Workshop › Asteroids › Step 30 of 41

A moment of safety

What we are doing

If a rock drifts through the middle when the ship respawns, the player loses another life without touching a key. The fix: two seconds of invulnerability. The ship remembers until when it is safe.

```js
const SAFE_TIME = 2000 // milliseconds of invulnerability after respawning

  ship = { x: canvas.width / 2, y: canvas.height / 2, angle: -Math.PI / 2, vx: 0, vy: 0, safeUntil: now + SAFE_TIME }

  if (now >= ship.safeUntil && asteroids.some((asteroid) => hits(ship, SHIP_R * 0.7, asteroid, asteroid.r))) {
```

What it means

• Every new ship gets safeUntil, two seconds from now.
• A crash counts only when now >= ship.safeUntil, that is, once the safe time is over.

Your turn

1. Under POINTS write SAFE_TIME.
2. In resetShip, add safeUntil: now + SAFE_TIME to the ship.
3. In update, put now >= ship.safeUntil && at the start of the crash condition.

Skills: Game states, Collision detection

← What time is it? Blink while safe →

All steps

1. Black space
2. Where the ship is
3. Which way it points
4. A triangle ship
5. Which keys are down?
6. Turning
7. The game loop
8. Thrust and drift
9. A little friction
10. A speed limit
11. Around the screen
12. Making a bullet
13. Fire!
14. Bullets fly
15. A lifetime for bullets
16. Making a rock
17. Four big rocks
18. Drawing the rocks
19. Jagged rocks
20. Drifting rocks
21. When do two circles touch?
22. Breaking a rock
23. Bullets hit rocks
24. Points
25. Show the score
26. Losing a life
27. A rock hits the ship
28. Show the lives
29. What time is it?
30. A moment of safety
31. Blink while safe
32. Waves of rocks
33. The next wave
34. Faster every wave
35. One function to start
36. Playing or over
37. Game over
38. Best score
39. GAME OVER
40. Play again
41. Build it yourself: hyperspace