## C Specification

The type of descriptors in a descriptor set is specified by VkWriteDescriptorSet::descriptorType, which must be one of the values:

// Provided by VK_VERSION_1_0
typedef enum VkDescriptorType {
VK_DESCRIPTOR_TYPE_SAMPLER = 0,
VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER = 1,
VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE = 2,
VK_DESCRIPTOR_TYPE_STORAGE_IMAGE = 3,
VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER = 4,
VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER = 5,
VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER = 6,
VK_DESCRIPTOR_TYPE_STORAGE_BUFFER = 7,
VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC = 8,
VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC = 9,
VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT = 10,
// Provided by VK_EXT_inline_uniform_block
VK_DESCRIPTOR_TYPE_INLINE_UNIFORM_BLOCK_EXT = 1000138000,
// Provided by VK_KHR_acceleration_structure
VK_DESCRIPTOR_TYPE_ACCELERATION_STRUCTURE_KHR = 1000150000,
// Provided by VK_NV_ray_tracing
VK_DESCRIPTOR_TYPE_ACCELERATION_STRUCTURE_NV = 1000165000,
// Provided by VK_VALVE_mutable_descriptor_type
VK_DESCRIPTOR_TYPE_MUTABLE_VALVE = 1000351000,
} VkDescriptorType;

## Description

When a descriptor set is updated via elements of VkWriteDescriptorSet, members of pImageInfo, pBufferInfo and pTexelBufferView are only accessed by the implementation when they correspond to descriptor type being defined - otherwise they are ignored. The members accessed are as follows for each descriptor type:

• For VK_DESCRIPTOR_TYPE_SAMPLER, only the sampler member of each element of VkWriteDescriptorSet::pImageInfo is accessed.

• For VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, or VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, only the imageView and imageLayout members of each element of VkWriteDescriptorSet::pImageInfo are accessed.

• For VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, all members of each element of VkWriteDescriptorSet::pImageInfo are accessed.

• For VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, or VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, all members of each element of VkWriteDescriptorSet::pBufferInfo are accessed.

• For VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER or VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, each element of VkWriteDescriptorSet::pTexelBufferView is accessed.

When updating descriptors with a descriptorType of VK_DESCRIPTOR_TYPE_INLINE_UNIFORM_BLOCK_EXT, none of the pImageInfo, pBufferInfo, or pTexelBufferView members are accessed, instead the source data of the descriptor update operation is taken from the VkWriteDescriptorSetInlineUniformBlockEXT structure in the pNext chain of VkWriteDescriptorSet. When updating descriptors with a descriptorType of VK_DESCRIPTOR_TYPE_ACCELERATION_STRUCTURE_KHR, none of the pImageInfo, pBufferInfo, or pTexelBufferView members are accessed, instead the source data of the descriptor update operation is taken from the VkWriteDescriptorSetAccelerationStructureKHR structure in the pNext chain of VkWriteDescriptorSet. When updating descriptors with a descriptorType of VK_DESCRIPTOR_TYPE_ACCELERATION_STRUCTURE_NV, none of the pImageInfo, pBufferInfo, or pTexelBufferView members are accessed, instead the source data of the descriptor update operation is taken from the VkWriteDescriptorSetAccelerationStructureNV structure in the pNext chain of VkWriteDescriptorSet.