144 lines
4.8 KiB
Plaintext
144 lines
4.8 KiB
Plaintext
// Copyright (c) 2014-2018 Khronos Group. This work is licensed under a
|
|
// Creative Commons Attribution 4.0 International License; see
|
|
// http://creativecommons.org/licenses/by/4.0/
|
|
|
|
include::meta/VK_KHR_win32_surface.txt[]
|
|
|
|
*Last Modified Date*::
|
|
2017-04-24
|
|
*IP Status*::
|
|
No known IP claims.
|
|
*Contributors*::
|
|
- Patrick Doane, Blizzard
|
|
- Jason 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
|
|
|
|
The `VK_KHR_win32_surface` extension is an instance extension.
|
|
It provides a mechanism to create a slink:VkSurfaceKHR object (defined by
|
|
the `<<VK_KHR_surface>>` extension) that refers to a Win32 code:HWND, as
|
|
well as a query to determine support for rendering to the windows desktop.
|
|
|
|
=== New Object Types
|
|
|
|
None
|
|
|
|
=== New Enum Constants
|
|
|
|
* Extending elink:VkStructureType:
|
|
** ename:VK_STRUCTURE_TYPE_WIN32_SURFACE_CREATE_INFO_KHR
|
|
|
|
=== New Enums
|
|
|
|
None
|
|
|
|
=== New Structures
|
|
|
|
* slink:VkWin32SurfaceCreateInfoKHR
|
|
|
|
=== New Functions
|
|
|
|
* flink:vkCreateWin32SurfaceKHR
|
|
* flink:vkGetPhysicalDeviceWin32PresentationSupportKHR
|
|
|
|
=== 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 (code: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 flink:vkCreateSwapchainKHR from succeeding on
|
|
the same window object.
|
|
|
|
* Creating then destroying a slink:VkSwapchainKHR on a window object can
|
|
prevent creation of a bitblt model DXGI swapchain on the same window
|
|
object.
|
|
|
|
* Creating then destroying a slink:VkSwapchainKHR on a window object can
|
|
effectively code:SetPixelFormat to a different format than the format
|
|
chosen by an OpenGL application.
|
|
|
|
* Creating then destroying a slink:VkSwapchainKHR on a window object on
|
|
one slink:VkPhysicalDevice can prevent flink:vkCreateSwapchainKHR from
|
|
succeeding on the same window object, but on a different
|
|
slink: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 slink:VkSwapchainKHR over the same window
|
|
object.
|
|
Mention of this alteration can be found in the remarks section of the
|
|
MSDN documentation for code:DXGI_SWAP_EFFECT.
|
|
|
|
* Calling GDI's code:SetPixelFormat (needed by OpenGL's WGL layer) on a
|
|
window object alters the object for the remainder of its lifetime.
|
|
The MSDN documentation for code:SetPixelFormat explains that a window
|
|
object's pixel format can be set only one time.
|
|
|
|
* Creating a slink:VkSwapchainKHR over a window object can alter the
|
|
object for the remaining life of its lifetime.
|
|
Either of the above alterations may occur as a side-effect of
|
|
slink:VkSwapchainKHR.
|
|
|
|
=== 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.
|