Workshop › Missile Command-style Defense › Step 19 of 35

Caught in the blast

What we are doing

A missile is destroyed when it is inside an explosion: its distance to the explosion's center is at most the explosion's radius right now.

```js
if (blasts.some((b) => Math.hypot(m.x - b.x, m.y - b.y) <= radius(b))) {
  m.done = true
  continue
}
```

What it means

• some is true if at least one blast satisfies the test.
• Math.hypot(m.x - b.x, m.y - b.y) is the distance from the missile to the blast's center.
• A caught missile is marked done, and continue skips the rest of the loop body for it (it does not move on).

Your turn

In update, write the if block at the top of the missile loop, above if (stepTowards(m, m.speed)) {.

Skills: Collision detection

← Impacts explode too Chain reactions →

All steps

1. Six cities to protect
2. Your missile base
3. Draw again and again
4. Cities that can fall
5. Rubble
6. Move towards a point
7. Launch an enemy missile
8. One missile a second
9. Missiles on their way
10. Smoke trails
11. Impact
12. Fire an interceptor
13. Click the sky
14. Interceptors fly
15. An explosion that grows and shrinks
16. Explode on arrival
17. Draw the explosions
18. Impacts explode too
19. Caught in the blast
20. Chain reactions
21. Only your explosions count
22. Points for every missile
23. Show the score
24. Limited ammo
25. Waves
26. Each wave is harder
27. The end of a wave
28. The end
29. Play again
30. Wave, ammo and messages
31. Launch from anywhere
32. Some missiles will split
33. Split into three
34. A high score
35. Build it yourself: a crosshair