Module flow 

Flow — the typed interface between Data and Lanes.

A Flow is a per-domain, read-only presenter of the World. It runs every tick during the Substrate Pass (before Lanes execute) in two steps:

1. select (read-only) — picks the entities relevant for this domain.
2. project (read-only) — builds a typed View published into the LaneBus. Lanes consume the view; they never query the World directly.

A Flow never mutates the World. Representation adaptation (AGDF memory layout) is the Data layer’s own self-maintenance; semantic / gameplay mutation is developer-authored (an opt-in DataSystem), never automatic here. See .agent/rules.md — adapt the HOW, never the WHAT.

Each domain (Render, UI, Physics, Audio, Shadow, …) defines its own Flow implementation. Adding a new domain costs one registration:

inventory::submit! {
    khora_data::flow::FlowRegistration {
        name: MyFlow::NAME,
        domain: MyFlow::DOMAIN,
        run: my_flow_runner_trampoline,
    }
}

Re-exports

pub use audio::AudioFlow;

pub use audio::AudioPlaybackUpdate;

pub use audio::AudioPlaybackWriteback;

pub use audio::AudioSourceSnapshot;

pub use audio::AudioView;

pub use physics::PhysicsFlow;

pub use physics::PhysicsStepResult;

pub use physics::PhysicsView;

pub use render::RenderFlow;

pub use shadow::ShadowFlow;

pub use shadow::ShadowMatrices;

pub use shadow::ShadowView;

pub use ui::UiFlow;

Modules

audio

AudioFlow — projects the ECS audio domain into a per-tick AudioView consumed by SpatialMixingLane.

physics

PhysicsFlow — read-only projection of the physics domain.

render

RenderFlow — projects the ECS World into a RenderWorld for the render lanes to consume from the LaneBus.

shadow

ShadowFlow — derives, per shadow-casting light, the view-projection matrix the shadow pass will use to render its depth slice.

ui

UiFlow — projects UI ECS data + text layout into a per-frame UiScene published into the LaneBus.

Macros

register_flow

Convenience macro for declaring a Flow registration with the standard trampoline (single static instance, no per-frame allocation).

Structs

FlowRegistration

Registration entry for a Flow — submitted by each concrete Flow implementation via inventory::submit!.

Selection

A snapshot of entities selected by a Flow for the current tick.

Traits

Flow

The typed interface between the Data layer and Lanes.

Functions

combine_cache_key

Folds an ordered sequence of cache-key ingredients (domain epochs, bit-level hashes of runtime state, the World instance id) into a single u64 via the std hasher. Deterministic within a process, which is all a per-process view cache needs.

run_flow_cached

One Substrate-Pass execution of flow, with view-cache support. This is the body of the [register_flow!] trampoline, extracted so the caching behaviour is a single, directly testable code path.