Certainly. As far as I can tell, Steffen's argument is to pay attention to the file extension when trying to decide if something is a part. I'm just trying to say that doing so doesn't help much. LDView ignores the file extension when determining if something is a part. It's my opinion that this is correct behavior.
As it happens the, "Is it a part?" question can give both yes and no answers for the exact same file, and LDView's seams option requires it to get the right answer in both cases. Mirrored parts tend to have a wrapper part with a mirror matrix pointing to the other one. If the non-mirrored part is referenced from the model, it is a part. If the mirrored part is also referenced from the model, it is a part, but its child (the same file that was a part before) is not a part.
This means that the logic to determine if something is a part has to both check to see if the current file itself is a part, and also verify that none of the current file's parent files is a part.
If I were writing LDView today, I would probably rely purely on the !LDRAW_ORG statement, in addition to the tree traversal logic mentioned above (no decendents of parts are parts). However, since LDView was initially created before that statement existed, I also have it so any file loaded from a parts directory is also a part, as long as it doesn't have any part parents, grandparents, etc. I also support a number of other meta commands that over the years have been used by people to denote that a file is a part.
As it happens the, "Is it a part?" question can give both yes and no answers for the exact same file, and LDView's seams option requires it to get the right answer in both cases. Mirrored parts tend to have a wrapper part with a mirror matrix pointing to the other one. If the non-mirrored part is referenced from the model, it is a part. If the mirrored part is also referenced from the model, it is a part, but its child (the same file that was a part before) is not a part.
This means that the logic to determine if something is a part has to both check to see if the current file itself is a part, and also verify that none of the current file's parent files is a part.
If I were writing LDView today, I would probably rely purely on the !LDRAW_ORG statement, in addition to the tree traversal logic mentioned above (no decendents of parts are parts). However, since LDView was initially created before that statement existed, I also have it so any file loaded from a parts directory is also a part, as long as it doesn't have any part parents, grandparents, etc. I also support a number of other meta commands that over the years have been used by people to denote that a file is a part.