[osg-users] [Persistent buffer implementation in osg]

[Julien Valentin]

Hi,
I began to integrate GL immutable storages in osg (glMapBufferRange)
but I blocked on the design problem of Persistent Buffer.

First I haven't find a way to use vector interface for both dma and ::new memory allocation policy without violating the standard (interact directly with vector allocator state of a boost::vector)

Second, DMA changes have to be commited using a valid context from the update thread ! I know it sound weird but It's how it is....No? 

here's the branch
https://github.com/mp3butcher/OpenSceneGraph/tree/bufferstorage

here's Robert review

> As for the actual functionality attempted here. Well pushing context specific data into BufferData which is designed to be graphics context agnostic is broken, the whole point of this design is to allow the subclasses of BufferData to just concentrate on application data and not have to worry about what context are created by the application - it's all about decoupling the scene graph from the viewer. It's one of the OSG great assets. And here you won't to throw away a clean design for a niche feature only usable on a GL4 and has absolutely no value for all other GL/GLES versions.
> 
> With niche feature think how to implement things in a custom way where the changes are kept local, not sprayed across the core OSG.


All insights is welcome

Thank you!

Cheers,
Julien

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http://forum.openscenegraph.org/viewtopic.php?p=72944#72944