VK_KHR_wayland_surface

Other Extension Metadata

Last Modified Date

2015-11-28

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_wayland_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 Wayland wl_surface, as well as a query to determine support for rendering to a Wayland compositor.

New Commands

• vkCreateWaylandSurfaceKHR
• vkGetPhysicalDeviceWaylandPresentationSupportKHR

New Structures

• VkWaylandSurfaceCreateInfoKHR

New Bitmasks

• VkWaylandSurfaceCreateFlagsKHR

New Enum Constants

• VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME
• VK_KHR_WAYLAND_SURFACE_SPEC_VERSION
• Extending VkStructureType:
  • VK_STRUCTURE_TYPE_WAYLAND_SURFACE_CREATE_INFO_KHR

Issues

1) Does Wayland need a way to query for compatibility between a particular physical device and a specific Wayland display? This would be a more general query than vkGetPhysicalDeviceSurfaceSupportKHR: if the Wayland-specific query returned VK_TRUE for a (VkPhysicalDevice, struct wl_display*) pair, then the physical device could be assumed to support presentation to any VkSurfaceKHR for surfaces on the display.

RESOLVED: Yes. vkGetPhysicalDeviceWaylandPresentationSupportKHR was added to address this issue.

2) Should we require surfaces created with vkCreateWaylandSurfaceKHR to support the VK_PRESENT_MODE_MAILBOX_KHR present mode?

RESOLVED: Yes. Wayland is an inherently mailbox window system and mailbox support is required for some Wayland compositor interactions to work as expected. While handling these interactions may be possible with VK_PRESENT_MODE_FIFO_KHR, it is much more difficult to do without deadlock and requiring all Wayland applications to be able to support implementations which only support VK_PRESENT_MODE_FIFO_KHR would be an onerous restriction on application developers.

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 vkGetPhysicalDeviceWaylandPresentationSupportKHR() to resolve issue #1.
  • Adjusted wording of issue #1 to match the agreed-upon solution.
  • Renamed window parameters to surface to match Wayland conventions.
• Revision 3, 2015-10-26 (Ian Elliott)
  • Renamed from VK_EXT_KHR_wayland_surface to VK_KHR_wayland_surface.
• Revision 4, 2015-11-03 (Daniel Rakos)
  • Added allocation callbacks to vkCreateWaylandSurfaceKHR.
• Revision 5, 2015-11-28 (Daniel Rakos)
  • Updated the surface create function to take a pCreateInfo structure.
• Revision 6, 2017-02-08 (Faith Ekstrand)
  • Added the requirement that implementations support VK_PRESENT_MODE_MAILBOX_KHR.
  • Added wording about interactions between vkQueuePresentKHR and the Wayland requests sent to the compositor.