Bindless Stuff

[charliejay]

Then if task1 + task2 take a long time and task3 + task4 can be completed while task1 + task2 are still running

GPUs are required to do things in order. Thus, task3 is guaranteed to complete after task2.

Is it more accurate to say that GPUs are required to do things in order if necessary? So task 3 could complete before task 2 and taks 1 provided it didn't depend on the state of any of the resources used by them?

[Alfonse Reinheart]

Is it more accurate to say that GPUs are required to do things in order if necessary?

Not in any terms that the user is allowed to see. The GPU cannot report completion of task 3 before tasks 1 and 2 complete. So even if it does reorder things, you are forcibly insulated from the effects of that.

[Dark Photon]

In the spirit of Rob's sharing, I'll throw this out there.

It's interesting to apply Rob's "streaming VBO" technique to static geometry too, and then take advantage of temporal coherence. That is, if you've uploaded a batch before and you haven't orphaned its buffer yet, then... yep, you guessed it. You don't need to upload it again. Just launch the batch from the old location, again.

In the ideal case (static/near-static scene, static/near-static viewpoint), you end up with perf that's pretty darn close to NVidia display lists (or bindless preloaded VBOs). Now that is sweet! Worst case, it's about client arrays perf, which isn't shabby. Afterall, you gotta get the data to the GPU at least once (though if GL4, you allegedly could use ARB_copy_buffer/bg thread to accelerate that).

You can think of all kinds of ways to improve upon this to maximize perf (maximize cache "hits").