Workshop › Frogger-style Crossing › Step 14 of 22

Stay on the logs

What we are doing

The river is deadly: in a log lane, the frog must stand on a log, which means its middle must be over one. Otherwise it falls in the water.

```js
function onLog(lane) {
  const middle = frog.x + 0.5
  return items(lane).some((x) => middle > x && middle < x + lane.len)
}

  if (!lane.log) {
    if (hitByCar(lane)) die()
    return
  }
  if (!onLog(lane)) {
    die()
    return
  }
```

What it means

middle is the middle of the frog's square; it must be between a log's two ends.
Road lanes keep the car check; log lanes use the new one.

Your turn

Above update, write onLog.
In update, split the check for road and river as shown.

Skills: Collision detection

← Logs on the river Ride the log →

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