Predefined Functions – lum
|Function name:||lum – Return luminance of argument|
|Input data type||Output data type|
This function takes a color variable as input and returns the luminance of the color. The luminance of a color is always between 0 and 1. For more information about hue, saturation and luminance see HSL Colorspace.
Colors can be created by using one of the color creation functions:
Internally colors are stored in RGBA format. So in order to return the luminance of a color, this function needs to do a color space conversion, which is quite slow.