Center view with aspect ratio

gistfile1.swift

func centerViewOn(point: CGPoint) {
        if let layer = self.layers.first?.layer {
            let viewSize = self.view!.bounds.size
            
            let ratioWidth = self.size.height / viewSize.height
            let newWidth = viewSize.width * ratioWidth
            
            let ratioHeight = self.size.width / viewSize.width
            let newHeight = viewSize.height * ratioHeight
            
            var offsetX = (self.size.width - newWidth) / 2
            var offsetY = (self.size.height - newHeight) / 2
            
            if offsetX < 0 {
                offsetX = 0
            }
            if offsetY < 0 {
                offsetY = 0
            }
            
            let x = point.x.clamped((self.size.width / 2) - offsetX, (layer.layerSize().width - self.size.width / 2) + offsetX)
            let y = point.y.clamped((self.size.height / 2) - offsetY, (layer.layerSize().height - self.size.height / 2) + offsetY)
            
            self.world.position = CGPointMake(-x, -y)
        }
    }