Layer
stored on 2 bits in the file, values represent bit values
@:value(3)staticLLayer1:Int = 3
@:value(2)staticLLayer2:Int = 2
@:value(1)staticLLayer3:Int = 1
@:value(0)staticLReserved:Int = 0
staticenum2Num(l:Layer):Int
staticnum2Enum(l:Int):Layer