title: Swift OpenGL unresolved identifier kCGImageAlphaPremultipliedLast
body: <p>I am getting a unresolved identifier error for 'kCGImageAlphaPremultipliedLast'. Swift can't find it. Is this available in Swift?</p>
  
  <pre><code>var gc = CGBitmapContextCreate(&amp;pixelData, width: width, height: height, bitsPerComponent: 8, bytesPerRow: width*4, imageCS, bitmapInfo: kCGImageAlphaPremultipliedLast);
  </code></pre>