* Vulkan 1.1 initial release. Bump API patch number and header version
number to 70 for this update. The patch number will be used for both
Vulkan 1.1 and Vulkan 1.0 updates, and continues to increment
continuously from the previous Vulkan 1.0.69 update.
NOTE: We are not publishing an updated 1.0.70 specification, or 1.1
reference pages, along with 1.1.70. There are still minor issues to work
out with those build targets. However, we will soon generate all three
types of documents as part of the regular spec update cycle.
NOTE: The GitHub KhronosGroup/Vulkan-Docs repository now maintains the
current specification in the `master` branch. The `1.0` branch is out of
date and will not be maintained, since we will be generating both 1.1
and 1.0 specifications from the `master` branch in the future.
Github Issues:
* Clarify how mapped memory ranges are flushed in
flink:vkFlushMappedMemoryRanges (public issue 127).
* Specify that <<synchronization-pipeline-stages, Pipeline Stages>> are a
list of tasks that each command performs, rather than necessarily being
discrete pieces of hardware that one task flows through. Add a
"`synchronization command`" pipeline type which all synchronization
command execute (it's just TOP + BOTTOM), with an explanatory note
(public issue 554).
Internal Issues:
* Regenerate all images used in the spec in Inkscape with a consistent
look-and-feel, and adjust image size attributes so they're all legible,
and not too large with respect to the spec body text (internal issue
701).
* Document in the <<extensions,extensions>> appendix and in the style
guide that `KHX` extensions are no longer supported or used in the
Vulkan 1.1 timeframe (internal issue 714).
* Remove the leftover equations_temp directory after PDF build completes
(internal issue 925).
* Update the <<credits, Credits (Informative)>> appendix to include
contributors to Vulkan 1.1, and to list them according to the API
version(s) they contributed to (internal issue 987).
* Add a NOTE to the introduction explaining that interfaces defined by
extensions which were promoted to Vulkan 1.1 are now expressed as
aliases of the Vulkan 1.1 type (internal issue 991).
* Instrument spec source conditionals so spec can be built with 1.1
features, extensions promoted to 1.1, or both (internal issues 992,
998).
* Modify the XML schema and tools to support explicit aliasing of types,
structures, and commands, and use this to express the promotion of 1.0
extensions to 1.1 core features, by making the extension interfaces
aliases of the core features they were promoted to. Mark up promoted
interfaces to allow still generating 1.0 + extension specifications
(internal issue 991).
* Platform names, along with corresponding preprocessor symbols to enable
extensions specific to those platforms, are now reserved in vk.xml using
the <platform> tag. Update the registry schema and schema specification
to match (internal issue 1011).
* Updated the <<textures-texel-replacement, Texel Replacement>> section to
clarify that reads from invalid texels for image resources result in
undefined values (internal issue 1014).
* Modify description of patch version so it continues to increment across
minor version changes (internal issue 1033).
* Clarify and unify language describing physical device-level core and
extension functionality in the <<fundamentals-validusage-extensions,
Valid Usage for Extensions>>, <<fundamentals-validusage-versions, Valid
Usage for Newer Core Versions>>, <<initialization-functionpointers
Command Function Pointers>>, <<initialization-phys-dev-extensions,
Extending Physical Device From Device Extensions>>
<<extended-functionality-instance-extensions-and-devices, Instance
Extensions and Device Extensions>> sections and for
flink:vkGetPhysicalDeviceImageFormatProperties2. This documents that
instance-level functionality is tied to the loader, and independent of
the ICD; physical device-level functionality is tied to the ICD, and
associated with device extensions; physical devices are treated more
uniformly between core and extensions; and instance and physical
versions can be different (internal issue 1048).
* Updated the <<commandbuffers-lifecycle, Command Buffer Lifecycle>>
section to clarify the ability for pending command buffers to transition
to the invalid state after submission, and add a command buffer
lifecycle diagram (internal issue 1050).
* Clarify that some flink:VkDescriptorUpdateTemplateCreateInfo parameters
are ignored when push descriptors are not supported (internal issue
1054).
* Specify that flink:vkCreateImage will return an error if the image is
too large, in a NOTE in the slink:VkImageFormatProperties description
(internal issue 1078).
