Change log for May 5, 2024 Vulkan 1.3.284 spec update:

Public Issues

  * Refactor "`proposals`" into a separate Antora component "`features`" and
    refer to published proposals more consistently as "`feature
    descriptions`" (public PR 2361).

Internal Issues

  * Partial synchronization with OpenXR scripts (internal MR 6419).
  * Refactor extensionmetadocgenerator.py to simplify adding new sections
    (internal MR 6624).
  * Restore structextends="VkPhysicalDeviceProperties2" back for
    VkPhysicalDeviceLegacyVertexAttributesPropertiesEXT (internal MR 6631).

New Extensions

  * VK_EXT_legacy_vertex_attributes

ChangeLog.adoc

@@ -14,6 +14,28 @@ appears frequently in the change log.
 
 '''
 
+Change log for May 5, 2024 Vulkan 1.3.284 spec update:
+
+Public Issues
+
+  * Refactor "`proposals`" into a separate Antora component "`features`" and
+    refer to published proposals more consistently as "`feature
+    descriptions`" (public PR 2361).
+
+Internal Issues
+
+  * Partial synchronization with OpenXR scripts (internal MR 6419).
+  * Refactor extensionmetadocgenerator.py to simplify adding new sections
+    (internal MR 6624).
+  * Restore structextends="VkPhysicalDeviceProperties2" back for
+    VkPhysicalDeviceLegacyVertexAttributesPropertiesEXT (internal MR 6631).
+
+New Extensions
+
+  * VK_EXT_legacy_vertex_attributes
+
+'''
+
 Change log for April 19, 2024 Vulkan 1.3.283 spec update:
 
 Public Issues

Makefile

@@ -138,7 +138,7 @@ VERBOSE =
 # ADOCOPTS options for asciidoc->HTML5 output
 
 NOTEOPTS     = -a editing-notes -a implementation-guide
-PATCHVERSION = 283
+PATCHVERSION = 284
 BASEOPTS     =
 
 ifneq (,$(findstring VKSC_VERSION_1_0,$(VERSIONS)))

appendices/VK_EXT_legacy_vertex_attributes.adoc

@@ -0,0 +1,47 @@
+// Copyright 2023-2024 The Khronos Group Inc.
+//
+// SPDX-License-Identifier: CC-BY-4.0
+
+include::{generated}/meta/{refprefix}VK_EXT_legacy_vertex_attributes.adoc[]
+
+=== Other Extension Metadata
+
+*Last Modified Date*::
+    2024-02-23
+*IP Status*::
+    No known IP claims.
+*Contributors*::
+  - Mike Blumenkrantz, Valve
+  - Piers Daniell, NVIDIA
+  - Spencer Fricke, LunarG
+  - Alyssa Rosenzweig, Valve
+
+=== Description
+
+This extension adds support for legacy features of (non-64-bit) vertex
+attributes as found in OpenGL:
+
+  - Vertex attributes loaded from arbitrary buffer alignments
+  - Vertex attributes using arbitrary strides
+  - Vertex attributes where the component data type of the binding does not
+    match the component numeric type of the shader input
+
+These features are only usable with dynamic vertex input.
+Unaligned loads of vertex attributes may incur performance penalties,
+indicated with a property.
+
+include::{generated}/interfaces/VK_EXT_legacy_vertex_attributes.adoc[]
+
+=== Issues
+
+1.) Should implementations convert float/integer values?
+
+*RESOLVED*: No.
+When fetching an integer data type from float values or float data types
+from integer values, the resulting shader values are
+implementation-dependent.
+
+=== Version History
+
+  * Revision 1, 2024-02-16 (Mike Blumenkrantz)
+  ** Initial revision

chapters/commonvalidity/draw_vertex_binding.adoc

@@ -102,6 +102,13 @@ ifdef::VK_EXT_vertex_input_dynamic_state[]
     the bound graphics pipeline state was created with the
     ename:VK_DYNAMIC_STATE_VERTEX_INPUT_EXT dynamic state enabled
 endif::VK_EXT_vertex_input_dynamic_state[]
+ifdef::VK_EXT_legacy_vertex_attributes[]
+    and either <<features-legacyVertexAttributes,
+    pname:legacyVertexAttributes>> is not enabled or the SPIR-V Type
+    associated with a given code:Input variable of the corresponding
+    code:Location in the code:Vertex {ExecutionModel} code:OpEntryPoint is
+    64-bit,
+endif::VK_EXT_legacy_vertex_attributes[]
     then the numeric type associated with all code:Input variables of the
     corresponding code:Location in the code:Vertex {ExecutionModel}
     code:OpEntryPoint must: be the same as

chapters/features.adoc

@@ -3804,6 +3804,30 @@ include::{generated}/validity/structs/VkPhysicalDeviceAttachmentFeedbackLoopDyna
 --
 endif::VK_EXT_attachment_feedback_loop_dynamic_state[]
 
