Struct vulkano::render_pass::SubpassDependency

pub struct SubpassDependency {
    pub source_subpass: Option<u32>,
    pub destination_subpass: Option<u32>,
    pub source_stages: PipelineStages,
    pub destination_stages: PipelineStages,
    pub source_access: AccessFlags,
    pub destination_access: AccessFlags,
    pub by_region: bool,
    pub view_local: Option<i32>,
    pub _ne: NonExhaustive,
}

A dependency between two subpasses of a render pass.

The implementation is allowed to change the order of the subpasses within a render pass, unless you specify that there exists a dependency between two subpasses (ie. the result of one will be used as the input of another one). Subpass dependencies work similar to pipeline barriers, except that they operate on whole subpasses instead of individual images.

If source_subpass and destination_subpass are equal, then this specifies a subpass self-dependency. The source_stages must all be logically earlier in the pipeline than the destination_stages, and if they both contain a framebuffer-space stage, then by_region must be activated.

If source_subpass or destination_subpass are set to None, this specifies an external dependency. An external dependency specifies a dependency on commands that were submitted before the render pass instance began (for source_subpass), or on commands that will be submitted after the render pass instance ends (for destination_subpass). The values must not both be None.

Fields

source_subpass: Option<u32>

The index of the subpass that writes the data that destination_subpass is going to use.

None specifies an external dependency.

The default value is None.

destination_subpass: Option<u32>

The index of the subpass that reads the data that source_subpass wrote.

None specifies an external dependency.

The default value is None.

source_stages: PipelineStages

The pipeline stages that must be finished on source_subpass before the destination_stages of destination_subpass can start.

The default value is PipelineStages::none().

destination_stages: PipelineStages

The pipeline stages of destination_subpass that must wait for the source_stages of source_subpass to be finished. Stages that are earlier than the stages specified here can start before the source_stages are finished.

The default value is PipelineStages::none().

source_access: AccessFlags

The way source_subpass accesses the attachments on which we depend.

The default value is AccessFlags::none().

destination_access: AccessFlags

The way destination_subpass accesses the attachments on which we depend.

The default value is AccessFlags::none().

by_region: bool

If false, then the source operations must be fully finished for the destination operations to start. If true, then the implementation can start the destination operation for some given pixels as long as the source operation is finished for these given pixels.

In other words, if the previous subpass has some side effects on other parts of an attachment, then you should set it to false.

Passing false is always safer than passing true, but in practice you rarely need to pass false.

The default value is false.

view_local: Option<i32>

If multiview rendering is being used (the subpasses have a nonzero view_mask), then setting this to Some creates a view-local dependency, between views in source_subpass and views in destination_subpass.

The inner value specifies an offset relative to the view index of destination_subpass: each view d in destination_subpass depends on view d + view_offset in source_subpass. If the source view index does not exist, the dependency is ignored for that view.

If multiview rendering is not being used, the value must be None. If source_subpass and destination_subpass are the same, only Some(0) and None are allowed as values, and if that subpass also has multiple bits set in its view_mask, the value must be Some(0).

The default value is None.

_ne: NonExhaustive

Trait Implementations

impl Clone for SubpassDependency

fn clone(&self) -> SubpassDependency

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SubpassDependency

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for SubpassDependency

fn default() -> Self

Returns the “default value” for a type.