Workshop › Endless Runner › Step 9 of 19

Cacti keep coming

What we are doing

A countdown decides when the next cactus appears at the right edge. After each one, the next wait is random, but never shorter than 50 frames, so there is always room to land.

```js
let nextIn = 60 // frames until the next obstacle

function spawn() {
  obstacles.push({ x: canvas.width, y: GROUND - 40, w: 20, h: 40 })
  // At least 50 frames apart, so there is always room to land and jump again.
  nextIn = 50 + Math.floor(Math.random() * 70)
}

  nextIn -= 1
  if (nextIn <= 0) spawn()
```

What it means

spawn adds a 20×40 cactus standing on the ground, just past the right edge.
The next wait is 50 plus a random whole number from 0 to 69.
In update, the countdown goes down by one each frame and spawns at zero.

Your turn

Under speed, write nextIn.
Under the pointer lines, write spawn.
In update, write the countdown right above the line that moves the obstacles.

Skills: Game states

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