+ifdef::VK_EXT_legacy_vertex_attributes[]
+[open,refpage='VkPhysicalDeviceLegacyVertexAttributesFeaturesEXT',desc='Structure describing compatibility features for vertex attributes',type='structs']
+--
+The sname:VkPhysicalDeviceLegacyVertexAttributesFeaturesEXT structure is
+defined as:
+
+include::{generated}/api/structs/VkPhysicalDeviceLegacyVertexAttributesFeaturesEXT.adoc[]
+
+This structure describes the following features:
+
+  * pname:sType is a elink:VkStructureType value identifying this structure.
+  * pname:pNext is `NULL` or a pointer to a structure extending this
+    structure.
+  * [[features-legacyVertexAttributes]] pname:legacyVertexAttributes
+    specifies whether compatibility features for vertex attributes are
+    supported when using dynamic vertex input state.
+
+:refpage: VkPhysicalDeviceLegacyVertexAttributesFeaturesEXT
+include::{chapters}/features.adoc[tag=features]
+
+include::{generated}/validity/structs/VkPhysicalDeviceLegacyVertexAttributesFeaturesEXT.adoc[]
+--
+endif::VK_EXT_legacy_vertex_attributes[]
+
 ifdef::VK_VERSION_1_3,VK_EXT_texture_compression_astc_hdr[]
 [open,refpage='VkPhysicalDeviceTextureCompressionASTCHDRFeatures',desc='Structure describing ASTC HDR features that can be supported by an implementation',type='structs',alias='VkPhysicalDeviceTextureCompressionASTCHDRFeaturesEXT']
 --
@@ -8449,6 +8473,10 @@ ifdef::VK_EXT_attachment_feedback_loop_dynamic_state[]
     `apiext:VK_EXT_attachment_feedback_loop_dynamic_state` extension is
     supported.
 endif::VK_EXT_attachment_feedback_loop_dynamic_state[]
+ifdef::VK_EXT_legacy_vertex_attributes[]
+  * <<features-legacyVertexAttributes, pname:legacyVertexAttributes>>, if
+    the `apiext:VK_EXT_legacy_vertex_attributes` extension is supported.
+endif::VK_EXT_legacy_vertex_attributes[]
 ifdef::VK_KHR_ray_tracing_position_fetch[]
   * <<features-rayTracingPositionFetch, pname:rayTracingPositionFetch>>, if
     the `apiext:VK_KHR_ray_tracing_position_fetch` extension is supported.

chapters/fxvertex.adoc

@@ -978,11 +978,22 @@ The numeric type of pname:format must: match the numeric type of the input
 variable in the shader.
 The input variable in the shader must: be declared as a 64-bit data type if
 and only if pname:format is a 64-bit data type.
-If pname:format is a packed format, `attribAddress` must: be a multiple of
-the size in bytes of the whole attribute data type as described in
+If
+ifdef::VK_EXT_legacy_vertex_attributes[]
+either pname:format is a 64-bit format or <<features-legacyVertexAttributes,
+pname:legacyVertexAttributes>> is not enabled, and
+endif::VK_EXT_legacy_vertex_attributes[]
+pname:format is a packed format, `attribAddress` must: be a multiple of the
+size in bytes of the whole attribute data type as described in
 <<formats-packed,Packed Formats>>.
-Otherwise, `attribAddress` must: be a multiple of the size in bytes of the
-component type indicated by pname:format (see <<formats,Formats>>).
+Otherwise,
+ifdef::VK_EXT_legacy_vertex_attributes[]
+if either pname:format is a 64-bit format or
+<<features-legacyVertexAttributes, pname:legacyVertexAttributes>> is not
+enabled,
+endif::VK_EXT_legacy_vertex_attributes[]
+`attribAddress` must: be a multiple of the size in bytes of the component
+type indicated by pname:format (see <<formats,Formats>>).
 For attributes that are not 64-bit data types, each component is converted
 to the format of the input variable based on its type and size (as defined
 in the <<formats-definition,Format Definition>> section for each

chapters/limits.adoc

@@ -1166,6 +1166,30 @@ include::{generated}/validity/structs/VkPhysicalDeviceSampleLocationsPropertiesE
 --
 endif::VK_EXT_sample_locations[]
 
