import type { Vec2 } from "./geometry.js";
/** Closest point on segment `a`→`b` to `p`, and the clamped parameter `t` in [0,1] where it lies. */
export interface ClosestOnSegment {
    point: Vec2;
    t: number;
}
/** Closest point on the segment `a`→`b` to point `p`, with the clamped parameter `t` (0 at `a`, 1 at `b`). */
export declare function closestPointOnSegment(p: Vec2, a: Vec2, b: Vec2): ClosestOnSegment;
/** A resolved circle-vs-segment contact. */
export interface CircleSegmentHit {
    /** Unit surface normal pointing from the segment toward the circle center — the axis to bounce off. */
    normal: Vec2;
    /** Penetration depth; push the center out by `normal · depth` to separate. */
    depth: number;
    /** Closest point on the segment (the contact point). */
    contact: Vec2;
    /** Circle center pushed just outside the segment — a tunnel-proof resolved position. */
    resolved: Vec2;
}
/**
 * Circle (center + `radius`) against a capsule segment `a`→`b` of half-thickness `thickness` (0 for a thin
 * wall). Returns the contact — surface normal, penetration depth, contact point, and the separated center —
 * or `null` when they do not overlap. Endpoints are rounded (the segment is a capsule), so a ball never
 * catches on a corner. Reflect the velocity across `normal` for the bounce; the pure geometry every 2D
 * ball game (pinball, breakout, air hockey) reimplemented per wall, bumper, and paddle.
 */
export declare function circleVsSegment(center: Vec2, radius: number, a: Vec2, b: Vec2, thickness?: number): CircleSegmentHit | null;