intent to handle multiple isolated substrate regions. A previous
version of this was added to the master branch but that method had
too many issues and is being deprecated. This version is also very
experimental and is a work in progress.
such that it looks for material connecting to the label at the
center point of the label and not the lower left corner. This keeps
the behavior of looking for tiles on the corners of a degenerate
label line or point between layers, but avoids problems with sticky
labels that are not quite aligned with the rectangle (due to certain
commercial EDA tools that have a sloppier notion of labeling).
Tim Edwards