itaps-parallel Questions about iMeshP

[Mark Beall]

In reading things again, there is this bullet above the one I quoted:

- Many iMesh functions that accept an iBase_EntitySetHandle are also  
useful in the context of a iMeshP_PartHandle. These functions are  
reinterpreted so that they can accept either an iBase_EntitySetHandle  
or an iMeshP_PartHandle.
What, exactly, does this imply? My concern is that it means that a  
part has to behave as an entity set for a call like iMesh_addEntSet  
(which adds an entity set to an existing set). The semantics of an  
entity set say that, if I make this call, the entity set that I added  
would have to be returned if I subsequently called iMesh_getEntSets on  
that part.
I don't really see how an implementation that doesn't represent parts  
as entity sets could reasonably be expected to do this.
If the intention isn't to require the above to work that way, it would  
seem that it would be better to say that a part is a "read-only"  
entity set and that there be part-specific functions to add/remove  
entities to/from a part. It seems to me that this would allow  
efficient implementations whether or not they are done using entity  
sets.
mark
On Dec 15, 2009, at 4:06 PM, Mark Beall wrote:

>
> On Dec 15, 2009, at 2:14 PM, Tim Tautges wrote:
>
>>>>
>>>> 4. It is mentioned that a part can act as an entityset. Since  
>>>> entitysets
>>>> can have parent-child and containment relationships with other
>>>> entitysets, does this mean that parts need to have them too? If  
>>>> so, it
>>>> is undefined what this means with respect to the partitioning. If  
>>>> not,
>>>> what is the expected course of action when a part is used in an  
>>>> iMesh
>>>> entityset function call which would result in a hierarchical  
>>>> relationship?
>>>>
>>> The only API requirement is that the functions for querying the  
>>> contents of
>>> sets also work for parts.  Whether or not those functions that  
>>> *modify* sets
>>> (either contents or parent/child links) can be called on a part is
>>> implementation-dependent.
>>
>> Actually, the v0.8 iMeshP.h states that *all* functions in the  
>> serial interface taking sets should also work for parts.  So, I  
>> think that includes things like parent/child relations.  Same goes  
>> for contains relations. I think that does imply the need for a  
>> recursive getEntities function (which I have in a set of extensions  
>> to iMesh, BTW).
>
> One thing it does say is the following:
>
> - In particular, entities are added to and removed from local parts  
> via the same functions that are used to manipulate entity sets. That  
> is, given a mesh instance, an entity handle, and a part handle, the  
> entity is added to or removed from the part via calls to the  
> following functions with the part handle passed as the entity set  
> handle:
> - Add entity to part --> iMesh_addEntToSet
> - Remove entity from part --> iMesh_rmvEntFromSet
> - Add array of entities to part --> iMesh_addEntArrToSet
> - Remove array of entities from part --> iMesh_rmvEntArrFromSet
>
> I didn't re-read the entire thing again to see if it says that all  
> other functions taking sets should also work for parts. However, if  
> that is the case, it would seem that that requires an implementation  
> that actually represents parts as entity lists.
>
> mark
>