Descriptor sets
===
  - hardcoded in SDL_gpu
  - for graphics pipelines there are always 4 of them:
    - 0 are vertex resources (first samplers, then storage images, then storage buffers)
    - 1 are vertex uniform buffers
    - 2 are fragment resources (again samplers, storage images and storage buffers)
    - 3 are fragment uniform buffers
  - compute has 3 sets:
    - 0 are read-only resources (samplers, storage images, storage buffers)
    - 1 are write-only resources (storage images and storage buffers)
    - 2 are uniform buffers

Cycling
===
  - due to the nature of in-flight frames, resources might still be in use in a previous frames
  - to make up for this, many SDL_gpu APIs have a `cycle` parameter
  - if set to true, SDL will provide an unused resource if the previous one is still in use

First Look At The Resulting Vulkan Calls
===
  - they are correct
  - but not really optimal, e.g.
    - double transitions
    - transition for the depth attachment in pass without depth?
    - vkCmdSetStencilReference even though there is no stencil buffer