private void AddLine(CircleType type, Coordinate start, Coordinate end, Plane test, CachedLines cache)
{
var line = new Line(start, end);
var cls = line.ClassifyAgainstPlane(test);
if (cls == PlaneClassification.Back) return;
if (cls == PlaneClassification.Spanning)
{
var isect = test.GetIntersectionPoint(line, true);
var first = test.OnPlane(line.Start) > 0 ? line.Start : line.End;
line = new Line(first, isect);
}
cache.Cache[type].Add(new Line(cache.Viewport3D.WorldToScreen(line.Start), cache.Viewport3D.WorldToScreen(line.End)));
}
