import { ISubscribable, Stream } from "@thi.ng/rstream";
import { Vec } from "@thi.ng/vectors";
import { ITransform, IParticle } from "./api";
export declare type IForce = (particle: IParticle) => Vec;
export declare class Transform implements ITransform {
    position: Vec;
    scale: Vec;
    rotation: Vec;
}
export declare class Particle extends Transform implements IParticle {
    acceleration: Vec;
    velocity: Vec;
    previous: Vec;
}
export declare const updateParticle: (particle: IParticle, forces: IForce[]) => void;
export declare const limitVelocityN: (particle: IParticle, speed: number) => void;
export declare const forceGravity: (grav?: number) => () => IForce;
export declare const forceFriction: (friction?: number) => IForce;
export declare type ForceStream = Stream<{
    forces: IForce[];
    pulses: IForce[];
}>;
export declare const forceStream: (forces: IForce[], pulses?: IForce[]) => [ForceStream, (forces: IForce[], pulses: IForce[]) => void];
export declare type ParticleMotionConfig = {
    maxSpeed?: number;
    threshold?: number;
};
/**
 * A singular particle Stream class for use in simple
 * particle style effects.  Think gestures ( throw, drag, etc ) and
 * simple primary motion elements like mouse follow effects.
 *
 * IS Very WIP.
 */
export declare const particleStream: (force$: ForceStream, config?: ISubscribable<ParticleMotionConfig>) => import("@thi.ng/rstream").ISubscription<import("./api").IMotionEvent<"particle">, import("./api").IMotionEvent<"particle">>;
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