commit

main.py

@@ -0,0 +1,80 @@
+from kivy.app import App
+from kivy.uix.widget import Widget
+from kivy.properties import (
+    NumericProperty, ReferenceListProperty, ObjectProperty
+)
+from kivy.vector import Vector
+from kivy.clock import Clock
+
+class PongPaddle(Widget):
+    score = NumericProperty(0)
+
+    def bounce_ball(self, ball):
+        if self.collide_widget(ball):
+            vx, vy = ball.velocity
+            offset = (ball.center_y - self.center_y) / (self.height / 2)
+            bounced = Vector(-1 * vx, vy)
+            vel = bounced * 1.1
+            ball.velocity = vel.x, vel.y + offset
+
+
+class PongBall(Widget):
+
+    # velocity of the ball on x and y axis
+    velocity_x = NumericProperty(0)
+    velocity_y = NumericProperty(0)
+
+    # referencelist property so we can use ball.velocity as
+    # a shorthand, just like e.g. w.pos for w.x and w.y
+    velocity = ReferenceListProperty(velocity_x, velocity_y)
+
+    # ``move`` function will move the ball one step. This
+    #  will be called in equal intervals to animate the ball
+    def move(self):
+        self.pos = Vector(*self.velocity) + self.pos
+
+
+class PongGame(Widget):
+    ball = ObjectProperty(None)
+    player1 = ObjectProperty(None)
+    player2 = ObjectProperty(None)
+
+    def serve_ball(self, vel=(4, 0)):
+        self.ball.center = self.center
+        self.ball.velocity = vel
+
+    def update(self, dt):
+        self.ball.move()
+
+        # bounce off paddles
+        self.player1.bounce_ball(self.ball)
+        self.player2.bounce_ball(self.ball)
+
+        # bounce ball off bottom or top
+        if (self.ball.y < self.y) or (self.ball.top > self.top):
+            self.ball.velocity_y *= -1
+
+        # went off to a side to score point?
+        if self.ball.x < self.x:
+            self.player2.score += 1
+            self.serve_ball(vel=(4, 0))
+        if self.ball.right > self.width:
+            self.player1.score += 1
+            self.serve_ball(vel=(-4, 0))
+
+    def on_touch_move(self, touch):
+        if touch.x < self.width / 3:
+            self.player1.center_y = touch.y
+        if touch.x > self.width - self.width / 3:
+            self.player2.center_y = touch.y
+
+class PongApp(App):
+    def build(self):
+        game = PongGame()
+        game.serve_ball()
+        Clock.schedule_interval(game.update, 1.0 / 60.0)
+        return game
+
+
+if __name__ == '__main__':
+    PongApp().run()

pong.kv

@@ -0,0 +1,50 @@
+#:kivy 1.0.9
+<PongPaddle>:
+    size: 25, 200
+    canvas:
+        Rectangle:
+            pos: self.pos
+            size: self.size
+
+<PongBall>:
+    size: 50, 50
+    canvas:
+        Ellipse:
+            pos: self.pos
+            size: self.size
+
+<PongGame>:  
+    ball: pong_ball
+    player1: player_left
+    player2: player_right
+
+    canvas:
+        Rectangle:
+            pos: self.center_x - 5, 0
+            size: 10, self.height
+            
+    Label:
+        font_size: 70  
+        center_x: root.width / 4
+        top: root.top - 50
+        text: str(root.player1.score)
+        
+    Label:
+        font_size: 70  
+        center_x: root.width * 3 / 4
+        top: root.top - 50
+        text: str(root.player2.score)
+
+    PongBall:
+        id: pong_ball
+        center: self.parent.center
+
+    PongPaddle:
+        id: player_left
+        x: root.x
+        center_y: root.center_y
+        
+    PongPaddle:
+        id: player_right
+        x: root.width - self.width
+        center_y: root.center_y