Run results for: Throughput of rectangle overlap calculator

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.167 Safari/537.36

Browser: Chrome 64

Operating system: Mac OS X 10.12.6

Device Platform: Other

Date tested: 2025 years ago

Test name	Executions per second
overlap	197690.9 Ops/sec
clip	408781.1 Ops/sec
intersect_2d	245939.1 Ops/sec

Script Preparation code:

var max = Math.max.bind(Math);
var min = Math.min.bind(Math);

function between(a, x, b) {
    return a <= x && x <= b;
}

function intersect_1d(start1, end1, start2, end2) {
    var c1 = between(start1, start2, end1) ? 1 : 0;
    var c2 = between(start1, end2, end1) ? 2 : 0;
    var c3 = between(start2, start1, end2) ? 4 : 0;
    var c4 = between(start2, end1, end2) ? 8 : 0;
    var _case = c1 | c2 | c3 | c4;
    switch (_case) {
        case 0: return [NaN, NaN];
        case 1: return [start2, start2];
        case 2: return [end2, end2];
        case 3: return [start2, end2];
        case 4: return [start1, start1];
        case 5: return [min(start1, start2), max(start1, start2)];
        case 6: return [min(start1, end2), max(start1, end2)];
        case 7: return [min(start1, start2), max(start1, end2)];
        case 8: return [end1, end1];
        case 9: return [min(end1, start2), max(end1, start2)];
        case 10: return [min(end1, end2), max(end1, end2)];
        case 11: return [min(end1, start2), max(end1, end2)];
        case 12: return [start1, end1];
        case 13: return [min(start1, start2), max(end1, start2)];
        case 14: return [min(start1, end2), max(end1, end2)];
        case 15: return [start1, end2];
        default: return [NaN, NaN];
    }
}

function intersect_2d(A, B) {
    var _a = intersect_1d(A.top, A.bottom, B.top, B.bottom), top = _a[0], bottom = _a[1];
    var _b = intersect_1d(A.left, A.right, B.left, B.right), left = _b[0], right = _b[1];
    if (isNaN(top) || isNaN(bottom) || isNaN(left) || isNaN(right) || (top === bottom) || (left === right)) {
        return null;
    }
    return { left: left, top: top, right: right, bottom: bottom };
}

function clip(A, B) {
    var rectangles = [];
    if (A.top < B.top) {
        rectangles.push({ left: A.left, top: A.top, right: A.right, bottom: B.top });
    }
    if (A.left < B.left) {
        rectangles.push({ left: A.left, top: max(A.top, B.top), right: B.left, bottom: min(A.bottom, B.bottom) });
    }
    if (A.right > B.right) {
        rectangles.push({ left: B.right, top: max(A.top, B.top), right: A.right, bottom: min(A.bottom, B.bottom) });
    }
    if (A.bottom > B.bottom) {
        rectangles.push({ left: A.left, top: B.bottom, right: A.right, bottom: A.bottom });
    }
    return rectangles;
}

function sign(owner) {
    return function (rect) { return ({ rect: rect, owner: owner }); };
}
var sign1 = sign(1);
var sign2 = sign(2);
var sign3 = sign(3);
function overlap(A, B) {
    var AB = intersect_2d(A, B);
    if (AB === null) {
        return [];
    }
    var rA = clip(A, AB).map(sign1);
    var rB = clip(B, AB).map(sign2);
    var rAB = sign3(AB);
    return rA.concat(rB).concat(rAB);
}

function randomRect() {
    var top = Math.random();
    var left = Math.random();
    var bottom = top + Math.random();
    var right = left + Math.random();
    return rect(top, left, bottom, right);
}

function rect(top, left, bottom, right) {
    return { left: left, top: top, right: right, bottom: bottom };
}

Tests:

overlap
overlap(randomRect(), randomRect())
clip
clip(randomRect(), randomRect())
intersect_2d
intersect_2d(randomRect(), randomRect())