Contact
-
Jesse Hall critsec
-
Ian Elliott ianelliottus
Other Extension Metadata
- Last Modified Date
-
2017-04-24
- IP Status
-
No known IP claims.
- Contributors
-
-
Patrick Doane, Blizzard
-
Faith Ekstrand, Intel
-
Ian Elliott, LunarG
-
Courtney Goeltzenleuchter, LunarG
-
Jesse Hall, Google
-
James Jones, NVIDIA
-
Antoine Labour, Google
-
Jon Leech, Khronos
-
David Mao, AMD
-
Norbert Nopper, Freescale
-
Alon Or-bach, Samsung
-
Daniel Rakos, AMD
-
Graham Sellers, AMD
-
Ray Smith, ARM
-
Jeff Vigil, Qualcomm
-
Chia-I Wu, LunarG
-
Description
The VK_KHR_win32_surface
extension is an instance extension.
It provides a mechanism to create a VkSurfaceKHR object (defined by
the VK_KHR_surface
extension) that refers to a Win32 HWND
, as
well as a query to determine support for rendering to the windows desktop.
New Enum Constants
-
VK_KHR_WIN32_SURFACE_EXTENSION_NAME
-
VK_KHR_WIN32_SURFACE_SPEC_VERSION
-
Extending VkStructureType:
-
VK_STRUCTURE_TYPE_WIN32_SURFACE_CREATE_INFO_KHR
-
Issues
1) Does Win32 need a way to query for compatibility between a particular physical device and a specific screen? Compatibility between a physical device and a window generally only depends on what screen the window is on. However, there is not an obvious way to identify a screen without already having a window on the screen.
RESOLVED: No. While it may be useful, there is not a clear way to do this on Win32. However, a method was added to query support for presenting to the windows desktop as a whole.
2) If a native window object (HWND
) is used by one graphics API, and
then is later used by a different graphics API (one of which is Vulkan), can
these uses interfere with each other?
RESOLVED: Yes.
Uses of a window object by multiple graphics APIs results in undefined behavior. Such behavior may succeed when using one Vulkan implementation but fail when using a different Vulkan implementation. Potential failures include:
-
Creating then destroying a flip presentation model DXGI swapchain on a window object can prevent vkCreateSwapchainKHR from succeeding on the same window object.
-
Creating then destroying a VkSwapchainKHR on a window object can prevent creation of a bitblt model DXGI swapchain on the same window object.
-
Creating then destroying a VkSwapchainKHR on a window object can effectively
SetPixelFormat
to a different format than the format chosen by an OpenGL application. -
Creating then destroying a VkSwapchainKHR on a window object on one VkPhysicalDevice can prevent vkCreateSwapchainKHR from succeeding on the same window object, but on a different VkPhysicalDevice that is associated with a different Vulkan ICD.
In all cases the problem can be worked around by creating a new window object.
Technical details include:
-
Creating a DXGI swapchain over a window object can alter the object for the remainder of its lifetime. The alteration persists even after the DXGI swapchain has been destroyed. This alteration can make it impossible for a conformant Vulkan implementation to create a VkSwapchainKHR over the same window object. Mention of this alteration can be found in the remarks section of the MSDN documentation for
DXGI_SWAP_EFFECT
. -
Calling GDI’s
SetPixelFormat
(needed by OpenGL’s WGL layer) on a window object alters the object for the remainder of its lifetime. The MSDN documentation forSetPixelFormat
explains that a window object’s pixel format can be set only one time. -
Creating a VkSwapchainKHR over a window object can alter the object for its remaining lifetime. Either of the above alterations may occur as a side effect of vkCreateSwapchainKHR.
Version History
-
Revision 1, 2015-09-23 (Jesse Hall)
-
Initial draft, based on the previous contents of VK_EXT_KHR_swapchain (later renamed VK_EXT_KHR_surface).
-
-
Revision 2, 2015-10-02 (James Jones)
-
Added presentation support query for win32 desktops.
-
-
Revision 3, 2015-10-26 (Ian Elliott)
-
Renamed from VK_EXT_KHR_win32_surface to VK_KHR_win32_surface.
-
-
Revision 4, 2015-11-03 (Daniel Rakos)
-
Added allocation callbacks to vkCreateWin32SurfaceKHR.
-
-
Revision 5, 2015-11-28 (Daniel Rakos)
-
Updated the surface create function to take a pCreateInfo structure.
-
-
Revision 6, 2017-04-24 (Jeff Juliano)
-
Add issue 2 addressing reuse of a native window object in a different Graphics API, or by a different Vulkan ICD.
-
Document Notes
For more information, see the Vulkan Specification
This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.