Workshop › Pong › Step 10 of 26

Stay on the court

What we are doing

A paddle must stop at the edges. clamp(value, min, max) squeezes a number into a range; we use it to keep each paddle's y between 0 and canvas.height - PADDLE_H.

```js
function clamp(value, min, max) {
  return Math.max(min, Math.min(max, value))
}

  left.y = clamp(left.y, 0, canvas.height - PADDLE_H)
  right.y = clamp(right.y, 0, canvas.height - PADDLE_H)
```

What it means

• Math.min(max, value) never lets the value above max; Math.max(min, ...) never below min.
• At the end of update, both paddles are squeezed between 0 and 320.

Your turn

1. Above function update, write clamp and an empty line.
2. At the end of update, write the two clamp lines.

Skills: Game states, Functions

← Move the paddles The ball →

All steps

1. Get the canvas and the pen
2. A black court
3. One dash of the net
4. The whole net
5. Two paddles
6. A function that draws
7. The game loop
8. Remember held keys
9. Move the paddles
10. Stay on the court
11. The ball
12. The ball moves
13. Bounce off the top and bottom
14. Does the ball touch a paddle?
15. The paddles hit back
16. Serve again
17. Keep the score
18. Show the score
19. First to five
20. Who won?
21. Play again
22. Aim with the paddle
23. Faster every hit
24. A computer opponent
25. One player or two
26. Build it yourself: a serve pause