Getting an exact node count and performance issues in Swift/SpriteKit

Question

I'm making my first game with SpriteKit in which enemies come on screen from one side and pass through- going off screen on the other side. I noticed that later on in the game when different types of enemies are being rendered the FPS drops and the CPU usage approaches 100% (~95-99%). I wanted to know if there was a way to get the exact node count on scene (Not just ones rendered on screen), to tell if I wasn't properly removing them. I already have a global node counter that I update and it seems to work properly-- the total node count is generally consistent. Are there other things that I can do to try and debug this? Thanks!

Answer 1

You can also create an extension of SKNode to calculate all the nodes in the subtree starting from the current node.

extension SKNode {
    func subtreeCount() -> Int {
        return children.reduce(1) { $0 + $1.subtreeCount() }
    }
}

Now inside your scene simply write

let totalNodes = subtreeCount()