2698 lines
113 KiB
Plaintext
2698 lines
113 KiB
Plaintext
// Copyright (c) 2015-2017 The Khronos Group Inc.
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// Copyright notice at https://www.khronos.org/registry/speccopyright.html
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[[descriptorsets]]
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= Resource Descriptors
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Shaders access buffer and image resources by using special shader variables
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which are indirectly bound to buffer and image views via the API.
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These variables are organized into sets, where each set of bindings is
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represented by a _descriptor set_ object in the API and a descriptor set is
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bound all at once.
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A _descriptor_ is an opaque data structure representing a shader resource
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such as a buffer view, image view, sampler, or combined image sampler.
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The content of each set is determined by its _descriptor set layout_ and the
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sequence of set layouts that can: be used by resource variables in shaders
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within a pipeline is specified in a _pipeline layout_.
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Each shader can: use up to pname:maxBoundDescriptorSets (see
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<<features-limits, Limits>>) descriptor sets, and each descriptor set can:
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include bindings for descriptors of all descriptor types.
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Each shader resource variable is assigned a tuple of (set number, binding
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number, array element) that defines its location within a descriptor set
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layout.
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In GLSL, the set number and binding number are assigned via layout
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qualifiers, and the array element is implicitly assigned consecutively
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starting with index equal to zero for the first element of an array (and
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array element is zero for non-array variables):
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.GLSL example
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[source,glsl]
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---------------------------------------------------
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// Assign set number = M, binding number = N, array element = 0
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layout (set=M, binding=N) uniform sampler2D variableName;
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// Assign set number = M, binding number = N for all array elements, and
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// array element = I for the I'th member of the array.
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layout (set=M, binding=N) uniform sampler2D variableNameArray[I];
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---------------------------------------------------
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.SPIR-V example
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[source,spirv]
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---------------------------------------------------
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// Assign set number = M, binding number = N, array element = 0
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %10 "variableName"
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OpDecorate %10 DescriptorSet M
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OpDecorate %10 Binding N
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeFloat 32
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%7 = OpTypeImage %6 2D 0 0 0 1 Unknown
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%8 = OpTypeSampledImage %7
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%9 = OpTypePointer UniformConstant %8
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%10 = OpVariable %9 UniformConstant
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...
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// Assign set number = M, binding number = N for all array elements, and
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// array element = I for the I'th member of the array.
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %13 "variableNameArray"
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OpDecorate %13 DescriptorSet M
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OpDecorate %13 Binding N
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeFloat 32
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%7 = OpTypeImage %6 2D 0 0 0 1 Unknown
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%8 = OpTypeSampledImage %7
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%9 = OpTypeInt 32 0
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%10 = OpConstant %9 I
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%11 = OpTypeArray %8 %10
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%12 = OpTypePointer UniformConstant %11
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%13 = OpVariable %12 UniformConstant
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...
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---------------------------------------------------
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[[descriptorsets-types]]
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== Descriptor Types
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The following sections outline the various descriptor types supported by
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Vulkan.
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Each section defines a descriptor type, and each descriptor type has a
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manifestation in the shading language and SPIR-V as well as in descriptor
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sets.
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There is mostly a one-to-one correspondence between descriptor types and
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classes of opaque types in the shading language, where the opaque types in
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the shading language must: refer to a descriptor in the pipeline layout of
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the corresponding descriptor type.
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But there is an exception to this rule as described in
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<<descriptorsets-combinedimagesampler,Combined Image Sampler>>.
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[[descriptorsets-storageimage]]
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=== Storage Image
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A _storage image_ (ename:VK_DESCRIPTOR_TYPE_STORAGE_IMAGE) is a descriptor
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type that is used for load, store, and atomic operations on image memory
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from within shaders bound to pipelines.
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Loads from storage images do not use samplers and are unfiltered and do not
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support coordinate wrapping or clamping.
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Loads are supported in all shader stages for image formats which report
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support for the
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<<features-formats-properties,ename:VK_FORMAT_FEATURE_STORAGE_IMAGE_BIT>>
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feature bit via flink:vkGetPhysicalDeviceFormatProperties.
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Stores to storage images are supported in compute shaders for image formats
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which report support for the ename:VK_FORMAT_FEATURE_STORAGE_IMAGE_BIT
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feature.
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Storage images also support atomic operations in compute shaders for image
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formats which report support for the
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<<features-formats-properties,ename:VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT>>
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feature.
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Load and store operations on storage images can: only be done on images in
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the
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ifdef::VK_KHR_shared_presentable_image[]
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ename:VK_IMAGE_LAYOUT_SHARED_PRESENT_KHR or
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endif::VK_KHR_shared_presentable_image[]
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ename:VK_IMAGE_LAYOUT_GENERAL layout.
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When the <<features-features-fragmentStoresAndAtomics,
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pname:fragmentStoresAndAtomics>> feature is enabled, stores and atomic
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operations are also supported for storage images in fragment shaders with
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the same set of image formats as supported in compute shaders.
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When the <<features-features-vertexPipelineStoresAndAtomics,
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pname:vertexPipelineStoresAndAtomics>> feature is enabled, stores and atomic
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operations are also supported in vertex, tessellation, and geometry shaders
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with the same set of image formats as supported in compute shaders.
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Storage image declarations must: specify the image format in the shader if
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the variable is used for atomic operations.
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If the <<features-features-shaderStorageImageReadWithoutFormat,
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pname:shaderStorageImageReadWithoutFormat>> feature is not enabled, storage
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image declarations must: specify the image format in the shader if the
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variable is used for load operations.
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If the <<features-features-shaderStorageImageWriteWithoutFormat,
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pname:shaderStorageImageWriteWithoutFormat>> feature is not enabled, storage
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image declarations must: specify the image format in the shader if the
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variable is used for store operations.
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Storage images are declared in GLSL shader source using uniform code:image
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variables of the appropriate dimensionality as well as a format layout
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qualifier (if necessary):
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.GLSL example
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[source,glsl]
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---------------------------------------------------
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layout (set=m, binding=n, r32f) uniform image2D myStorageImage;
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---------------------------------------------------
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.SPIR-V example
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[source,spirv]
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---------------------------------------------------
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %9 "myStorageImage"
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OpDecorate %9 DescriptorSet m
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OpDecorate %9 Binding n
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeFloat 32
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%7 = OpTypeImage %6 2D 0 0 0 2 R32f
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%8 = OpTypePointer UniformConstant %7
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%9 = OpVariable %8 UniformConstant
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...
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---------------------------------------------------
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[[descriptorsets-sampler]]
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=== Sampler
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A _sampler_ (ename:VK_DESCRIPTOR_TYPE_SAMPLER) represents a set of
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parameters which control address calculations, filtering behavior, and other
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properties, that can: be used to perform filtered loads from _sampled
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images_ (see <<descriptorsets-sampledimage, Sampled Image>>).
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Samplers are declared in GLSL shader source using uniform code:sampler
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variables, where the sampler type has no associated texture dimensionality:
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.GLSL Example
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[source,glsl]
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---------------------------------------------------
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layout (set=m, binding=n) uniform sampler mySampler;
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---------------------------------------------------
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.SPIR-V example
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[source,spirv]
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---------------------------------------------------
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %8 "mySampler"
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OpDecorate %8 DescriptorSet m
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OpDecorate %8 Binding n
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeSampler
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%7 = OpTypePointer UniformConstant %6
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%8 = OpVariable %7 UniformConstant
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...
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---------------------------------------------------
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[[descriptorsets-sampledimage]]
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=== Sampled Image
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A _sampled image_ (ename:VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE) can: be used
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(usually in conjunction with a sampler) to retrieve sampled image data.
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Shaders use a sampled image handle and a sampler handle to sample data,
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where the image handle generally defines the shape and format of the memory
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and the sampler generally defines how coordinate addressing is performed.
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The same sampler can: be used to sample from multiple images, and it is
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possible to sample from the same sampled image with multiple samplers, each
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containing a different set of sampling parameters.
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Sampled images are declared in GLSL shader source using uniform code:texture
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variables of the appropriate dimensionality:
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.GLSL example
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[source,glsl]
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---------------------------------------------------
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layout (set=m, binding=n) uniform texture2D mySampledImage;
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---------------------------------------------------
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.SPIR-V example
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[source,spirv]
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---------------------------------------------------
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %9 "mySampledImage"
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OpDecorate %9 DescriptorSet m
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OpDecorate %9 Binding n
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeFloat 32
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%7 = OpTypeImage %6 2D 0 0 0 1 Unknown
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%8 = OpTypePointer UniformConstant %7
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%9 = OpVariable %8 UniformConstant
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...
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---------------------------------------------------
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[[descriptorsets-combinedimagesampler]]
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=== Combined Image Sampler
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A _combined image sampler_ (ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER)
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represents a sampled image along with a set of sampling parameters.
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It is logically considered a sampled image and a sampler bound together.
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[NOTE]
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.Note
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====
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On some implementations, it may: be more efficient to sample from an image
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using a combination of sampler and sampled image that are stored together in
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the descriptor set in a combined descriptor.
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====
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Combined image samplers are declared in GLSL shader source using uniform
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code:sampler variables of the appropriate dimensionality:
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.GLSL example
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[source,glsl]
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---------------------------------------------------
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layout (set=m, binding=n) uniform sampler2D myCombinedImageSampler;
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---------------------------------------------------
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.SPIR-V example
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[source,spirv]
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---------------------------------------------------
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %10 "myCombinedImageSampler"
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OpDecorate %10 DescriptorSet m
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OpDecorate %10 Binding n
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeFloat 32
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%7 = OpTypeImage %6 2D 0 0 0 1 Unknown
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%8 = OpTypeSampledImage %7
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%9 = OpTypePointer UniformConstant %8
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%10 = OpVariable %9 UniformConstant
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...
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---------------------------------------------------
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ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER descriptor set entries can:
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also be accessed via separate sampler and sampled image shader variables.
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Such variables refer exclusively to the corresponding half of the
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descriptor, and can: be combined in the shader with samplers or sampled
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images that can: come from the same descriptor or from other combined or
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separate descriptor types.
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There are no additional restrictions on how a separate sampler or sampled
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image variable is used due to it originating from a combined descriptor.
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[[descriptorsets-uniformtexelbuffer]]
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=== Uniform Texel Buffer
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A _uniform texel buffer_ (ename:VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER)
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represents a tightly packed array of homogeneous formatted data that is
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stored in a buffer and is made accessible to shaders.
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Uniform texel buffers are read-only.
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Uniform texel buffers are declared in GLSL shader source using uniform
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code:samplerBuffer variables:
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.GLSL example
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[source,glsl]
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---------------------------------------------------
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layout (set=m, binding=n) uniform samplerBuffer myUniformTexelBuffer;
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---------------------------------------------------
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.SPIR-V example
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[source,spirv]
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---------------------------------------------------
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %9 "myUniformTexelBuffer"
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OpDecorate %9 DescriptorSet m
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OpDecorate %9 Binding n
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeFloat 32
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%7 = OpTypeImage %6 Buffer 0 0 0 1 Unknown
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%8 = OpTypePointer UniformConstant %7
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%9 = OpVariable %8 UniformConstant
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...
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---------------------------------------------------
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[[descriptorsets-storagetexelbuffer]]
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=== Storage Texel Buffer
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A _storage texel buffer_ (ename:VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER)
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represents a tightly packed array of homogeneous formatted data that is
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stored in a buffer and is made accessible to shaders.
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Storage texel buffers differ from uniform texel buffers in that they support
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stores and atomic operations in shaders, may: support a different maximum
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length, and may: have different performance characteristics.
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Storage texel buffers are declared in GLSL shader source using uniform
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code:imageBuffer variables:
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.GLSL example
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[source,glsl]
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---------------------------------------------------
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layout (set=m, binding=n, r32f) uniform imageBuffer myStorageTexelBuffer;
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---------------------------------------------------
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.SPIR-V example
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[source,spirv]
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---------------------------------------------------
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %9 "myStorageTexelBuffer"
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OpDecorate %9 DescriptorSet m
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OpDecorate %9 Binding n
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeFloat 32
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%7 = OpTypeImage %6 Buffer 0 0 0 2 R32f
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%8 = OpTypePointer UniformConstant %7
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%9 = OpVariable %8 UniformConstant
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...
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---------------------------------------------------
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[[descriptorsets-uniformbuffer]]
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=== Uniform Buffer
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A _uniform buffer_ (ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER) is a region of
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structured storage that is made accessible for read-only access to shaders.
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It is typically used to store medium sized arrays of constants such as
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shader parameters, matrices and other related data.
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Uniform buffers are declared in GLSL shader source using the uniform storage
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qualifier and block syntax:
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.GLSL example
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[source,glsl]
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---------------------------------------------------
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layout (set=m, binding=n) uniform myUniformBuffer
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{
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vec4 myElement[32];
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};
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---------------------------------------------------
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.SPIR-V example
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[source,spirv]
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---------------------------------------------------
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %11 "myUniformBuffer"
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OpMemberName %11 0 "myElement"
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OpName %13 ""
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OpDecorate %10 ArrayStride 16
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OpMemberDecorate %11 0 Offset 0
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OpDecorate %11 Block
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OpDecorate %13 DescriptorSet m
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OpDecorate %13 Binding n
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeFloat 32
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%7 = OpTypeVector %6 4
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%8 = OpTypeInt 32 0
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%9 = OpConstant %8 32
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%10 = OpTypeArray %7 %9
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%11 = OpTypeStruct %10
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%12 = OpTypePointer Uniform %11
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%13 = OpVariable %12 Uniform
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...
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---------------------------------------------------
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[[descriptorsets-storagebuffer]]
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=== Storage Buffer
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A _storage buffer_ (ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER) is a region of
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structured storage that supports both read and write access for shaders.
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In addition to general read and write operations, some members of storage
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buffers can: be used as the target of atomic operations.
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In general, atomic operations are only supported on members that have
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unsigned integer formats.
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Storage buffers are declared in GLSL shader source using buffer storage
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qualifier and block syntax:
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.GLSL example
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[source,glsl]
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---------------------------------------------------
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layout (set=m, binding=n) buffer myStorageBuffer
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{
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vec4 myElement[];
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};
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---------------------------------------------------
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.SPIR-V example
|
|
[source,spirv]
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---------------------------------------------------
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...
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%1 = OpExtInstImport "GLSL.std.450"
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...
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OpName %9 "myStorageBuffer"
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OpMemberName %9 0 "myElement"
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OpName %11 ""
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OpDecorate %8 ArrayStride 16
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OpMemberDecorate %9 0 Offset 0
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OpDecorate %9 BufferBlock
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OpDecorate %11 DescriptorSet m
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OpDecorate %11 Binding n
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%2 = OpTypeVoid
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%3 = OpTypeFunction %2
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%6 = OpTypeFloat 32
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%7 = OpTypeVector %6 4
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%8 = OpTypeRuntimeArray %7
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%9 = OpTypeStruct %8
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%10 = OpTypePointer Uniform %9
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%11 = OpVariable %10 Uniform
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...
