C Specification
The VkMemoryDedicatedRequirements structure is defined as:
// Provided by VK_VERSION_1_1
typedef struct VkMemoryDedicatedRequirements {
VkStructureType sType;
void* pNext;
VkBool32 prefersDedicatedAllocation;
VkBool32 requiresDedicatedAllocation;
} VkMemoryDedicatedRequirements;
or the equivalent
// Provided by VK_KHR_dedicated_allocation
typedef VkMemoryDedicatedRequirements VkMemoryDedicatedRequirementsKHR;
Members
-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
prefersDedicatedAllocationspecifies that the implementation would prefer a dedicated allocation for this resource. The application is still free to suballocate the resource but it may get better performance if a dedicated allocation is used. -
requiresDedicatedAllocationspecifies that a dedicated allocation is required for this resource.
Description
To determine the dedicated allocation requirements of a buffer or image
resource, add a VkMemoryDedicatedRequirements structure to the
pNext chain of the VkMemoryRequirements2 structure passed as the
pMemoryRequirements parameter of vkGetBufferMemoryRequirements2
or vkGetImageMemoryRequirements2, respectively.
Constraints on the values returned for buffer resources are:
-
requiresDedicatedAllocationmay beVK_TRUEif thepNextchain of VkBufferCreateInfo for the call tovkCreateBufferused to create the buffer being queried included a VkExternalMemoryBufferCreateInfo structure, and any of the handle types specified in VkExternalMemoryBufferCreateInfo::handleTypesrequires dedicated allocation, as reported by vkGetPhysicalDeviceExternalBufferProperties inVkExternalBufferProperties::externalMemoryProperties.externalMemoryFeatures. Otherwise,requiresDedicatedAllocationwill beVK_FALSE. -
When the implementation sets
requiresDedicatedAllocationtoVK_TRUE, it must also setprefersDedicatedAllocationtoVK_TRUE. -
If
VK_BUFFER_CREATE_SPARSE_BINDING_BITwas set in VkBufferCreateInfo::flagswhenbufferwas created, then bothprefersDedicatedAllocationandrequiresDedicatedAllocationwill beVK_FALSE.
Constraints on the values returned for image resources are:
-
requiresDedicatedAllocationmay beVK_TRUEif thepNextchain of VkImageCreateInfo for the call to vkCreateImage used to create the image being queried included a VkExternalMemoryImageCreateInfo structure, and any of the handle types specified in VkExternalMemoryImageCreateInfo::handleTypesrequires dedicated allocation, as reported by vkGetPhysicalDeviceImageFormatProperties2 inVkExternalImageFormatProperties::externalMemoryProperties.externalMemoryFeatures. -
requiresDedicatedAllocationmay beVK_TRUEif the image’s tiling isVK_IMAGE_TILING_DRM_FORMAT_MODIFIER_EXT. -
requiresDedicatedAllocationwill otherwise beVK_FALSE -
If
VK_IMAGE_CREATE_SPARSE_BINDING_BITwas set in VkImageCreateInfo::flagswhenimagewas created, then bothprefersDedicatedAllocationandrequiresDedicatedAllocationwill beVK_FALSE.
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.