Add Code to Destroy Collectibles

Apple Game Frameworks and Technologies — by Tammy Coron (119 / 193)

👈 Place Collectibles and Doors | TOC | Next Steps 👉

Switch back to the Player.swift file, and in the attack() method, above the line that reads var throwDirection = CGVector(dx: 0, dy: 0), add the following code:

​ ​// Set up physics for projectile​
​ ​let​ physicsBody = ​SKPhysicsBody​(rectangleOf: projectile.size)
​ 
​ physicsBody.affectedByGravity = ​false​
​ physicsBody.allowsRotation = ​true​
​ physicsBody.isDynamic = ​true​
​ 
​ physicsBody.categoryBitMask = ​PhysicsBody​.projectile.categoryBitMask
​ physicsBody.contactTestBitMask = ​PhysicsBody​.projectile.contactTestBitMask
​ physicsBody.collisionBitMask = ​PhysicsBody​.projectile.collisionBitMask
​ 
​ projectile.physicsBody = physicsBody

This sets the projectile’s physics body to use the projectile category.

Next, back in the GameScene+PhysicsContact.swift file, add the code necessary to handle the contacts between the projectile and collectible categories:

​   ​// MARK: -  Projectile | Collectible​
​ 
​ ​case​ ​PhysicsBody​.projectile.categoryBitMask |
​   ​PhysicsBody​.collectible.categoryBitMask:
​   ​let​ projectileNode = contact.bodyA.categoryBitMask ==
​     ​PhysicsBody​.projectile.categoryBitMask ?
​       contact.bodyA.node : contact.bodyB.node
​ 
​   ​let​ collectibleNode = contact.bodyA.categoryBitMask ==
​…