Struct PhysicsFlow 

pub struct PhysicsFlow;

Read-only physics presentation Flow.

Deliberately uncached (no cache_key override): while the simulation runs, the per-frame provider sync and transform writeback mutate the Physics/Spatial domains anyway, so a cache would never hit — it would only add key computation and a clone to every tick.

Trait Implementations

impl Default for PhysicsFlow

fn default() -> PhysicsFlow

Returns the “default value” for a type.

impl Flow for PhysicsFlow

const DOMAIN: SemanticDomain = SemanticDomain::Physics

Domain identifier — matches the agent’s domain.

const NAME: &'static str = "physics"

Stable identifier — used for telemetry and ordering.

type View = PhysicsView

The typed view this Flow publishes into the LaneBus. Clone so the registration trampoline can republish a cached view without re-running select/project (views hold Arcs and plain data, so cloning is cheap relative to a full re-projection).

fn project( &self, world: &World, _sel: &Selection, _runtime: &Runtime, ) -> Self::View

Stage 2 — read-only projection of the world into a View.

fn select(&mut self, world: &World, runtime: &Runtime) -> Selection

Stage 1 — read-only selection of relevant entities.

fn cache_key(&self, world: &World, runtime: &Runtime) -> Option<u64>

Cache key for view reuse. When Some(k) matches the key of the previously published view, the registration trampoline republishes the cached view without re-running select/project. None (default) disables caching — correct for flows whose projection depends on inputs without a change signal.