Getting point values from primitives

Here's a way to get point values from specific vertices. The application here is quite specific actually..
When you make glue constraints for Bullet simming you get a bunch of 2 vertex lines and one method I've been ripping off is to use voronoi noise patterns to cluster the vertices. The aim of this is to check what voronoi cluster value i've assigned to the vertex.

primvertex(0,@primnum, 0);
returns the vertex number, of @primnum's primitive.

vertexpoint(0, vertexnumber);
returns the point number of the vertex you feed it.. Cos points and vertices aren't the same :)

so.. to get a point number from a primitive (say the first point in a line), we combine it all a bit..

int pt= vertexpoint(0,primvertex(0,@primnum,0));

Then you might access some values

float value=point(0, @something, pt);