// Javascript program to check if two given line segments intersect


// Given three collinear points p, q, r, the function checks if
// point q lies on line segment 'pr'
function onSegment(p, q, r)
{
	if (q.x <= Math.max(p.x, r.x) && q.x >= Math.min(p.x, r.x) &&
		q.y <= Math.max(p.y, r.y) && q.y >= Math.min(p.y, r.y))
	return true;

	return false;
}

// To find orientation of ordered triplet (p, q, r).
// The function returns following values
// 0 --> p, q and r are collinear
// 1 --> Clockwise
// 2 --> Counterclockwise
function orientation(p, q, r)
{

	// See https://www.geeksforgeeks.org/orientation-3-ordered-points/
	// for details of below formula.
	let val = (q.y - p.y) * (r.x - q.x) -
			(q.x - p.x) * (r.y - q.y);

	if (val == 0) return 0; // collinear

	return (val > 0)? 1: 2; // clock or counterclock wise
}

// The main function that returns true if line segment 'p1q1'
// and 'p2q2' intersect.
function doIntersect(p1, q1, p2, q2)
{

	// Find the four orientations needed for general and
	// special cases
	let o1 = orientation(p1, q1, p2);
	let o2 = orientation(p1, q1, q2);
	let o3 = orientation(p2, q2, p1);
	let o4 = orientation(p2, q2, q1);

	// General case
	if (o1 != o2 && o3 != o4)
		return true;

	// Special Cases
	// p1, q1 and p2 are collinear and p2 lies on segment p1q1
	if (o1 == 0 && onSegment(p1, p2, q1)) return true;

	// p1, q1 and q2 are collinear and q2 lies on segment p1q1
	if (o2 == 0 && onSegment(p1, q2, q1)) return true;

	// p2, q2 and p1 are collinear and p1 lies on segment p2q2
	if (o3 == 0 && onSegment(p2, p1, q2)) return true;

	// p2, q2 and q1 are collinear and q1 lies on segment p2q2
	if (o4 == 0 && onSegment(p2, q1, q2)) return true;

	return false; // Doesn't fall in any of the above cases
}


function test_intersect(){
    // Driver code
    let p1 = new Vector(1, 1);
    let q1 = new Vector(10, 1);
    let p2 = new Vector(1, 2);
    let q2 = new Vector(10, 2);

    if(doIntersect(p1, q1, p2, q2))
	    console.log("Yes<br>");
    else
	    console.log("No<br>");

    p1 = new Vector(10, 1); q1 = new Vector(0, 10);
    p2 = new Vector(0, 0); q2 = new Vector(10, 10);
    if(doIntersect(p1, q1, p2, q2))
	    console.log("Yes<br>");
    else
	    console.log("No<br>");

    p1 = new Vector(-5, -5); q1 = new Vector(0, 0);
    p2 = new Vector(1, 1); q2 = new Vector(10, 10);;
    if(doIntersect(p1, q1, p2, q2))
	    console.log("Yes<br>");
    else
	    console.log("No<br>");
}

// This code is contributed by avanitrachhadiya2155