I've been having a little success with NSAffineTransform but have come across AffineTransform which is presumably more Swifty. However it doesn't have a concat method, so how do you use it? I'm aiming to draw the same little BezierPath rotated several times round the centre.
Sorry if it's obvious; I guess others might find this useful.
Here's how I see it. If you're drawing with an NSBezierPath you apply it to the path with myPath.transform(using: tr), e.g.:
let tr1 = AffineTransform(translationByX: 20, byY: 20)
bez = NSBezierPath()
// add some elements to the path here
bez.transform(using: tr1)
bez.stroke()
As I see it, the transform affects all the elements already in the path, but not any elements subsequently added. Transforms are cumulative, in that re-applying a transform, or applying another will affect all the elements so far entered.
You can also use the AffineTransform's own methods to transform individual points or sizes.