+ifdef::VK_EXT_legacy_vertex_attributes[]
+[open,refpage='VkPhysicalDeviceLegacyVertexAttributesPropertiesEXT',desc='Structure describing properties for legacy vertex attributes',type='structs']
+--
+The sname:VkPhysicalDeviceLegacyVertexAttributesPropertiesEXT structure is
+defined as:
+
+include::{generated}/api/structs/VkPhysicalDeviceLegacyVertexAttributesPropertiesEXT.adoc[]
+
+This structure describes the following features:
+
+  * pname:sType is a elink:VkStructureType value identifying this structure.
+  * pname:pNext is `NULL` or a pointer to a structure extending this
+    structure.
+  * [[limits-nativeUnalignedPerformance]] pname:nativeUnalignedPerformance
+    specifies whether unaligned vertex fetches do not incur significant
+    performance penalties as compared to aligned fetches.
+
+:refpage: VkPhysicalDeviceLegacyVertexAttributesPropertiesEXT
+include::{chapters}/features.adoc[tag=features]
+
+include::{generated}/validity/structs/VkPhysicalDeviceLegacyVertexAttributesPropertiesEXT.adoc[]
+--
+endif::VK_EXT_legacy_vertex_attributes[]
+
 ifdef::VK_EXT_external_memory_host[]
 [open,refpage='VkPhysicalDeviceExternalMemoryHostPropertiesEXT',desc='Structure describing external memory host pointer limits that can be supported by an implementation',type='structs']
 --
@@ -5163,6 +5187,9 @@ ifdef::VK_EXT_sample_locations[]
 | pname:sampleLocationSubPixelBits           | - | 4   | min
 | pname:variableSampleLocations              | - |false| implementation-dependent
 endif::VK_EXT_sample_locations[]
+ifdef::VK_EXT_legacy_vertex_attributes[]
+| pname:nativeUnalignedPerformance              | - |false| implementation-dependent
+endif::VK_EXT_legacy_vertex_attributes[]
 ifdef::VK_EXT_external_memory_host[]
 | pname:minImportedHostPointerAlignment      | - | 65536 | max
 endif::VK_EXT_external_memory_host[]

proposals/VK_EXT_legacy_vertex_attributes.adoc

@@ -0,0 +1,73 @@
+// Copyright 2024 The Khronos Group Inc.
+//
+// SPDX-License-Identifier: CC-BY-4.0
+
+# VK_EXT_legacy_vertex_attributes
+:toc: left
+:refpage: https://registry.khronos.org/vulkan/specs/1.3-extensions/man/html/
+:sectnums:
+
+This document proposes adding legacy features for vertex attributes as found in OpenGL.
+
+## Problem Statement
+
+OpenGL allows three features that Vulkan explicitly prohibits:
+
+  - Vertex attributes loaded from arbitrary buffer alignments
+  - Vertex attributes using arbitrary strides
+  - Vertex attributes where the component data type of the binding does not match the component numeric type of the shader input
+
+This proposal aims to provide this legacy functionality for non-64-bit attributes.
+
+
+## Solution Space
+
+These legacy features can be emulated by rewriting vertex buffers and generating shader variants. Neither option
+is as optimal as having the underlying driver handle the functionality, where it may be a no-op.
+
+## Proposal
+
+### API Features
+
+The following features are exposed by this extension:
+
+[source,c]
+----
+typedef struct VkPhysicalDeviceLegacyVertexAttributesFeaturesEXT {
+    VkStructureType    sType;
+    void*              pNext;
+    VkBool32           legacyVertexAttributes;
+} VkPhysicalDeviceLegacyVertexAttributesFeaturesEXT;
+----
+
+`legacyVertexAttributes` is the core feature enabling this extension's functionality.
+
+The following properties are exposed by this extension:
+
+[source,c]
+----
+typedef struct VkPhysicalDeviceLegacyVertexAttributesPropertiesEXT {
+    VkStructureType    sType;
+    void*              pNext;
+    VkBool32           nativeUnalignedPerformance;
+} VkPhysicalDeviceLegacyVertexAttributesPropertiesEXT;
+----
+
+`nativeUnalignedPerformance` indicates that using unaligned vertex fetches on this implementation will not incur significant performance penalties.
+
+## Examples
+
+Enabling this feature allows the following example scenarios for a user with dynamic vertex input active:
+
+  - Binding a vertex buffer at offset=7
+  - Binding a VK_FORMAT_R32_UINT attribute with stride=1
+  - Binding a VK_FORMAT_R8_UINT attribute and reading it as signed `int` in a shader
+
+## Issues
+
+
+### RESOLVED: Should implementations convert float/integer values?
+
+No. When fetching an integer data type from float values or float
+data types from integer values, the resulting shader values are
+implementation-dependent.

