export type VisionPoint = readonly [number, number];
/** Structurally matches `world/walls` `WallSegment` — pass those straight in as occluders. */
export interface VisionWall {
    from: VisionPoint;
    to: VisionPoint;
}
export interface VisionConeConfig {
    range: number;
    /** Full cone opening angle in radians (matches `TelegraphShape`'s cone `angle`). */
    angle: number;
}
/** 2D segment intersection on the XZ plane (collinear overlaps count) — the LoS building block `revealQuery`/`frustumSensor` never shipped (#286.5).
 * @internal
 */
export declare function segmentsIntersect(a1: VisionPoint, a2: VisionPoint, b1: VisionPoint, b2: VisionPoint): boolean;
/** True when no wall segment crosses the sight line.
 * @internal
 */
export declare function hasWallLineOfSight(from: VisionPoint, to: VisionPoint, walls: readonly VisionWall[]): boolean;
/** Angle + range test only — no occlusion. `heading` is engine yaw (radians, `atan2(dx, dz)`).
 * @internal
 */
export declare function pointInCone(origin: VisionPoint, heading: number, config: VisionConeConfig, point: VisionPoint): boolean;
export interface VisionTarget<TId extends string = string> {
    id: TId;
    at: VisionPoint;
}
/**
 * The guard-sight primitive every stealth game hand-rolled: an angle+range cone on the XZ plane
 * whose sight lines are blocked by 2D wall segments (`world/walls` segments fit structurally).
 * Pure math — feed entity positions and heading each tick.
 */
export interface VisionCone {
    canSee(origin: VisionPoint, heading: number, target: VisionPoint): boolean;
    visibleTargets<TId extends string>(origin: VisionPoint, heading: number, targets: readonly VisionTarget<TId>[]): TId[];
}
/** @internal */
export declare function createVisionCone(config: VisionConeConfig, walls?: readonly VisionWall[]): VisionCone;