pub const EDGE_ON_COS: f64 = 1e-3;Expand description
When an annotation plane is EDGE-ON to the view: the cosine of the angle
between the plane’s normal and the viewing direction. Below this the
plane projects to a line, and so does everything laid out in it. The bar
is the kernel’s own (annotation_plane accepts a plane against its
geometry at sin < 1e-3), read on the other axis.