Module schema 

TOML preset schema: which built-in system a preset drives and the expression bound to each of its named parameters.

Parsing happens once at load: the raw TOML is deserialized, each parameter expression is compiled (a malformed one is rejected with a surfaced error), and the result is an in-memory Preset whose bindings are ready to evaluate. A bad preset returns Err — it never panics, so the caller can degrade to the last good preset (ADR-0002 / NFR 10).

Re-exports

pub use export::KeyDesc;

pub use export::KeyKind;

pub use export::Roster;

pub use export::TableDesc;

Modules

export

What a preset may contain, as a machine-readable document (Plan 0158 Phase 4).

Structs

Binding

A named parameter bound to a compiled expression.

Easing

A binding’s easing time constants in seconds (ADR-0019, widened to a pair by ADR-0035).

Latch

One [latch] entry, compiled (ADR-0137): a gate armed on one condition and fired by the first rising edge of another inside the arming window.

Layer

The optional second scene layer (ADR-0090 / Plan 0076): a full authoring surface — its own system, params, bindings, [layer.smoothing] and structural tables — joined to the composite at LayerJoin. The preset’s single [palette] serves both layers (one colour language, one baked LUT), and layer params are namespaced to the layer: they reach the layer’s scene only, never the main scene’s first-owner-wins routing and never the compositing stages, which belong to the preset as a whole.

Preset

A loaded, ready-to-evaluate preset.

Enums

HoldEdge

When a held binding takes a new value (ADR-0180 rule 2). Between edges the scene keeps reading the value taken at the last one.

LayerBlend

How an over layer blends into the chain (ADR-0090): fixed at load, like every structural key, and applied in linear light within the layer’s premultiplied-alpha footprint. Parsed now; consumed by the blend pass (Plan 0076 Phase 3).

LayerJoin

Where a preset’s second scene joins the composite (ADR-0090): before the post chain, sharing every stage with the main scene, or between the kaleidoscope and bloom in its own offscreen (Phase 3).

PresetError

Why a preset failed to load. Every variant is recoverable — the caller keeps the previous good preset.

SystemKind

The built-in system a preset drives. Extend as Plan 0003 (and later plans) add systems; unknown names are rejected at load.

Constants

GLOBAL_PARAMS

The parameter names any preset may bind regardless of its system: the five compositing stages that run around the scene (bg_*, trails, kaleido_*, exposure, ink_*/paper_*). Gathered from each stage’s own declared vocabulary so there is no third copy to drift.

Functions

is_known_param

Whether name is a parameter system (or the global compositing layer) actually consumes. An unknown name is a load-time warning, not an error: the preset still loads and applies its good bindings (ADR-0020, NFR 10).

kind_of_param

The ParamKind name is declared with, searching system’s own roster first and then the global compositing stages — the same rosters in the same order is_known_param tests, so a name that is known there has a kind here.