C Specification
The VkImageMemoryBarrier
structure is defined as:
typedef struct VkImageMemoryBarrier {
VkStructureType sType;
const void* pNext;
VkAccessFlags srcAccessMask;
VkAccessFlags dstAccessMask;
VkImageLayout oldLayout;
VkImageLayout newLayout;
uint32_t srcQueueFamilyIndex;
uint32_t dstQueueFamilyIndex;
VkImage image;
VkImageSubresourceRange subresourceRange;
} VkImageMemoryBarrier;
Members
-
sType
is the type of this structure. -
pNext
isNULL
or a pointer to an extension-specific structure. -
srcAccessMask
is a bitmask of VkAccessFlagBits specifying a source access mask. -
dstAccessMask
is a bitmask of VkAccessFlagBits specifying a destination access mask. -
oldLayout
is the old layout in an image layout transition. -
newLayout
is the new layout in an image layout transition. -
srcQueueFamilyIndex
is the source queue family for a queue family ownership transfer. -
dstQueueFamilyIndex
is the destination queue family for a queue family ownership transfer. -
image
is a handle to the image affected by this barrier. -
subresourceRange
describes the image subresource range withinimage
that is affected by this barrier.
Description
The first access scope is
limited to access to memory through the specified image subresource range,
via access types in the source access mask
specified by srcAccessMask
.
If srcAccessMask
includes VK_ACCESS_HOST_WRITE_BIT
, memory
writes performed by that access type are also made visible, as that access
type is not performed through a resource.
The second access scope is
limited to access to memory through the specified image subresource range,
via access types in the destination access
mask specified by dstAccessMask
.
If dstAccessMask
includes VK_ACCESS_HOST_WRITE_BIT
or
VK_ACCESS_HOST_READ_BIT
, available memory writes are also made visible
to accesses of those types, as those access types are not performed through
a resource.
If srcQueueFamilyIndex
is not equal to dstQueueFamilyIndex
, and
srcQueueFamilyIndex
is equal to the current queue family, then the
memory barrier defines a queue
family release operation for the specified image subresource range, and
the second access scope includes no access, as if dstAccessMask
was
0
.
If dstQueueFamilyIndex
is not equal to srcQueueFamilyIndex
, and
dstQueueFamilyIndex
is equal to the current queue family, then the
memory barrier defines a queue
family acquire operation for the specified image subresource range, and
the first access scope includes no access, as if srcAccessMask
was
0
.
If oldLayout
is not equal to newLayout
, then the memory barrier
defines an image layout
transition for the specified image subresource range.
Layout transitions that are performed via image memory barriers execute in their entirety in submission order, relative to other image layout transitions submitted to the same queue, including those performed by render passes. In effect there is an implicit execution dependency from each such layout transition to all layout transitions previously submitted to the same queue.
The image layout of each image subresource of a depth/stencil image created
with VK_IMAGE_CREATE_SAMPLE_LOCATIONS_COMPATIBLE_DEPTH_BIT_EXT
is
dependent on the last sample locations used to render to the image
subresource as a depth/stencil attachment, thus when the image
member
of an VkImageMemoryBarrier
is an image created with this flag the
application can chain a VkSampleLocationsInfoEXT structure to the
pNext
chain of VkImageMemoryBarrier
to specify the sample
locations to use during the image layout transition.
If the VkSampleLocationsInfoEXT
structure in the pNext
chain of
VkImageMemoryBarrier
does not match the sample location state last
used to render to the image subresource range specified by
subresourceRange
or if no VkSampleLocationsInfoEXT
structure is
in the pNext
chain of VkImageMemoryBarrier
then the contents of
the given image subresource range becomes undefined as if oldLayout
would equal VK_IMAGE_LAYOUT_UNDEFINED
.
If image
has a multi-planar format and the image is disjoint, then
including VK_IMAGE_ASPECT_COLOR_BIT
in the aspectMask
member of
subresourceRange
is equivalent to including
VK_IMAGE_ASPECT_PLANE_0_BIT
, VK_IMAGE_ASPECT_PLANE_1_BIT
, and
(for three-plane formats only) VK_IMAGE_ASPECT_PLANE_2_BIT
.
See Also
Document Notes
For more information, see the Vulkan Specification at URL
This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.
Copyright
Copyright (c) 2014-2019 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.