For the curious:

Here's a capture of some sample output (with text added to each row) - each image is 16x16

In answer to another comment - yes, it's easy to work out the 'treepath' by parent lookup, but that doesn't tell you whether to use an 'L' or a '|-', or a '|' or a '|-' for parts of the tree, so I fail to see how you can 'trivially' build the graphic ;-)

cLive ;-)