openscad tubes

// Tube with measurements to fit around something.
module fit_outside_tube(dim, thickness, radius) {
	w = dim[0];
	l = dim[1];
	h = dim[2];
	
	or = min(w, l) * 0.1;
	ir = radius;
	
	// Extrude the tube
	linear_extrude(height = h)
	difference() {
		rounded_square(
			[w + thickness*2, l+thickness*2],
			[or,or,or,or], true);
		rounded_square([w, l],
			[ir,ir,ir,ir], true);
	}
}

// Tube with measurements to fit inside something.
module fit_inside_tube(dim, thickness, radius) {
	w = dim[0];
	l = dim[1];
	h = dim[2];
	
	or = radius;
	ir = min(w, l) * 0.1;
	
	linear_extrude(height = h)

	difference() {
		rounded_square(
			[w-slop , l-slop],
			[or,or,or,or], true);
		rounded_square(
			[w - thickness*2, l - thickness*2],
			[ir,ir,ir,ir], true);
	}
}

Would be nice if it had an example of use