iOS to Mac GraphicContext Explanation/Conversion

Question

I have been programming for two years on iOS and never on mac. I am working on a little utility for handling some simple image needs that I have in my iOS development. Anywa

Answer 1

Here is a Swift (2.1 / 10.11 API-compliant) version of Cobbal's answer

    let size = NSMakeSize(50, 50);
    let im = NSImage.init(size: size)

    let rep = NSBitmapImageRep.init(bitmapDataPlanes: nil,
        pixelsWide: Int(size.width),
        pixelsHigh: Int(size.height),
        bitsPerSample: 8,
        samplesPerPixel: 4,
        hasAlpha: true,
        isPlanar: false,
        colorSpaceName: NSCalibratedRGBColorSpace,
        bytesPerRow: 0,
        bitsPerPixel: 0)

    im.addRepresentation(rep!)
    im.lockFocus()

    let rect = NSMakeRect(0, 0, size.width, size.height)
    let ctx = NSGraphicsContext.currentContext()?.CGContext
    CGContextClearRect(ctx, rect)
    CGContextSetFillColorWithColor(ctx, NSColor.blackColor().CGColor)
    CGContextFillRect(ctx, rect)

    im.unlockFocus()