Cocoa to Quartz point conversion

quartz-point.swift

/// Converts a Cocoa global point (origin at lower-left) into Quartz display coordinates (origin at upper-left). - #763
static func quartzPoint(from cocoaPoint: CGPoint) -> CGPoint {
    let screens = NSScreen.screens
    // Find screen containing the point; fall back to main screen
    let targetScreen = screens.first { NSMouseInRect(cocoaPoint, $0.frame, false) } ?? NSScreen.main

    guard let screen = targetScreen else { return cocoaPoint }

    // Translate into screen-local coordinates
    let localY = cocoaPoint.y - screen.frame.origin.y
    let flippedLocalY = screen.frame.size.height - localY
    let quartzY = screen.frame.origin.y + flippedLocalY

    return CGPoint(x: cocoaPoint.x, y: quartzY)
}