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---------------------------------------------------
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[[descriptorsets-uniformbufferdynamic]]
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=== Dynamic Uniform Buffer
|
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A _dynamic uniform buffer_ (ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC)
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differs from a uniform buffer only in how its address and length are
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specified.
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Uniform buffers bind a buffer address and length that is specified in the
|
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descriptor set update by a buffer handle, offset and range (see
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<<descriptorsets-updates, Descriptor Set Updates>>).
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With dynamic uniform buffers the buffer handle, offset and range specified
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in the descriptor set define the base address and length.
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The dynamic offset which is relative to this base address is taken from the
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pname:pDynamicOffsets parameter to flink:vkCmdBindDescriptorSets (see
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<<descriptorsets-binding, Descriptor Set Binding>>).
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The address used for a dynamic uniform buffer is the sum of the buffer base
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address and the relative offset.
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The length is unmodified and remains the range as specified in the
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descriptor update.
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The shader syntax is identical for uniform buffers and dynamic uniform
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buffers.
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[[descriptorsets-storagebufferdynamic]]
|
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=== Dynamic Storage Buffer
|
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|
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A _dynamic storage buffer_ (ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC)
|
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differs from a storage buffer only in how its address and length are
|
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specified.
|
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The difference is identical to the difference between uniform buffers and
|
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dynamic uniform buffers (see <<descriptorsets-uniformbufferdynamic, Dynamic
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Uniform Buffer>>).
|
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The shader syntax is identical for storage buffers and dynamic storage
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buffers.
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[[descriptorsets-inputattachment]]
|
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=== Input Attachment
|
|
|
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An _input attachment_ (ename:VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT) is an
|
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image view that can: be used for pixel local load operations from within
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fragment shaders bound to pipelines.
|
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Loads from input attachments are unfiltered.
|
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All image formats that are supported for color attachments
|
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(ename:VK_FORMAT_FEATURE_COLOR_ATTACHMENT_BIT) or depth/stencil attachments
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(ename:VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT) for a given image
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tiling mode are also supported for input attachments.
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|
|
|
In the shader, input attachments must: be decorated with their input
|
|
attachment index in addition to descriptor set and binding numbers.
|
|
|
|
.GLSL example
|
|
[source,glsl]
|
|
---------------------------------------------------
|
|
layout (input_attachment_index=i, set=m, binding=n) uniform subpassInput myInputAttachment;
|
|
---------------------------------------------------
|
|
|
|
.SPIR-V example
|
|
[source,spirv]
|
|
---------------------------------------------------
|
|
...
|
|
%1 = OpExtInstImport "GLSL.std.450"
|
|
...
|
|
OpName %9 "myInputAttachment"
|
|
OpDecorate %9 DescriptorSet m
|
|
OpDecorate %9 Binding n
|
|
OpDecorate %9 InputAttachmentIndex i
|
|
%2 = OpTypeVoid
|
|
%3 = OpTypeFunction %2
|
|
%6 = OpTypeFloat 32
|
|
%7 = OpTypeImage %6 SubpassData 0 0 0 2 Unknown
|
|
%8 = OpTypePointer UniformConstant %7
|
|
%9 = OpVariable %8 UniformConstant
|
|
...
|
|
---------------------------------------------------
|
|
|
|
|
|
[[descriptorsets-sets]]
|
|
== Descriptor Sets
|
|
|
|
Descriptors are grouped together into descriptor set objects.
|
|
A descriptor set object is an opaque object that contains storage for a set
|
|
of descriptors, where the types and number of descriptors is defined by a
|
|
descriptor set layout.
|
|
The layout object may: be used to define the association of each descriptor
|
|
binding with memory or other hardware resources.
|
|
The layout is used both for determining the resources that need to be
|
|
associated with the descriptor set, and determining the interface between
|
|
shader stages and shader resources.
|
|
|
|
|
|
[[descriptorsets-setlayout]]
|
|
=== Descriptor Set Layout
|
|
|
|
// refBegin VkDescriptorSetLayout Opaque handle to a descriptor set layout object
|
|
|
|
A descriptor set layout object is defined by an array of zero or more
|
|
descriptor bindings.
|
|
Each individual descriptor binding is specified by a descriptor type, a
|
|
count (array size) of the number of descriptors in the binding, a set of
|
|
shader stages that can: access the binding, and (if using immutable
|
|
samplers) an array of sampler descriptors.
|
|
|
|
Descriptor set layout objects are represented by sname:VkDescriptorSetLayout
|
|
handles:
|
|
|
|
include::../api/handles/VkDescriptorSetLayout.txt[]
|
|
|
|
// refEnd VkDescriptorSetLayout
|
|
|
|
// refBegin vkCreateDescriptorSetLayout Create a new descriptor set layout
|
|
|
|
To create descriptor set layout objects, call:
|
|
|
|
include::../api/protos/vkCreateDescriptorSetLayout.txt[]
|
|
|
|
* pname:device is the logical device that creates the descriptor set
|
|
layout.
|
|
* pname:pCreateInfo is a pointer to an instance of the
|
|
slink:VkDescriptorSetLayoutCreateInfo structure specifying the state of
|
|
the descriptor set layout object.
|
|
* pname:pAllocator controls host memory allocation as described in the
|
|
<<memory-allocation, Memory Allocation>> chapter.
|
|
* pname:pSetLayout points to a sname:VkDescriptorSetLayout handle in which
|
|
the resulting descriptor set layout object is returned.
|
|
|
|
include::../validity/protos/vkCreateDescriptorSetLayout.txt[]
|
|
|
|
// refBegin VkDescriptorSetLayoutCreateInfo Structure specifying parameters of a newly created descriptor set layout
|
|
|
|
Information about the descriptor set layout is passed in an instance of the
|
|
sname:VkDescriptorSetLayoutCreateInfo structure:
|
|
|
|
include::../api/structs/VkDescriptorSetLayoutCreateInfo.txt[]
|
|
|
|
* pname:sType is the type of this structure.
|
|
* pname:pNext is `NULL` or a pointer to an extension-specific structure.
|
|
* pname:flags is a bitmask
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
of elink:VkDescriptorSetLayoutCreateFlags.
|
|
endif::VK_KHR_push_descriptor[]
|
|
specifying options for descriptor set layout creation.
|
|
* pname:bindingCount is the number of elements in pname:pBindings.
|
|
* pname:pBindings is a pointer to an array of
|
|
slink:VkDescriptorSetLayoutBinding structures.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkDescriptorSetLayoutCreateInfo-binding-00279]]
|
|
The slink:VkDescriptorSetLayoutBinding::pname:binding members of the
|
|
elements of the pname:pBindings array must: each have different values.
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
* [[VUID-VkDescriptorSetLayoutCreateInfo-flags-00280]]
|
|
If pname:flags contains
|
|
ename:VK_DESCRIPTOR_SET_LAYOUT_CREATE_PUSH_DESCRIPTOR_BIT_KHR, then all
|
|
elements of pname:pBindings must: not have a pname:descriptorType of
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC or
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC
|
|
* [[VUID-VkDescriptorSetLayoutCreateInfo-flags-00281]]
|
|
If pname:flags contains
|
|
ename:VK_DESCRIPTOR_SET_LAYOUT_CREATE_PUSH_DESCRIPTOR_BIT_KHR, then the
|
|
total number of elements of all bindings must: be less than or equal to
|
|
slink:VkPhysicalDevicePushDescriptorPropertiesKHR::pname:maxPushDescriptors
|
|
endif::VK_KHR_push_descriptor[]
|
|
****
|
|
|
|
include::../validity/structs/VkDescriptorSetLayoutCreateInfo.txt[]
|
|
|
|
// refBegin VkDescriptorSetLayoutCreateFlagBits Bitmask specifying descriptor set layout properties
|
|
|
|
Bits which can: be set in slink:VkDescriptorSetLayoutCreateInfo::pname:flags
|
|
to specify options for descriptor set layout are:
|
|
|
|
include::../api/enums/VkDescriptorSetLayoutCreateFlagBits.txt[]
|
|
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
* ename:VK_DESCRIPTOR_SET_LAYOUT_CREATE_PUSH_DESCRIPTOR_BIT_KHR specifies
|
|
that descriptor sets must: not be allocated using this layout, and
|
|
descriptors are instead pushed by flink:vkCmdPushDescriptorSetKHR.
|
|
endif::VK_KHR_push_descriptor[]
|
|
|
|
// refEnd VkDescriptorSetLayoutCreateFlagBits
|
|
|
|
// refBegin VkDescriptorSetLayoutBinding Structure specifying a descriptor set layout binding
|
|
|
|
The sname:VkDescriptorSetLayoutBinding structure is defined as:
|
|
|
|
include::../api/structs/VkDescriptorSetLayoutBinding.txt[]
|
|
|
|
* pname:binding is the binding number of this entry and corresponds to a
|
|
resource of the same binding number in the shader stages.
|
|
* pname:descriptorType is a elink:VkDescriptorType specifying which type
|
|
of resource descriptors are used for this binding.
|
|
* pname:descriptorCount is the number of descriptors contained in the
|
|
binding, accessed in a shader as an array.
|
|
If pname:descriptorCount is zero this binding entry is reserved and the
|
|
resource must: not be accessed from any stage via this binding within
|
|
any pipeline using the set layout.
|
|
* pname:stageFlags member is a bitmask of elink:VkShaderStageFlagBits
|
|
specifying which pipeline shader stages can: access a resource for this
|
|
binding.
|
|
ename:VK_SHADER_STAGE_ALL is a shorthand specifying that all defined
|
|
shader stages, including any additional stages defined by extensions,
|
|
can: access the resource.
|
|
+
|
|
--
|
|
If a shader stage is not included in pname:stageFlags, then a resource must:
|
|
not be accessed from that stage via this binding within any pipeline using
|
|
the set layout.
|
|
There are no limitations on what combinations of stages can: be used by a
|
|
descriptor binding, and in particular a binding can: be used by both
|
|
graphics stages and the compute stage.
|
|
--
|
|
* pname:pImmutableSamplers affects initialization of samplers.
|
|
If pname:descriptorType specifies a ename:VK_DESCRIPTOR_TYPE_SAMPLER or
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER type descriptor, then
|
|
pname:pImmutableSamplers can: be used to initialize a set of _immutable
|
|
samplers_.
|
|
Immutable samplers are permanently bound into the set layout; later
|
|
binding a sampler into an immutable sampler slot in a descriptor set is
|
|
not allowed.
|
|
If pname:pImmutableSamplers is not `NULL`, then it is considered to be a
|
|
pointer to an array of sampler handles that will be consumed by the set
|
|
layout and used for the corresponding binding.
|
|
If pname:pImmutableSamplers is `NULL`, then the sampler slots are
|
|
dynamic and sampler handles must: be bound into descriptor sets using
|
|
this layout.
|
|
If pname:descriptorType is not one of these descriptor types, then
|
|
pname:pImmutableSamplers is ignored.
|
|
|
|
The above layout definition allows the descriptor bindings to be specified
|
|
sparsely such that not all binding numbers between 0 and the maximum binding
|
|
number need to be specified in the pname:pBindings array.
|
|
Bindings that are not specified have a pname:descriptorCount and
|
|
pname:stageFlags of zero, and the pname:descriptorType is treated as
|
|
undefined.
|
|
However, all binding numbers between 0 and the maximum binding number in the
|
|
slink:VkDescriptorSetLayoutCreateInfo::pname:pBindings array may: consume
|
|
memory in the descriptor set layout even if not all descriptor bindings are
|
|
used, though it should: not consume additional memory from the descriptor
|
|
pool.
|
|
|
|
[NOTE]
|
|
.Note
|
|
====
|
|
The maximum binding number specified should: be as compact as possible to
|
|
avoid wasted memory.
|
|
====
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkDescriptorSetLayoutBinding-descriptorType-00282]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_SAMPLER or
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, and
|
|
pname:descriptorCount is not `0` and pname:pImmutableSamplers is not
|
|
`NULL`, pname:pImmutableSamplers must: be a pointer to an array of
|
|
pname:descriptorCount valid sname:VkSampler handles
|
|
* [[VUID-VkDescriptorSetLayoutBinding-descriptorCount-00283]]
|
|
If pname:descriptorCount is not `0`, pname:stageFlags must: be a valid
|
|
combination of elink:VkShaderStageFlagBits values
|
|
****
|
|
|
|
include::../validity/structs/VkDescriptorSetLayoutBinding.txt[]
|
|
|
|
The following examples show a shader snippet using two descriptor sets, and
|
|
application code that creates corresponding descriptor set layouts.
|
|
|
|
.GLSL example
|
|
[source,glsl]
|
|
---------------------------------------------------
|
|
//
|
|
// binding to a single sampled image descriptor in set 0
|
|
//
|
|
layout (set=0, binding=0) uniform texture2D mySampledImage;
|
|
|
|
//
|
|
// binding to an array of sampled image descriptors in set 0
|
|
//
|
|
layout (set=0, binding=1) uniform texture2D myArrayOfSampledImages[12];
|
|
|
|
//
|
|
// binding to a single uniform buffer descriptor in set 1
|
|
//
|
|
layout (set=1, binding=0) uniform myUniformBuffer
|
|
{
|
|
vec4 myElement[32];
|
|
};
|
|
---------------------------------------------------
|
|
|
|
.SPIR-V example
|
|
[source,spirv]
|
|
---------------------------------------------------
|
|
...
|
|
%1 = OpExtInstImport "GLSL.std.450"
|
|
...
|
|
OpName %9 "mySampledImage"
|
|
OpName %14 "myArrayOfSampledImages"
|
|
OpName %18 "myUniformBuffer"
|
|
OpMemberName %18 0 "myElement"
|
|
OpName %20 ""
|
|
OpDecorate %9 DescriptorSet 0
|
|
OpDecorate %9 Binding 0
|
|
OpDecorate %14 DescriptorSet 0
|
|
OpDecorate %14 Binding 1
|
|
OpDecorate %17 ArrayStride 16
|
|
OpMemberDecorate %18 0 Offset 0
|
|
OpDecorate %18 Block
|
|
OpDecorate %20 DescriptorSet 1
|
|
OpDecorate %20 Binding 0
|
|
%2 = OpTypeVoid
|
|
%3 = OpTypeFunction %2
|
|
%6 = OpTypeFloat 32
|
|
%7 = OpTypeImage %6 2D 0 0 0 1 Unknown
|
|
%8 = OpTypePointer UniformConstant %7
|
|
%9 = OpVariable %8 UniformConstant
|
|
%10 = OpTypeInt 32 0
|
|
%11 = OpConstant %10 12
|
|
%12 = OpTypeArray %7 %11
|
|
%13 = OpTypePointer UniformConstant %12
|
|
%14 = OpVariable %13 UniformConstant
|
|
%15 = OpTypeVector %6 4
|
|
%16 = OpConstant %10 32
|
|
%17 = OpTypeArray %15 %16
|
|
%18 = OpTypeStruct %17
|
|
%19 = OpTypePointer Uniform %18
|
|
%20 = OpVariable %19 Uniform
|
|
...
