* There's not a good accepted terminology for this kind of event, and for
historical reasons 'drawcall' has been the accepted term, even though
that can be quite confusing when a dispatch or a copy is a 'drawcall'.
* This is particularly highlighted by the event browser filters where
$draw() includes draws and dispatches, but $dispatch() only includes
dispatches, it's hard to intuitively understand why $draw() matches all
of these calls.
* As a result we've defined the term 'action' to cover these types of
events in the same way that we defined 'event' in the first place to
mean a single atomic API call.
* The first time a draw is selected bindless feedback runs, ensure the clear-
before-draw overlay works even then. This is a little bit of a hack but it
tests for a known issue.
* For the most part we implement this as a thin pass-through layer. Where we
care about things (image barriers for layout transitions and queue
submissions) we do two different things:
- For image barriers, we "downcast" to plain VkImageMemoryBarrier. Currently
the only thing that's unique to VkImageMemoryBarrier2KHR is extra access
flags and pipeline stages, which we don't care about. This keeps a lot of
code from having to either handle two paths or handle the new path and then
do lots of conversions back to VkImageMemoryBarrier when running on older
drivers.
- For queue submissions we do the opposite. We promote old VkSubmitInfo to
VkSubmitInfo2KHR and process that in a common function, then if necessary
we decay back to VkSubmitInfo before sending to the driver.
* These map more naturally to python tuples and are easier to wrap in and out.
* We also tidy up the FloatVecVal etc and standardise the members of
ShaderValue.
* This helps catches cases where a discarded image is accidentally used and in
many cases may still have valid data. Particularly on Vulkan this is relevant
for DONT_CARE renderpass load and store ops.
* E.g. on D3D12 we can debug DXBC shaders but not DXIL shaders. On vulkan this
will allow us to have the UI work better when encountering shaders with
unsupported capabilities or extensions.
- Separate the pixel history copy pixel shader into two separate
shaders, one for colour copy and one for depth
- Allocate and update descriptor sets on demand
- Add another compute shader for pixel history depth copy
baldurk