Getting hue from UIColor yields wrong result
rgb, swift, uicolor
Solution
First of all the range of the red/green/blue components in `UIColor` is 0.0 .. 1.0, not 0.0 .. 255.0, so you probably want
let rgbColour = UIColor(red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)
But even then you get the output `1.0,1.0,1.0` and this is correct. The hue component ranges from 0.0 to 1.0, which corresponds to the angle from 0º to 360º in a color wheel (see for example HSL and HSV).
Therefore `hue = 0.0` and `hue = 1.0` describe an identical color. If you need to normalize the hue component to the half-open interval `0.0 <= hue < 1.0` then you could do that with
hue = fmod(hue, 1.0)
Problem
I'm doing the following in order to retrieve the `hue` from a `UIColor()`: ``` let rgbColour = UIColor(red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0) var hue: CGFloat = 0 var saturation: CGFloat = 0 var brightness: CGFloat = 0 var alpha: CGFloat = 0 rgbColour.getHue(&hue, saturation: &saturation, brightness: &brightness, alpha: &alpha) println("\(hue),\(saturation),\(brightness)") ``` Output: `1.0,1.0,1.0` According to this link, I'm meant to be getting `0.0,1.0,1.0` for RGB (red) `1.0,0.0,0.0`. Am I doing something wrong?