* Update release number to 91.
Public Issues:
* Update Ubuntu subsystem build instructions in `BUILD.adoc` (public pull
request 624).
* Delete the `VK_KHR_mir_surface` extension from the Specification and
XML, due to EOL of the only driver known to have supported it, and
near-EOL of Mir itself (public issue 814).
* Fix options for some figures that were using old ones (public pull
request 841).
* Fix various accidentally repeated words (public pull request 843).
* Use `time.process_time()`, introduced in Python 3.3, in the scripts
instead of `time.clock()`, which will be removed in Python 3.8 (public
pull request 844).
Internal Issues:
* Update valid usage statements for
`VK_ANDROID_external_memory_android_hardware_buffer` in
slink:VkMemoryAllocateInfo,
slink:VkImportAndroidHardwareBufferInfoANDROID, and
flink:vkGetAndroidHardwareBufferPropertiesANDROID to actually be
verifiable (internal issue 1419).
* Update valid usage statements for
`VK_ANDROID_external_memory_android_hardware_buffer` in
slink:VkMemoryAllocateInfo, slink:VkImageCreateInfo, and
slink:VkImageViewCreateInfo to move valid usage statements in
doubly-nested bullet points up one level, accomodating limitations of
the valid usage extraction script that creates `validusage.json`
(internal issue 1434).
* Fix typo etext:VK_ACCESS_SHADING_RATE_IMAGE_BIT_NV to the correct
ename:VK_ACCESS_SHADING_RATE_IMAGE_READ_BIT_NV.
* Add missing etext:VK_STRUCTURE_TYPE_* tokens to appendices for
extensions missing them.
New Extensions:
* `VK_AMD_memory_overallocation_behavior`
* `VK_NV_ray_tracing`, replacing `VK_NVX_raytracing`
* Update release number to 87.
Public Issues:
* Merge flink:vkCmdPipelineBarrier self-dependency barrier VUs referring
to the same subpass dependency (public pull request 756).
* Describe default value of `"optional"` attribute in the registry schema
document (public issue 769)
* Fix links in <<VK_NVX_raytracing>> extension (public pull request 805).
* Mark the <<VK_KHR_mir_surface>> extension obsolete (see public issue 814
- does not close this, however).
* Fix missing endif in Image Creation block (public issue 817).
Internal Issues:
* Clarify that the compressed texture formats corresponding to
<<features-features-textureCompressionETC2>>,
<<features-features-textureCompressionASTC_LDR>>, and
<<features-features-textureCompressionBC>> is not contingent on the
feature bits, and may be supported even if the features are not enabled
(internal issue 663).
* Clarify that code:FragStencilRefEXT is output only in the
<<interfaces-builtin-variables, Built-In Variables>> section (internal
issue 1173).
* Identify and correct many overly-aggressive uses of "`undefined`", and
narrow them down, where straightforward to do so. Mark such resolved
uses of "`undefined`" with the custom undefined: macro. Add a new
<<writing-undefined, Describing Undefined Behavior>> section (internal
issue 1267).
* Don't require code:inline_uniform_block descriptors to be populated
before use in the flink:vkAllocateDescriptorSets section (internal issue
1380).
* Allow suppressing inline SVG images by controlling this with an
attribute set in the Makefile, rather than the explicit [%inline]
directive (internal issue 1391).
* Mark 'Khronos' as a registered trademark in several places, now that it
is one.
* Fix typo in the <<VK_KHR_shader_atomic_int64>> appendix using the GLSL
naming of the compare exchange op when referring to the SPIR-V op.
* Specify in the flink:vkGetPhysicalDeviceQueueFamilyProperties section
that all implementations must support at least one queue family, and
that every queue family must contain at least one queue.
* Make slink:VkPipelineDynamicStateCreateInfo::pname:dynamicStateCount,
slink:VkSampleLocationsInfoEXT::pname:sampleLocationsPerPixel, and
slink:VkSampleLocationsInfoEXT::pname:sampleLocationsCount optional, to
fix bogus implicit valid usage checks that were causing failures in the
conformance tests.
* Fix vendor tag in reserved extension 237 constants. Does not affect
anything since it's just a placeholder, but this should avoid further
comments.
* Minor markup fixes in some extension appendices.
New Extensions:
* `<<VK_FUCHSIA_imagepipe_surface>>`
associated material at the top level, vk.xml and associated material in
xml/, and generated include and source files in include/vulkan/ and
src/ext_loader/, respectively (public issue 436).
Jon Leech