/**
 * Calculate intersection point of two line segments
 *
 * @param p1 - Line 1 start point {x: number, y: number}
 * @param p2 - Line 1 end point
 * @param p3 - Line 2 start point
 * @param p4 - Line 2 end point
 *
 * @returns Intersection coordinates or null for parallel lines
 *
 * @example
 * ```typescript
 * // Intersecting lines
 * calcIntersection({x:0,y:0}, {x:2,y:2}, {x:0,y:2}, {x:2,y:0}); // {x:1,y:1}
 *
 * // Parallel lines
 * calcIntersection({x:0,y:0}, {x:1,y:1}, {x:0,y:1}, {x:1,y:2}); // null
 * ```
 *
 * @remarks
 * - Handles vertical/horizontal edge cases
 * - Uses 1e4 scaling factor for floating-point precision
 * - 0.1**12 parallel threshold
 */
export declare const calcIntersection: (p1: Coord, p2: Coord, p3: Coord, p4: Coord) => Coord | null;