Workshop › Mario-style Platformer › Step 31 of 37

Stomp!

What we are doing

Touching an enemy has two outcomes, and the difference is only direction. Coming down onto its head is a stomp: the enemy is squashed and the player bounces up. Anything else hurts. The rule is forgiving: falling, with the feet still in the top half of the enemy.

```js
  if (line[col] === 'e') enemies.push({ x: x + 2, y: y + 4, w: 28, h: 28, vx: 0, vy: 0, dir: -1, alive: true })

if (!enemy.alive || !overlaps(player, enemy)) continue
// A stomp: falling, with the feet still in the top half of the enemy. Anything else is a hit.
const stomp = player.vy > 0 && player.y + player.h < enemy.y + enemy.h / 2
if (stomp) {
  enemy.alive = false
  player.vy = JUMP * 0.6
} else {
  die()
  return
}
```

What it means

Every enemy starts alive: true; dead ones are skipped.
stomp is true when falling (vy > 0) and the feet (y + h) are above the enemy's middle (y + h / 2).
A stomp kills the enemy and bounces the player up at 60% of a jump; otherwise die().

Your turn

In loadLevel, add alive: true to the enemy.
In update, replace the three lines inside the enemy loop with the new ones.

Skills: Collision detection, Game states

← Enemies hurt Squashed enemies are gone →

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