/**
 * Per-session player-spawn override — a capture-harness ergonomics seam that lets a single
 * screenshot or drive run place the player somewhere other than the authored `player_spawn`
 * marker *without mutating `editor.scene.json`*. The runner installs one from the `?spawn=` URL
 * overlay (mirroring `?cam=`); {@link authoredSpawnPosition} consults it for the default
 * player-spawn resolution only, so authored content is untouched and the override evaporates the
 * moment the page reloads without the param.
 *
 * Genre-agnostic: it moves whatever a game treats as its player spawn. It never changes markers of
 * other kinds or an explicit marker `id`, so an override taken for a close-up cannot perturb enemy
 * or prop placement queries that share {@link authoredSpawnPosition}.
 *
 * Install-style module state is the established runner pattern here (`installAssetBase`,
 * `installEditorHost`, `installSaveEndpoint`); the default is `null`, so nothing changes and every
 * pure query stays deterministic until a runner explicitly installs an override.
 */
/** A spawn point that replaces the authored player spawn for one capture session. */
export interface SpawnOverride {
    x: number;
    y: number;
    z: number;
    /** Optional facing (yaw radians); when omitted the authored/`0` rotation is kept. */
    rotationY?: number;
}
/** Install (or, with `null`, clear) the active player-spawn override. Idempotent; last write wins. */
export declare function installSpawnOverride(override: SpawnOverride | null): void;
/** Clear any installed player-spawn override. */
export declare function clearSpawnOverride(): void;
/** The currently installed player-spawn override, or `null` when none is active. */
export declare function readSpawnOverride(): SpawnOverride | null;
/**
 * Parse a `?spawn=` / `--spawn` value into a {@link SpawnOverride}, or `null` when it is absent or
 * malformed. Accepts `"x,y,z"` and `"x,y,z,yaw"` (yaw in radians); whitespace around components is
 * tolerated. A non-finite or short tuple yields `null` so a typo never silently teleports the
 * player to `NaN`.
 */
export declare function parseSpawnOverride(raw: string | null | undefined): SpawnOverride | null;