Struct SceneLayerCounts 

pub struct SceneLayerCounts {
    pub wanted: u32,
    pub used: u32,
    pub max_depth: u32,
    pub by_site: [u32; 8],
}

How many layers one painted scene asked for, and what it got.

Clip and opacity layers are the part of scene complexity a renderer pays most for: each one is a push, a pop and a region the rasteriser has to composite separately. When render_to_texture inside vello is the largest item in a frame, this count is the lever on it, because the submit path is not the cost and the encode is charged elsewhere.

wanted exceeding used is not just a performance note. It means the scene hit LAYER_LIMIT and clipping was silently skipped, so content that should have been cut off was drawn in full.

Fields

wanted: u32

Layers the painter asked to push.

used: u32

Layers actually pushed. Lower than wanted only past the limit.

max_depth: u32

Deepest nesting reached, which bounds what the rasteriser holds at once.

by_site: [u32; 8]

Layers pushed per LayerSite, indexed by LayerSite::ALL.

These count pushes, including the three sites the manager never sees, so their sum is larger than used rather than a breakdown of it.

Trait Implementations

impl Clone for SceneLayerCounts

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SceneLayerCounts

impl Debug for SceneLayerCounts

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

Formats the value using the given formatter.

impl Default for SceneLayerCounts

fn default() -> Self

Returns the “default value” for a type.

impl Eq for SceneLayerCounts

impl PartialEq for SceneLayerCounts

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SceneLayerCounts