A JavaScript function that returns the x,y points of intersection between two circles?

Translated the C function on the site to JavaScript:

function intersection(x0, y0, r0, x1, y1, r1) {        var a, dx, dy, d, h, rx, ry;        var x2, y2;        /* dx and dy are the vertical and horizontal distances between         * the circle centers.         */        dx = x1 - x0;        dy = y1 - y0;        /* Determine the straight-line distance between the centers. */        d = Math.sqrt((dy*dy) + (dx*dx));        /* Check for solvability. */        if (d > (r0 + r1)) {            /* no solution. circles do not intersect. */            return false;        }        if (d < Math.abs(r0 - r1)) {            /* no solution. one circle is contained in the other */            return false;        }        /* 'point 2' is the point where the line through the circle         * intersection points crosses the line between the circle         * centers.           */        /* Determine the distance from point 0 to point 2. */        a = ((r0*r0) - (r1*r1) + (d*d)) / (2.0 * d) ;        /* Determine the coordinates of point 2. */        x2 = x0 + (dx * a/d);        y2 = y0 + (dy * a/d);        /* Determine the distance from point 2 to either of the         * intersection points.         */        h = Math.sqrt((r0*r0) - (a*a));        /* Now determine the offsets of the intersection points from         * point 2.         */        rx = -dy * (h/d);        ry = dx * (h/d);        /* Determine the absolute intersection points. */        var xi = x2 + rx;        var xi_prime = x2 - rx;        var yi = y2 + ry;        var yi_prime = y2 - ry;        return [xi, xi_prime, yi, yi_prime];    }

Based on AutoMonkey's answer I made some adjustments to give some more information in the response and also handle when the circles are the same.

/** * @description Get information about the intersection points of a circle. * Adapted from: https://stackoverflow.com/a/12221389/5553768. * @param {Object} c1 An object describing the first circle. * @param {float} c1.x The x coordinate of the circle. * @param {float} c1.y The y coordinate of the circle. * @param {float} c1.r The radius of the circle. * @param {Object} c2 An object describing the second circle. * @param {float} c2.x The x coordinate of the circle. * @param {float} c2.y The y coordinate of the circle. * @param {float} c2.r The radius of the circle. * @returns {Object} Data about the intersections of the circles. */function intersection(c1, c2) {    // Start constructing the response object.    const result = {        intersect_count: 0,        intersect_occurs: true,        one_is_in_other: false,        are_equal: false,        point_1: { x: null, y: null },        point_2: { x: null, y: null },    };    // Get vertical and horizontal distances between circles.    const dx = c2.x - c1.x;    const dy = c2.y - c1.y;    // Calculate the distance between the circle centers as a straight line.    const dist = Math.hypot(dy, dx);    // Check if circles intersect.    if (dist > c1.r + c2.r) {        result.intersect_occurs = false;    }    // Check one circle isn't inside the other.    if (dist < Math.abs(c1.r - c2.r)) {        result.intersect_occurs = false;        result.one_is_in_other = true;    }    // Check if circles are the same.    if (c1.x === c2.x && c1.y === c2.y && c1.r === c2.r) {        result.are_equal = true;        result.are_equal = true;    }    // Find the intersection points    if (result.intersect_occurs) {        // Centroid is the pt where two lines cross. A line between the circle centers        // and a line between the intersection points.        const centroid = (c1.r * c1.r - c2.r * c2.r + dist * dist) / (2.0 * dist);        // Get the coordinates of centroid.        const x2 = c1.x + (dx * centroid) / dist;        const y2 = c1.y + (dy * centroid) / dist;        // Get the distance from centroid to the intersection points.        const h = Math.sqrt(c1.r * c1.r - centroid * centroid);        // Get the x and y dist of the intersection points from centroid.        const rx = -dy * (h / dist);        const ry = dx * (h / dist);        // Get the intersection points.        result.point_1.x = Number((x2 + rx).toFixed(15));        result.point_1.y = Number((y2 + ry).toFixed(15));        result.point_2.x = Number((x2 - rx).toFixed(15));        result.point_2.y = Number((y2 - ry).toFixed(15));        // Add intersection count to results        if (result.are_equal) {            result.intersect_count = null;        } else if (result.point_1.x === result.point_2.x && result.point_1.y === result.point_2.y) {            result.intersect_count = 1;        } else {            result.intersect_count = 2;        }    }    return result;}

Usage:

intersection(    {x: 1, y: 1, r: 2},    {x: 0, y: -1, r: 1})// Resultresult = {    intersect_count: 2,    intersect_occurs: true,    one_is_in_other: false,    are_equal: false,    point_1: { x: 1, y: -1 },    point_2: { x: -0.6, y: -0.2 },}

Confirmation:

https://www.desmos.com/calculator/cj12hc9jsk