Workshop › Pool › Step 23 of 33

Choose the power

What we are doing

Every shot has power 8 so far. The up and down arrows change it by 1, between 2 and MAX_POWER.

```js
const MAX_POWER = 16

  else if (event.key === 'ArrowUp') power = Math.min(MAX_POWER, power + 1)
  else if (event.key === 'ArrowDown') power = Math.max(2, power - 1)
```

What it means

• Math.min(MAX_POWER, power + 1) adds one but never goes past 16; Math.max(2, power - 1) takes one off but never goes under 2.

Your turn

1. Under BOUNCE write MAX_POWER.
2. In the key listener, under the ArrowRight line, write the two lines.

Skills: Keyboard and mouse input

← Clear the table A power bar →

All steps

1. The room
2. The table
3. The cue ball
4. Draw the balls
5. The rack
6. Numbers on the balls
7. An aim line
8. Turn the aim
9. A shot is a velocity
10. Roll
11. Friction
12. Cushions
13. Aiming and rolling
14. Hide the aim while rolling
15. Count the shots
16. Balls that touch
17. Swap the push
18. Six pockets
19. In the pocket
20. Scratch
21. Balls left
22. Clear the table
23. Choose the power
24. A power bar
25. A slingshot
26. Press to aim
27. Pull back and let go
28. Smaller steps
29. Predict the hit
30. Draw the ghost ball
31. Where the hit ball goes
32. Your best
33. Build it yourself: two players