Struct SceneLimits 

pub struct SceneLimits {
    pub max_entities: u32,
    pub max_snapshot_instances: u32,
    pub max_snapshots: u32,
    pub managed_cpu_bytes: u64,
}

CPU ownership budgets. The byte ceiling accounts columns, slots, free indices, snapshots and step scratch, excluding allocator overhead and independently owned mesh/material assets.

Fields

max_entities: u32

Maximum live/retired identity slots and capacity of each maintained archetype.

max_snapshot_instances: u32

Maximum instances copied into one frame snapshot.

max_snapshots: u32

Maximum simultaneously owned snapshots, in 1..8.

managed_cpu_bytes: u64

Accounted CPU reservation ceiling, at most 512 MiB.

Implementations

impl SceneLimits

pub fn reservation_bytes(self) -> Result<u64, RenderError>

Validate capacity and compute the conservative reservation before allocating columns.

Examples found in repository

examples/scene_admission.rs (line 23)

fn sample(count: u32, binding: RenderBinding) -> Result<(u128, u128, u64)> {
    let limits = SceneLimits {
        max_entities: count,
        max_snapshot_instances: count,
        max_snapshots: 1,
        managed_cpu_bytes: 512 * 1024 * 1024,
    };
    let bytes = limits.reservation_bytes()?;
    let mut world = SceneWorld::new(limits)?;
    let mut entities = Vec::with_capacity(count as usize);
    let started = Instant::now();
    for _ in 0..count {
        entities.push(world.spawn(black_box(Transform::default()), black_box(binding), None)?);
    }
    let initial = started.elapsed().as_nanos();
    let started = Instant::now();
    for id in entities.drain(..) {
        world.despawn(black_box(id))?;
    }
    for _ in 0..count {
        entities.push(world.spawn(black_box(Transform::default()), black_box(binding), None)?);
    }
    let reuse = started.elapsed().as_nanos();
    black_box((&world, &entities));
    assert_eq!(world.len(), count as usize);
    Ok((initial, reuse, bytes))
}

Trait Implementations

impl Clone for SceneLimits

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 SceneLimits

impl Debug for SceneLimits

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

Formats the value using the given formatter.

impl Default for SceneLimits

fn default() -> Self

Returns the “default value” for a type.