Journal: Thoughts about work - directed graph drawing, operating syst

I have this problem - how do I display a graph. It's a relatively simple graph. Each node can be connected by one or more directed edges, (or none, but that's unlikely - let's ignore that for now).

There are two levels to this: physical and logical.

On the physical level, the nodes represent modules in the system and the edges represent ATM and Fibre Channel connections between the modules. (OK. there are two switches in there too, one for each network type - do I represent them as nodes or not?)

In the logical view the nodes represent processes. The links represent Virtual Channels (VCs) and Transfer Connections (TCs). A virtual channel connects two processes directly or indirectly. A TC is placed in between the two halves of a VC if the processes it connects are physically separate.

With that explanation out of the way, the problem is still how to draw these connections. I had imagined a row of boxes (future: any arrangement - preferably grid-based) for the nodes and a set of orthogonal links for the edges. Drawing the boxes is a piece of piss.

Drawing the connections is more difficult. I got as far as working out where the start of the edge would be, and then realised I didn't have the information to determine the end location. Determining the points at which it bends 90 degrees is going to be quite tricky, too. I'll leave that problem for now.