worldBorder
Returns the world-border circle infinite shapes are clipped against, for a surface of size showing a scene with bounds at the draw scale.
With declared bounds this is the scene's own circumscribed circle — SceneBounds.worldBorder(), origin-centered, ignoring the bounds' offset — so the visible span of an infinite line is a property of the scene, not of the surface showing it. Null bounds circumscribes the visible viewport instead, size / scale in CGA units: with no declared bounds the surface is the world, and lines run edge-to-edge.
Return
The clip Circle in model space, classic orientation.
Parameters
The surface size in physical px.
The scene's SceneBounds, or null when the scene declares none.
The draw scale in physical px per CGA unit — the matching fitScale value.