js/circle-mode.js

// *********** HERE STARTS circle-mode.js *************

window.addEventListener("load", initCircleMode);

circleMode = false;

function initCircleMode() {
	document.querySelector("#circle-mode").addEventListener('click', function() {		
		if(circleMode) {
			circleMode = false;
			document.querySelector("#circle-mode i").innerText = "trip_origin";

			s.graph.nodes().forEach(function(n) {
				n.x = n.originalX;
				n.y = n.originalY;
				n.size = 10;
			});
			
			s.refresh();
			
		}
		else {	
			circleMode = true;
			document.querySelector("#circle-mode i").innerText = "shuffle";
			
			s.graph.nodes().forEach(function(n) {
				n.x = n.circleX;
				n.y = n.circleY;		
			});
			
			s.refresh();
		}
	});
}

function isInRect (x, y, rect) {
	if (x < -10000 || x > 10000) return true;
	if (y < -10000 || y > 10000) return true;
	
	var ans = true;
	var c = crossProd (rect[0], rect[1], x, y);
	
	for(var i=1; i<4; i++) {	
		var temp = crossProd (rect[i], rect[(i+1)%4], x, y);
		if (c*temp < 0) ans = false;
	}
	return ans;
}

function crossProd(r1, r2, x, y) {
	return r1[0]*r2[1] + r2[0]*y + x*r1[1] - r1[0]*y - r2[0]*r1[1] - x*r2[1]; 
}