Struct Round 

pub struct Round {
    pub target: RoundTarget,
    pub ops: Vec<RoundOp>,
    pub released: Vec<PageParity>,
    pub filter: Option<FilterPass>,
    pub copy: Option<RegionCopy>,
    pub samples: Vec<BackdropSample>,
}

One render pass over one target.

A target is not a round: the surface, and a layer’s page, can each take several, and the rounds of one target run in the order they are listed with every one after the first loading what the one before it left. The surface’s first round that draws is the one that clears it — the renderer folds the frame’s clear and its opaque strips into that round’s pass.

Fields

target: RoundTarget

What this pass renders into.

ops: Vec<RoundOp>

The pass’s work, in execution order. Empty on a filter round, which issues no draw and composites nothing.

released: Vec<PageParity>

Pages whose contents this round consumed; they return to the pool once it completes.

filter: Option<FilterPass>

The filter pass this round runs, on a filter round.

A field rather than a RoundOp variant, and it stays one now that the renderer executes filter rounds: a filter round is only a filter pass — it draws nothing and composites nothing, and it is drawn through a different pipeline, off a different instance buffer, with no viewport uniform and no strip bind groups. Naming it here is what lets the frame path branch on the round before it starts issuing a list, and keeps RoundOp exactly the set of things one strip pass can interleave.

copy: Option<RegionCopy>

The region of the frame’s own target this round seeds its page with, on a region-copy round (see the module header’s Backdrop rounds).

A field rather than a RoundOp for the reason Self::filter is one: a copy round is only a copy — it draws nothing, composites nothing, and is recorded through no strip pipeline — and its ops are empty.

samples: Vec<BackdropSample>

The pages this round’s draws sample rather than composite: one per backdrop blur whose rectangle this round draws, each holding the blurred region (see the module header’s Backdrop rounds). Every page named here is also in Self::released. Empty on every round of a frame with no backdrop, and on every round but a surface one.

Implementations

impl Round

pub fn page(&self) -> Option<&PageTarget>

The pooled page this round renders into, or None for the surface and for a retained page.

pub fn retained(&self) -> Option<&RetainedTarget>

The retained page this round renders a body into, if it does.

pub fn filter_pass(&self) -> Option<&FilterPass>

The filter pass this round runs, or None on an ordinary round.

pub fn region_copy(&self) -> Option<&RegionCopy>

The region this round copies into its page, or None on every round but a region-copy one.

pub fn is_root(&self) -> bool

Whether this round renders into the frame’s own surface.

pub fn composites(&self) -> impl Iterator<Item = &Composite>

The composites this round performs, in execution order.

pub fn draw_count(&self) -> u32

How many recorded draws this round issues.

Trait Implementations

impl Clone for Round

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Round

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

Formats the value using the given formatter.

impl PartialEq for Round

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Round