VK_KHR_swapchain_mutable_format

Other Extension Metadata

Last Modified Date

2018-03-28

IP Status

No known IP claims.

Contributors

• Faith Ekstrand, Intel
• Jan-Harald Fredriksen, ARM
• Jesse Hall, Google
• Daniel Rakos, AMD
• Ray Smith, ARM

Description

This extension 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.

It 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 Enum Constants

• VK_KHR_SWAPCHAIN_MUTABLE_FORMAT_EXTENSION_NAME
• VK_KHR_SWAPCHAIN_MUTABLE_FORMAT_SPEC_VERSION
• Extending VkSwapchainCreateFlagBitsKHR:
  • VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHR

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 VK_SWAPCHAIN_CREATE_EXTENDED_USAGE_BIT_KHR?

RESOLVED: No. This extension requires VK_KHR_maintenance2 and presentable images of swapchains created with VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHR are created internally in a way equivalent to specifying both VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT and 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 VkImageFormatListCreateInfoKHR structure introduced by VK_KHR_image_format_list. The structure is required to be included in the pNext chain of VkSwapchainCreateInfoKHR for swapchains created with VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHR.

Version History

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