Queue::write_texture finished callback?

[MatrixDev]

So I'm reading documentation and just can't understand how to know when texture upload has finished.

As I understood we need to use on_submitted_work_done to check when submitted operation has finished. But it is said in the write_texture documentation that:

This method is intended to have low performance costs. As such, the write is not immediately submitted,
and instead enqueued internally to happen at the start of the next submit() call.

Taking this to account on_submitted_work_done will not wait for write_texture but instead for some "random" previous submit call because no submit has actually happen.

Is there any other way to know when write_texture has finished instead of submitting buffers manually? I really like the convinience of this function and no "multiple of 256" limitation.

[kpreid]

Normally, you do not need to care exactly when write_texture() has finished; you enqueue draw/compute operations after write_texture(), and you know that they will execute afterward and thus predictably be able to read the written texels.

If that's not sufficient, can you say more about your use case — exactly what operation needs to wait for the write?

[MatrixDev]

@kpreid, yes, I know that texture can be used right after creation even without calling write_texture.
Here are my use-cases:

1. "loading screen" until all initial textures are uploaded (before main scene is rendered)
2. Add some kind of animation after texture is uploaded to avoid pop-in (when main scene is already rendering)

[cwfitzgerald]

write_texture is defined such that the data will be available on the gpu for all commands that are submitted after the write_texture call returns to the caller.

[cwfitzgerald]

In both of your cases, as long as you have called write_texture, you can assume all future work will see it available.