Workshop › Breakout › Step 13 of 39

Aim with the paddle

What we are doing

Where the ball lands on the paddle should decide its angle: the middle sends it straight up, the ends send it off to the side. That gives the player control.

```js
// -1 at the paddle's left end, 0 in the middle, 1 at the right end
const offset = (ball.x - (paddle.x + PADDLE_W / 2)) / (PADDLE_W / 2)
ball.vx = offset * 5
```

What it means

• paddle.x + PADDLE_W / 2 is the paddle's middle; ball.x minus it is how far right (+) or left (-) the ball is.
• Dividing by half the paddle's width turns that into a number from -1 to 1.
• * 5: the sideways speed is at most 5 pixels per frame.

Your turn

Write the three lines at the top of the if (onPaddle) { block, above ball.vy = ....

Skills: Velocity and gravity

← Bounce off the paddle A row of bricks →

All steps

1. The field and the paddle
2. Draw again and again
3. Keep a number inside limits
4. Follow the mouse
5. A canvas shown at another size
6. A ball with a velocity
7. Draw a round ball
8. Move the ball
9. Bounce off the side walls
10. Bounce off the ceiling
11. The open floor
12. Bounce off the paddle
13. Aim with the paddle
14. A row of bricks
15. Draw the bricks
16. A whole wall: a loop inside a loop
17. A color for every row
18. Circle meets box
19. Break a brick
20. Hitting the side of a brick
21. Wait on the paddle
22. Ride along with the paddle
23. Launch the ball
24. Click or press Space
25. Remember which keys are held
26. Steer with the arrow keys
27. Three lives
28. Lives and a hint on screen
29. Game over
30. Keep score
31. Show the score
32. Win the game
33. One function for a new game
34. Play again
35. A burst of particles
36. Break into sparks
37. Move, fall and disappear
38. Fade out
39. Build it yourself: tough bricks