# VkDescriptorSetVariableDescriptorCountLayoutSupport(3) Manual Page

## Name

VkDescriptorSetVariableDescriptorCountLayoutSupport - Structure returning information about whether a descriptor set layout can be supported

## C Specification

If the `pNext` chain of a VkDescriptorSetLayoutSupport structure includes a `VkDescriptorSetVariableDescriptorCountLayoutSupport` structure, then that structure returns additional information about whether the descriptor set layout is supported.

    typedef struct VkDescriptorSetVariableDescriptorCountLayoutSupport {
        VkStructureType    sType;
        void*              pNext;
        uint32_t           maxVariableDescriptorCount;
    } VkDescriptorSetVariableDescriptorCountLayoutSupport;

or the equivalent

    typedef VkDescriptorSetVariableDescriptorCountLayoutSupport VkDescriptorSetVariableDescriptorCountLayoutSupportEXT;

## Members

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to an extension-specific structure.

- `maxVariableDescriptorCount` indicates the maximum number of descriptors supported in the highest numbered binding of the layout, if that binding is variable-sized. If the highest numbered binding of the layout has a descriptor type of `VK_DESCRIPTOR_TYPE_INLINE_UNIFORM_BLOCK_EXT` then `maxVariableDescriptorCount` indicates the maximum byte size supported for the binding, if that binding is variable-sized.

## Description

If the create info includes a variable-sized descriptor, then `supported` is determined assuming the requested size of the variable-sized descriptor, and `maxVariableDescriptorCount` is set to the maximum size of that descriptor that can be successfully created (which is greater than or equal to the requested size passed in). If the create info does not include a variable-sized descriptor or if the VkPhysicalDeviceDescriptorIndexingFeatures::`descriptorBindingVariableDescriptorCount` feature is not enabled, then `maxVariableDescriptorCount` is set to zero. For the purposes of this command, a variable-sized descriptor binding with a `descriptorCount` of zero is treated as if the `descriptorCount` is one, and thus the binding is not ignored and the maximum descriptor count will be returned. If the layout is not supported, then the value written to `maxVariableDescriptorCount` is undefined.

Valid Usage (Implicit)

- `sType` must be `VK_STRUCTURE_TYPE_DESCRIPTOR_SET_VARIABLE_DESCRIPTOR_COUNT_LAYOUT_SUPPORT`

## See Also

VkStructureType

## Document Notes

For more information, see the Vulkan Specification

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

## Copyright

Copyright (c) 2014-2020 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.