[osg-submissions] Group::removeChildren fix

[Daniel Stien]

Hi Robert,

childRemoved() didn't seem to serve any purpose if there was no way to
determine which children were affected. You're right, if childRemoved()
is supposed to be fed an index position in _children it should probably
be given a more suitable name. What about childRemoving()?

I'm subclassing Group to encapsulate a third party collision/dynamics  
world,
using childInserted()/childRemoved() to internally add/remove rigid body  
nodes.

--
Daniel Stien

On Mon, 14 Jan 2008 10:38:52 +0100, Robert Osfield  
<robert.osfield at gmail.com> wrote:

> Hi Daniel,
>
> You change looks OK, but given the naming of the method - childRemoved
> gives us the clue that it a child has been removed, rather than about
> to be removed as is your interpretation.  childRemoved is only done
> with the nodes that subclass from Group and override childRemoved to
> handle the update of their local data structures without getting out
> of sync so if there is a problem then its as down to the local
> childRemoved() implementation making an incorrect assumption rather
> than the Group code itself being done in the wrong order.
>
> Despite your fix being not really being a fix, rather masking an bug
> in a sublcass of Group, I have gone ahead and merged it, as there is
> chance that others might make the same mistake.  BTW, did you subclass
> from Group yourself?  I can't find any placing in the core OSG
> distribution that actually override childRemoved() so there are
> instances where an mistake of interpretation has been made.
>
> Robert.
>
>
>
> On Jan 13, 2008 11:11 PM, Daniel Stien <daniel at stien.org> wrote:
>> When removing a child from a osg::Group, childRemoved is called after  
>> the
>> node has already been erased from the node list, causing childRemoved  
>> to be
>> performed on the consecutive node.
>>
>> Lines 180 and 182 are swapped in the attached Group.cpp.
>>
>> --
>> Daniel Stien
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