C Specification
The VkSubpassDependency structure is defined as:
// Provided by VK_VERSION_1_0
typedef struct VkSubpassDependency {
uint32_t srcSubpass;
uint32_t dstSubpass;
VkPipelineStageFlags srcStageMask;
VkPipelineStageFlags dstStageMask;
VkAccessFlags srcAccessMask;
VkAccessFlags dstAccessMask;
VkDependencyFlags dependencyFlags;
} VkSubpassDependency;Members
-
srcSubpassis the subpass index of the first subpass in the dependency, orVK_SUBPASS_EXTERNAL. -
dstSubpassis the subpass index of the second subpass in the dependency, orVK_SUBPASS_EXTERNAL. -
srcStageMaskis a bitmask of VkPipelineStageFlagBits specifying the source stage mask. -
dstStageMaskis a bitmask of VkPipelineStageFlagBits specifying the destination stage mask -
srcAccessMaskis a bitmask of VkAccessFlagBits specifying a source access mask. -
dstAccessMaskis a bitmask of VkAccessFlagBits specifying a destination access mask. -
dependencyFlagsis a bitmask of VkDependencyFlagBits.
Description
If srcSubpass is equal to dstSubpass then the
VkSubpassDependency does not directly define a
dependency.
Instead, it enables pipeline barriers to be used in a render pass instance
within the identified subpass, where the scopes of one pipeline barrier
must be a subset of those described by one subpass dependency.
Subpass dependencies specified in this way that include
framebuffer-space stages in the
srcStageMask must only include
framebuffer-space stages in
dstStageMask, and must include VK_DEPENDENCY_BY_REGION_BIT.
When a subpass dependency is specified in this way for a subpass that has
more than one view in its view mask, its dependencyFlags must include
VK_DEPENDENCY_VIEW_LOCAL_BIT.
If srcSubpass and dstSubpass are not equal, when a render pass
instance which includes a subpass dependency is submitted to a queue, it
defines a dependency between the subpasses
identified by srcSubpass and dstSubpass.
If srcSubpass is equal to VK_SUBPASS_EXTERNAL, the first
synchronization scope includes
commands that occur earlier in submission
order than the vkCmdBeginRenderPass used to begin the render pass
instance.
Otherwise, the first set of commands includes all commands submitted as part
of the subpass instance identified by srcSubpass and any
load, store, or multisample resolve
operations on attachments used in srcSubpass.
In either case, the first synchronization scope is limited to operations on
the pipeline stages determined by the
source stage mask specified by
srcStageMask.
If dstSubpass is equal to VK_SUBPASS_EXTERNAL, the second
synchronization scope includes
commands that occur later in submission
order than the vkCmdEndRenderPass used to end the render pass
instance.
Otherwise, the second set of commands includes all commands submitted as
part of the subpass instance identified by dstSubpass and any
load, store, and multisample resolve
operations on attachments used in dstSubpass.
In either case, the second synchronization scope is limited to operations on
the pipeline stages determined by the
destination stage mask specified
by dstStageMask.
The first access scope is
limited to accesses in the pipeline stages determined by the
source stage mask specified by
srcStageMask.
It is also limited to access types in the source access mask specified by srcAccessMask.
The second access scope is
limited to accesses in the pipeline stages determined by the
destination stage mask specified
by dstStageMask.
It is also limited to access types in the destination access mask specified by dstAccessMask.
The availability and visibility operations defined by a subpass dependency affect the execution of image layout transitions within the render pass.
|
Note
For non-attachment resources, the memory dependency expressed by subpass
dependency is nearly identical to that of a VkMemoryBarrier (with
matching For attachments however, subpass dependencies work more like a
VkImageMemoryBarrier defined similarly to the VkMemoryBarrier
above, the queue family indices set to
|
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.