|
|
---------------------------------------------------
|
|
|
|
.API example
|
|
[source,c++]
|
|
-------------------------------------------------------------------------------
|
|
VkResult myResult;
|
|
|
|
const VkDescriptorSetLayoutBinding myDescriptorSetLayoutBinding[] =
|
|
{
|
|
// binding to a single image descriptor
|
|
{
|
|
0, // binding
|
|
VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, // descriptorType
|
|
1, // descriptorCount
|
|
VK_SHADER_STAGE_FRAGMENT_BIT, // stageFlags
|
|
NULL // pImmutableSamplers
|
|
},
|
|
|
|
// binding to an array of image descriptors
|
|
{
|
|
1, // binding
|
|
VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, // descriptorType
|
|
12, // descriptorCount
|
|
VK_SHADER_STAGE_FRAGMENT_BIT, // stageFlags
|
|
NULL // pImmutableSamplers
|
|
},
|
|
|
|
// binding to a single uniform buffer descriptor
|
|
{
|
|
0, // binding
|
|
VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, // descriptorType
|
|
1, // descriptorCount
|
|
VK_SHADER_STAGE_FRAGMENT_BIT, // stageFlags
|
|
NULL // pImmutableSamplers
|
|
}
|
|
};
|
|
|
|
const VkDescriptorSetLayoutCreateInfo myDescriptorSetLayoutCreateInfo[] =
|
|
{
|
|
// Create info for first descriptor set with two descriptor bindings
|
|
{
|
|
VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO, // sType
|
|
NULL, // pNext
|
|
0, // flags
|
|
2, // bindingCount
|
|
&myDescriptorSetLayoutBinding[0] // pBindings
|
|
},
|
|
|
|
// Create info for second descriptor set with one descriptor binding
|
|
{
|
|
VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO, // sType
|
|
NULL, // pNext
|
|
0, // flags
|
|
1, // bindingCount
|
|
&myDescriptorSetLayoutBinding[2] // pBindings
|
|
}
|
|
};
|
|
|
|
VkDescriptorSetLayout myDescriptorSetLayout[2];
|
|
|
|
//
|
|
// Create first descriptor set layout
|
|
//
|
|
myResult = vkCreateDescriptorSetLayout(
|
|
myDevice,
|
|
&myDescriptorSetLayoutCreateInfo[0],
|
|
NULL,
|
|
&myDescriptorSetLayout[0]);
|
|
|
|
//
|
|
// Create second descriptor set layout
|
|
//
|
|
myResult = vkCreateDescriptorSetLayout(
|
|
myDevice,
|
|
&myDescriptorSetLayoutCreateInfo[1],
|
|
NULL,
|
|
&myDescriptorSetLayout[1]);
|
|
-------------------------------------------------------------------------------
|
|
|
|
// refBegin vkDestroyDescriptorSetLayout Destroy a descriptor set layout object
|
|
|
|
To destroy a descriptor set layout, call:
|
|
|
|
include::../api/protos/vkDestroyDescriptorSetLayout.txt[]
|
|
|
|
* pname:device is the logical device that destroys the descriptor set
|
|
layout.
|
|
* pname:descriptorSetLayout is the descriptor set layout to destroy.
|
|
* pname:pAllocator controls host memory allocation as described in the
|
|
<<memory-allocation, Memory Allocation>> chapter.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkDestroyDescriptorSetLayout-descriptorSetLayout-00284]]
|
|
If sname:VkAllocationCallbacks were provided when
|
|
pname:descriptorSetLayout was created, a compatible set of callbacks
|
|
must: be provided here
|
|
* [[VUID-vkDestroyDescriptorSetLayout-descriptorSetLayout-00285]]
|
|
If no sname:VkAllocationCallbacks were provided when
|
|
pname:descriptorSetLayout was created, pname:pAllocator must: be `NULL`
|
|
****
|
|
|
|
include::../validity/protos/vkDestroyDescriptorSetLayout.txt[]
|
|
|
|
|
|
[[descriptorsets-pipelinelayout]]
|
|
=== Pipeline Layouts
|
|
|
|
// refBegin VkPipelineLayout Opaque handle to a pipeline layout object
|
|
|
|
Access to descriptor sets from a pipeline is accomplished through a
|
|
_pipeline layout_.
|
|
Zero or more descriptor set layouts and zero or more push constant ranges
|
|
are combined to form a pipeline layout object which describes the complete
|
|
set of resources that can: be accessed by a pipeline.
|
|
The pipeline layout represents a sequence of descriptor sets with each
|
|
having a specific layout.
|
|
This sequence of layouts is used to determine the interface between shader
|
|
stages and shader resources.
|
|
Each pipeline is created using a pipeline layout.
|
|
|
|
Pipeline layout objects are represented by sname:VkPipelineLayout handles:
|
|
|
|
include::../api/handles/VkPipelineLayout.txt[]
|
|
|
|
// refEnd VkPipelineLayout
|
|
|
|
// refBegin vkCreatePipelineLayout Creates a new pipeline layout object
|
|
|
|
To create a pipeline layout, call:
|
|
|
|
include::../api/protos/vkCreatePipelineLayout.txt[]
|
|
|
|
* pname:device is the logical device that creates the pipeline layout.
|
|
* pname:pCreateInfo is a pointer to an instance of the
|
|
slink:VkPipelineLayoutCreateInfo structure specifying the state of the
|
|
pipeline layout object.
|
|
* pname:pAllocator controls host memory allocation as described in the
|
|
<<memory-allocation, Memory Allocation>> chapter.
|
|
* pname:pPipelineLayout points to a sname:VkPipelineLayout handle in which
|
|
the resulting pipeline layout object is returned.
|
|
|
|
include::../validity/protos/vkCreatePipelineLayout.txt[]
|
|
|
|
// refBegin VkPipelineLayoutCreateInfo Structure specifying the parameters of a newly created pipeline layout object
|
|
|
|
The slink:VkPipelineLayoutCreateInfo structure is defined as:
|
|
|
|
include::../api/structs/VkPipelineLayoutCreateInfo.txt[]
|
|
|
|
* pname:sType is the type of this structure.
|
|
* pname:pNext is `NULL` or a pointer to an extension-specific structure.
|
|
* pname:flags is reserved for future use.
|
|
* pname:setLayoutCount is the number of descriptor sets included in the
|
|
pipeline layout.
|
|
* pname:pSetLayouts is a pointer to an array of
|
|
sname:VkDescriptorSetLayout objects.
|
|
* pname:pushConstantRangeCount is the number of push constant ranges
|
|
included in the pipeline layout.
|
|
* pname:pPushConstantRanges is a pointer to an array of
|
|
sname:VkPushConstantRange structures defining a set of push constant
|
|
ranges for use in a single pipeline layout.
|
|
In addition to descriptor set layouts, a pipeline layout also describes
|
|
how many push constants can: be accessed by each stage of the pipeline.
|
|
+
|
|
[NOTE]
|
|
.Note
|
|
====
|
|
Push constants represent a high speed path to modify constant data in
|
|
pipelines that is expected to outperform memory-backed resource updates.
|
|
====
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkPipelineLayoutCreateInfo-setLayoutCount-00286]]
|
|
pname:setLayoutCount must: be less than or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxBoundDescriptorSets
|
|
* [[VUID-VkPipelineLayoutCreateInfo-pSetLayouts-00287]]
|
|
The total number of descriptors of the type
|
|
ename:VK_DESCRIPTOR_TYPE_SAMPLER and
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER accessible to any given
|
|
shader stage across all elements of pname:pSetLayouts must: be less than
|
|
or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxPerStageDescriptorSamplers
|
|
* [[VUID-VkPipelineLayoutCreateInfo-pSetLayouts-00288]]
|
|
The total number of descriptors of the type
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER and
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC accessible to any given
|
|
shader stage across all elements of pname:pSetLayouts must: be less than
|
|
or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxPerStageDescriptorUniformBuffers
|
|
* [[VUID-VkPipelineLayoutCreateInfo-pSetLayouts-00289]]
|
|
The total number of descriptors of the type
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER and
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC accessible to any given
|
|
shader stage across all elements of pname:pSetLayouts must: be less than
|
|
or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxPerStageDescriptorStorageBuffers
|
|
* [[VUID-VkPipelineLayoutCreateInfo-pSetLayouts-00290]]
|
|
The total number of descriptors of the type
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
|
|
ename:VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, and
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER accessible to any given
|
|
shader stage across all elements of pname:pSetLayouts must: be less than
|
|
or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxPerStageDescriptorSampledImages
|
|
* [[VUID-VkPipelineLayoutCreateInfo-pSetLayouts-00291]]
|
|
The total number of descriptors of the type
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, and
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER accessible to any given
|
|
shader stage across all elements of pname:pSetLayouts must: be less than
|
|
or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxPerStageDescriptorStorageImages
|
|
* [[VUID-VkPipelineLayoutCreateInfo-pPushConstantRanges-00292]]
|
|
Any two elements of pname:pPushConstantRanges must: not include the same
|
|
stage in pname:stageFlags
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
* [[VUID-VkPipelineLayoutCreateInfo-pSetLayouts-00293]]
|
|
pname:pSetLayouts must: not contain more than one descriptor set layout
|
|
that was created with
|
|
ename:VK_DESCRIPTOR_SET_LAYOUT_CREATE_PUSH_DESCRIPTOR_BIT_KHR set
|
|
endif::VK_KHR_push_descriptor[]
|
|
****
|
|
|
|
include::../validity/structs/VkPipelineLayoutCreateInfo.txt[]
|
|
|
|
// refBegin VkPushConstantRange Structure specifying a push constant range
|
|
|
|
The sname:VkPushConstantRange structure is defined as:
|
|
|
|
include::../api/structs/VkPushConstantRange.txt[]
|
|
|
|
* pname:stageFlags is a set of stage flags describing the shader stages
|
|
that will access a range of push constants.
|
|
If a particular stage is not included in the range, then accessing
|
|
members of that range of push constants from the corresponding shader
|
|
stage will result in undefined data being read.
|
|
* pname:offset and pname:size are the start offset and size, respectively,
|
|
consumed by the range.
|
|
Both pname:offset and pname:size are in units of bytes and must: be a
|
|
multiple of 4.
|
|
The layout of the push constant variables is specified in the shader.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkPushConstantRange-offset-00294]]
|
|
pname:offset must: be less than
|
|
sname:VkPhysicalDeviceLimits::pname:maxPushConstantsSize
|
|
* [[VUID-VkPushConstantRange-offset-00295]]
|
|
pname:offset must: be a multiple of `4`
|
|
* [[VUID-VkPushConstantRange-size-00296]]
|
|
pname:size must: be greater than `0`
|
|
* [[VUID-VkPushConstantRange-size-00297]]
|
|
pname:size must: be a multiple of `4`
|
|
* [[VUID-VkPushConstantRange-size-00298]]
|
|
pname:size must: be less than or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxPushConstantsSize minus
|
|
pname:offset
|
|
****
|
|
|
|
include::../validity/structs/VkPushConstantRange.txt[]
|
|
|
|
Once created, pipeline layouts are used as part of pipeline creation (see
|
|
<<pipelines, Pipelines>>), as part of binding descriptor sets (see
|
|
<<descriptorsets-binding, Descriptor Set Binding>>), and as part of setting
|
|
push constants (see <<descriptorsets-push-constants, Push Constant
|
|
Updates>>).
|
|
Pipeline creation accepts a pipeline layout as input, and the layout may: be
|
|
used to map (set, binding, arrayElement) tuples to hardware resources or
|
|
memory locations within a descriptor set.
|
|
The assignment of hardware resources depends only on the bindings defined in
|
|
the descriptor sets that comprise the pipeline layout, and not on any shader
|
|
source.
|
|
|
|
[[descriptorsets-pipelinelayout-consistency]]
|
|
All resource variables <<shaders-staticuse,statically used>> in all shaders
|
|
in a pipeline must: be declared with a (set,binding,arrayElement) that
|
|
exists in the corresponding descriptor set layout and is of an appropriate
|
|
descriptor type and includes the set of shader stages it is used by in
|
|
pname:stageFlags.
|
|
The pipeline layout can: include entries that are not used by a particular
|
|
pipeline, or that are dead-code eliminated from any of the shaders.
|
|
The pipeline layout allows the application to provide a consistent set of
|
|
bindings across multiple pipeline compiles, which enables those pipelines to
|
|
be compiled in a way that the implementation may: cheaply switch pipelines
|
|
without reprogramming the bindings.
|
|
|
|
Similarly, the push constant block declared in each shader (if present)
|
|
must: only place variables at offsets that are each included in a push
|
|
constant range with pname:stageFlags including the bit corresponding to the
|
|
shader stage that uses it.
|
|
The pipeline layout can: include ranges or portions of ranges that are not
|
|
used by a particular pipeline, or for which the variables have been
|
|
dead-code eliminated from any of the shaders.
|
|
|
|
There is a limit on the total number of resources of each type that can: be
|
|
included in bindings in all descriptor set layouts in a pipeline layout as
|
|
shown in <<descriptorsets-pipelinelayout-limits,Pipeline Layout Resource
|
|
Limits>>.
|
|
The "`Total Resources Available`" column gives the limit on the number of
|
|
each type of resource that can: be included in bindings in all descriptor
|
|
sets in the pipeline layout.
|
|
Some resource types count against multiple limits.
|
|
Additionally, there are limits on the total number of each type of resource
|
|
that can: be used in any pipeline stage as described in
|
|
<<interfaces-resources-limits,Shader Resource Limits>>.
|
|
|
|
[[descriptorsets-pipelinelayout-limits]]
|
|
.Pipeline Layout Resource Limits
|
|
[width="80%",cols="<37,<22",options="header"]
|
|
|====
|
|
| Total Resources Available | Resource Types
|
|
.2+<.^| pname:maxDescriptorSetSamplers
|
|
| sampler | combined image sampler
|
|
.3+<.^| pname:maxDescriptorSetSampledImages
|
|
| sampled image | combined image sampler | uniform texel buffer
|
|
.2+<.^| pname:maxDescriptorSetStorageImages
|
|
| storage image | storage texel buffer
|
|
.2+<.^| pname:maxDescriptorSetUniformBuffers
|
|
| uniform buffer | uniform buffer dynamic
|
|
| pname:maxDescriptorSetUniformBuffersDynamic
|
|
| uniform buffer dynamic
|
|
.2+<.^| pname:maxDescriptorSetStorageBuffers
|
|
| storage buffer | storage buffer dynamic
|
|
| pname:maxDescriptorSetStorageBuffersDynamic
|
|
| storage buffer dynamic
|
|
| pname:maxDescriptorSetInputAttachments
|
|
| input attachment
|
|
|====
|
|
|
|
|
|
// refBegin vkDestroyPipelineLayout Destroy a pipeline layout object
|
|
|
|
To destroy a pipeline layout, call:
|
|
|
|
include::../api/protos/vkDestroyPipelineLayout.txt[]
|
|
|
|
* pname:device is the logical device that destroys the pipeline layout.
