Agus Made agusmade

agusmade / IntersectTwoCircles.js

Created December 25, 2022 08:30 — forked from jupdike/IntersectTwoCircles.js

Find the intersections (two points) of two circles, if they intersect at all

	// based on the math here:
	// http://math.stackexchange.com/a/1367732

	// x1,y1 is the center of the first circle, with radius r1
	// x2,y2 is the center of the second ricle, with radius r2
	function intersectTwoCircles(x1,y1,r1, x2,y2,r2) {
	var centerdx = x1 - x2;
	var centerdy = y1 - y2;
	var R = Math.sqrt(centerdx * centerdx + centerdy * centerdy);
	if (!(Math.abs(r1 - r2) <= R && R <= r1 + r2)) { // no intersection

agusmade / polygon-area.js

Created December 25, 2022 08:27

Calculating Polygon Area

	function polygonArea(X, Y) {
	var area = 0; // Accumulates area in the loop
	var numPoints = X.length;
	var j = numPoints-1; // The last vertex is the 'previous' one to the first

	for (var i=0; i<numPoints; i++) {
	area = area + (X[j]+X[i]) * (Y[j]-Y[i]);
	j = i; //j is previous vertex to i
	}
	return area/2;