* Remove near-duplicate NOTEs about when to query function pointers
dynamically in the <<initialization, Initialization>> chapter and
replace by extending the NOTE in the <<fundamentals-abi, Application
Binary Interface>> section (internal issue 1085).
* Restore missing references to "`Sparse Resource Features`" in the
flink:VkBufferCreateFlagBits description (internal issue 1086).
* Tidy up definitions of descriptor types in the `GL_KHR_vulkan_glsl`
specification, the <<descriptorsets, Resource Descriptors>> section and
its subsections, and the <<interfaces-resources-descset, Descriptor Set
Interface>> for consistency, reduction of duplicate information, and
removal of GLSL correspondance/examples (internal issue 1090).
* Correctly describe code:PrimitiveId as an Input for tessellation control
and evaluation shaders, not an Output (internal issue 1109).
* Relax the requirements on chroma offsets for nearest filtering in
<<textures-implict-reconstruction, Implicit Reconstruction>> (internal
issue 1116).
Other Issues:
* Clarify the intended relationship between specification language and
certain terms defined in the Khronos Intellectual Property Rights
policy. Specific changes include:
** Rewrote IP/Copyright preamble and introduction to better agree with
normative language both as laid out in the introduction, and the
Khronos IPR policy.
** Added notion of fully informative sections, which are now tagged with
"`(Informative)`" in their titles.
** Removed non-normative uses of the phrase "`not required`"
** Clarified the distinction between terms "`optional`" and "`not
required:`" as they relate to the IPR Policy, and updated specification
text to use terms consistent with the intent.
** Reduced additions to RFC 2119, and ensured the specification agreed
with the leaner language.
** Removed the terms "`hardware`", "`software`", "`CPU`", and "`GPU`" from
normative text.
** Moved several paragraphs that should not have been normative to
informative notes.
** Clarified a number of definitions in the Glossary.
** Updated the document writing guide to match new terminology changes.
* Explicitly state in the <<fundamentals-objectmodel-lifetime-acquire,
application memory lifetime>> language that that for objects other than
descriptor sets, a slink:VkDescriptorSetLayout object used in the
creation of another object (such as slink:VkPipelineLayout or
slink:VkDescriptorUpdateTemplateKHR) is only in use during the creation
of that object and can be safely destroyed afterwards.
* Updated the <<textures-scale-factor, Scale Factor Operation>> section to
use the ratio of anisotropy, rather than the integer sample rate, to
perform the LOD calculation. The spec still allows use of the sample
rate as the value used to calculate the LOD, but no longer requires it.
* Update `vulkan_ext.c` to include all platform-related definitions from
the Vulkan platform headers, following the split of the headers into
platform-specific and non-platform-specific files.
* Fix bogus anchor name in the <<commandbuffers, Command Buffers>> chapter
which accidentally duplicated an anchor in the pipelines chapter. There
were no reference to this anchor, fortunately.
* Add valid usage statement for slink:VkWriteDescriptorSet and
slink:VkCopyDescriptorSet requiring that the slink:VkDescriptorSetLayout
used to allocate the source and destination sets must not have been
destroyed at the time flink:vkUpdateDescriptorSets is called.
* Document mapping of subgroup barrier functions to SPIR-V, and clarify a
place where subgroupBarrier sounds like it's execution-only in the
standalone `GL_KHR_shader_subgroup` specification.
* Use an HTML stylesheet derived from the Asciidoctor `colony` theme, with
the default Arial font family replaced by the sans-serif Noto font
family.
* Numerous minor updates to README.adoc, build scripts, Makefiles, and
registry and style guide specifications to support Vulkan 1.1 outputs,
use them as defaults, and remove mention of `KHX` extensions, which are
no longer supported.
New Extensions:
* `VK_EXT_vertex_attrib_divisor`
* Bump API patch number and header version number to 67 for this update.
* Update copyright dates to 2018
Github Issues:
* Fix texture lookup functions in `GL_KHR_vulkan_glsl` specification
(public pull request 363).
* Clarify the state waited semaphores are left in when a call to
flink:vkQueuePresentKHR fails (public issue 572).
* Cleanup descriptions of slink:VkObjectTablePushConstantEntryNVX and
slink:VkObjectTableDescriptorSetEntryNVX (public issue 583)
* Remove redundant flink:vkCmdSetDiscardRectangleEXT valid usage
statements (public pull 586).
