Accessing to the edges?

[ote]

Hi,

I am discovering Houdini and the hdk for a couple of weeks for now, so I'm quite new .

I'm having problems to have access to the edges of my input geometry. I know how to get every point (FOR_ALL_OPT_GROUP_POINTS) but I haven't found a way to do the same with edges. With the help of some reading from the forum, I've tried to use getEdgeList() from class GQ_Detail, but it only works if the polygon is closed and it is not always the case for me.

Basically, my input geometry is a set of points which may or not contain some edges/segments connecting two points. I need to be able to find the index in the gdp->points() (or the coordinates) of the two points at each end of every edge/segment. How can I do that?

Edited February 1, 2012 by ote

[edward]

If you only care a about segments with two points, then perhaps GEO_PointRefArray (derived from GB_PointRefArray):

http://www.sidefx.com/docs/hdk11.1/_g_e_o___point_ref_8h_source.html

http://www.sidefx.com/docs/hdk11.1/_g_b___point_ref_8h_source.html

GEO_PointRefArray pointrefs(gdp);
size_t n = pointrefs.entries();
for (size_t pt_i = 0; pt_i < n; ++pt_i)
{
 const GB_PointRef *ref = pointrefs(pt_i);
 if (!ref)
 continue;
 const GEO_Point *adj_pt = ref->vtx->getBasePt();

 size_t pt_j = adj_pt->getNum();

 // We now have an edge for points (pt_i,pt_j)
 // NOTE: You will need to check for duplicates (pt_j, pt_i).
 // A boost::unordered_map perhaps?
}

[ote]

I was on something else and only try today your solution, but it doesn't work. I tested that on a box and try printf("%d-%d", pt_i, pt_j) and get 0-0 1-1, ... 7-7 instead of 0-1, 1-2. Besides, I would like to have all the edge from every point, like for the point 0 of the cube 0-1, 0-3 and 0-4. Do you know how I could get that ?