# getValues(_:forAttribute:forVirtualScreen:) Gets the value for the specified pixel format attribute. ``` func getValues(_ vals: UnsafeMutablePointer, forAttribute attrib: NSOpenGLPixelFormatAttribute, forVirtualScreen screen: GLint) ``` ## Parameters `vals` On input, a pointer to a `long` variable. On output, the variable contains the value of the requested attribute. `attrib` The requested attribute. For a list of attribute constants, see the table in Constants. `screen` The screen from which you want to retrieve the attribute. This parameter must be a value between 0 and the number of virtual screens ([`numberOfVirtualScreens`](/documentation/AppKit/NSOpenGLPixelFormat/numberOfVirtualScreens)) minus 1. ## Discussion Because the value for an attribute may be different on each virtual screen, the virtual screen must be specified along with the attribute. ## See Also [`- initWithAttributes:`](/documentation/AppKit/NSOpenGLPixelFormat/init(attributes:)) Returns an OpenGL pixel format object initialized with specified pixel format attributes. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)