|
|
* pname:pipelineLayout is the pipeline layout to destroy.
|
|
* pname:pAllocator controls host memory allocation as described in the
|
|
<<memory-allocation, Memory Allocation>> chapter.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkDestroyPipelineLayout-pipelineLayout-00299]]
|
|
If sname:VkAllocationCallbacks were provided when pname:pipelineLayout
|
|
was created, a compatible set of callbacks must: be provided here
|
|
* [[VUID-vkDestroyPipelineLayout-pipelineLayout-00300]]
|
|
If no sname:VkAllocationCallbacks were provided when
|
|
pname:pipelineLayout was created, pname:pAllocator must: be `NULL`
|
|
****
|
|
|
|
include::../validity/protos/vkDestroyPipelineLayout.txt[]
|
|
|
|
|
|
[[descriptorsets-compatibility]]
|
|
==== Pipeline Layout Compatibility
|
|
|
|
Two pipeline layouts are defined to be "`compatible for
|
|
<<descriptorsets-push-constants, push constants>>`" if they were created
|
|
with identical push constant ranges.
|
|
Two pipeline layouts are defined to be "`compatible for set N`" if they were
|
|
created with _identically defined_ descriptor set layouts for sets zero
|
|
through N, and if they were created with identical push constant ranges.
|
|
|
|
When binding a descriptor set (see <<descriptorsets-binding, Descriptor Set
|
|
Binding>>) to set number N, if the previously bound descriptor sets for sets
|
|
zero through N-1 were all bound using compatible pipeline layouts, then
|
|
performing this binding does not disturb any of the lower numbered sets.
|
|
If, additionally, the previous bound descriptor set for set N was bound
|
|
using a pipeline layout compatible for set N, then the bindings in sets
|
|
numbered greater than N are also not disturbed.
|
|
|
|
Similarly, when binding a pipeline, the pipeline can: correctly access any
|
|
previously bound descriptor sets which were bound with compatible pipeline
|
|
layouts, as long as all lower numbered sets were also bound with compatible
|
|
layouts.
|
|
|
|
Layout compatibility means that descriptor sets can: be bound to a command
|
|
buffer for use by any pipeline created with a compatible pipeline layout,
|
|
and without having bound a particular pipeline first.
|
|
It also means that descriptor sets can: remain valid across a pipeline
|
|
change, and the same resources will be accessible to the newly bound
|
|
pipeline.
|
|
|
|
ifdef::implementation-guide[]
|
|
.Implementor's Note
|
|
****
|
|
A consequence of layout compatibility is that when the implementation
|
|
compiles a pipeline layout and assigns hardware units to resources, the
|
|
mechanism to assign hardware units for set N should: only be a function of
|
|
sets [0..N].
|
|
****
|
|
endif::implementation-guide[]
|
|
|
|
[NOTE]
|
|
.Note
|
|
====
|
|
Place the least frequently changing descriptor sets near the start of the
|
|
pipeline layout, and place the descriptor sets representing the most
|
|
frequently changing resources near the end.
|
|
When pipelines are switched, only the descriptor set bindings that have been
|
|
invalidated will need to be updated and the remainder of the descriptor set
|
|
bindings will remain in place.
|
|
====
|
|
|
|
The maximum number of descriptor sets that can: be bound to a pipeline
|
|
layout is queried from physical device properties (see
|
|
pname:maxBoundDescriptorSets in <<features-limits, Limits>>).
|
|
|
|
.API example
|
|
[source,c++]
|
|
---------------------------------------------------
|
|
const VkDescriptorSetLayout layouts[] = { layout1, layout2 };
|
|
|
|
const VkPushConstantRange ranges[] =
|
|
{
|
|
{
|
|
VK_PIPELINE_STAGE_VERTEX_SHADER_BIT, // stageFlags
|
|
0, // offset
|
|
4 // size
|
|
},
|
|
|
|
{
|
|
VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, // stageFlags
|
|
4, // offset
|
|
4 // size
|
|
},
|
|
};
|
|
|
|
const VkPipelineLayoutCreateInfo createInfo =
|
|
{
|
|
VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO, // sType
|
|
NULL, // pNext
|
|
0, // flags
|
|
2, // setLayoutCount
|
|
layouts, // pSetLayouts
|
|
2, // pushConstantRangeCount
|
|
ranges // pPushConstantRanges
|
|
};
|
|
|
|
VkPipelineLayout myPipelineLayout;
|
|
myResult = vkCreatePipelineLayout(
|
|
myDevice,
|
|
&createInfo,
|
|
NULL,
|
|
&myPipelineLayout);
|
|
---------------------------------------------------
|
|
|
|
|
|
[[descriptorsets-allocation]]
|
|
=== Allocation of Descriptor Sets
|
|
|
|
// refBegin VkDescriptorPool Opaque handle to a descriptor pool object
|
|
|
|
A _descriptor pool_ maintains a pool of descriptors, from which descriptor
|
|
sets are allocated.
|
|
Descriptor pools are externally synchronized, meaning that the application
|
|
must: not allocate and/or free descriptor sets from the same pool in
|
|
multiple threads simultaneously.
|
|
|
|
Descriptor pools are represented by sname:VkDescriptorPool handles:
|
|
|
|
include::../api/handles/VkDescriptorPool.txt[]
|
|
|
|
// refEnd VkDescriptorPool
|
|
|
|
// refBegin vkCreateDescriptorPool Creates a descriptor pool object
|
|
|
|
To create a descriptor pool object, call:
|
|
|
|
include::../api/protos/vkCreateDescriptorPool.txt[]
|
|
|
|
* pname:device is the logical device that creates the descriptor pool.
|
|
* pname:pCreateInfo is a pointer to an instance of the
|
|
slink:VkDescriptorPoolCreateInfo structure specifying the state of the
|
|
descriptor pool object.
|
|
* pname:pAllocator controls host memory allocation as described in the
|
|
<<memory-allocation, Memory Allocation>> chapter.
|
|
* pname:pDescriptorPool points to a sname:VkDescriptorPool handle in which
|
|
the resulting descriptor pool object is returned.
|
|
|
|
pname:pAllocator controls host memory allocation as described in the
|
|
<<memory-allocation, Memory Allocation>> chapter.
|
|
|
|
The created descriptor pool is returned in pname:pDescriptorPool.
|
|
|
|
include::../validity/protos/vkCreateDescriptorPool.txt[]
|
|
|
|
// refBegin VkDescriptorPoolCreateInfo Structure specifying parameters of a newly created descriptor pool
|
|
|
|
Additional information about the pool is passed in an instance of the
|
|
sname:VkDescriptorPoolCreateInfo structure:
|
|
|
|
include::../api/structs/VkDescriptorPoolCreateInfo.txt[]
|
|
|
|
* pname:sType is the type of this structure.
|
|
* pname:pNext is `NULL` or a pointer to an extension-specific structure.
|
|
* pname:flags is a bitmask of elink:VkDescriptorPoolCreateFlagBits
|
|
specifying certain supported operations on the pool.
|
|
* pname:maxSets is the maximum number of descriptor sets that can: be
|
|
allocated from the pool.
|
|
* pname:poolSizeCount is the number of elements in pname:pPoolSizes.
|
|
* pname:pPoolSizes is a pointer to an array of sname:VkDescriptorPoolSize
|
|
structures, each containing a descriptor type and number of descriptors
|
|
of that type to be allocated in the pool.
|
|
|
|
If multiple sname:VkDescriptorPoolSize structures appear in the
|
|
pname:pPoolSizes array then the pool will be created with enough storage for
|
|
the total number of descriptors of each type.
|
|
|
|
Fragmentation of a descriptor pool is possible and may: lead to descriptor
|
|
set allocation failures.
|
|
A failure due to fragmentation is defined as failing a descriptor set
|
|
allocation despite the sum of all outstanding descriptor set allocations
|
|
from the pool plus the requested allocation requiring no more than the total
|
|
number of descriptors requested at pool creation.
|
|
Implementations provide certain guarantees of when fragmentation must: not
|
|
cause allocation failure, as described below.
|
|
|
|
If a descriptor pool has not had any descriptor sets freed since it was
|
|
created or most recently reset then fragmentation must: not cause an
|
|
allocation failure (note that this is always the case for a pool created
|
|
without the ename:VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT bit
|
|
set).
|
|
Additionally, if all sets allocated from the pool since it was created or
|
|
most recently reset use the same number of descriptors (of each type) and
|
|
the requested allocation also uses that same number of descriptors (of each
|
|
type), then fragmentation must: not cause an allocation failure.
|
|
|
|
If an allocation failure occurs due to fragmentation, an application can:
|
|
create an additional descriptor pool to perform further descriptor set
|
|
allocations.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkDescriptorPoolCreateInfo-maxSets-00301]]
|
|
pname:maxSets must: be greater than `0`
|
|
****
|
|
|
|
include::../validity/structs/VkDescriptorPoolCreateInfo.txt[]
|
|
|
|
// refBegin VkDescriptorPoolCreateFlagBits Bitmask specifying certain supported operations on a descriptor pool
|
|
|
|
Bits which can: be set in slink:VkDescriptorPoolCreateInfo::pname:flags to
|
|
enable operations on a descriptor pool are:
|
|
|
|
include::../api/enums/VkDescriptorPoolCreateFlagBits.txt[]
|
|
|
|
* ename:VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT specifies that
|
|
descriptor sets can: return their individual allocations to the pool,
|
|
i.e. all of flink:vkAllocateDescriptorSets, flink:vkFreeDescriptorSets,
|
|
and flink:vkResetDescriptorPool are allowed.
|
|
Otherwise, descriptor sets allocated from the pool must: not be
|
|
individually freed back to the pool, i.e. only
|
|
flink:vkAllocateDescriptorSets and flink:vkResetDescriptorPool are
|
|
allowed.
|
|
|
|
// refEnd VkDescriptorPoolCreateFlagBits
|
|
|
|
// refBegin VkDescriptorPoolSize Structure specifying descriptor pool size
|
|
|
|
The sname:VkDescriptorPoolSize structure is defined as:
|
|
|
|
include::../api/structs/VkDescriptorPoolSize.txt[]
|
|
|
|
* pname:type is the type of descriptor.
|
|
* pname:descriptorCount is the number of descriptors of that type to
|
|
allocate.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkDescriptorPoolSize-descriptorCount-00302]]
|
|
pname:descriptorCount must: be greater than `0`
|
|
****
|
|
|
|
include::../validity/structs/VkDescriptorPoolSize.txt[]
|
|
|
|
// refBegin vkDestroyDescriptorPool Destroy a descriptor pool object
|
|
|
|
To destroy a descriptor pool, call:
|
|
|
|
include::../api/protos/vkDestroyDescriptorPool.txt[]
|
|
|
|
* pname:device is the logical device that destroys the descriptor pool.
|
|
* pname:descriptorPool is the descriptor pool to destroy.
|
|
* pname:pAllocator controls host memory allocation as described in the
|
|
<<memory-allocation, Memory Allocation>> chapter.
|
|
|
|
When a pool is destroyed, all descriptor sets allocated from the pool are
|
|
implicitly freed and become invalid.
|
|
Descriptor sets allocated from a given pool do not need to be freed before
|
|
destroying that descriptor pool.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkDestroyDescriptorPool-descriptorPool-00303]]
|
|
All submitted commands that refer to pname:descriptorPool (via any
|
|
allocated descriptor sets) must: have completed execution
|
|
* [[VUID-vkDestroyDescriptorPool-descriptorPool-00304]]
|
|
If sname:VkAllocationCallbacks were provided when pname:descriptorPool
|
|
was created, a compatible set of callbacks must: be provided here
|
|
* [[VUID-vkDestroyDescriptorPool-descriptorPool-00305]]
|
|
If no sname:VkAllocationCallbacks were provided when
|
|
pname:descriptorPool was created, pname:pAllocator must: be `NULL`
|
|
****
|
|
|
|
include::../validity/protos/vkDestroyDescriptorPool.txt[]
|
|
|
|
// refBegin VkDescriptorSet Opaque handle to a descriptor set object
|
|
|
|
Descriptor sets are allocated from descriptor pool objects, and are
|
|
represented by sname:VkDescriptorSet handles:
|
|
|
|
include::../api/handles/VkDescriptorSet.txt[]
|
|
|
|
// refEnd VkDescriptorSet
|
|
|
|
// refBegin vkAllocateDescriptorSets Allocate one or more descriptor sets
|
|
|
|
To allocate descriptor sets from a descriptor pool, call:
|
|
|
|
include::../api/protos/vkAllocateDescriptorSets.txt[]
|
|
|
|
* pname:device is the logical device that owns the descriptor pool.
|
|
* pname:pAllocateInfo is a pointer to an instance of the
|
|
slink:VkDescriptorSetAllocateInfo structure describing parameters of the
|
|
allocation.
|
|
* pname:pDescriptorSets is a pointer to an array of sname:VkDescriptorSet
|
|
handles in which the resulting descriptor set objects are returned.
|
|
The array must: be at least the length specified by the
|
|
pname:descriptorSetCount member of pname:pAllocateInfo.
|
|
|
|
The allocated descriptor sets are returned in pname:pDescriptorSets.
|
|
|
|
When a descriptor set is allocated, the initial state is largely
|
|
uninitialized and all descriptors are undefined.
|
|
However, the descriptor set can: be bound in a command buffer without
|
|
causing errors or exceptions.
|
|
All entries that are statically used by a pipeline in a drawing or
|
|
dispatching command must: have been populated before the descriptor set is
|
|
bound for use by that command.
|
|
Entries that are not statically used by a pipeline can: have uninitialized
|
|
descriptors or descriptors of resources that have been destroyed, and
|
|
executing a draw or dispatch with such a descriptor set bound does not cause
|
|
undefined behavior.
|
|
This means applications need not populate unused entries with dummy
|
|
descriptors.
|
|
|
|
If an allocation fails due to fragmentation, an indeterminate error is
|
|
returned with an unspecified error code.
|
|
Any returned error other than
|
|
ifdef::VK_KHR_maintenance1[]
|
|
ename:VK_ERROR_OUT_OF_POOL_MEMORY_KHR or
|
|
endif::VK_KHR_maintenance1[]
|
|
ename:VK_ERROR_FRAGMENTED_POOL does not imply its usual meaning:
|
|
applications should: assume that the allocation failed due to fragmentation,
|
|
and create a new descriptor pool.
