How to convert points between UIViews and SKNodes - ios

Question

I would like to convert CGPoint between UIView and SKNode, similarly to how you can convert between views/layers via their respective convert(_:to/from:) methods.
What is the correct way to do this?

Answer 1

Here is what I came up with:
extension SKNode {
/// Find point in node relative to it's containing SKView
/// so that it can be further converted relative to other views.
func pointInContainingView(_ point:CGPoint) -> (SKView, CGPoint)? {
guard let scene = scene, let view = scene.view else {
return nil
}
// Invert Y to match view coordinate system.
let invertedY = CGPoint(x: point.x, y: -point.y)
// Get the point in it's containing scene.
let pointInScene = convert(invertedY, from: scene)
// Get the resulting point in the containing SKView
let pointInView = view.convert(pointInScene, from: scene)
return (view, pointInView)
}
}
Used like this:
// view/node
let origin = node.frame.origin
if let (nodeView, point) = node.parent?.pointInContainingView(origin) {
let converted = nodeView.convert(point, from:view)
}

Answer 2

All you need to do is scene.convertPoint(toView:pointOnScene)
If you need to convert a node that is not a child of the scene but a descendent of the scene , you do:
let absolutePosition = node.convert(node.position,toNode:node.scene)
scene.convertPoint(toView: absolutePosition)
A nice little extension to use:
extension SKNode {
/// Find point in node relative to it's containing SKView
/// so that it can be further converted relative to other views.
func pointInContainingView(_ point:CGPoint) -> (SKView, CGPoint)? {
guard let scene = scene, let view = scene.view else {
return nil
}
let pointInView.convertPoint(toView: convert(point,toNode:scene))
return (view, pointInView)
}
}