The STOPPING state has two possible follow up paths:
STOPPING -> IDLE -> READY
STOPPING -> IDLE -> EXITING
After EXITING, the application must call xrDestroySession; there is no meaningful
session state after EXITING.
To go to the READY state again, the application should first create a new session.
Applications that are lazy and drain the entire event queue and only handle
the last encountered state would be affected by "skipping" the EXITING state.
XR_KHR_vulkan_enable2:
physicalDevice VkPhysicalDevice must match the device specified by xrGetVulkanGraphicsDevice2KHR
XR_KHR_vulkan_enable:
physicalDevice VkPhysicalDevice must match the device specified by xrGetVulkanGraphicsDeviceKHR
XR_KHR_vulkan_enable:
Add a trivial check that xrGetVulkanGraphicsDeviceKHR is called before xrCreateSession.
(our cached suggested device will be XR_NULL_HANDLE if it has not been called).
The XR_KHR_vulkan_enable2 code path already contains this check.
It was necessary to add a list of xdevs to oxr_sdl2_hack_start and to
populate such list from its callees.
That includes sdl2_program.gui_program->xdevs which was not being filled
for the monado-service target.
The problem:
* xrCreateVulkanDeviceKHR is passed a VkPhysicalDevice, but not a VkInstance.
* xrGetVulkanGraphicsDevice2KHR is passed a VkInstance and returns a VkPhysicalDevice
that is a child of that instance.
* xrCreateVulkanDeviceKHR must verify that the xrGetVulkanGraphicsDevice2KHR
has been called and that the passed VkPhysicalDevice matches the one returned
by xrGetVulkanGraphicsDevice2KHR.
We have to consider:
* xrCreateVulkanDeviceKHR has to work on the "correct" VkInstance, which the passed
VkPhysicalDevice is a child of.
The reqirement
> If the vulkanPhysicalDevice parameter does not match the output of
> xrGetVulkanGraphicsDeviceKHR, then the runtime must return XR_ERROR_HANDLE_INVALID.
is not 100% clear whether calling xrCreateVulkanInstance multiple times is allowed
and how a second call to xrGetVulkanGraphicsDevice2KHR with a dfferent VkInstance
should be handled.
For this implementation xrCreateVulkanDeviceKHR will only consider the most recent call
to xrGetVulkanGraphicsDevice2KHR and the VkInstance that was used for this call.
This enforces at least that VkPhysicalDevice is a child of the cached VkInstance when
xrCreateVulkanDeviceKHR is called, because using a different VkPhysicalDevice would be
an error.
