setFlags(QGraphicsItem.ItemIsSelectable| 7 QGraphicsItem.ItemIsMovable) 8 self.setPos(pos) 9 # def setPos(self,pos): 10 # super(Segment,self).setPos(pos) 11 def pixmap(self): 12 return self.pix 13 def setPixmap(self,pix): 14 self.pix = pix 15 def paint(self,painter,option,widget): 16 painter.drawPixmap(QRect(0,0,self.width,self.width), 17 self.pixmap()) 18 def boundingRect (self): 19 return QRectF(0,0,self.width,self.width)
为了让蛇身蛇头的大小一致,设置了一个width作为蛇身的静态成员变量,并且在 蛇头1 class Head(Segment): 2 speed = Segment.width 3 UP = 0 4 DOWN = 1 5 LEFT = 2 6 RIGHT = 3 7 TimeGap = 500 8 CURVE_TYPES = [(n, c) for n, c in QEasingCurve.__dict__.items() 9 if isinstance(c, QEasingCurve.Type) and c != QEasingCurve.Custom] 10 def _set_pos(self,pos): 11 self.setPos(pos) 12 def _get_pos(self): 13 return self.pos() 14 15 position = pyqtProperty(QPointF,fset = _set_pos, 16 fget = _get_pos) 17 def __init__(self,pos,parent=None): 18 super(Head,self).__init__(pos,parent) 19 self.setPixmap(QPixmap(":/img/person.jpg")) 20 self.setFlags(QGraphicsItem.ItemIsSelectable| 21 QGraphicsItem.ItemIsMovable| 22 QGraphicsItem.ItemIsFocusable) 23 self.curveType = QEasingCurve.OutBounce 24 self.setPos(pos) 25 self.setFocus(Qt.OtherFocusReason) 26 self.direction = self.RIGHT 27 self.timer = QTimer() 28 self.timer.start(self.TimeGap) 29 QObject.connect(self.timer, SIGNAL("timeout()"), 30 self.move) 31 def move(self): 32 pos = self.pos() 33 # add animation,i dont know why must do this 34 # else it wont be move 35 if self.direction == self.LEFT: 36 position = pos + QPointF(-self.speed,0) 37 elif self.direction == self.RIGHT: 38 position = pos + QPointF(self.speed,0) 39 elif self.direction == self.UP: 40 position = pos + QPointF(0,-self.speed) 41 elif self.direction == self.DOWN: 42 position = pos + QPointF(0,self.speed) 43 44 pre = pos = position 45 46 rect = QRectF(self.boundingRect()) 47 if self.direction == self.LEFT: 48 self.setPos(pos+QPointF(-self.speed,0)) 49 elif self.direction == self.RIGHT: 50 self.setPos(pos+QPointF(self.speed,0)) 51 elif self.direction == self.UP: 52 self.setPos(pos+QPointF(0,-self.speed)) 53 elif self.direction == self.DOWN: 54 self.setPos(pos+QPointF(0,self.speed)) 55 current = self.pos() 56 self.animationChanged(pre, current) 57 58 def animationChanged(self,pre,current): 59 self.anim= QPropertyAnimation(self,'position') 60 self.anim.setStartValue(pre) 61 self.anim.setEndValue(current) 62 63 self.anim.setEasingCurve(self.curveType) 64 self.anim.setDirection(self.TimeGap-200) 65 self.anim.start() 66 def keyPressEvent (self,event): 67 key = event.key() 68 if key == Qt.Key_Left: 69 self.direction = self.LEFT 70 return 71 if key == Qt.Key_Right: 72 self.direction = self.RIGHT 73 return 74 if key == Qt.Key_Up: 75 self.direction = self.UP 76 return 77 if key == Qt.Key_Down: 78 self.direction = self.DOWN 79 return
设置了四个方向,并且重写了 CURVE_TYPES是动画的所有可能取值,有40多种,可查阅QEasingCurve的文档。 蛇头的运动,是在
1 def _set_pos(self,pos): 2 self.setPos(pos) 3 def _get_pos(self): 4 return self.pos() 5 6 position = pyqtProperty(QPointF,fset = _set_pos, 7 fget = _get_pos)
构造方法的定时器让蛇身连续移动,这个在我之前的博客中有介绍,不在啰嗦。 蛇身Group1 class SegmentGroup(QObject): 2 def __init__(self,scene,parent = None): 3 super(SegmentGroup,self).__init__(parent) 4 self.scene = scene 5 self.items = deque() 6 7 def addSegment(self,segment): 8 self.scene.addItem(segment) 9 self.items.append(segment) 10 11 def move(self,headPos): 12 if not self.items:return 13 tail = self.items.pop() 14 tail.setPos(headPos) 15 self.items.appendleft(tail) 16 17 def tail(self): 18 if not self.items:return 19 return self.items[-1]
这是为了方便管理,将蛇头和整段身体分离而做的一个容器,因为主要实在第一节蛇身和蛇尾之间进行插入删除操作,所以使用python的deque()来实现这个容器,并且这个容器直接将蛇身添加到scene中去。代码木有神马特别需要说明的。 Scene1 class SnackScene(QGraphicsScene): 2 def __init__(self,parent=None): 3 super(SnackScene,self).__init__(parent) 4 self.setSceneRect(0,0,400,300) 5 self.segmentGroup = SegmentGroup(self) 6 self.segmentGroup.addSegment(Segment(QPointF(0,0))) 7 8 self.head = Head(QPointF(Segment.width,0)) 9 self.addItem(self.head) 10 11 self.setFocusItem(self.head) 12 self.timer = QTimer() 13 self.timer.start(Head.TimeGap) 14 15 self.connect(self.timer, SIGNAL("timeout()"), 16 self.segmentMove) 17 def segmentMove(self): 18 self.segmentGroup.move(self.head.pos()) 19 def mousePressEvent (self, event): 20 if event.button() == Qt.LeftButton: 21 tail = self.segmentGroup.tail() 22 self.segmentGroup.addSegment( 23 Segment(tail.pos()) 24 ) 25 elif event.button() == Qt.RightButton: 26 curveType = random.choice(Head.CURVE_TYPES) 27 self.head.curveType = QEasingCurve(curveType[1])
在这个类中添加数据,蛇头,蛇身管理器,设置了简单的增长蛇身的事件——按下鼠标左键;而按下右键则是更改蛇头的动画效果。将蛇身的移动与蛇头的移动对应起来,用一个与蛇头定时器时间相同的定时器来实现。 最后的form则是使用mainwindow在实现的应用程序。 1 class Form(QMainWindow): 2 def __init__(self,parent=None): 3 super(Form,self).__init__(parent) 4 self.fileMenu = self.menuBar().addMenu("&File") 5 self.statusBar().showMessage("Ready", 5000) 6 self.scene = SnackScene() 7 8 self.view = QGraphicsView(self.scene) 9 self.view.setRenderHint(QPainter.SmoothPixmapTransform) 10 self.view.setDragMode(QGraphicsView.RubberBandDrag) 11 self.setCentralWidget(self.view)
后记:做这个依然是为了熟练qt,本来是想用图形界面做设计模式的,但是有些模式想不好写神马好,就像装饰者模式,用神马例子捏? |
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