// 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_swapchain_mutable_format.txt[]

*Last Modified Date*::
    2018-03-28
*IP Status*::
    No known IP claims.
*Contributors*::
  - Jason Ekstrand, Intel
  - Jan-Harald Fredriksen, ARM
  - Jesse Hall, Google
  - Daniel Rakos, AMD
  - Ray Smith, ARM

=== Short Description

Allows processing of swapchain images as different formats to that used by
the window system, which is particularly useful for switching between sRGB
and linear RGB formats.

=== Description

This extension adds a new swapchain creation flag that enables creating
image views from presentable images with a different format than the one
used to create the swapchain.

=== New Object Types

None.

=== New Enum Constants

  * Extending elink:VkSwapchainCreateFlagBitsKHR:
  ** ename:VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHR

=== New Enums

None.

=== New Structures

None.

=== New Functions

None.

=== Issues

1) Are there any new capabilities needed?

*RESOLVED*: No.
It is expected that all implementations exposing this extension support
swapchain image format mutability.

2) Do we need a separate etext:VK_SWAPCHAIN_CREATE_EXTENDED_USAGE_BIT_KHR?

*RESOLVED*: No.
This extension requires `VK_KHR_maintenance2` and presentable images of
swapchains created with ename:VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHR are
created internally in a way equivalent to specifying both
ename:VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT and
ename:VK_IMAGE_CREATE_EXTENDED_USAGE_BIT_KHR.

3) Do we need a separate structure to allow specifying an image format list
for swapchains?

*RESOLVED*: No.
We simply use the same slink:VkImageFormatListCreateInfoKHR structure
introduced by `VK_KHR_image_format_list`.
The structure is required to be included in the pname:pNext chain of
slink:VkSwapchainCreateInfoKHR for swapchains created with
ename:VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHR.


=== Version History

 * Revision 1, 2018-03-28 (Daniel Rakos)
   - Internal revisions.