scripts/cgenerator.py

@@ -243,7 +243,7 @@ def endFeature(self):
                 if self.genOpts.conventions is None:
                     raise MissingGeneratorOptionsConventionsError()
                 is_core = self.featureName and self.featureName.startswith(self.conventions.api_prefix + 'VERSION_')
-                if self.genOpts.conventions.writeFeature(self.featureExtraProtect, self.genOpts.filename):
+                if self.genOpts.conventions.writeFeature(self.featureName, self.featureExtraProtect, self.genOpts.filename):
                     self.newline()
                     if self.genOpts.protectFeature:
                         write('#ifndef', self.featureName, file=self.outFile)
@@ -507,7 +507,7 @@ def genCmd(self, cmdinfo, name, alias):
             self.appendSection('commandPointer', decls[1])
 
     def misracstyle(self):
-        return self.genOpts.misracstyle;
+        return self.genOpts.misracstyle
 
     def misracppstyle(self):
-        return self.genOpts.misracppstyle;
+        return self.genOpts.misracppstyle

scripts/check_spec_links.py

@@ -19,6 +19,7 @@
 from spec_tools.main import checkerMain
 from spec_tools.shared import (AUTO_FIX_STRING, EXTENSION_CATEGORY, MessageId,
                                MessageType)
+from apiconventions import APIConventions
 
 ###
 # "Configuration" constants
@@ -50,6 +51,33 @@
                     'int32_t', 'uint32_t',
                     'int64_t', 'uint64_t'))
 
+# Exceptions to:
+# error: Definition of link target {} with macro etext (used for category enums) does not exist. (-Wwrong_macro)
+# typically caused by using Vulkan-only enums in Vulkan SC blocks with "etext", or because they
+# are suffixed differently.
+CHECK_UNRECOGNIZED_ETEXT_EXCEPTIONS = (
+    "VK_COLORSPACE_SRGB_NONLINEAR_KHR",
+    "VK_COLOR_SPACE_DCI_P3_LINEAR_EXT",
+    "VK_PIPELINE_CACHE_CREATE_READ_ONLY_BIT",
+    "VK_STENCIL_FRONT_AND_BACK",
+    "VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_DRAW_PARAMETER_FEATURES",
+    "VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VARIABLE_POINTER_FEATURES",
+    "VK_STRUCTURE_TYPE_SURFACE_CAPABILITIES2_EXT",
+)
+
+# Exceptions to:
+# warning: Definition of link target {} with macro ename (used for category enums) does not exist. (-Wbad_enumerant)
+# typically caused by Vulkan SC enums not being recognized in Vulkan build
+CHECK_UNRECOGNIZED_ENAME_EXCEPTIONS = (
+    "VK_ERROR_INVALID_PIPELINE_CACHE_DATA",
+    "VK_ERROR_NO_PIPELINE_MATCH",
+    "VK_ERROR_VALIDATION_FAILED",
+    "VK_MEMORY_HEAP_SEU_SAFE_BIT",
+    "VK_PIPELINE_CACHE_CREATE_READ_ONLY_BIT",
+    "VK_PIPELINE_CACHE_CREATE_USE_APPLICATION_STORAGE_BIT",
+    "VK_PIPELINE_CACHE_HEADER_VERSION_SAFETY_CRITICAL_ONE",
+)
+
 ROOT = Path(__file__).resolve().parent.parent
 DEFAULT_DISABLED_MESSAGES = set((
     MessageId.LEGACY,
@@ -121,6 +149,12 @@ def perform_entity_check(self, type):
 
         return type != 'builtins' and type != 'spirv'
 
+    def shouldSkipUnrecognizedEntity(self, macro, entity_name):
+        """Return True if we should not warn about not recognizing a macro invocation for entity_name."""
+        if macro == "ename":
+            return entity_name in CHECK_UNRECOGNIZED_ENAME_EXCEPTIONS
+        return entity_name in CHECK_UNRECOGNIZED_ETEXT_EXCEPTIONS
+
     def handleWrongMacro(self, msg, data):
         """Report an appropriate message when we found that the macro used is incorrect.
 
@@ -157,15 +191,13 @@ def handleWrongMacro(self, msg, data):
     def allowEnumXrefs(self):
         """Returns True if enums can be specified in the 'xrefs' attribute
         of a refpage.
-
-        Overrides base class behavior. OpenXR does not allow this.
         """
         return True
 
 def makeMacroChecker(enabled_messages):
     """Create a correctly-configured MacroChecker instance."""
     entity_db = VulkanEntityDatabase()
-    return MacroChecker(enabled_messages, entity_db, VulkanMacroCheckerFile, ROOT)
+    return MacroChecker(enabled_messages, entity_db, VulkanMacroCheckerFile, ROOT, APIConventions)
 
 
 if __name__ == '__main__':