#1698 Improve GmshReader interface

Metadata

Property	Value
Reported by	Jö Fahlke (jorrit@jorrit.de)
Reported at	Jul 19, 2015 10:26
Type	Bug Report
Version	2.3
Operating System	Unspecified / All

Description

The GmshReader interface has some really counter-intuitive aspects.

For instance, it allows you to read physical entities, even though you did not specify a grid factory. This makes it impossible to later access the physical entities, since you need the grid factory used for creation of the grid to determine the indices into the vectors of physical entities. Users have run into this a few times, they usually try to index the vector with whatever looks like an index to them (e.g. IndexSet, Map, the index induced by the iteration order) and wonder why their physical entity numbers are all garbled.

As another example, (e.g. #1696 (closed)): why is it possible to specify insertBoundarySegments=false together with a vector to store the boundary physical entities into? You won't be able to access this vector, even if you specified a gridfactory, because automatically generated boundary intersections do not have an insertion index.