* Make dynamic state array length valid usage statements implicit for
flink:vkCmdSetViewportWScalingNV, flink:vkCmdSetDiscardRectangleEXT, and
flink:vkCmdSetViewport (public pull 589).
* Clarify meaning of window extent (0,0) in slink:VkSwapchainKHR for the
Windows and X11 platforms, in their respective extensions (public issue
590).
* Allow flink:vkGetPastPresentationTimingGOOGLE to return
ename:VK_INCOMPLETE (public issue 604).
* Add synchronization valid usage statements to flink:vkAcquireNextImage
(public pull 611).
* Fix some broken external links and internal xrefs (public pull 613).
* Clean up slink:VkViewport valid usage statements in the presence or
absence of relevant extensions (public pull 623).
* Remove
ename:VK_IMAGE_LAYOUT_DEPTH_READ_ONLY_STENCIL_ATTACHMENT_OPTIMAL_KHR
token from VK_KHR_maintenance2 from the non-extension VU path for
slink:VkGraphicsPipelineCreateInfo (public issue 628).
* Miscellaneous minor markup fixes - extension name strings (public pull
631), Notes (pull 633), queue names emitted by generator scripts (pull
634), block formatting in slink:VkDescriptorUpdateTemplateEntryKHR (pull
635), ename:VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_CUBIC_BIT_IMG (pull
641), quotes and apostrophes (pull 643),
* Miscellaneous minor grammar fixes (public pull 644).
* Fix markup macros so usage like ptext:*Src* works (public pull 647).
Internal Issues:
* Clarify in the `VK_KHR_surface` and `VK_KHR_swapchain` extensions that
parameter combinations which aren't supported for normal images are also
unsupported for presentable images, even if the parameter values are
individually supported as reported by the surface capability queries
(internal issue 1029).
* Fixed XML typo in the valid value field of the pname:sType member of
slink:VkPhysicalDeviceExternalMemoryHostPropertiesEXT (internal issue
1100).
Other Issues:
* Add memory semantics validity rules to the <<spirvenv-module-validation,
Validation Rules within a Module>> section of the SPIR-V environment
appendix, and specify that sequentiality consistency is not supported.
This forbids certain cases like "`Load+Release`" that we don't expect to
ever be meaningful.
* Document mapping of OpenGL Shading Language barriers to SPIR-V scope and
semantics in the `GL_KHR_vulkan_glsl` specification.
New Extensions:
* `VK_EXT_conservative_rasterization`
* Bump API patch number and header version number to 66 for this update.
Github Issues:
* Clarified how and when ename:VK_ERROR_TOO_MANY_OBJECTS is generated in
flink:vkAllocate Memory, and remove incorrect valid usage statement
about exceeding the API limit (public issue 356).
* Minor clarification of the description of
flink:vkUpdateDescriptorSetWithTemplateKHR::pname:descriptorUpdateTemplate
(public issue 564).
* Minor fixes for flink:vkCmdSetViewportWScalingNV (public pull request
588).
* Fix random name markup issues (public pull request 603).
* Fix code:BuiltIn decoration typo in the <<fxvertex-attrib, Vertex
Attributes>> section (public pull request 606).
* Fix synchronization language following the definition of
flink:vkAcquireNextImageKHR (public issue 607).
* Restore descriptions of several commands and structures missing from the
generated spec due to a mistyped asciidoctor conditional (public issue
612).
* Fix 1.0.41 changelog to refer to public issues 403/404 (public issue
618).
Internal Issues:
* Refactor valid usage statements with internal conditionals in
`copies.txt`, `pipelines.txt`, `renderpass.txt`, and `resources.txt` so
each branch of the conditional appears as a standalone statement which
can contain a separate VUID. This should have no impact on the generated
specs, but is necessary given the present state of the VU extractor and
the validation layer code that consumes them (internal issue 1043).
* Fix VkQueueGlobalPriorityEXT enum values missing _EXT suffix (internal
issue 1045).
* Clarified initial ownership of resources bound to shared memory objects,
(internal issue 1068).
* Fix duplicated valid usage ID tag for flink:vkCmdCopyImage, and make the
required layouts include ename:VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIONAL in
both cases (internal issue 1084).
Other Issues:
* Remove the noise functions from GLSL for SPIR-V for Vulkan in the
`GL_KHR_vulkan_glsl.txt` extension.
