let a = rect();
a.top_left = anchor_offset(0.5, 0.5, -200.0, -100.0);
a.bottom_right = anchor_offset(0.5, 0.5, 100.0, 100.0);
a.radius = 40.0;
a.inner_radius = 30.0;
a.thickness = 10.0;

let b = rect();
b.top_left = anchor_offset(0.25, 0.25, -100.0, -100.0);
b.bottom_right = anchor_offset(0.25, 0.25, 100.0, 100.0);
b.radius = 40.0;
b.inner_radius = 30.0;
b.thickness = 10.0;

[a, b]