This extension adds a new VkFormatFeatureFlagBits2KHR 64bits format feature flag type to extend the existing VkFormatFeatureFlagBits which is limited to 31 flags. At the time of this writing 29 bits of VkFormatFeatureFlagBits are already used.

Because VkFormatProperties2 is already defined to extend the Vulkan 1.0 GetPhysicalDeviceFormatProperties entry point, this extension defines a new VkFormatProperties3KHR to extend the VkFormatProperties.

On top of replicating all the bits from VkFormatFeatureFlagBits, VkFormatFeatureFlagBits2KHR adds the following bits :

• FORMAT_FEATURE_2_STORAGE_READ_WITHOUT_FORMAT_BIT_KHR and FORMAT_FEATURE_2_STORAGE_WRITE_WITHOUT_FORMAT_BIT_KHR indicate that an implementation supports respectively reading and writing a given VkFormat through storage operations without specifying the format in the shader.
• FORMAT_FEATURE_2_SAMPLED_IMAGE_DEPTH_COMPARISON_BIT_KHR indicates that an implementation supports depth comparison performed by OpImage*Dref* instructions on a given VkFormat. Previously the result of executing a OpImage*Dref* instruction on an image view, where the format was not one of the depth/stencil formats with a depth component, was undefined. This bit clarifies on which formats such instructions can be used.

Prior to version 2 of this extension, implementations exposing the shaderStorageImageReadWithoutFormat and shaderStorageImageWriteWithoutFormat features may not report FORMAT_FEATURE_2_STORAGE_READ_WITHOUT_FORMAT_BIT_KHR and FORMAT_FEATURE_2_STORAGE_WRITE_WITHOUT_FORMAT_BIT_KHR in VkFormatProperties3KHR::bufferFeatures. Despite this, buffer reads/writes are supported as intended by the original features.

Promotion to Vulkan 1.3

Functionality in this extension is included in core Vulkan 1.3, with the KHR suffix omitted. The original type, enum and command names are still available as aliases of the core functionality.

VK_KHR_format_feature_flags2

Name String

VK_KHR_format_feature_flags2

Extension Type

Device extension

Registered Extension Number

361

Revision

2

Extension and Version Dependencies

VK_KHR_get_physical_device_properties2

Deprecation state

• Promoted to Vulkan 1.3

Contact

• Lionel Landwerlin llandwerlin

Other Extension Metadata

Last Modified Date

2021-07-01

Interactions and External Dependencies

• Promoted to Vulkan 1.3 Core

IP Status

No known IP claims.

Contributors

• Lionel Landwerlin, Intel
• Faith Ekstrand, Intel
• Tobias Hector, AMD
• Spencer Fricke, Samsung Electronics
• Graeme Leese, Broadcom
• Jan-Harald Fredriksen, ARM