New Extensions:
* `VK_EXT_external_memory_host`
* `VK_EXT_external_memory_dma_buf`
* `VK_EXT_queue_family_foreign`
- add missing `*name` and `*link` and `code`
- change where wrong macro was used
- swap `*name` and `*link` where appropriate
- correct misspelled names
- that sort of thing...
* Bump API patch number and header version number to 61 for this update.
Github Issues:
* Provide alternate length attributes (altlen=) in the XML schema, for
those using length attributes to generate code instead of documentation
(public issue 555).
* Fix erroneous references to `latex:` being used for asciidoc math
markup, rather than `latexmath:` (public pull request 556).
* Add author ID to XML for Kazan software renderer (public pull request
557).
Internal Issues:
* Add the <<fundamentals-abi,Application Binary Interface>> section
describing platform ABI requirements and recommendations, add examples
of function and function pointer declarations to the
<<boilerplate-platform-specific-calling-conventions, Platform-Specific
Calling Conventions>> section, and remove related language that existed
elsewhere in the specification (internal issue 64).
* Describe where to document valid usage interactions of chained
structures in the style guide, and fix one case now appearing in
slink:VkBufferCreateInfo instead of the child
slink:VkDedicatedAllocationBufferCreateInfoNV structure (internal issue
715).
* Add example to the style guide of describing enumerated types which are
empty when the spec is built without relevant extensions enabled, and
apply it to existing examples for
elink:VkDescriptorSetLayoutCreateFlagBits and
elink:VkSubpassDescriptionFlagBits (internal issue 864).
* Add a note to the <<fundamentals-validusage-enums, Valid Usage for
Enumerated Types>> section that the special values suffixed with
etext:_BEGIN_RANGE, etext:_END_RANGE, etext:_RANGE_SIZE and
etext:_MAX_ENUM are not part of the API and should: not be used by
applications (internal issue 872).
* Added note to flink:vkCmdUpdateBuffers explaining the performance
penalty for copies done in this way, and why the upper copy limit is
what it is (internal issue 952).
* Update `VK_KHX_device_group` to split some functionality into the new
`VK_KHR_bind_memory2` extension, and rename that functionality (internal
issue 969).
* Remove *Status* fields from extension appendices, since they are by
definition published and complete by the time they reach the public
github repository (internal issue 973).
Other Issues:
* Update Data Format specification dependency to version 1.2 and change
references to DF sections accordingly.
* Update XML to make the pname:pAllocator parameter of
flink:vkRegisterDeviceEventEXT and flink:vkRegisterDisplayEventEXT in
the `VK_EXT_display_control` extension as optional.
New Extensions:
* `VK_KHR_bind_memory2`
* `VK_KHR_image_format_list`
* `VK_KHR_maintenance2`
* `VK_KHR_sampler_ycbcr_conversion`
* Bump API patch number and header version number to 60 for this update.
Github Issues:
* Document that <<queries-timestamps, Timestamp Queries>> can only be
meaningfully compared when they are written from the same queue (public
issue 216).
* Document that the `<extension>` tag `type` attribute is required for
non-disabled extensions (derived from, but does not close public issue
354).
* Clean up registry schema length attribute descriptions to be consistent
and correct (public issue 555).
Internal Issues:
* Replace as much of the hand-written extension appendix metadata as
possible with asciidoc includes generated from corresponding attributes
of +vk.xml+, and enhance the style guide to match. This avoids
inconsistencies between +vk.xml+ and the appendices, and produces a more
uniform style (internal issue 137).
* Remove the generated extDependency.{py,sh} files from the tree and
create them dynamically on demand instead, reducing merge conflicts
(internal issue 713).
* Add a prototype tool for generating in-place difference markup for
sections guarded by asciidoc conditionals, and new syntax for open
blocks to support it (internal issue 833).
* Remove unnecessary restriction of etext:*SYNC_FD_BIT_KHR external handle
types to the same physical device in the
slink:VkPhysicalDeviceIDPropertiesKHR,
flink:VkImportMemoryWin32HandleInfoKHR,
slink:VkImportFenceWin32HandleInfoKHR, slink:VkImportFenceFdInfoKHR,
slink:VkImportSemaphoreWin32HandleInfoKHR,
slink:VkImportSemaphoreFdInfoKHR
<<external-memory-handle-types-compatibility, External memory handle
types compatibility>>, <<external-semaphore-handle-types-compatibility,
External semaphore handle types compatibility>>, and
<<external-fence-handle-types-compatibility, External fence handle types
compatibility>> sections (internal issue 956).
