/**
 * Returns `true` if the 2 given axis-aligned rectangular boxes intersect.
 * 
 * * **exact**: not susceptible to floating point round-off
 * 
 * @param closed if `true`, interpret boxes as being closed (i.e. they contain 
 * their border), otherwise open.
 * @param a an axis-aligned rectangular box (given by an array of two points,
 * e.g. `[[1,2], [3,4]]`)
 * @param b another axis-aligned rectangular box
 * 
 * @doc mdx
 */
 function areBoxesIntersecting(
        closed: boolean,
        a: number[][],
        b: number[][]): boolean {

    let [[ax0, ay0], [ax1, ay1]] = a;
    let [[bx0, by0], [bx1, by1]] = b;

    // Swap so smaller coordinate comes first
    if (ay0 > ay1) { [ay0,ay1] = [ay1,ay0] }
    if (by0 > by1) { [by0,by1] = [by1,by0] }
    if (ax0 > ax1) { [ax0,ax1] = [ax1,ax0] }
    if (bx0 > bx1) { [bx0,bx1] = [bx1,bx0] }

    return closed
        ? ax0 <= bx1 && ax1 >= bx0 && 
          by0 <= ay1 && by1 >= ay0
        : ax0 < bx1 && ax1 > bx0 && 
          by0 < ay1 && by1 > ay0
}


export { areBoxesIntersecting }