Vulkan-Docs/doc/specs/vulkan/appendices/VK_NV_dedicated_allocation.txt

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[[VK_NV_dedicated_allocation]]
== VK_NV_dedicated_allocation
*Name String*::
+VK_NV_dedicated_allocation+
*Extension Type*::
Device extension
*Registered Extension Number*::
27
*Status*::
Draft.
*Last Modified Date*::
2016-05-31
*Revision*::
1
*IP Status*::
No known IP claims.
*Dependencies*::
- This extension is written against version 1.0.
of the Vulkan API.
*Contributors*::
- Jeff Bolz, NVIDIA
*Contacts*::
- Jeff Bolz (jbolz 'at' nvidia.com)
This extension allows device memory to be allocated for a particular buffer
or image resource, which on some devices can significantly improve the
performance of that resource.
Normal device memory allocations must support memory aliasing and sparse
binding, which could interfere with optimizations like framebuffer
compression or efficient page table usage.
This is important for render targets and very large resources, but need not
(and probably should not) be used for smaller resources that can benefit
from suballocation.
This extension adds a few small structures to resource creation and memory
allocation: a new structure that flags whether am image/buffer will have a
dedicated allocation, and a structure indicating the image or buffer that an
allocation will be bound to.
=== New Object Types
None.
=== New Enum Constants
* Extending elink:VkStructureType:
** ename:VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_IMAGE_CREATE_INFO_NV
** ename:VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_BUFFER_CREATE_INFO_NV
** ename:VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_MEMORY_ALLOCATE_INFO_NV
=== New Enums
None.
=== New Structures
* slink:VkDedicatedAllocationImageCreateInfoNV
* slink:VkDedicatedAllocationBufferCreateInfoNV
* slink:VkDedicatedAllocationMemoryAllocateInfoNV
=== New Functions
None.
=== Issues
None.
=== Examples
[source,{basebackend@docbook:c++:cpp}]
--------------------------------------
// Create an image with
// VkDedicatedAllocationImageCreateInfoNV::dedicatedAllocation
// set to VK_TRUE
VkDedicatedAllocationImageCreateInfoNV dedicatedImageInfo =
{
VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_IMAGE_CREATE_INFO_NV, // sType
NULL, // pNext
VK_TRUE, // dedicatedAllocation
};
VkImageCreateInfo imageCreateInfo =
{
VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO, // sType
&dedicatedImageInfo // pNext
// Other members set as usual
};
VkImage image;
VkResult result = vkCreateImage(
device,
&imageCreateInfo,
NULL, // pAllocator
&image);
VkMemoryRequirements memoryRequirements;
vkGetImageMemoryRequirements(
device,
image,
&memoryRequirements);
// Allocate memory with VkDedicatedAllocationMemoryAllocateInfoNV::image
// pointing to the image we are allocating the memory for
VkDedicatedAllocationMemoryAllocateInfoNV dedicatedInfo =
{
VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_MEMORY_ALLOCATE_INFO_NV, // sType
NULL, // pNext
image, // image
VK_NULL_HANDLE, // buffer
};
VkMemoryAllocateInfo memoryAllocateInfo =
{
VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO, // sType
&dedicatedInfo, // pNext
memoryRequirements.size, // allocationSize
FindMemoryTypeIndex(memoryRequirements.memoryTypeBits), // memoryTypeIndex
};
VkDeviceMemory memory;
vkAllocateMemory(
device,
&memoryAllocateInfo,
NULL, // pAllocator
&memory);
// Bind the image to the memory
vkBindImageMemory(
device,
image,
memory,
0);
--------------------------------------
=== Version History
* Revision 1, 2016-05-31 (Jeff Bolz)
- Internal revisions