Other Issues:
* Remove dependency of +VK_KHX_device_group+ on +VK_KHR_swapchain+ (there
is an interaction, but not a strict dependency), and add a new
`extension` attribute to the `<require` XML tag to allow classifying a
subset of interfaces of an extension as requiring another extension.
Update the registry schema and documentation accordingly.
New Extensions:
* `VK_AMD_shader_fragment_mask` (and related `GL_AMD_shader_fragment_mask`
GLSL extension)
* `VK_EXT_sample_locations`
* `VK_EXT_validation_cache`
* Bump API patch number and header version number to 54 for this update.
Github Issues:
Internal Issues:
* Fix tessellation domain to have an upper-left origin in the
<<img-tessellation-topology-ul, tessellation toplogy image>> and related
language. CTS and all implementations were already doing this, it was
just a documentation bug that it was flipped to lower-left (internal
issue 603).
* Add a section to the style guide describing how VUID tags are changed
and removed when the corresponding Valid Usage statements are modified
(internal issue 829).
* Add explicit Valid Usage statement to
slink:VkPipelineDynamicStateCreateInfo to require that members of
pname:pDynamicStates must be unique (internal issue 851).
New Extensions:
* `VK_KHR_16bit_storage`
* `VK_KHR_dedicated_allocation`
* `VK_KHR_external_fence`
* `VK_KHR_external_fence_capabilities`
* `VK_KHR_external_fence_fd`
* `VK_KHR_external_fence_win32`
* `VK_KHR_get_memory_requirements2`
* `VK_KHR_storage_buffer_storage_class`
* `VK_KHR_variable_pointers`
Extensions Promoted From KHX To KHR Status:
* `VK_KHR_external_memory`
* `VK_KHR_external_memory_capabilities`
* `VK_KHR_external_memory_fd`
* `VK_KHR_external_memory_win32`
* `VK_KHR_external_semaphore`
* `VK_KHR_external_semaphore_capabilities`
* `VK_KHR_external_semaphore_fd`
* `VK_KHR_external_semaphore_win32`
* `VK_KHR_win32_keyed_mutex`
* Bump API patch number and header version number to 53 for this update.
Github Issues:
Internal Issues:
* Clarify mappings of coordinates for mutable, compatible image views in
slink:VkImageViewCreateInfo (internal issue 815).
* Make ename:VK_BIND_SFR_BIT require a logical device with multiple
physical devices, so that standard sparse image block dimensions are
only required on systems that support multi-GPU (internal issue 835).
* Convert all files from use of // refBegin .. // refEnd comments to
delimit ref pages, to use of open blocks, and update style guide
accordingly (internal issue 839).
* Add valid usage for slink:VkWriteDescriptorSet when performing updates
to a ename:VK_STORAGE_IMAGE descriptor with layout
ename:VK_IMAGE_LAYOUT_GENERAL.
* Add a hack to the validity generator script to support an odd
interaction between flink:vkCmdFillBuffer and an extension (internal
issue 853).
* Remove redundant text describing slink:VkBufferCreateInfo::pname:usage,
which was already covered by implicit valid usage (internal issue 854).
* Update implicit validity generator script to properly handle the
pname:sType and pname:pNext members of "returnedonly" structures
(internal issue 874).
* Note that slink:VkApplicationInfo::pname:pApplicationName &
slink:VkApplicationInfo::pname:pEngineName are optional, and add missing
implicit valid usage statements for flink:vkDestroyInstance.
* Added missing valid usage for flink:vkCmdWriteTimestamp to require a
timestamp query pool.
* Simplify and/or split "`non-atomic`" valid usage statements.
New Extensions:
* `VK_AMD_gpu_shader_int16`
* `VK_EXT_blend_operation_advanced`
* `VK_EXT_sampler_filter_minmax`
* `VK_NV_framebuffer_mixed_samples`
-----------------------------------------------------
Note: the 1.0.52 spec wasn't published on github, so the 1.0.53 release
combines both change sets.
