drawGroupPrimitives abstract method
Renders primitive elements of all tuples of a group.
The tuples are rendered in groups. the Attributes.shape of the first tuple of a group will be taken as a represent, and it's drawGroupPrimitives method decides the basic way to render the whole group. If different tuples have different shapes, define and call special element rendering methods for each item.
List<MarkElement> drawGroupPrimitives( List<Attributes> group, CoordConv coord, Offset origin, );