For now add only the depth formats mandated by OpenGL to maximize the
chances of the Vulkan driver supporting a reasonable set of usage flags
for the formats.
As before, on the service side the GPU index the compositor runs on can be selected with
* XRT_COMPOSITOR_FORCE_GPU_INDEX=INDEX1
By default xrGetVulkanGraphicsDevice() will suggest the same GPU the compositor runs on.
It is also possible to override the GPU index suggested to applications with
* XRT_COMPOSITOR_FORCE_CLIENT_GPU_INDEX=INDEX2
The reason this is both done on the service side is that if compositor and client run
on different GPUs, the swapchains use linear tiling instead of optimal tiling.
To make chosen GPUs comparable across the compositor's and the client's vulkan instance,
VkPhysicalDeviceIDProperties.deviceUUID is used.
Many functions returned void and were assumed to always succeed, and some functions
returned only a bool to indicate vague success/failure.
Now that these functions get piped over IPC all of them have to be able to indicate
an IPC failure like for example an unreachable service.
With the xrt_result_t return type they now have the opportunity to report various
types of failures.
Instead of maintaining this chunk of code and build options, the Vulkan
loader can be used to load up validation. This has the advantage that no
layer name needs to be hard coded inside Monado, which was subject of
change recently.
Instead of using our own environment variable we can easily set the one
from the loader, e.g. `VK_INSTANCE_LAYERS=VK_LAYER_KHRONOS_validation`.
This fixes a regression introduced by the IPC and layer rendering
patchsets and passes the array_index to the correct places, so the
correct VkImageView is used instead of the one with index 0.
Make the renderer and IPC aware of multiple projection and quad layers
using the layer renderer.
Remove redundant code related to idle images and imported buffers and
command buffer rebuild, since we now always just display the layer
renderer's frame buffer.
Get view and projection properties from xrt_device.
In order to save redundancy with initializing empty fields with NULL / 0
values and improve readability of the Vulkan code.
This patch also uses struct initializers where possible.
This essentially reverts 1eae45212e.
