* Bump API patch number and header version number to 28 for this update.
Github Issues:
* Minor spelling and typography cleanup, add definitions of
ename:VK_FALSE and ename:VK_TRUE as just what their names say
(public issues 220, 318, 325, 365; internal issues 451, 496)
* Clarify that the pname:maxDescriptorSet limits in the
<<features-limits-required,Required Limits>> table are n *
maxPerStage limit (where n=number of supported stages) (public issue
254).
* Minor cleanup to <<boilerplate-platform-macros,Platform-Specific
Macro Definitions>> appendix (public issue 314).
* Add valid usage statement to slink:VkPipelineLayoutCreateInfo
disallowing multiple push constant ranges for the same shader stage
(public issue 340).
* Clarify the elink:VkSharingMode description of what executing the
"same" barriers means in case of ownership transfer (public issue
347).
* Rename copyright.txt and add COPYING.md to try and reduce confusion
about applicable copyrights (public issue 350).
* Extend the table in the <<boilerplate-wsi-header, Window System-Specific
Header Control>> section to describe the external headers included when
each etext:VK_USE_PLATFORM_* macro is defined (public issue 376).
Internal Issues:
* Add "Revision History" to the PDF outputs following the table of
contents, to match HTML outputs (internal issue 43).
* Clarified that flink:vkMapMemory may fail due to virtual address
space limitations (internal issue 346).
* Add +refBody+ comment markup for ref page autoextraction when required
(internal issue 400).
* Document proper use of "mipmap" and "mip" in the style guide API
naming rules, matching the spelling rules (internal issue 471).
* Tweak the <<extensions,Layers and Extensions>> appendix to note that
the Specification may be built with arbitrary combinations of
extensions (internal issue 483).
* Remove incorrect statement allowing
slink:VkClearAttachment::pname:colorAttachment to be >=
slink:VkSubpassDescription::pname:colorAttachmentCount (internal
issue 488).
* The <<features-limits-viewportboundsrange,viewportBoundsRange>> is
expressed in terms of the pname:maxViewportDimensions but this is
actually two values. Clarify that it's based on the larger of the two
(if they differ) (internal issue 499).
Other Issues:
* Reflowed text of the entire spec using the 'reflow' Makefile gater,
to (hopefully) reduce future internal git churn as edits are made
and extensions added in return for one-time pain. This has no
perceptible change on the spec outputs but considerable changes on
the asciidoc source (internal issue 367).
* Bump API patch number and header version number to 27 for this update.
Github Issues:
* Weaken flink:vkGetPipelineCacheData invariance conditions; previous
conditions were stronger than agreed and can't be guaranteed (public
issue 280).
* Add link to "Vulkan Loader Specification and Architecture Overview"
document to Normative References section (public issue 359).
Internal Issues:
* Be more clear in the <<interfaces-resources-layout-std140, uniform
buffer layout>> section that block offsets can be out of order
(internal issue 396).
* Document that extension authors should add support for their extensions
to the validation layers (internal issue 398).
* Clarify that the valid range of depth clear values should be limited
to the 0..1 range and that copies to depth aspect must also be in this
range (internal issue 412).
* Specify ``a'' vs. ``an'' use in the style guide (internal issue 432).
* Increase the maximum pname:nonCoherentAtomSize value in the
<<features-limits-required,Required Limits>> section from 128 to 256
(internal issue 435).
* Fix vk_platform.h for compiler errors on some Android platforms
(internal issue 441).
* Clarify that slink:VkPhysicalDeviceFeatures::pname:pEnabledFeatures ==
`NULL` disables all features, including the "required" feature
pname:robustBufferAccess (internal issue 479).
Other Issues:
* Expand style guide and make it more self-consistent.
* Use ISO 8601 date format everywhere.
* Emphasise the correct way of using
slink:VkSurfaceCapabilitiesKHR::pname:maxImageCount.
* Added +VK_EXT_validation_flags+ extension for validation flag mechanism.
* Fix an <<credits,author credit>> to include their current employer.
Jon Leech