NSImageを反転させるextension

自分用メモ

NSImage+Flip.swift

extension NSImage {

    func flipHorizontal() {
        let flipper = NSAffineTransform()
        let dimensions = self.size
        self.lockFocus()

        flipper.scaleX(by: -1, yBy: 1)
        flipper.concat()

        self.draw(at: NSPoint(x: -dimensions.width, y: 0), from: NSMakeRect(0,0, dimensions.width, dimensions.height), operation: .copy, fraction: 1)
        self.unlockFocus()
    }

    func flipVartical() {
        let flipper = NSAffineTransform()
        let dimensions = self.size
        self.lockFocus()

        flipper.scaleX(by: 1, yBy: -1)
        flipper.concat()

        self.draw(at: NSPoint(x: 0, y: -dimensions.height), from: NSMakeRect(0,0, dimensions.width, dimensions.height), operation: .copy, fraction: 1)
        self.unlockFocus()
    }
}