Hi Chris, I'll hold back from doing any more review until you've submitted the other work that depends upon it. I still am of the view that it's probably not the right way to tackle the problem in hand.
> I don't believe the ReadFileCallback is a safe way to integrate with the > pseudoloader. Could you explain why you don't think it's a safe way to integrate with a pseudoload? Robert. On Thu, Nov 19, 2009 at 2:55 PM, Chris 'Xenon' Hanson <[email protected]> wrote: > Robert Osfield wrote: >> Hi Chris, >> I have just reviewed the your suffix change and I'm not sure I quite >> get why you need it. > > This code is to support additional functionality that I haven't yet been > permitted to > release, but I expect to soon. > >> The PagedLOD's DatabasePath member is required to make sure that path >> that a tile is loaded from at runtime it recorded so that it's >> children can be found, this DatabasePath is set on load of the node so >> is actively used. >> This contrasts your new DatabaseSuffix change, it's not recorded or >> set anywhere in the OSG, so I can only assume it's your app that is >> setting, and if so then why not just append the suffix to the >> childrens filenames directly? Also if this appending of the suffix is >> something done dynamically then the route I would take is to write a >> custom Registry::ReadFileCallback that intercepts all readNodeFile() >> etc calls and then adds the suffix there. Such a callback avoids the >> need to modify the scene graph at all so will be easier to implement >> and more more efficient. >> Given that I feel that your changes tackle a problem in way that I >> would recommend I don't feel it's appropriate to merge them as they >> just add complexity to the implementation for little or no value add, >> and in fact may just confuse users into tackle things in a less >> optimal way. > > The non-persistent suffix is there to support propagation of a pseudoloader > suffix > throughout the process of loading a PagedLOD database, without persistently > altering the > structure or filenames of the resulting database once it is loaded. This way > it can be > re-saved with the modifications caused by the pseudo-loader, but without any > permanent > alteration to the filename structure of the database. This is needed because > if you apply > a pseudoloader to the top-level PagedLOD scenegraph file, the filenames > embedded in the > PagedLOD nodes' perRangeLists don't automatically inherit this. > > I have a visitor that appplies this suffix to the PagedLODs automatically, > but it needs > to do it without permanently tainting the perRangeList child filenames -- > thus the > emphemeral suffix which isn't saved. > > You and I discussed the terrain-modification approach this summer and the > pseudoloader > technique was your own suggestion. > > I don't believe the ReadFileCallback is a safe way to integrate with the > pseudoloader. > >> Robert. > > -- > Chris 'Xenon' Hanson, omo sanza lettere Xenon AlphaPixel.com > PixelSense Landsat processing now available! http://www.alphapixel.com/demos/ > "There is no Truth. There is only Perception. To Perceive is to Exist." - Xen > _______________________________________________ > osg-submissions mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org > _______________________________________________ osg-submissions mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
