export type RingPoint = [number, number];
export interface RingPhase {
    startTime: number;
    shrinkDuration: number;
    fromRadius: number;
    toRadius: number;
    damagePerSecond: number;
    center?: RingPoint;
}
export interface RingConfig {
    center: RingPoint;
    phases: readonly RingPhase[];
}
export interface RingSample {
    center: RingPoint;
    radius: number;
    damagePerSecond: number;
    phase: number;
    shrinking: boolean;
}
export interface RingHit {
    id: string;
    damage: number;
    distanceOutside: number;
}
export interface Ring {
    at(time: number): RingSample;
    isOutside(time: number, position: RingPoint): boolean;
    distanceOutside(time: number, position: RingPoint): number;
    damageOutside(time: number, dt: number, positions: Iterable<{
        id: string;
        position: RingPoint;
    }>): RingHit[];
}
export declare function ringSampleAt(config: RingConfig, time: number): RingSample;
export declare function createRing(config: RingConfig): Ring;