Is there some way to get bounding box of a specific node in a graph?

hi, all:
I’m using cgraph to layout dot graph in my program, and drawing nodes/edges on the basis of the location/size generated in layout process. I want to get bounding box of a node, but it seems can’t work, the returned box is incorrect. The schematic code is as follows:

gvLayout( m_gvc, m_graph, “circo” );

Agnode_t* m_node;
m_node = agnode( gl->graph(), name, TRUE );
boxf boundingBox = ND_bb( m_node );

the returned boundingBox is: {LL = {x = 0, y = 0}, UR = {x = 0, y = 0}}
There can be some box returned with GD_bb, but it is the graph’s bounding box,
not the node’s.

const boxf bb = GD_bb( agraphof( m_node ) );

So my question is:
Will the layout process only set the size of the graph, but not the size of the node?
Is there any way to obtain the size or the bouding box of a specific node?

I don’t use the C interface, but …
Nodes do not have bb (bounding box) values, but they have the equivalent.
Take the node’s pos value and add/subtract the height value/2 and the width value/2
All values should now be in point units, so should work.

thanks for your reply, see this:
I think height/width are of inches, but maybe POINTS can be used.
I’ll check it… Thank you.