• added DescriptorSet::invalidate() to make vulkano forget about resources that bound to a descriptor_set, so they can be freed. As (normal) descriptors are validated when bound, this is entirely safe to do.
• disable validation for individual descriptors if the descriptor set is UPDATE_AFTER_BIND or PARTIALLY_BOUND, making them actually usable
  • I'm not sure these changes are entirely safe. For it to be, we'd need to validate the descriptor set is properly populated just before flushing any commands to the GPU. And I'm not sure if that's done already, or where it should be added. We could ofc also decide to just leave these two flags as unsafe, somehow.
• some small Descriptor optimizations:
  • More SmallVec use in DescriptorPool to improve variable descriptor count allocation. It only ever allocates one descriptor set at a time, i.e. allocate_infos only ever has one entry in that code path. Annoyed me and just had to fix :D
  • Descriptor updates with no writes or copies return early instead of calling into vulkan. Particularly useful when creating a new descriptor, writing nothing, and updating it properly later.

1. Update documentation to reflect any user-facing changes - in this repository.

2. Make sure that the changes are covered by unit-tests.

3. Run cargo clippy on the changes.

4. Run cargo +nightly fmt on the changes.

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Changelog:

### Additions
* added `DescriptorSet::invalidate()` to make vulkano forget about resources that bound to a descriptor_set, so they can be freed

### Bugs fixed
* fixed descriptor sets with `UPDATE_AFTER_BIND` or `PARTIALLY_BOUND` being wrongly validated on bind