|
|
|
|
ifdef::VK_KHR_maintenance1[]
|
|
fname:vkAllocateDescriptorSets can: be used to create multiple descriptor
|
|
sets.
|
|
If the creation of any of those descriptor sets fails, then the
|
|
implementation must: destroy all successfully created descriptor set objects
|
|
from this command, set all entries of the pname:pDescriptorSets array to
|
|
dlink:VK_NULL_HANDLE and return the error.
|
|
endif::VK_KHR_maintenance1[]
|
|
|
|
[NOTE]
|
|
.Note
|
|
====
|
|
Applications should: check for a negative return value when allocating new
|
|
descriptor sets, assume that any error
|
|
ifdef::VK_KHR_maintenance1[]
|
|
other than ename:VK_ERROR_OUT_OF_POOL_MEMORY_KHR
|
|
endif::VK_KHR_maintenance1[]
|
|
effectively means ename:VK_ERROR_FRAGMENTED_POOL, and try to create a new
|
|
descriptor pool.
|
|
If ename:VK_ERROR_FRAGMENTED_POOL is the actual return value, it adds
|
|
certainty to that decision.
|
|
|
|
The reason for this is that ename:VK_ERROR_FRAGMENTED_POOL was only added in
|
|
a later revision of the 1.0 specification, and so drivers may: return other
|
|
errors if they were written against earlier revisions.
|
|
To ensure full compatibility with earlier patch revisions, these other
|
|
errors are allowed.
|
|
====
|
|
|
|
include::../validity/protos/vkAllocateDescriptorSets.txt[]
|
|
|
|
// refBegin VkDescriptorSetAllocateInfo Structure specifying the allocation parameters for descriptor sets
|
|
|
|
The sname:VkDescriptorSetAllocateInfo structure is defined as:
|
|
|
|
include::../api/structs/VkDescriptorSetAllocateInfo.txt[]
|
|
|
|
* pname:sType is the type of this structure.
|
|
* pname:pNext is `NULL` or a pointer to an extension-specific structure.
|
|
* pname:descriptorPool is the pool which the sets will be allocated from.
|
|
* pname:descriptorSetCount determines the number of descriptor sets to be
|
|
allocated from the pool.
|
|
* pname:pSetLayouts is an array of descriptor set layouts, with each
|
|
member specifying how the corresponding descriptor set is allocated.
|
|
|
|
ifndef::VK_KHR_maintenance1[]
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkDescriptorSetAllocateInfo-descriptorSetCount-00306]]
|
|
pname:descriptorSetCount must: not be greater than the number of sets
|
|
that are currently available for allocation in pname:descriptorPool
|
|
* [[VUID-VkDescriptorSetAllocateInfo-descriptorPool-00307]]
|
|
pname:descriptorPool must: have enough free descriptor capacity
|
|
remaining to allocate the descriptor sets of the specified layouts
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
* [[VUID-VkDescriptorSetAllocateInfo-pSetLayouts-00308]]
|
|
Any given element of pname:pSetLayouts must: not have been created with
|
|
ename:VK_DESCRIPTOR_SET_LAYOUT_CREATE_PUSH_DESCRIPTOR_BIT_KHR set
|
|
endif::VK_KHR_push_descriptor[]
|
|
****
|
|
endif::VK_KHR_maintenance1[]
|
|
|
|
include::../validity/structs/VkDescriptorSetAllocateInfo.txt[]
|
|
|
|
// refBegin vkFreeDescriptorSets Free one or more descriptor sets
|
|
|
|
To free allocated descriptor sets, call:
|
|
|
|
include::../api/protos/vkFreeDescriptorSets.txt[]
|
|
|
|
* pname:device is the logical device that owns the descriptor pool.
|
|
* pname:descriptorPool is the descriptor pool from which the descriptor
|
|
sets were allocated.
|
|
* pname:descriptorSetCount is the number of elements in the
|
|
pname:pDescriptorSets array.
|
|
* pname:pDescriptorSets is an array of handles to sname:VkDescriptorSet
|
|
objects.
|
|
|
|
After a successful call to fname:vkFreeDescriptorSets, all descriptor sets
|
|
in pname:pDescriptorSets are invalid.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkFreeDescriptorSets-pDescriptorSets-00309]]
|
|
All submitted commands that refer to any element of
|
|
pname:pDescriptorSets must: have completed execution
|
|
* [[VUID-vkFreeDescriptorSets-pDescriptorSets-00310]]
|
|
pname:pDescriptorSets must: be a pointer to an array of
|
|
pname:descriptorSetCount sname:VkDescriptorSet handles, each element of
|
|
which must: either be a valid handle or dlink:VK_NULL_HANDLE
|
|
* [[VUID-vkFreeDescriptorSets-pDescriptorSets-00311]]
|
|
Each valid handle in pname:pDescriptorSets must: have been allocated
|
|
from pname:descriptorPool
|
|
* [[VUID-vkFreeDescriptorSets-descriptorPool-00312]]
|
|
pname:descriptorPool must: have been created with the
|
|
ename:VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT flag
|
|
****
|
|
|
|
include::../validity/protos/vkFreeDescriptorSets.txt[]
|
|
|
|
// refBegin vkResetDescriptorPool Resets a descriptor pool object
|
|
|
|
To return all descriptor sets allocated from a given pool to the pool,
|
|
rather than freeing individual descriptor sets, call:
|
|
|
|
include::../api/protos/vkResetDescriptorPool.txt[]
|
|
|
|
* pname:device is the logical device that owns the descriptor pool.
|
|
* pname:descriptorPool is the descriptor pool to be reset.
|
|
* pname:flags is reserved for future use.
|
|
|
|
Resetting a descriptor pool recycles all of the resources from all of the
|
|
descriptor sets allocated from the descriptor pool back to the descriptor
|
|
pool, and the descriptor sets are implicitly freed.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkResetDescriptorPool-descriptorPool-00313]]
|
|
All uses of pname:descriptorPool (via any allocated descriptor sets)
|
|
must: have completed execution
|
|
****
|
|
|
|
include::../validity/protos/vkResetDescriptorPool.txt[]
|
|
|
|
|
|
[[descriptorsets-updates]]
|
|
=== Descriptor Set Updates
|
|
|
|
// refBegin vkUpdateDescriptorSets Update the contents of a descriptor set object
|
|
|
|
Once allocated, descriptor sets can: be updated with a combination of write
|
|
and copy operations.
|
|
To update descriptor sets, call:
|
|
|
|
include::../api/protos/vkUpdateDescriptorSets.txt[]
|
|
|
|
* pname:device is the logical device that updates the descriptor sets.
|
|
* pname:descriptorWriteCount is the number of elements in the
|
|
pname:pDescriptorWrites array.
|
|
* pname:pDescriptorWrites is a pointer to an array of
|
|
slink:VkWriteDescriptorSet structures describing the descriptor sets to
|
|
write to.
|
|
* pname:descriptorCopyCount is the number of elements in the
|
|
pname:pDescriptorCopies array.
|
|
* pname:pDescriptorCopies is a pointer to an array of
|
|
slink:VkCopyDescriptorSet structures describing the descriptor sets to
|
|
copy between.
|
|
|
|
The operations described by pname:pDescriptorWrites are performed first,
|
|
followed by the operations described by pname:pDescriptorCopies.
|
|
Within each array, the operations are performed in the order they appear in
|
|
the array.
|
|
|
|
Each element in the pname:pDescriptorWrites array describes an operation
|
|
updating the descriptor set using descriptors for resources specified in the
|
|
structure.
|
|
|
|
Each element in the pname:pDescriptorCopies array is a
|
|
slink:VkCopyDescriptorSet structure describing an operation copying
|
|
descriptors between sets.
|
|
|
|
If the pname:dstSet member of any given element of pname:pDescriptorWrites
|
|
or pname:pDescriptorCopies is bound, accessed, or modified by any command
|
|
that was recorded to a command buffer which is currently in the
|
|
<<commandbuffers-lifecycle, recording or executable state>>, that command
|
|
buffer becomes <<commandbuffers-lifecycle, invalid>>.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkUpdateDescriptorSets-dstSet-00314]]
|
|
The pname:dstSet member of any given element of pname:pDescriptorWrites
|
|
or pname:pDescriptorCopies must: not be used by any command that was
|
|
recorded to a command buffer which is in the <<commandbuffers-lifecycle,
|
|
pending state>>.
|
|
****
|
|
|
|
include::../validity/protos/vkUpdateDescriptorSets.txt[]
|
|
|
|
// refBegin VkWriteDescriptorSet Structure specifying the parameters of a descriptor set write operation
|
|
|
|
The sname:VkWriteDescriptorSet structure is defined as:
|
|
|
|
include::../api/structs/VkWriteDescriptorSet.txt[]
|
|
|
|
* pname:sType is the type of this structure.
|
|
* pname:pNext is `NULL` or a pointer to an extension-specific structure.
|
|
* pname:dstSet is the destination descriptor set to update.
|
|
* pname:dstBinding is the descriptor binding within that set.
|
|
* pname:dstArrayElement is the starting element in that array.
|
|
* pname:descriptorCount is the number of descriptors to update (the number
|
|
of elements in pname:pImageInfo, pname:pBufferInfo, or
|
|
pname:pTexelBufferView).
|
|
* pname:descriptorType is a elink:VkDescriptorType specifying the type of
|
|
each descriptor in pname:pImageInfo, pname:pBufferInfo, or
|
|
pname:pTexelBufferView, as described below.
|
|
It must: be the same type as that specified in
|
|
sname:VkDescriptorSetLayoutBinding for pname:dstSet at pname:dstBinding.
|
|
The type of the descriptor also controls which array the descriptors are
|
|
taken from.
|
|
* pname:pImageInfo points to an array of slink:VkDescriptorImageInfo
|
|
structures or is ignored, as described below.
|
|
* pname:pBufferInfo points to an array of slink:VkDescriptorBufferInfo
|
|
structures or is ignored, as described below.
|
|
* pname:pTexelBufferView points to an array of slink:VkBufferView handles
|
|
as described in the <<resources-buffer-views,Buffer Views>> section or
|
|
is ignored, as described below.
|
|
|
|
Only one of pname:pImageInfo, pname:pBufferInfo, or pname:pTexelBufferView
|
|
members is used according to the descriptor type specified in the
|
|
pname:descriptorType member of the containing sname:VkWriteDescriptorSet
|
|
structure, as specified below.
|
|
|
|
[[descriptorsets-updates-consecutive, consecutive binding updates]]
|
|
If the pname:dstBinding has fewer than pname:descriptorCount array elements
|
|
remaining starting from pname:dstArrayElement, then the remainder will be
|
|
used to update the subsequent binding - pname:dstBinding+1 starting at array
|
|
element zero.
|
|
If a binding has a pname:descriptorCount of zero, it is skipped.
|
|
This behavior applies recursively, with the update affecting consecutive
|
|
bindings as needed to update all pname:descriptorCount descriptors.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkWriteDescriptorSet-dstBinding-00315]]
|
|
pname:dstBinding must: be less than or equal to the maximum value of
|
|
pname:binding of all slink:VkDescriptorSetLayoutBinding structures
|
|
specified when pname:dstSet's descriptor set layout was created
|
|
* [[VUID-VkWriteDescriptorSet-dstBinding-00316]]
|
|
pname:dstBinding must: be a binding with a non-zero
|
|
pname:descriptorCount
|
|
* [[VUID-VkWriteDescriptorSet-descriptorCount-00317]]
|
|
All consecutive bindings updated via a single sname:VkWriteDescriptorSet
|
|
structure, except those with a pname:descriptorCount of zero, must: have
|
|
identical pname:descriptorType and pname:stageFlags.
|
|
* [[VUID-VkWriteDescriptorSet-descriptorCount-00318]]
|
|
All consecutive bindings updated via a single sname:VkWriteDescriptorSet
|
|
structure, except those with a pname:descriptorCount of zero, must: all
|
|
either use immutable samplers or must: all not use immutable samplers.
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00319]]
|
|
pname:descriptorType must: match the type of pname:dstBinding within
|
|
pname:dstSet
|
|
* [[VUID-VkWriteDescriptorSet-dstSet-00320]]
|
|
pname:dstSet must: be a valid slink:VkDescriptorSet handle
|
|
* [[VUID-VkWriteDescriptorSet-dstArrayElement-00321]]
|
|
The sum of pname:dstArrayElement and pname:descriptorCount must: be less
|
|
than or equal to the number of array elements in the descriptor set
|
|
binding specified by pname:dstBinding, and all applicable consecutive
|
|
bindings, as described by <<descriptorsets-updates-consecutive>>
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00322]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_SAMPLER,
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
|
|
ename:VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE,
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, or
|
|
ename:VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, pname:pImageInfo must: be a
|
|
pointer to an array of pname:descriptorCount valid
|
|
sname:VkDescriptorImageInfo structures
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00323]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER
|
|
or ename:VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, pname:pTexelBufferView
|
|
must: be a pointer to an array of pname:descriptorCount valid
|
|
sname:VkBufferView handles
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00324]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER,
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, or
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, pname:pBufferInfo must:
|
|
be a pointer to an array of pname:descriptorCount valid
|
|
sname:VkDescriptorBufferInfo structures
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00325]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_SAMPLER or
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, and pname:dstSet was
|
|
not allocated with a layout that included immutable samplers for
|
|
pname:dstBinding with pname:descriptorType, the pname:sampler member of
|
|
any given element of pname:pImageInfo must: be a valid sname:VkSampler
|
|
object
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00326]]
|
|
If pname:descriptorType is
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
|
|
ename:VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE,
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, or
|
|
ename:VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, the pname:imageView and
|
|
pname:imageLayout members of any given element of pname:pImageInfo must:
|
|
be a valid sname:VkImageView and elink:VkImageLayout, respectively
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00327]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER or
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, the pname:offset member
|
|
of any given element of pname:pBufferInfo must: be a multiple of
|
|
sname:VkPhysicalDeviceLimits::pname:minUniformBufferOffsetAlignment
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00328]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER or
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, the pname:offset member
|
|
of any given element of pname:pBufferInfo must: be a multiple of
|
|
sname:VkPhysicalDeviceLimits::pname:minStorageBufferOffsetAlignment
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00329]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC,
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, or
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, the pname:buffer member
|
|
of any given element of pname:pBufferInfo that is non-sparse must: be
|
|
bound completely and contiguously to a single sname:VkDeviceMemory
|
|
object
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00330]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER or
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, the pname:buffer member
|
|
of any given element of pname:pBufferInfo must: have been created with
|
|
ename:VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT set
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00331]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER or
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, the pname:buffer member
|
|
of any given element of pname:pBufferInfo must: have been created with
|
|
ename:VK_BUFFER_USAGE_STORAGE_BUFFER_BIT set
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00332]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER or
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, the pname:range member
|
|
of any given element of pname:pBufferInfo, or the effective range if
|
|
pname:range is ename:VK_WHOLE_SIZE, must: be less than or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxUniformBufferRange
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00333]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER or
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, the pname:range member
|
|
of any given element of pname:pBufferInfo, or the effective range if
|
|
pname:range is ename:VK_WHOLE_SIZE, must: be less than or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxStorageBufferRange
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00334]]
|
|
If pname:descriptorType is
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER, the sname:VkBuffer that
|
|
any given element of pname:pTexelBufferView was created from must: have
|
|
been created with ename:VK_BUFFER_USAGE_UNIFORM_TEXEL_BUFFER_BIT set
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00335]]
|
|
If pname:descriptorType is
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, the sname:VkBuffer that
|
|
any given element of pname:pTexelBufferView was created from must: have
|
|
been created with ename:VK_BUFFER_USAGE_STORAGE_TEXEL_BUFFER_BIT set
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00336]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_STORAGE_IMAGE or
|
|
ename:VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, the pname:imageView member of
|
|
any given element of pname:pImageInfo must: have been created with the
|
|
identity swizzle
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00337]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE or
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, the pname:imageView
|
|
member of any given element of pname:pImageInfo must: have been created
|
|
with ename:VK_IMAGE_USAGE_SAMPLED_BIT set
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00338]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT,
|
|
the pname:imageView member of any given element of pname:pImageInfo
|
|
must: have been created with ename:VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT
|
|
set
|
|
* [[VUID-VkWriteDescriptorSet-descriptorType-00339]]
|
|
If pname:descriptorType is ename:VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, the
|
|
pname:imageView member of any given element of pname:pImageInfo must:
|
|
have been created with ename:VK_IMAGE_USAGE_STORAGE_BIT set
|
|
****
|
|
|
|
include::../validity/structs/VkWriteDescriptorSet.txt[]
|
|
|
|
// refBegin VkDescriptorType Specifies the type of a descriptor in a descriptor set
|
|
|
|
The type of descriptors in a descriptor set is specified by
|
|
slink:VkWriteDescriptorSet::pname:descriptorType, which must: be one of the
|
|
values:
|
|
|
|
include::../api/enums/VkDescriptorType.txt[]
|
|
|
|
* ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER,
|
|
ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, or
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC specify that the
|
|
elements of the slink:VkWriteDescriptorSet::pname:pBufferInfo array of
|
|
slink:VkDescriptorBufferInfo structures will be used to update the
|
|
descriptors, and other arrays will be ignored.
