Macro projection 

macro_rules! projection {
    (cut=$cut:expr, $($child:expr);+;) => { ... };
    ($($child:expr);+;) => { ... };
}

Create a 2D projection of a 3D object.

#params

cut: When true the 2D shape is the part of the 3D object that is on the xy plane. When false the 2D shape is the ‘shadow’ of the 3D object on the xy plane.

children: A list of 1 or more Scad structs separated by and ending with a semicolon.

expansion: Scad struct literal

#patterns

projection!(‘child: Scad’; …;);

projection!(cut=‘cut: bool’, ‘child: Scad’; …;);