Workshop › Bomberman-style Arena › Step 31 of 42

No turning back

What we are doing

The classic fix for shaky enemies: on each tile, leave out going back and pick among the rest. Only at a dead end, when going back is the only way, does an enemy turn round. Now they stroll along corridors like they have somewhere to be.

```js
// Enemies wander: at each tile they pick a way they can go, and only turn back at a dead end.
function updateEnemy(e) {

    const forward = options.filter(([dr, dc]) => dr !== -e.dir[0] || dc !== -e.dir[1])
    const pick = forward.length ? forward : options
    e.dir = pick[Math.floor(Math.random() * pick.length)]
```

What it means

Your turn

  1. In updateEnemy, replace the e.dir = options[...] line with the three new lines.
  2. Above function updateEnemy(e) { write the comment.

Skills: Game states, Arrays and objects

All steps

  1. Measure the arena
  2. A floor of tiles
  3. Draw it every frame
  4. The arena as data
  5. Draw what the grid says
  6. Pillars
  7. Crates
  8. Keep the corners clear
  9. The player
  10. Keys being held
  11. Slide towards a target
  12. Walk
  13. Drop a bomb
  14. Space drops, bombs show
  15. One bomb at a time
  16. Bombs are in the way
  17. The fuse burns down
  18. Fire!
  19. Flames die down
  20. A cross of flames
  21. Crates burn
  22. Chain reactions
  23. Bombs blink
  24. Flames hurt
  25. A moment of safety
  26. Hearts
  27. Out of lives
  28. Game over
  29. Enemies
  30. Enemies wander
  31. No turning back
  32. Fight and touch
  33. All enemies gone
  34. Hidden power-ups
  35. Uncover the power-ups
  36. Pick them up
  37. Show the powers
  38. Which way is the finger?
  39. Play with a finger
  40. A clock
  41. The fastest win
  42. Build it yourself: a smarter enemy