[Bf-committers] EGL_CONTEXT_LOST and GL_ARB_create_context_robustness

Brecht Van Lommel brechtvanlommel at pandora.be
Wed Jul 31 15:33:01 CEST 2013

On Wed, Jul 31, 2013 at 10:09 AM, Antony Riakiotakis <kalast at gmail.com> wrote:
> I think a good example of that is GPU_free_images that takes care of
> centrally deallocating all resources and zeroing their identifiers. The
> design here is that the data structure (image) is the owner (holds the ID
> resource) of the GPU data so it is easy to invalidate the GPU data for all
> owners. For shared resources this would not work if the identifier was
> shared, we need to share an owner that will hold the ID and that owner can
> be centrally notified for deallocation/zeroing. That means keeping a list
> of owners of course.
> I think GPU buffers also have an encapsulating inteface though, possibly
> shaders too?

There are GPUTexture, GPUShader, GPUDrawObject, .. wrappers. There's a
few places that hold OpenGL ids directly but these could be changed.

I guess in general the issue is more having a way to clear all of them
which the current wrappers don't help with. You could have these
wrappers store a pointer to a pointer so that they can be
automatically set to NULL in the owner (like a weak reference). And
then put them in some global array so that you can loop over all of

I'm not sure if that makes the code more clear, I don't really have a
strong opinion here, having a function that loops over all of them
isn't so terrible either.

> Note, GPU_free_images also deletes the resources besides zeroing the IDs,
> I'm not sure if on context loss this is already done, so possibly a version
> that only zeroes the IDs may need to be written.

I imagine this might give an OpenGL error but not actually cause any
problems, not sure. But might as well check for it and only delete
when needed.


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