VK_EXT_descriptor_indexing
Other Extension Metadata
Last Modified Date
2017-10-02
Interactions and External Dependencies
- This extension provides API support for
GL_EXT_nonuniform_qualifier
Contributors
- Jeff Bolz, NVIDIA
- Daniel Rakos, AMD
- Slawomir Grajewski, Intel
- Tobias Hector, Imagination Technologies
Description
This extension adds several small features which together enable
applications to create large descriptor sets containing substantially all of
their resources, and selecting amongst those resources with dynamic
(non-uniform) indexes in the shader.
There are feature enables and SPIR-V capabilities for non-uniform descriptor
indexing in the shader, and non-uniform indexing in the shader requires use
of a new NonUniformEXT
decoration defined in the
SPV_EXT_descriptor_indexing
SPIR-V extension.
There are descriptor set layout binding creation flags enabling several
features:
- Descriptors can be updated after they are bound to a command buffer, such that the execution of the command buffer reflects the most recent update to the descriptors.
- Descriptors that are not used by any pending command buffers can be updated, which enables writing new descriptors for frame N+1 while frame N is executing.
- Relax the requirement that all descriptors in a binding that is
statically used
must be valid, such that descriptors that are not accessed by a submission need not be valid and can be updated while that submission is executing. - The final binding in a descriptor set layout can have a variable size
(and unsized arrays of resources are allowed in the
GL_EXT_nonuniform_qualifier
andSPV_EXT_descriptor_indexing
extensions).
Note that it is valid for multiple descriptor arrays in a shader to use the same set and binding number, as long as they are all compatible with the descriptor type in the pipeline layout. This means a single array binding in the descriptor set can serve multiple texture dimensionalities, or an array of buffer descriptors can be used with multiple different block layouts.
There are new descriptor set layout and descriptor pool creation flags that
are required to opt in to the update-after-bind functionality, and there are
separate maxPerStage
* and maxDescriptorSet
* limits that apply to
these descriptor set layouts which may be much higher than the pre-existing
limits.
The old limits only count descriptors in non-updateAfterBind descriptor set
layouts, and the new limits count descriptors in all descriptor set layouts
in the pipeline layout.
New Structures
- Extending VkDescriptorSetAllocateInfo:
- Extending VkDescriptorSetLayoutCreateInfo:
- Extending VkDescriptorSetLayoutSupport:
- Extending VkPhysicalDeviceFeatures2, VkDeviceCreateInfo:
- Extending VkPhysicalDeviceProperties2:
New Enums
New Bitmasks
New Enum Constants
VK_EXT_DESCRIPTOR_INDEXING_EXTENSION_NAME
VK_EXT_DESCRIPTOR_INDEXING_SPEC_VERSION
- Extending VkDescriptorBindingFlagBits:
VK_DESCRIPTOR_BINDING_PARTIALLY_BOUND_BIT_EXT
VK_DESCRIPTOR_BINDING_UPDATE_AFTER_BIND_BIT_EXT
VK_DESCRIPTOR_BINDING_UPDATE_UNUSED_WHILE_PENDING_BIT_EXT
VK_DESCRIPTOR_BINDING_VARIABLE_DESCRIPTOR_COUNT_BIT_EXT
- Extending VkDescriptorPoolCreateFlagBits:
VK_DESCRIPTOR_POOL_CREATE_UPDATE_AFTER_BIND_BIT_EXT
- Extending VkDescriptorSetLayoutCreateFlagBits:
VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT_EXT
- Extending VkResult:
VK_ERROR_FRAGMENTATION_EXT
- Extending VkStructureType:
VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_BINDING_FLAGS_CREATE_INFO_EXT
VK_STRUCTURE_TYPE_DESCRIPTOR_SET_VARIABLE_DESCRIPTOR_COUNT_ALLOCATE_INFO_EXT
VK_STRUCTURE_TYPE_DESCRIPTOR_SET_VARIABLE_DESCRIPTOR_COUNT_LAYOUT_SUPPORT_EXT
VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DESCRIPTOR_INDEXING_FEATURES_EXT
VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DESCRIPTOR_INDEXING_PROPERTIES_EXT
Promotion to Vulkan 1.2
Functionality in this extension is included in core Vulkan 1.2, with the EXT
suffix omitted.
However, if Vulkan 1.2 is supported and this extension is not, the
descriptorIndexing
capability is optional.
The original type, enum, and command names are still available as aliases of
the core functionality.
Version History
- Revision 1, 2017-07-26 (Jeff Bolz)
- Internal revisions
- Revision 2, 2017-10-02 (Jeff Bolz)
- ???