|
|
* ename:VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER or
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER specify that the
|
|
slink:VkWriteDescriptorSet::pname:pTexelBufferView array will be used to
|
|
update the descriptors, and other arrays will be ignored.
|
|
* ename:VK_DESCRIPTOR_TYPE_SAMPLER,
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
|
|
ename:VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE,
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, or
|
|
ename:VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT specify that the elements of
|
|
the slink:VkWriteDescriptorSet::pname:pImageInfo array of
|
|
slink:VkDescriptorImageInfo structures will be used to update the
|
|
descriptors, and other arrays will be ignored.
|
|
|
|
// refEnd VkDescriptorType
|
|
|
|
// refBegin VkDescriptorBufferInfo Structure specifying descriptor buffer info
|
|
|
|
The sname:VkDescriptorBufferInfo structure is defined as:
|
|
|
|
include::../api/structs/VkDescriptorBufferInfo.txt[]
|
|
|
|
* pname:buffer is the buffer resource.
|
|
* pname:offset is the offset in bytes from the start of pname:buffer.
|
|
Access to buffer memory via this descriptor uses addressing that is
|
|
relative to this starting offset.
|
|
* pname:range is the size in bytes that is used for this descriptor
|
|
update, or ename:VK_WHOLE_SIZE to use the range from pname:offset to the
|
|
end of the buffer.
|
|
+
|
|
--
|
|
[NOTE]
|
|
.Note
|
|
====
|
|
When using ename:VK_WHOLE_SIZE, the effective range must: not be larger than
|
|
the maximum range for the descriptor type
|
|
(<<features-limits-maxUniformBufferRange, maxUniformBufferRange>> or
|
|
<<features-limits-maxStorageBufferRange, maxStorageBufferRange>>).
|
|
This means that ename:VK_WHOLE_SIZE is not typically useful in the common
|
|
case where uniform buffer descriptors are suballocated from a buffer that is
|
|
much larger than pname:maxUniformBufferRange.
|
|
====
|
|
|
|
For ename:VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC and
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC descriptor types,
|
|
pname:offset is the base offset from which the dynamic offset is applied and
|
|
pname:range is the static size used for all dynamic offsets.
|
|
--
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkDescriptorBufferInfo-offset-00340]]
|
|
pname:offset must: be less than the size of pname:buffer
|
|
* [[VUID-VkDescriptorBufferInfo-range-00341]]
|
|
If pname:range is not equal to ename:VK_WHOLE_SIZE, pname:range must: be
|
|
greater than `0`
|
|
* [[VUID-VkDescriptorBufferInfo-range-00342]]
|
|
If pname:range is not equal to ename:VK_WHOLE_SIZE, pname:range must: be
|
|
less than or equal to the size of pname:buffer minus pname:offset
|
|
****
|
|
|
|
include::../validity/structs/VkDescriptorBufferInfo.txt[]
|
|
|
|
// refBegin VkDescriptorImageInfo Structure specifying descriptor image info
|
|
|
|
The sname:VkDescriptorImageInfo structure is defined as:
|
|
|
|
include::../api/structs/VkDescriptorImageInfo.txt[]
|
|
|
|
* pname:sampler is a sampler handle, and is used in descriptor updates for
|
|
types ename:VK_DESCRIPTOR_TYPE_SAMPLER and
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER if the binding being
|
|
updated does not use immutable samplers.
|
|
* pname:imageView is an image view handle, and is used in descriptor
|
|
updates for types ename:VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE,
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, and
|
|
ename:VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT.
|
|
* pname:imageLayout is the layout that the image subresources accessible
|
|
from pname:imageView will be in at the time this descriptor is accessed.
|
|
pname:imageLayout is used in descriptor updates for types
|
|
ename:VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE,
|
|
ename:VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
|
|
ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, and
|
|
ename:VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT.
|
|
|
|
Members of sname:VkDescriptorImageInfo that are not used in an update (as
|
|
described above) are ignored.
|
|
|
|
.Valid Usage
|
|
****
|
|
ifdef::VK_KHR_maintenance1[]
|
|
* [[VUID-VkDescriptorImageInfo-imageView-00343]]
|
|
pname:imageView must: not be 2D or 2D array image view created from a 3D
|
|
image
|
|
endif::VK_KHR_maintenance1[]
|
|
* [[VUID-VkDescriptorImageInfo-imageLayout-00344]]
|
|
pname:imageLayout must: match the actual elink:VkImageLayout of each
|
|
subresource accessible from pname:imageView at the time this descriptor
|
|
is accessed
|
|
****
|
|
|
|
|
|
include::../validity/structs/VkDescriptorImageInfo.txt[]
|
|
|
|
// refBegin VkCopyDescriptorSet Structure specifying a copy descriptor set operation
|
|
|
|
The sname:VkCopyDescriptorSet structure is defined as:
|
|
|
|
include::../api/structs/VkCopyDescriptorSet.txt[]
|
|
|
|
* pname:sType is the type of this structure.
|
|
* pname:pNext is `NULL` or a pointer to an extension-specific structure.
|
|
* pname:srcSet, pname:srcBinding, and pname:srcArrayElement are the source
|
|
set, binding, and array element, respectively.
|
|
* pname:dstSet, pname:dstBinding, and pname:dstArrayElement are the
|
|
destination set, binding, and array element, respectively.
|
|
* pname:descriptorCount is the number of descriptors to copy from the
|
|
source to destination.
|
|
If pname:descriptorCount is greater than the number of remaining array
|
|
elements in the source or destination binding, those affect consecutive
|
|
bindings in a manner similar to slink:VkWriteDescriptorSet above.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkCopyDescriptorSet-srcBinding-00345]]
|
|
pname:srcBinding must: be a valid binding within pname:srcSet
|
|
* [[VUID-VkCopyDescriptorSet-srcArrayElement-00346]]
|
|
The sum of pname:srcArrayElement and pname:descriptorCount must: be less
|
|
than or equal to the number of array elements in the descriptor set
|
|
binding specified by pname:srcBinding, and all applicable consecutive
|
|
bindings, as described by <<descriptorsets-updates-consecutive>>
|
|
* [[VUID-VkCopyDescriptorSet-dstBinding-00347]]
|
|
pname:dstBinding must: be a valid binding within pname:dstSet
|
|
* [[VUID-VkCopyDescriptorSet-dstArrayElement-00348]]
|
|
The sum of pname:dstArrayElement and pname:descriptorCount must: be less
|
|
than or equal to the number of array elements in the descriptor set
|
|
binding specified by pname:dstBinding, and all applicable consecutive
|
|
bindings, as described by <<descriptorsets-updates-consecutive>>
|
|
* [[VUID-VkCopyDescriptorSet-srcSet-00349]]
|
|
If pname:srcSet is equal to pname:dstSet, then the source and
|
|
destination ranges of descriptors must: not overlap, where the ranges
|
|
may: include array elements from consecutive bindings as described by
|
|
<<descriptorsets-updates-consecutive>>
|
|
****
|
|
|
|
include::../validity/structs/VkCopyDescriptorSet.txt[]
|
|
|
|
|
|
ifdef::VK_KHR_descriptor_update_template[]
|
|
[[descriptorsets-updates-with-template]]
|
|
=== Descriptor Update Templates
|
|
|
|
// refBegin VkDescriptorUpdateTemplateKHR Opaque handle to a descriptor update template
|
|
|
|
A descriptor update template specifies a mapping from descriptor update
|
|
information in host memory to descriptors in a descriptor set.
|
|
It is designed to avoid passing redundant information to the driver when
|
|
frequently updating the same set of descriptors in descriptor sets.
|
|
|
|
Descriptor update template objects are represented by
|
|
sname:VkDescriptorUpdateTemplateKHR handles:
|
|
|
|
include::../api/handles/VkDescriptorUpdateTemplateKHR.txt[]
|
|
|
|
// refEnd VkDescriptorUpdateTemplateKHR
|
|
|
|
=== Descriptor Set Updates with Templates
|
|
|
|
// refBegin vkCreateDescriptorUpdateTemplateKHR Create a new descriptor update template
|
|
|
|
Updating a large sname:VkDescriptorSet array can: be an expensive operation
|
|
since an application must: specify one slink:VkWriteDescriptorSet structure
|
|
for each descriptor or descriptor array to update, each of which
|
|
re-specifies the same state when updating the same descriptor in multiple
|
|
descriptor sets.
|
|
For cases when an application wishes to update the same set of descriptors
|
|
in multiple descriptor sets allocated using the same
|
|
sname:VkDescriptorSetLayout, flink:vkUpdateDescriptorSetWithTemplateKHR can:
|
|
be used as a replacement for flink:vkUpdateDescriptorSets.
|
|
|
|
sname:VkDescriptorUpdateTemplateKHR allows implementations to convert a set
|
|
of descriptor update operations on a single descriptor set to an internal
|
|
format that, in conjunction with flink:vkUpdateDescriptorSetWithTemplateKHR
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
or flink:vkCmdPushDescriptorSetWithTemplateKHR
|
|
endif::VK_KHR_push_descriptor[]
|
|
, can: be more efficient compared to calling flink:vkUpdateDescriptorSets
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
or flink:vkCmdPushDescriptorSetKHR
|
|
endif::VK_KHR_push_descriptor[]
|
|
.
|
|
The descriptors themselves are not specified in the
|
|
sname:VkDescriptorUpdateTemplateKHR, rather, offsets into an application
|
|
provided pointer to host memory are specified, which are combined with a
|
|
pointer passed to flink:vkUpdateDescriptorSetWithTemplateKHR
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
or flink:vkCmdPushDescriptorSetWithTemplateKHR
|
|
endif::VK_KHR_push_descriptor[]
|
|
.
|
|
This allows large batches of updates to be executed without having to
|
|
convert application data structures into a strictly-defined Vulkan data
|
|
structure.
|
|
|
|
To create a descriptor update template, call:
|
|
|
|
include::../api/protos/vkCreateDescriptorUpdateTemplateKHR.txt[]
|
|
|
|
* pname:device is the logical device that creates the descriptor update
|
|
template.
|
|
* pname:pCreateInfo is a pointer to an instance of the
|
|
slink:VkDescriptorUpdateTemplateCreateInfoKHR structure specifying the
|
|
set of descriptors to update with a single call to
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
flink:vkCmdPushDescriptorSetWithTemplateKHR or
|
|
endif::VK_KHR_push_descriptor[]
|
|
flink:vkUpdateDescriptorSetWithTemplateKHR.
|
|
* pname:pAllocator controls host memory allocation as described in the
|
|
<<memory-allocation, Memory Allocation>> chapter.
|
|
* pname:pDescriptorUpdateTemplate points to a
|
|
sname:VkDescriptorUpdateTemplateKHR handle in which the resulting
|
|
descriptor update template object is returned.
|
|
|
|
include::../validity/protos/vkCreateDescriptorUpdateTemplateKHR.txt[]
|
|
|
|
// refEnd vkCreateDescriptorUpdateTemplateKHR
|
|
|
|
// refBegin VkDescriptorUpdateTemplateCreateInfoKHR Structure specifying parameters of a newly created descriptor update template
|
|
|
|
The slink:VkDescriptorUpdateTemplateCreateInfoKHR structure is defined as:
|
|
include::../api/structs/VkDescriptorUpdateTemplateCreateInfoKHR.txt[]
|
|
|
|
* pname:sType is the type of this structure.
|
|
* pname:pNext is `NULL` or a pointer to an extension-specific structure.
|
|
* pname:flags is reserved for future use.
|
|
* pname:descriptorUpdateEntryCount is the number of elements in the
|
|
pname:pDescriptorUpdateEntries array.
|
|
* pname:pDescriptorUpdateEntries is a pointer to an array of
|
|
slink:VkDescriptorUpdateTemplateEntryKHR structures describing the
|
|
descriptors to be updated by the descriptor update template.
|
|
* pname:templateType Specifies the type of the descriptor update template.
|
|
If set to ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_DESCRIPTOR_SET_KHR it
|
|
can: only be used to update descriptor sets with a fixed
|
|
pname:descriptorSetLayout.
