vkAllocateDescriptorSets

To allocate descriptor sets from a descriptor pool, call:

VkResult vkAllocateDescriptorSets(
    VkDevice device,
    const VkDescriptorSetAllocateInfo* pAllocateInfo,
    VkDescriptorSet* pDescriptorSets);

• device is the logical device that owns the descriptor pool.
• pAllocateInfo is a pointer to a VkDescriptorSetAllocateInfo structure describing parameters of the allocation.
• pDescriptorSets is a pointer to an array of VkDescriptorSet handles in which the resulting descriptor set objects are returned.

The allocated descriptor sets are returned in pDescriptorSets.

When a descriptor set is allocated, the initial state is largely uninitialized and all descriptors are undefined:, with the exception that samplers with a non-null pImmutableSamplers are initialized on allocation. Descriptors also become undefined: if the underlying resource or view object is destroyed. Descriptor sets containing undefined: descriptors can still be bound and used, subject to the following conditions:

• For descriptor set bindings created with the VK_DESCRIPTOR_BINDING_PARTIALLY_BOUND_BIT bit set, all descriptors in that binding that are dynamically used must have been populated before the descriptor set is consumed.
• For descriptor set bindings created without the VK_DESCRIPTOR_BINDING_PARTIALLY_BOUND_BIT bit set, all descriptors in that binding that are statically used must have been populated before the descriptor set is consumed.
• Descriptor bindings with descriptor type of VK_DESCRIPTOR_TYPE_INLINE_UNIFORM_BLOCK can be undefined: when the descriptor set is consumed; though values in that block will be undefined:.
• Entries that are not used by a pipeline can have undefined: descriptors.

If a call to vkAllocateDescriptorSets would cause the total number of descriptor sets allocated from the pool to exceed the value of VkDescriptorPoolCreateInfo::maxSets used to create pAllocateInfo→descriptorPool, then the allocation may fail due to lack of space in the descriptor pool. Similarly, the allocation may fail due to lack of space if the call to vkAllocateDescriptorSets would cause the number of any given descriptor type to exceed the sum of all the descriptorCount members of each element of VkDescriptorPoolCreateInfo::pPoolSizes with a type equal to that type.

Additionally, the allocation may also fail if a call to vkAllocateDescriptorSets would cause the total number of inline uniform block bindings allocated from the pool to exceed the value of VkDescriptorPoolInlineUniformBlockCreateInfo::maxInlineUniformBlockBindings used to create the descriptor pool.

If the allocation fails due to no more space in the descriptor pool, and not because of system or device memory exhaustion, then VK_ERROR_OUT_OF_POOL_MEMORY must be returned.

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 pDescriptorSets array to VK_NULL_HANDLE and return the error.