Workshop › Pinball › Step 16 of 42

Three bumpers

What we are doing

Bumpers are the round red posts that throw the ball around. Each is a circle { x, y, r }; we list three and draw them.

```js
const BUMPERS = [
  { x: 100, y: 160, r: 22 },
  { x: 200, y: 120, r: 22 },
  { x: 280, y: 280, r: 22 },
]

  BUMPERS.forEach((b) => {
    ctx.fillStyle = '#e11d48'
    ctx.beginPath()
    ctx.arc(b.x, b.y, b.r, 0, Math.PI * 2)
    ctx.fill()
  })
```

What it means

• BUMPERS is a list of objects, one per bumper: centre and radius.
• BUMPERS.forEach((b) => { ... }) runs the function once for each bumper, with the bumper as b.
• Each is drawn as a filled red circle, before the ball so the ball shows on top.

Your turn

1. Under the WALLS list write BUMPERS.
2. In draw, above ctx.fillStyle = '#e7e5e4' (the ball), write the forEach block.

Skills: Arrays and objects, Drawing on a canvas

← The next ball The ball meets a bumper →

All steps

1. Paint the table
2. Draw one wall
3. A list of walls
4. The game loop
5. A ball in the lane
6. Draw the ball
7. Move by the velocity
8. Launch with Space
9. Gravity
10. Does the ball touch a wall?
11. Push the ball out
12. Bounce off the wall
13. Small steps and a speed limit
14. Ready or playing
15. The next ball
16. Three bumpers
17. The ball meets a bumper
18. A bumper kicks
19. A score and a fresh start
20. Points for every hit
21. Remember which bumper was hit
22. Light it up
23. Lit for a moment, points once
24. Two flippers
25. Where is the tip?
26. Flippers stop the ball
27. Which keys are held?
28. Which way to turn
29. Flip!
30. A moving wall
31. The flipper throws
32. Three balls
33. Balls left and game over
34. Play again
35. Remember the best score
36. Launch on letting go
37. Pull the spring
38. Show the spring
39. Two thumbs
40. Pull with a finger
41. Tap to play again
42. Build it yourself: slingshots