-----------------------------------------------------
Change log for June 13, 2017 Vulkan 1.0.52 spec update:
* Bump API patch number and header version number to 52 for this update.
Github Issues:
Internal Issues:
* Clarify behavior when non-coherent memory has
<<memory-device-unmap-does-not-flush, not been flushed before being
unmapped>> (internal issue 819).
* Fix description of code:WorkgroupSize builtin to note it decorates an
object, not a variable (internal issue 836).
* Fix asciidoc attributes so that trailing '{plus}' symbols in [eq] style
equations are rendered properly (internal issue 845).
* Add language to the "`Extension Handles, Objects, Enums, and Typedefs`"
section of the Procedures and Conventions document stating that any new
handle type requires a corresponding entry in the elink:VkObjectType
enumerated type (internal issue 856).
* Update style guide to use slink macro for Vulkan handle type names, and
define narrow conditions under which to use the *name and *text macros
instead of *link (internal issue 886).
* Add a dependency of the <<VK_KHX_device_group,VK_KHX_device_group>>
extension on VK_KHX_device_group_creation to +vk.xml+ and the extension
appendix.
* Change the copyright on Vulkan specification asciidoc *source* files to
CC-BY 4.0, and update the proprietary Khronos copyright applied to the
generated *output* formats (internal issue 327). This enables broader
re-use and modification of the Vulkan specification sources, while not
affecting the Reciprocal IP License between Vulkan Adopters and Working
Group Members.
New Extensions:
* `VK_NV_fill_rectangle`
* `VK_NV_fragment_coverage_to_color`
* Bump API patch number and header version number to 39 for this update.
Github Issues:
* Clarified that only accesses via the specified buffer/image subresource
ranges are included in the access scopes (public issue 306).
* Add missing valid usage statements for flink:vkCreateComputePipelines
and flink:vkCreateGraphicsPipelines (public issue 427).
Internal Issues:
* Add a Note to the <<invariance,Invariance>> appendix about a difference
between OpenGL and Vulkan with regards to how primitives derived from
offsets are handled (internal issue 355).
* Add the +<<VK_KHR_get_physical_device_properties2>>+,
+<<VK_KHR_maintenance1>>+, and +<<VK_KHR_shader_draw_parameters>>+
extensions (internal issue 448).
* Add the +<<VK_EXT_shader_subgroup_vote>>+ and
+<<VK_EXT_shader_subgroup_ballot>>+ extensions (internal issue 449).
* Update the texture level-of-detail equation in the
<<textures-scale-factor,Scale Factor Operation>> section to better
approximate the ellipse major and minor axes (internal issue 547).
* Forbid non-explicitly allowed uses of interface decorations in the
introduction to the <<interfaces,Shader Interfaces>> chapter (internal
issue 607).
* Replace use of MathJax with KaTeX, for improved load-time performance as
well as avoiding the scrolling-and-scrolling behavior due to MathJax
asynchronous rendering when loading at an anchor inside the spec. This
change also requires moving to HTML5 output for the spec instead of
XHTML, and there is a visible difference in that the chapter navigation
index is now in a scrollable sidebar instead of at the top of the
document. We may or may not retain the nav sidebar based on feedback
(internal issue 613).
* Improve consistency of markup and formatting in extension appendices
(internal issue 631).
Other Issues:
* Add explicit valid usage statements to slink:VkImageCopy requiring that
the source and destination layer ranges be contained in their respective
source and destination images.
* Add valid usage language for swapchain of flink:vkAcquireNextImage. If
the swapchain has been replaced, then it should not be passed to
flink:vkAcquireNextImage.
* Add a valid usage statement to flink:vkCreateImageView, that the image
must have been created with an appropriate usage bit set.
* Noted that slink:VkDisplayPresentInfoKHR is a valid extension of
slink:VkPresentInfoKHR in the <<wsi_swapchain,WSI Swapchain>> section.
* Update valid usage for flink:vkCmdSetViewport and flink:vkCmdSetScissor
to account for the multiple viewport feature. If the feature is not
enabled, the parameters for these functions have required values that
are defined in the <<features-features-multiViewport,multiple
viewports>> section of the spec but were not reflected in the valid
usage text for these functions.
* Add the +<<VK_EXT_swapchain_colorspace>>+ extension defining common
color spaces.