Workshop › Endless Runner › Step 6 of 19

Short hops

What we are doing

Good platform games let you control the jump: hold the key for a high jump, tap it for a short hop. When the key is let go while still rising fast, the upward speed is cut to -4.

```js
const CUT = -4 // letting go early caps the upward speed at this

// Letting go early makes a short hop: cap the upward speed.
function endJump() {
  if (runner.vy < CUT) runner.vy = CUT
}

document.addEventListener('keyup', (event) => {
  if (event.key === ' ' || event.key === 'ArrowUp') endJump()
})
```

What it means

vy < CUT means rising faster than 4 pixels a frame (more negative).
Then the speed becomes -4: the jump ends lower. If the runner is already slower or falling, nothing changes.
keyup fires when a key is let go.

Your turn

Under JUMP, write CUT.
Under jump, write the comment and endJump.
Under the keydown listener, write the keyup listener.

Skills: Velocity and gravity, Keyboard and mouse input

← Jump Tap to jump →

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