Workshop › Angry Birds-style Slingshot › Step 31 of 47

Hard hits hurt

What we are doing

How hard was a hit? collide already knows: closing. Only the speed above 2 hurts, 25 hp per unit, so a block settling on another is never hurt. Landing on the ground hurts with the falling speed.

```js
  damage(a, closing)
  damage(b, closing)
}

// Hits harder than a gentle landing hurt; things fall apart at 0 hp.
function damage(b, speed) {
  if (speed > 2) b.hp -= (speed - 2) * 25
}

    if (b.y + b.h > GROUND) {
      if (b.vy > 0) damage(b, b.vy)
```

What it means

At the end of collide, both bodies are damaged by the closing speed.
damage takes away (speed - 2) * 25 hp, only when speed is over 2.
Hitting the ground while falling (vy > 0) damages a body by its falling speed.

Your turn

At the end of collide, under the last friction line, write the two damage calls.
Between collide and step, write the damage function.
In step, write the ground-damage line as the first line inside if (b.y + b.h > GROUND) {.

Skills: Collision detection

← Hit points Things break →

All steps