Can't always provide Win32Monitor handle when full_screen_exclusive is not FullScreenExclusive::Default

[AlexMcFarland]

• Version of vulkano: 0.34
• OS: Windows
• GPU (the selected PhysicalDevice): NVIDIA GeForce GTX 1080
• GPU Driver: GeForce Game Ready Driver 536.23

Issue

Currently when a full_screen_exclusive value other than FullScreenExclusive::Default is provided in SurfaceInfo or SwapchainCreateInfo, Vulkan will output a validation error if a Win32Monitor handle is not provided.
Vulkano however expects that if and only if full_screen_exclusive is FullScreenExclusive::ApplicationControlled should a Win32Monitor handle also be provided.
Since Vulkano will not let you provide a Win32Monitor handle alongside other full_screen_exclusive values like FullScreenExclusive::Allowed or FullScreenExclusive::Disallowed, it is impossible to use these values without triggering the following validation error:

VUID-vkGetPhysicalDeviceSurfaceCapabilities2KHR-pNext-02671(ERROR / SPEC): msgNum: -1949531159 - Validation Error: [ VUID-vkGetPhysicalDeviceSurfaceCapabilities2KHR-pNext-02671 ] Object 0: handle = 0x2298a106fe0, type = VK_OBJECT_TYPE_PHYSICAL_DEVICE; | MessageID = 0x8bcc83e9 | vkGetPhysicalDeviceSurfaceCapabilities2KHR():  pSurfaceCapabilities->pNext contains VkSurfaceCapabilitiesFullScreenExclusiveEXT, but pSurfaceInfo->pNext does not contain VkSurfaceFullScreenExclusiveWin32InfoEXT. The Vulkan spec states: If a VkSurfaceCapabilitiesFullScreenExclusiveEXT structure is included in the pNext chain of pSurfaceCapabilities, a VkSurfaceFullScreenExclusiveWin32InfoEXT structure must be included 
in the pNext chain of pSurfaceInfo (https://vulkan.lunarg.com/doc/view/1.3.268.0/windows/1.3-extensions/vkspec.html#VUID-vkGetPhysicalDeviceSurfaceCapabilities2KHR-pNext-02671)

As the Vulkan spec states (for surface capabilities):

VUID-vkGetPhysicalDeviceSurfaceCapabilities2KHR-pNext-02671
If a VkSurfaceCapabilitiesFullScreenExclusiveEXT structure is included in the pNext chain of pSurfaceCapabilities, a VkSurfaceFullScreenExclusiveWin32InfoEXT structure must be included in the pNext chain of pSurfaceInfo

Note that it makes no mention of VK_FULL_SCREEN_EXCLUSIVE_APPLICATION_CONTROLLED_EXT specifically.

As far as I'm aware, the fix would be to update these conditional checks (these are only the ones that I know of in Vulkano, but maybe there are more?):
https://github.com/vulkano-rs/vulkano/blob/master/vulkano/src/device/physical.rs#L2412
https://github.com/vulkano-rs/vulkano/blob/master/vulkano/src/device/physical.rs#L2683
https://github.com/vulkano-rs/vulkano/blob/master/vulkano/src/swapchain/mod.rs#L609-L610
https://github.com/vulkano-rs/vulkano/blob/master/vulkano/src/swapchain/mod.rs#L633-L634

surface.api() == SurfaceApi::Win32 && full_screen_exclusive == FullScreenExclusive::ApplicationControlled

To instead be:

surface.api() == SurfaceApi::Win32 && full_screen_exclusive != FullScreenExclusive::Default

[Rua]

The spec isn't really clear on when the monitor value will be used when provided, and when it will be ignored. I had assumed that if the value is not required, then the driver will always ignore it, but apparently that's not the case? Do you have any information on that perhaps?

[AlexHickie]

vkGetPhysicalDeviceSurfaceCapabilities2KHR()

VUID-vkGetPhysicalDeviceSurfaceCapabilities2KHR-pNext-02671
If a VkSurfaceCapabilitiesFullScreenExclusiveEXT structure is included in the pNext chain of pSurfaceCapabilities, a VkSurfaceFullScreenExclusiveWin32InfoEXT structure must be included in the pNext chain of pSurfaceInfo

Spec

On windows, if full_screen_exclusive != Default then VkSurfaceCapabilitiesFullScreenExclusiveEXT is added to the chain so VkSurfaceFullScreenExclusiveWin32InfoEXT is required. It is currently only added if full_screen_exclusive == ApplicationControlled.

The ValidationError provided in PhysicalDevice::surface_capabilities references VUID-VkPhysicalDeviceSurfaceInfo2KHR-pNext-02672 which is a subset of the requirements of VUID-vkGetPhysicalDeviceSurfaceCapabilities2KHR-pNext-02671.

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VkPhysicalDeviceSurfaceInfo2KHR

... chaining a VkSurfaceFullScreenExclusiveWin32InfoEXT structure may also report additional surface capabilities

VUID-VkPhysicalDeviceSurfaceInfo2KHR-pNext-02672
If the pNext chain includes a VkSurfaceFullScreenExclusiveInfoEXT structure with its fullScreenExclusive member set to VK_FULL_SCREEN_EXCLUSIVE_APPLICATION_CONTROLLED_EXT, and surface was created using vkCreateWin32SurfaceKHR, a VkSurfaceFullScreenExclusiveWin32InfoEXT structure must be included in the pNext chain

Spec

I.e. on windows VkSurfaceFullScreenExclusiveWin32InfoEXT is required if full_screen_exclusive == ApplicationControlled and may be optionally provided for additional capabilities (that are required by vkGetPhysicalDeviceSurfaceCapabilities2KHR()).

PhysicalDevice::surface_formats and PhysicalDevice::surface_present_modes use VkPhysicalDeviceSurfaceInfo2KHR.

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VkSwapchainCreateInfoKHR

Spec

Same as VkPhysicalDeviceSurfaceInfo2KHR but there is no advantage to providing it outside the required full_screen_exclusive == ApplicationControlled.

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So on windows, VkSurfaceFullScreenExclusiveWin32InfoEXT is optional if full_screen_exclusive != Default. It is required for VkPhysicalDeviceSurfaceInfo2KHR with full_screen_exclusive == ApplicationControlled and vkGetPhysicalDeviceSurfaceCapabilities2KHR() with full_screen_exclusive != Default.