How to check if a SpriteNode touches another SpriteNote? - swift

Question

So what I'm trying to do is a player which is able to jump when he's on the ground but when he's in the air he is not. And to be honest I have no idea how to accomplish this because I'm new to stuff like that.

Answer 1

I would have an instance variable in the player class like var isOnGround: Bool = true. I would then set up a physics body for the player and the ground using SKPhysicsBody. Then check for collisions in the didBegin(...) and didEnd(...) (contact methods) for the player and the ground. Set the isOnGround variable to true in didBegin(...) and set it to false in the didEnd(...) methods.
Here's an example of the different bit masks properties:
let playerCollisionNumber: UInt32 = 0x1 << 0
let groundCollisionNumber: UInt32 = 0x1 << 1
//node's own collision number
player.physicsBody.categoryBitMask = playerCollisionNumber
//makes the player's physics body interact/collide with the ground's physics body
player.physicsBody.collisionBitMask = groundCollisionNumber
//setting this allows you to be able to interject your own code when the player's physics body and the ground's physics body interact (in the didBegin and didEnd methods)
player.physicsBody.contactTestBitMask = groundCollisionNumber
Then do the same for the ground:
groundNode.physicsBody.categoryBitMask = groundCollisionNumber
groundNode.physicsBody.collisionBitMask = playerCollisionNumber
groundNode.physicsBody.categoryBitMask = playerCollisionNumber
You'll set the isOnGround variable in the didBegin() and didEnd() methods like this:
let contactMask = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask
//in didBegin()
if contactMask == (playerCollisionNumber | groundCollisionNumber) {
player.isOnGround = true
}
//in didEnd()
if contactMask == (playerCollisionNumber | groundCollisionNumber) {
player.isOnGround = false
}