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
If set to ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_PUSH_DESCRIPTORS_KHR
|
|
it can: only be used to push descriptor sets using the provided
|
|
pname:pipelineBindPoint, pname:pipelineLayout, and pname:set number.
|
|
endif::VK_KHR_push_descriptor[]
|
|
* pname:descriptorSetLayout is the descriptor set layout the parameter
|
|
update template will be used with.
|
|
All descriptor sets which are going to be updated through the newly
|
|
created descriptor update template must: be created with this layout.
|
|
pname:descriptorSetLayout is the descriptor set layout used to build the
|
|
descriptor update template.
|
|
All descriptor sets which are going to be updated through the newly
|
|
created descriptor update template must: be created with a layout that
|
|
matches (is the same as, or defined identically to) this layout.
|
|
This parameter is ignored if pname:templateType is not
|
|
ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_DESCRIPTOR_SET_KHR.
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
* pname:pipelineBindPoint is a elink:VkPipelineBindPoint indicating
|
|
whether the descriptors will be used by graphics pipelines or compute
|
|
pipelines.
|
|
This parameter is ignored if pname:templateType is not
|
|
ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_PUSH_DESCRIPTORS_KHR
|
|
* pname:pipelineLayout is a sname:VkPipelineLayout object used to program
|
|
the bindings.
|
|
This parameter is ignored if pname:templateType is not
|
|
ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_PUSH_DESCRIPTORS_KHR
|
|
* pname:set is the set number of the descriptor set in the pipeline layout
|
|
that will be updated.
|
|
This parameter is ignored if pname:templateType is not
|
|
ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_PUSH_DESCRIPTORS_KHR
|
|
endif::VK_KHR_push_descriptor[]
|
|
ifndef::VK_KHR_push_descriptor[]
|
|
* pname:pipelineBindPoint is reserved for future use
|
|
* pname:pipelineLayout is reserved for future use
|
|
* pname:set is reserved for future use
|
|
endif::VK_KHR_push_descriptor[]
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkDescriptorUpdateTemplateCreateInfoKHR-templateType-00350]]
|
|
If pname:templateType is
|
|
ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_DESCRIPTOR_SET_KHR,
|
|
pname:descriptorSetLayout must: be a valid sname:VkDescriptorSetLayout
|
|
handle
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
* [[VUID-VkDescriptorUpdateTemplateCreateInfoKHR-templateType-00351]]
|
|
If pname:templateType is
|
|
ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_PUSH_DESCRIPTORS_KHR,
|
|
pname:pipelineBindPoint must: be a valid elink:VkPipelineBindPoint value
|
|
* [[VUID-VkDescriptorUpdateTemplateCreateInfoKHR-templateType-00352]]
|
|
If pname:templateType is
|
|
ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_PUSH_DESCRIPTORS_KHR,
|
|
pname:pipelineLayout must: be a valid sname:VkPipelineLayout handle
|
|
* [[VUID-VkDescriptorUpdateTemplateCreateInfoKHR-templateType-00353]]
|
|
If pname:templateType is
|
|
ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_PUSH_DESCRIPTORS_KHR, pname:set
|
|
must: be the unique set number in the pipeline layout that uses a
|
|
descriptor set layout that was created with
|
|
ename:VK_DESCRIPTOR_SET_LAYOUT_CREATE_PUSH_DESCRIPTOR_BIT_KHR
|
|
endif::VK_KHR_push_descriptor[]
|
|
****
|
|
|
|
|
|
include::../validity/structs/VkDescriptorUpdateTemplateCreateInfoKHR.txt[]
|
|
|
|
// refEnd VkDescriptorUpdateTemplateCreateInfoKHR
|
|
|
|
// refBegin VkDescriptorUpdateTemplateTypeKHR Indicates the valid usage of the descriptor update template
|
|
|
|
The descriptor update template type is determined by the
|
|
slink:VkDescriptorUpdateTemplateCreateInfoKHR::pname:templateType property,
|
|
which takes the following values:
|
|
|
|
include::../api/enums/VkDescriptorUpdateTemplateTypeKHR.txt[]
|
|
|
|
* ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_DESCRIPTOR_SET_KHR specifies
|
|
that the descriptor update template will be used for descriptor set
|
|
updates only.
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
* ename:VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_PUSH_DESCRIPTORS_KHR specifies
|
|
that the descriptor update template will be used for push descriptor
|
|
updates only.
|
|
endif::VK_KHR_push_descriptor[]
|
|
|
|
// refEnd VkDescriptorUpdateTemplateTypeKHR
|
|
|
|
|
|
// refBegin VkDescriptorUpdateTemplateEntryKHR Describes a single descriptor update of the descriptor update template
|
|
|
|
The sname:VkDescriptorUpdateTemplateEntryKHR structure is defined as:
|
|
include::../api/structs/VkDescriptorUpdateTemplateEntryKHR.txt[]
|
|
|
|
* pname:dstBinding is the descriptor binding to update when using this
|
|
descriptor update template.
|
|
* pname:dstArrayElement is the starting element in the array belonging to
|
|
pname:dstBinding.
|
|
* pname:descriptorCount is the number of descriptors to update.
|
|
If pname:descriptorCount is greater than the number of remaining array
|
|
elements in the destination binding, those affect consecutive bindings
|
|
in a manner similar to slink:VkWriteDescriptorSet above.
|
|
* pname:descriptorType is a elink:VkDescriptorType specifying the type of
|
|
the descriptor.
|
|
* pname:offset is the offset in bytes of the first binding in the raw data
|
|
structure.
|
|
* pname:stride is the stride in bytes between two consecutive array
|
|
elements of the descriptor update informations in the raw data
|
|
structure.
|
|
The actual pointer ptr for each array element j of update entry i is
|
|
computed using the following formula:
|
|
[source,c++]
|
|
---------------------------------------------------
|
|
const char *ptr = (const char *)pData + pDescriptorUpdateEntries[i].offset + j * pDescriptorUpdateEntries[i].stride
|
|
---------------------------------------------------
|
|
The stride is useful in case the bindings are stored in structs along
|
|
with other data.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-VkDescriptorUpdateTemplateEntryKHR-dstBinding-00354]]
|
|
pname:dstBinding must: be a valid binding in the descriptor set layout
|
|
implicitly specified when using a descriptor update template to update
|
|
descriptors.
|
|
* [[VUID-VkDescriptorUpdateTemplateEntryKHR-dstArrayElement-00355]]
|
|
pname:dstArrayElement and pname:descriptorCount must: be less than or
|
|
equal to the number of array elements in the descriptor set binding
|
|
implicitly specified when using a descriptor update template to update
|
|
descriptors, and all applicable consecutive bindings, as described by
|
|
<<descriptorsets-updates-consecutive>>
|
|
****
|
|
|
|
include::../validity/structs/VkDescriptorUpdateTemplateEntryKHR.txt[]
|
|
|
|
// refEnd VkDescriptorUpdateTemplateEntryKHR
|
|
|
|
// refBegin vkDestroyDescriptorUpdateTemplateKHR Destroy a descriptor update template object
|
|
|
|
To destroy a descriptor update template, call:
|
|
|
|
include::../api/protos/vkDestroyDescriptorUpdateTemplateKHR.txt[]
|
|
|
|
* pname:device is the logical device that has been used to create the
|
|
descriptor update template
|
|
* pname:descriptorUpdateTemplate is the descriptor update template to
|
|
destroy.
|
|
* pname:pAllocator controls host memory allocation as described in the
|
|
<<memory-allocation, Memory Allocation>> chapter.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkDestroyDescriptorUpdateTemplateKHR-descriptorSetLayout-00356]]
|
|
If sname:VkAllocationCallbacks were provided when
|
|
pname:descriptorSetLayout was created, a compatible set of callbacks
|
|
must: be provided here
|
|
* [[VUID-vkDestroyDescriptorUpdateTemplateKHR-descriptorSetLayout-00357]]
|
|
If no sname:VkAllocationCallbacks were provided when
|
|
pname:descriptorSetLayout was created, pname:pAllocator must: be `NULL`
|
|
****
|
|
|
|
include::../validity/protos/vkDestroyDescriptorUpdateTemplateKHR.txt[]
|
|
|
|
// refEnd vkDestroyDescriptorUpdateTemplateKHR
|
|
|
|
// refBegin vkUpdateDescriptorSetWithTemplateKHR Update the contents of a descriptor set object using an update template
|
|
|
|
Once a sname:VkDescriptorUpdateTemplateKHR has been created, descriptor sets
|
|
can: be updated by calling:
|
|
|
|
include::../api/protos/vkUpdateDescriptorSetWithTemplateKHR.txt[]
|
|
|
|
* pname:device is the logical device that updates the descriptor sets.
|
|
* pname:descriptorSet is the descriptor set to update
|
|
* pname:descriptorUpdateTemplate is the
|
|
sname:VkDescriptorUpdateTemplateKHR which specifies the update mapping
|
|
between the application pointer and the descriptor set to update.
|
|
* pname:pData is a pointer to memory which contains one or more structures
|
|
of slink:VkDescriptorImageInfo, slink:VkDescriptorBufferInfo, or
|
|
slink:VkBufferView used to write the descriptors.
|
|
|
|
include::../validity/protos/vkUpdateDescriptorSetWithTemplateKHR.txt[]
|
|
|
|
.API example
|
|
[source,c++]
|
|
---------------------------------------------------
|
|
|
|
struct AppBufferView {
|
|
VkBufferView bufferView;
|
|
uint32_t applicationRelatedInformation;
|
|
};
|
|
|
|
struct AppDataStructure
|
|
{
|
|
VkDescriptorImageInfo imageInfo; // a single image info
|
|
VkDescriptorBufferInfo bufferInfoArray[3]; // 3 buffer infos in an array
|
|
AppBufferView bufferView[2]; // An application defined structure containing a bufferView
|
|
// ... some more application related data
|
|
};
|
|
|
|
const VkDescriptorUpdateTemplateEntryKHR descriptorUpdateTemplateEntries[] =
|
|
{
|
|
// binding to a single image descriptor
|
|
{
|
|
0, // binding
|
|
0, // dstArrayElement
|
|
1, // descriptorCount
|
|
VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, // descriptorType
|
|
offsetof(AppDataStructure, imageInfo), // offset
|
|
0 // stride is not required if descriptorCount is 1.
|
|
},
|
|
|
|
// binding to an array of buffer descriptors
|
|
{
|
|
0, // binding
|
|
0, // dstArrayElement
|
|
3, // descriptorCount
|
|
VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, // descriptorType
|
|
offsetof(AppDataStructure, bufferInfoArray), // offset
|
|
sizeof(VkDescriptorBufferInfo) // stride, descriptor buffer infos are compact
|
|
},
|
|
|
|
// binding to an array of buffer views
|
|
{
|
|
0, // binding
|
|
3, // dstArrayElement
|
|
1, // descriptorCount
|
|
VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, // descriptorType
|
|
offsetof(AppDataStructure, bufferView), // offset
|
|
sizeof(AppBufferView) // stride, bufferViews do not have to be compact
|
|
},
|
|
};
|
|
|
|
// create an descriptor update template for descriptor set updates
|
|
const VkDescriptorUpdateTemplateCreateInfoKHR createInfo =
|
|
{
|
|
VK_STRUCTURE_TYPE_DESCRIPTOR_UPDATE_TEMPLATE_CREATE_INFO_KHR, // sType
|
|
NULL, // pNext
|
|
0, // flags
|
|
3, // descriptorUpdateEntryCount
|
|
descriptorUpdateTemplateEntries, // pDescriptorUpdateEntries
|
|
VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_DESCRIPTOR_SET_KHR, // templateType
|
|
myLayout, // descriptorSetLayout
|
|
0, // pipelineBindPoint, ignored by given templateType
|
|
0, // pipelineLayout, ignored by given templateType
|
|
0, // set, ignored by given templateType
|
|
};
|
|
|
|
VkDescriptorUpdateTemplateKHR myDescriptorUpdateTemplate;
|
|
myResult = vkCreatePipelineLayout(
|
|
myDevice,
|
|
&createInfo,
|
|
NULL,
|
|
&myDescriptorUpdateTemplate);
|
|
}
|
|
|
|
|
|
AppDataStructure appData;
|
|
|
|
// fill appData here or cache it in your engine
|
|
vkUpdateDescriptorSetWithTemplateKHR(myDevice, myDescriptorSet, myDescriptorUpdateTemplate, &appData);
|
|
---------------------------------------------------
|
|
|
|
// refEnd vkUpdateDescriptorSetWithTemplateKHR
|
|
|
|
endif::VK_KHR_descriptor_update_template[]
|
|
|
|
|
|
[[descriptorsets-binding]]
|
|
=== Descriptor Set Binding
|
|
|
|
// refBegin vkCmdBindDescriptorSets Binds descriptor sets to a command buffer
|
|
|
|
To bind one or more descriptor sets to a command buffer, call:
|
|
|
|
include::../api/protos/vkCmdBindDescriptorSets.txt[]
|
|
|
|
* pname:commandBuffer is the command buffer that the descriptor sets will
|
|
be bound to.
|
|
* pname:pipelineBindPoint is a elink:VkPipelineBindPoint indicating
|
|
whether the descriptors will be used by graphics pipelines or compute
|
|
pipelines.
|
|
There is a separate set of bind points for each of graphics and compute,
|
|
so binding one does not disturb the other.
|
|
* pname:layout is a sname:VkPipelineLayout object used to program the
|
|
bindings.
|
|
* pname:firstSet is the set number of the first descriptor set to be
|
|
bound.
|
|
* pname:descriptorSetCount is the number of elements in the
|
|
pname:pDescriptorSets array.
|
|
* pname:pDescriptorSets is an array of handles to sname:VkDescriptorSet
|
|
objects describing the descriptor sets to write to.
|
|
* pname:dynamicOffsetCount is the number of dynamic offsets in the
|
|
pname:pDynamicOffsets array.
|
|
* pname:pDynamicOffsets is a pointer to an array of code:uint32_t values
|
|
specifying dynamic offsets.
|
|
|
|
fname:vkCmdBindDescriptorSets causes the sets numbered [pname:firstSet..
|
|
pname:firstSet+pname:descriptorSetCount-1] to use the bindings stored in
|
|
pname:pDescriptorSets[0..pname:descriptorSetCount-1] for subsequent
|
|
rendering commands (either compute or graphics, according to the
|
|
pname:pipelineBindPoint).
|
|
Any bindings that were previously applied via these sets are no longer
|
|
valid.
|
|
|
|
Once bound, a descriptor set affects rendering of subsequent graphics or
|
|
compute commands in the command buffer until a different set is bound to the
|
|
same set number, or else until the set is disturbed as described in
|
|
<<descriptorsets-compatibility, Pipeline Layout Compatibility>>.
|
|
|
|
A compatible descriptor set must: be bound for all set numbers that any
|
|
shaders in a pipeline access, at the time that a draw or dispatch command is
|
|
recorded to execute using that pipeline.
|
|
However, if none of the shaders in a pipeline statically use any bindings
|
|
with a particular set number, then no descriptor set need be bound for that
|
|
set number, even if the pipeline layout includes a non-trivial descriptor
|
|
set layout for that set number.
