// 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/

[[platformCreateSurface_wayland,platformCreateSurface_wayland]]

=== Wayland Platform

[open,refpage='vkCreateWaylandSurfaceKHR',desc='Create a slink:VkSurfaceKHR object for a Wayland window',type='protos']
--

To create a sname:VkSurfaceKHR object for a Wayland surface, call:

include::../../api/protos/vkCreateWaylandSurfaceKHR.txt[]

  * pname:instance is the instance to associate the surface with.
  * pname:pCreateInfo is a pointer to an instance of the
    slink:VkWaylandSurfaceCreateInfoKHR structure containing parameters
    affecting the creation of the surface object.
  * pname:pAllocator is the allocator used for host memory allocated for the
    surface object when there is no more specific allocator available (see
    <<memory-allocation,Memory Allocation>>).
  * pname:pSurface points to a slink:VkSurfaceKHR handle in which the
    created surface object is returned.

include::../../validity/protos/vkCreateWaylandSurfaceKHR.txt[]
--

[open,refpage='VkWaylandSurfaceCreateInfoKHR',desc='Structure specifying parameters of a newly created Wayland surface object',type='structs']
--

The sname:VkWaylandSurfaceCreateInfoKHR structure is defined as:

include::../../api/structs/VkWaylandSurfaceCreateInfoKHR.txt[]

  * pname:sType is the type of this structure.
  * pname:pNext is `NULL` or a pointer to an extension-specific structure.
  * pname:flags is reserved for future use.
  * pname:display and pname:surface are pointers to the Wayland
    code:wl_display and code:wl_surface to associate the surface with.

.Valid Usage
****
  * [[VUID-VkWaylandSurfaceCreateInfoKHR-display-01304]]
    pname:display must: point to a valid Wayland code:wl_display.
  * [[VUID-VkWaylandSurfaceCreateInfoKHR-surface-01305]]
    pname:surface must: point to a valid Wayland code:wl_surface.
****

include::../../validity/structs/VkWaylandSurfaceCreateInfoKHR.txt[]
--

On Wayland, pname:currentExtent is undefined [eq]#(0xFFFFFFFF, 0xFFFFFFFF)#.
Whatever the application sets a swapchain's pname:imageExtent to will be the
size of the window, after the first image is presented.
pname:minImageExtent is [eq]#(1,1)#, and pname:maxImageExtent is the maximum
supported surface size.
Any calls to flink:vkGetPhysicalDeviceSurfacePresentModesKHR on a surface
created with fname:vkCreateWaylandSurfaceKHR are required: to return
ename:VK_PRESENT_MODE_MAILBOX_KHR as one of the valid present modes.

Some Vulkan functions may: send protocol over the specified code:wl_display
connection when using a swapchain or presentable images created from a
sname:VkSurfaceKHR referring to a code:wl_surface.
Applications must: therefore ensure that both the code:wl_display and the
code:wl_surface remain valid for the lifetime of any sname:VkSwapchainKHR
objects created from a particular code:wl_display and code:wl_surface.
Also, calling flink:vkQueuePresentKHR will result in Vulkan sending
code:wl_surface.commit requests to the underlying code:wl_surface of each
sname:VkSwapchainKHR objects referenced by pname:pPresentInfo.
If the swapchain is created with a present mode of
ename:VK_PRESENT_MODE_MAILBOX_KHR or ename:VK_PRESENT_MODE_IMMEDIATE_KHR,
then the corresponding code:wl_surface.attach, code:wl_surface.damage, and
code:wl_surface.commit request must: be issued by the implementation during
the call to flink:vkQueuePresentKHR and must: not be issued by the
implementation outside of flink:vkQueuePresentKHR.
This ensures that any Wayland requests sent by the client after the call to
flink:vkQueuePresentKHR returns will be received by the compositor after the
code:wl_surface.commit.
Regardless of the mode of swapchain creation, a new code:wl_event_queue
must: be created for each successful flink:vkCreateWaylandSurfaceKHR call,
and every Wayland object created by the implementation must: be assigned to
this event queue.
If the platform provides Wayland 1.11 or greater, this must: be implemented
by the use of Wayland proxy object wrappers, to avoid race conditions.

If the application wishes to synchronize any window changes with a
particular frame, such requests must: be sent to the Wayland display server
prior to calling flink:vkQueuePresentKHR.
For full control over interactions between Vulkan rendering and other
Wayland protocol requests and events, a present mode of
ename:VK_PRESENT_MODE_MAILBOX_KHR should: be used.