import { EnvPayload } from "../debug-protocol.js";
import { Vector2 } from "three";
//#region src/debug/EnvCollector.d.ts
/**
 * Subset of `WebGPURenderer` we inspect. Fields are all optional /
 * unknown so three's concrete `Backend` type is still assignable — we
 * narrow defensively at runtime. `getSize(target)` mutates `target`
 * via `target.set(w, h)` so it must be a real `Vector2`, not a plain
 * `{x, y}` object literal.
 */
interface RendererLike {
  backend?: unknown;
  getSize?(target: Vector2): Vector2;
  getPixelRatio?(): number;
}
/**
 * Runtime environment collector for the `env` feature.
 *
 * Two modes:
 *
 * - **`snapshot(renderer)`** — full env snapshot, used on `subscribe:ack`
 *   so a fresh consumer gets bootstrap capability info without having
 *   to subscribe to env just to find out whether (e.g.) GPU timing is
 *   available.
 *
 * - **`fillEnv(out, renderer)`** — delta-encoded payload written into
 *   a caller-owned scratch. Returns `true` if anything differed from
 *   the last emit. Fields absent = no change; `null` = clear (rare for
 *   env — values don't usually *disappear*, just change).
 *
 * Almost every env field is static (versions fixed at build time,
 * renderer backend fixed at construction); only canvas `width`,
 * `height`, `pixelRatio` change at runtime. So `fillEnv` is cheap — it
 * usually returns `false` once the first snapshot has been emitted.
 *
 * `resetDelta()` clears `_prev` so the next `fillEnv` emits a full
 * snapshot (re-subscribe path).
 */
declare class EnvCollector {
  private _prev;
  /** Real Vector2 — three's `getSize(target)` calls `target.set(w, h)`. */
  private _sizeScratch;
  /**
   * Build a full env snapshot. Used for bootstrap info in the
   * `subscribe:ack` message so consumers see capabilities immediately.
   * Does NOT update the delta tracker — callers that want to count
   * this as the baseline should call `resetDelta()` first and then
   * `fillEnv(out)` on the next tick to synchronise.
   */
  snapshot(renderer: RendererLike | undefined, gpuVerified?: boolean): EnvPayload;
  /**
   * Write delta-encoded env updates into `out`. Returns `true` if any
   * field changed since the last emit.
   *
   * `out` must be an EnvPayload the caller owns (typically a scratch).
   * All fields should be `undefined` on entry; `fillEnv` leaves
   * unchanged fields as `undefined` (meaning "no change" on the wire)
   * and sets changed fields to their new value or `null`.
   */
  fillEnv(out: EnvPayload, renderer: RendererLike | undefined, gpuVerified?: boolean): boolean;
  /**
   * Reset the delta tracker so the next `fillEnv` emits a full snapshot.
   * Called when subscriptions change. Also useful after `snapshot()` is
   * consumed as bootstrap: reset then the next tick's delta is relative
   * to that bootstrap rather than to an empty prev.
   */
  resetDelta(): void;
  /**
   * Record a full snapshot as the current prev. Call this after
   * `snapshot()` is used for bootstrap so subsequent `fillEnv` calls
   * compute deltas relative to what the consumer already has.
   */
  recordSnapshotAsPrev(renderer: RendererLike | undefined, gpuVerified?: boolean): void;
}
//#endregion
export { EnvCollector };
//# sourceMappingURL=EnvCollector.d.ts.map