|
|
|
|
If any of the sets being bound include dynamic uniform or storage buffers,
|
|
then pname:pDynamicOffsets includes one element for each array element in
|
|
each dynamic descriptor type binding in each set.
|
|
Values are taken from pname:pDynamicOffsets in an order such that all
|
|
entries for set N come before set N+1; within a set, entries are ordered by
|
|
the binding numbers in the descriptor set layouts; and within a binding
|
|
array, elements are in order.
|
|
pname:dynamicOffsetCount must: equal the total number of dynamic descriptors
|
|
in the sets being bound.
|
|
|
|
The effective offset used for dynamic uniform and storage buffer bindings is
|
|
the sum of the relative offset taken from pname:pDynamicOffsets, and the
|
|
base address of the buffer plus base offset in the descriptor set.
|
|
The length of the dynamic uniform and storage buffer bindings is the buffer
|
|
range as specified in the descriptor set.
|
|
|
|
Each of the pname:pDescriptorSets must: be compatible with the pipeline
|
|
layout specified by pname:layout.
|
|
The layout used to program the bindings must: also be compatible with the
|
|
pipeline used in subsequent graphics or compute commands, as defined in the
|
|
<<descriptorsets-compatibility, Pipeline Layout Compatibility>> section.
|
|
|
|
The descriptor set contents bound by a call to fname:vkCmdBindDescriptorSets
|
|
may: be consumed during host execution of the command, or during shader
|
|
execution of the resulting draws, or any time in between.
|
|
Thus, the contents must: not be altered (overwritten by an update command,
|
|
or freed) between when the command is recorded and when the command
|
|
completes executing on the queue.
|
|
The contents of pname:pDynamicOffsets are consumed immediately during
|
|
execution of fname:vkCmdBindDescriptorSets.
|
|
Once all pending uses have completed, it is legal to update and reuse a
|
|
descriptor set.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkCmdBindDescriptorSets-pDescriptorSets-00358]]
|
|
Any given element of pname:pDescriptorSets must: have been allocated
|
|
with a sname:VkDescriptorSetLayout that matches (is the same as, or
|
|
identically defined as) the sname:VkDescriptorSetLayout at set _n_ in
|
|
pname:layout, where _n_ is the sum of pname:firstSet and the index into
|
|
pname:pDescriptorSets
|
|
* [[VUID-vkCmdBindDescriptorSets-dynamicOffsetCount-00359]]
|
|
pname:dynamicOffsetCount must: be equal to the total number of dynamic
|
|
descriptors in pname:pDescriptorSets
|
|
* [[VUID-vkCmdBindDescriptorSets-firstSet-00360]]
|
|
The sum of pname:firstSet and pname:descriptorSetCount must: be less
|
|
than or equal to sname:VkPipelineLayoutCreateInfo::pname:setLayoutCount
|
|
provided when pname:layout was created
|
|
* [[VUID-vkCmdBindDescriptorSets-pipelineBindPoint-00361]]
|
|
pname:pipelineBindPoint must: be supported by the pname:commandBuffer's
|
|
parent sname:VkCommandPool's queue family
|
|
* [[VUID-vkCmdBindDescriptorSets-pDynamicOffsets-00362]]
|
|
Any given element of pname:pDynamicOffsets must: satisfy the required
|
|
alignment for the corresponding descriptor binding's descriptor type
|
|
****
|
|
|
|
include::../validity/protos/vkCmdBindDescriptorSets.txt[]
|
|
|
|
|
|
ifdef::VK_KHR_push_descriptor[]
|
|
[[descriptorsets-push-descriptors]]
|
|
=== Push Descriptor Updates
|
|
|
|
// refBegin vkCmdPushDescriptorSetKHR Pushes descriptor updates into a command buffer
|
|
|
|
In addition to allocating descriptor sets and binding them to a command
|
|
buffer, an application can: record descriptor updates into the command
|
|
buffer.
|
|
|
|
To push descriptor updates into a command buffer, call:
|
|
|
|
include::../api/protos/vkCmdPushDescriptorSetKHR.txt[]
|
|
|
|
* pname:commandBuffer is the command buffer that the descriptors will be
|
|
recorded in.
|
|
* pname:pipelineBindPoint is a elink:VkPipelineBindPoint indicating
|
|
whether the descriptors will be used by graphics pipelines or compute
|
|
pipelines.
|
|
There is a separate set of push descriptor bindings for each of graphics
|
|
and compute, so binding one does not disturb the other.
|
|
* pname:layout is a sname:VkPipelineLayout object used to program the
|
|
bindings.
|
|
* pname:set is the set number of the descriptor set in the pipeline layout
|
|
that will be updated.
|
|
* pname:descriptorWriteCount is the number of elements in the
|
|
pname:pDescriptorWrites array.
|
|
* pname:pDescriptorWrites is a pointer to an array of
|
|
slink:VkWriteDescriptorSet structures describing the descriptors to be
|
|
updated.
|
|
|
|
_Push descriptors_ are a small bank of descriptors whose storage is
|
|
internally managed by the command buffer rather than being written into a
|
|
descriptor set and later bound to a command buffer.
|
|
Push descriptors allow for incremental updates of descriptors without
|
|
managing the lifetime of descriptor sets.
|
|
|
|
When a command buffer begins recording, all push descriptors have undefined
|
|
contents.
|
|
Push descriptors can: be updated incrementally and cause shaders to use the
|
|
updated descriptors for subsequent rendering commands (either compute or
|
|
graphics, according to the pname:pipelineBindPoint) until the descriptor is
|
|
overwritten, or else until the set is disturbed as described in
|
|
<<descriptorsets-compatibility, Pipeline Layout Compatibility>>.
|
|
When the set is disturbed or push descriptors with a different descriptor
|
|
set layout are set, all push descriptors become invalid.
|
|
|
|
Valid descriptors must: be pushed for all bindings that any shaders in a
|
|
pipeline access, at the time that a draw or dispatch command is recorded to
|
|
execute using that pipeline.
|
|
This includes immutable sampler descriptors, which must: be pushed before
|
|
they are accessed by a pipeline.
|
|
However, if none of the shaders in a pipeline statically use certain
|
|
bindings in the push descriptor set, then those descriptors need not be
|
|
valid.
|
|
|
|
Push descriptors do not use dynamic offsets.
|
|
Instead, the corresponding non-dynamic descriptor types can: be used and the
|
|
pname:offset member of slink:VkDescriptorBufferInfo can: be changed each
|
|
time the descriptor is written.
|
|
|
|
Each element of pname:pDescriptorWrites is interpreted as in
|
|
slink:VkWriteDescriptorSet, except the pname:dstSet member is ignored.
|
|
|
|
To push an immutable sampler, use a slink:VkWriteDescriptorSet with
|
|
pname:dstBinding and pname:dstArrayElement selecting the immutable sampler's
|
|
binding.
|
|
If the descriptor type is ename:VK_DESCRIPTOR_TYPE_SAMPLER, the
|
|
pname:pImageInfo parameter is ignored and the immutable sampler is taken
|
|
from the push descriptor set layout in the pipeline layout.
|
|
If the descriptor type is ename:VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
|
|
the pname:sampler member of the the pname:pImageInfo parameter is ignored
|
|
and the immutable sampler is taken from the push descriptor set layout in
|
|
the pipeline layout.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkCmdPushDescriptorSetKHR-pipelineBindPoint-00363]]
|
|
pname:pipelineBindPoint must: be supported by the pname:commandBuffer's
|
|
parent sname:VkCommandPool's queue family
|
|
* [[VUID-vkCmdPushDescriptorSetKHR-set-00364]]
|
|
pname:set must: be less than
|
|
sname:VkPipelineLayoutCreateInfo::pname:setLayoutCount provided when
|
|
pname:layout was created
|
|
* [[VUID-vkCmdPushDescriptorSetKHR-set-00365]]
|
|
pname:set must: be the unique set number in the pipeline layout that
|
|
uses a descriptor set layout that was created with
|
|
ename:VK_DESCRIPTOR_SET_LAYOUT_CREATE_PUSH_DESCRIPTOR_BIT_KHR
|
|
****
|
|
|
|
include::../validity/protos/vkCmdPushDescriptorSetKHR.txt[]
|
|
|
|
// refEnd vkCmdPushDescriptorSetKHR
|
|
|
|
ifdef::VK_KHR_descriptor_update_template[]
|
|
=== Push Descriptor Updates with Descriptor Update Templates
|
|
|
|
// refBegin vkCmdPushDescriptorSetWithTemplateKHR Pushes descriptor updates into a command buffer using a descriptor update template
|
|
|
|
It is also possible to use a descriptor update template to specify the push
|
|
descriptors to update.
|
|
To do so, call:
|
|
|
|
include::../api/protos/vkCmdPushDescriptorSetWithTemplateKHR.txt[]
|
|
|
|
* pname:commandBuffer is the command buffer that the descriptors will be
|
|
recorded in.
|
|
* pname:descriptorUpdateTemplate A descriptor update template which
|
|
defines how to interpret the descriptor information in pData.
|
|
* pname:layout is a sname:VkPipelineLayout object used to program the
|
|
bindings.
|
|
It must: be compatible with the layout used to create the
|
|
pname:descriptorUpdateTemplate handle.
|
|
* pname:set is the set number of the descriptor set in the pipeline layout
|
|
that will be updated.
|
|
This must: be the same number used to create the
|
|
pname:descriptorUpdateTemplate handle.
|
|
* pname:pData Points to memory which contains the descriptors for the
|
|
templated update.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkCmdPushDescriptorSetWithTemplateKHR-commandBuffer-00366]]
|
|
The pipelineBindPoint specified during the creation of the descriptor
|
|
update template must: be supported by the pname:commandBuffer's parent
|
|
sname:VkCommandPool's queue family
|
|
****
|
|
|
|
include::../validity/protos/vkCmdPushDescriptorSetWithTemplateKHR.txt[]
|
|
|
|
.API example
|
|
[source,c++]
|
|
---------------------------------------------------
|
|
|
|
struct AppBufferView {
|
|
VkBufferView bufferView;
|
|
uint32_t applicationRelatedInformation;
|
|
};
|
|
|
|
struct AppDataStructure
|
|
{
|
|
VkDescriptorImageInfo imageInfo; // a single image info
|
|
// ... some more application related data
|
|
};
|
|
|
|
const VkDescriptorUpdateTemplateEntryKHR descriptorUpdateTemplateEntries[] =
|
|
{
|
|
// binding to a single image descriptor
|
|
{
|
|
0, // binding
|
|
0, // dstArrayElement
|
|
1, // descriptorCount
|
|
VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, // descriptorType
|
|
offsetof(AppDataStructure, imageInfo), // offset
|
|
0 // stride is not required if descriptorCount is 1.
|
|
}
|
|
|
|
};
|
|
|
|
// create an descriptor update template for descriptor set updates
|
|
const VkDescriptorUpdateTemplateCreateInfoKHR createInfo =
|
|
{
|
|
VK_STRUCTURE_TYPE_DESCRIPTOR_UPDATE_TEMPLATE_CREATE_INFO_KHR, // sType
|
|
NULL, // pNext
|
|
0, // flags
|
|
1, // descriptorUpdateEntryCount
|
|
descriptorUpdateTemplateEntries, // pDescriptorUpdateEntries
|
|
VK_DESCRIPTOR_UPDATE_TEMPLATE_TYPE_PUSH_DESCRIPTORS_KHR, // templateType
|
|
0, // descriptorSetLayout, ignored by given templateType
|
|
VK_PIPELINE_BIND_POINT_GRAPHICS, // pipelineBindPoint
|
|
myPipelineLayout, // pipelineLayout
|
|
0, // set
|
|
};
|
|
|
|
VkDescriptorUpdateTemplateKHR myDescriptorUpdateTemplate;
|
|
myResult = vkCreatePipelineLayout(
|
|
myDevice,
|
|
&createInfo,
|
|
NULL,
|
|
&myDescriptorUpdateTemplate);
|
|
}
|
|
|
|
AppDataStructure appData;
|
|
// fill appData here or cache it in your engine
|
|
vkCmdPushDescriptorSetWithTemplateKHR(myCmdBuffer, myDescriptorUpdateTemplate, myPipelineLayout, 0,&appData);
|
|
---------------------------------------------------
|
|
|
|
// refEnd vkCmdPushDescriptorSetWithTemplateKHR
|
|
endif::VK_KHR_descriptor_update_template[]
|
|
|
|
endif::VK_KHR_push_descriptor[]
|
|
|
|
|
|
=== Push Constant Updates
|
|
|
|
[[descriptorsets-push-constants]]
|
|
|
|
As described above in section <<descriptorsets-pipelinelayout, Pipeline
|
|
Layouts>>, the pipeline layout defines shader push constants which are
|
|
updated via Vulkan commands rather than via writes to memory or copy
|
|
commands.
|
|
|
|
[NOTE]
|
|
.Note
|
|
====
|
|
Push constants represent a high speed path to modify constant data in
|
|
pipelines that is expected to outperform memory-backed resource updates.
|
|
====
|
|
|
|
The values of push constants are undefined at the start of a command buffer.
|
|
|
|
// refBegin vkCmdPushConstants Update the values of push constants
|
|
|
|
To update push constants, call:
|
|
|
|
include::../api/protos/vkCmdPushConstants.txt[]
|
|
|
|
* pname:commandBuffer is the command buffer in which the push constant
|
|
update will be recorded.
|
|
* pname:layout is the pipeline layout used to program the push constant
|
|
updates.
|
|
* pname:stageFlags is a bitmask of elink:VkShaderStageFlagBits specifying
|
|
the shader stages that will use the push constants in the updated range.
|
|
* pname:offset is the start offset of the push constant range to update,
|
|
in units of bytes.
|
|
* pname:size is the size of the push constant range to update, in units of
|
|
bytes.
|
|
* pname:pValues is an array of pname:size bytes containing the new push
|
|
constant values.
|
|
|
|
.Valid Usage
|
|
****
|
|
* [[VUID-vkCmdPushConstants-stageFlags-00367]]
|
|
pname:stageFlags must: match exactly the shader stages used in
|
|
pname:layout for the range specified by pname:offset and pname:size
|
|
* [[VUID-vkCmdPushConstants-offset-00368]]
|
|
pname:offset must: be a multiple of `4`
|
|
* [[VUID-vkCmdPushConstants-size-00369]]
|
|
pname:size must: be a multiple of `4`
|
|
* [[VUID-vkCmdPushConstants-offset-00370]]
|
|
pname:offset must: be less than
|
|
sname:VkPhysicalDeviceLimits::pname:maxPushConstantsSize
|
|
* [[VUID-vkCmdPushConstants-size-00371]]
|
|
pname:size must: be less than or equal to
|
|
sname:VkPhysicalDeviceLimits::pname:maxPushConstantsSize minus
|
|
pname:offset
|
|
****
|
|
|
|
include::../validity/protos/vkCmdPushConstants.txt[]
|