Add in remainder of game.

DEV_NOTES.md

@@ -47,3 +47,5 @@
 - Documentation on language does not have an explicit section on adding comments.
 - Nice to have tips for syntax-highlighting inside Kv files for PyCharm
     - Thanks @kjell for pointing out [PyCharm settings](https://github.com/kivy/kivy/wiki/Setting-Up-Kivy-with-various-popular-IDE's#kv-lang-auto-completion-and-highlighting)
+
+- The resulting game is quite sluggish... maybe framerate issues?

main.py

@@ -7,23 +7,34 @@ from kivy.uix import widget
 class PongGame(widget.Widget):
     # ADD note: why the None needed... the API allows for *args, **kwargs
     ball = properties.ObjectProperty(None)
+    player_one = properties.ObjectProperty(None)
+    player_two = properties.ObjectProperty(None)
 
-    def serve_ball(self):
+    def serve_ball(self, vel=(4, 0)):
         self.ball.center = self.center
-        # NOTE: Breaking this out
-        random_ball_direction = random.randint(0, 360)
-        self.ball.velocity = vector.Vector(4, 0).rotate(random_ball_direction)
+        self.ball.velocity = vel
 
     def update(self, dt):
         self.ball.move()
 
-        # bounce off top and bottom
-        if (self.ball.y < 0) or (self.ball.top > self.height):
+        # bounce ball off bottom or top
+        if (self.ball.y < self.y) or (self.ball.top > self.top):
             self.ball.velocity_y *= -1
 
-        # bounce off left and right
-        if (self.ball.x < 0) or (self.ball.right > self.width):
-            self.ball.velocity_x *= -1
+        # went of to a side to score point?
+        if self.ball.x < self.x:
+            self.player_two.score += 1
+            self.serve_ball(vel=(4, 0))
+        if self.ball.x > self.width:
+            self.player_one.score += 1
+            self.serve_ball(vel=(-4, 0))
+
+    def on_touch_move(self, touch):
+        if touch.x < self.width / 3:
+            self.player_one.center_y = touch.y
+
+        if touch.x > self.width - self.width / 3:
+            self.player_two.center_y = touch.y
 
 
 class PongBall(widget.Widget):
@@ -36,6 +47,18 @@ class PongBall(widget.Widget):
         self.pos = vector.Vector(*self.velocity) + self.pos
 
 
+class PongPaddle(widget.Widget):
+    score = properties.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.Vector(-1 * vx, vy)
+            vel = bounced * 1.1
+            ball.velocity = vel.x, vel.y + offset
+
+
 class PongApp(app.App):
 
     def build(self):

pong.kv

@@ -3,6 +3,8 @@
 <PongGame>:
     # This needs to be up top, otherwise the properties are not defined.
     ball: pong_ball
+    player_one: player_left
+    player_two: player_right
 
     canvas:
         Rectangle:
@@ -25,9 +27,26 @@
         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
+
 <PongBall>:
     size: 50, 50
     canvas:
         Ellipse:
             pos: self.pos
             size: self.size
+
+<PongPaddle>:
+    size: 25, 200
+    canvas:
+        Rectangle:
+            pos:self.pos
+            size:self.size