Interface BoundsLedgerConfig

Bounds ledger — the adaptive DPR manager's learned operating bounds.

Where minDPR/native are STATIC bounds, the ledger holds EVIDENCE-BASED ones learned at runtime:

Floor: the lowest DPR known not to help (set when a U-shape probe is rejected). Scale-down never moves to-or-below it. Decays after a TTL — but repeated IDENTICAL rejections escalate the TTL exponentially (30s → 60s → 2min → capped), so a scene where DPR reduction never helps stops paying a probe/blur/revert cycle every 30 seconds forever.
Ceiling: on HiDPI displays, DPR above 1.0 is a luxury — 1.0 is exactly what every standard display renders — with a 4x fill cost at 2x native. When scale-ups above 1.0 keep getting PUNISHED (FPS collapses shortly after the ascent), or the estimator reports sustained sub-throttle DISTRESS (demoteCeiling called directly), the scene has proven it can't sustain the luxury: the operating ceiling demotes from native to exactly 1.0, killing the up/down oscillation instead of slowing it. Session-only; decays after a TTL (backed off on re-demotion).
Content changes soften the ledger: expiries are pulled forward so re-probes/re-ascents happen within recheckMs, and the escalation streaks reset — new content deserves fresh evidence.

Pure and timestamp-driven; no clocks, no window, no config imports.

interface BoundsLedgerConfig {
    minDPR: number;
    floorTtlMs: number;
    backoffMultiplier: number;
    backoffMaxTtlMs: number;
    ceilingTtlMs: number;
    punishedAscentWindowMs: number;
    punishedAscentThreshold: number;
}

Properties

minDPR: number

Static lower bound — the floor decays back to this.

floorTtlMs: number

First-rung TTL for a rejected-probe floor, ms.

backoffMultiplier: number

TTL multiplier per consecutive identical rejection (>= 1).

backoffMaxTtlMs: number

Ceiling for the backed-off TTL, ms.

ceilingTtlMs: number

First-rung TTL for a demoted DPR ceiling, ms.

punishedAscentWindowMs: number

An ascent punished within this window counts toward demotion, ms.

punishedAscentThreshold: number

Punished ascents required to demote the ceiling to 1.0 (>= 1).