What's wrong with this Objective-C method?

+(void)getPixelColor:(NSPoint *)passedPoint

“getPixelColor” is the method I am creating.

“passedPoint” is the parameter, a point, the method receives.

NSReadPixel is a function that uses an NSPoint and returns the NSColor
at that point.

But I am getting an error saying "error: incompatible type for argument
1 of NSReadPixel.