The effective diameter is either the width or height of the node, whichever is larger; This will cause circular nodes to touch when CircularLayout.spacing is 0; This is ideal when the nodes are circular.
The effective diameter is sqrt(width^2+height^2); The corners of square nodes will touch at 45 degrees when CircularLayout.spacing is 0.
This enumeration specifies a method for finding the size of a node. Used for CircularLayout.nodeDiameterFormula.
since3.0