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
-
sType
is a VkStructureType value identifying this structure. -
pNext
isNULL
or a pointer to a structure extending this structure. -
prefersDedicatedAllocation
specifies 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. -
requiresDedicatedAllocation
specifies 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:
-
requiresDedicatedAllocation
may beVK_TRUE
if thepNext
chain of VkBufferCreateInfo for the call tovkCreateBuffer
used to create the buffer being queried included a VkExternalMemoryBufferCreateInfo structure, and any of the handle types specified in VkExternalMemoryBufferCreateInfo::handleTypes
requires dedicated allocation, as reported by vkGetPhysicalDeviceExternalBufferProperties inVkExternalBufferProperties
::externalMemoryProperties.externalMemoryFeatures
. Otherwise,requiresDedicatedAllocation
will beVK_FALSE
. -
When the implementation sets
requiresDedicatedAllocation
toVK_TRUE
, it must also setprefersDedicatedAllocation
toVK_TRUE
. -
If
VK_BUFFER_CREATE_SPARSE_BINDING_BIT
was set in VkBufferCreateInfo::flags
whenbuffer
was created, then bothprefersDedicatedAllocation
andrequiresDedicatedAllocation
will beVK_FALSE
.
Constraints on the values returned for image resources are:
-
requiresDedicatedAllocation
may beVK_TRUE
if thepNext
chain 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::handleTypes
requires dedicated allocation, as reported by vkGetPhysicalDeviceImageFormatProperties2 inVkExternalImageFormatProperties
::externalMemoryProperties.externalMemoryFeatures
. -
requiresDedicatedAllocation
may beVK_TRUE
if the image’s tiling isVK_IMAGE_TILING_DRM_FORMAT_MODIFIER_EXT
. -
requiresDedicatedAllocation
will otherwise beVK_FALSE
-
If
VK_IMAGE_CREATE_SPARSE_BINDING_BIT
was set in VkImageCreateInfo::flags
whenimage
was created, then bothprefersDedicatedAllocation
andrequiresDedicatedAllocation
will 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.