pub fn angular_chip_anchor(
ann: &FeatureDimAnnotation,
world_per_pixel: f64,
) -> [f64; 3]Expand description
The world-space chip anchor for an ANGULAR annotation: the arc mid-sweep point
at the screen-constant radius (center + rotate(ref_dir, axis, value/2) * radius) — i.e. labelAnchor = vertex + bisector * radius. Camera-dependent
(via world_per_pixel), so the engine computes it per frame.