function makeSimple()

in seriously.js [2587:2690]
79 lines of code
10 McCabe index (conditional complexity)

			function makeSimple(poly) {
				/*
				this uses a slow, naive approach to detecting line intersections.
				Use Bentley-Ottmann Algorithm
				see: http://softsurfer.com/Archive/algorithm_0108/algorithm_0108.htm#Bentley-Ottmann Algorithm
				see: https://github.com/tokumine/sweepline
				*/
				var i, j,
					edge1, edge2,
					intersect,
					intersections = [],
					newPoly,
					head, point,
					newPolygons,
					point1, point2;

				if (poly.simple) {
					return;
				}

				for (i = 0; i < poly.edges.length; i++) {
					edge1 = poly.edges[i];
					for (j = i + 1; j < poly.edges.length; j++) {
						edge2 = poly.edges[j];
						intersect = linesIntersect(edge1[0], edge1[1], edge2[0], edge2[1]);
						if (intersect) {
							intersect.edge1 = edge1;
							intersect.edge2 = edge2;
							intersections.push(intersect);
						}
					}
				}

				if (intersections.length) {
					newPolygons = [];

					for (i = 0; i < intersections.length; i++) {
						intersect = intersections[i];
						edge1 = intersect.edge1;
						edge2 = intersect.edge2;

						//make new points
						//todo: set ids for points
						point1 = {
							x: intersect.x,
							y: intersect.y,
							prev: edge1[0],
							next: edge2[1],
							id: vertices.length
						};
						poly.vertices.push(point1);
						vertices.push(point1);

						point2 = {
							x: intersect.x,
							y: intersect.y,
							prev: edge2[0],
							next: edge1[1],
							id: vertices.length
						};
						poly.vertices.push(point2);
						vertices.push(point1);

						//modify old points
						point1.prev.next = point1;
						point1.next.prev = point1;
						point2.prev.next = point2;
						point2.next.prev = point2;

						//don't bother modifying the old edges. we're just gonna throw them out
					}

					//make new polygons
					do {
						newPoly = {
							edges: [],
							vertices: [],
							simple: true
						};
						newPolygons.push(newPoly);
						point = poly.vertices[0];
						head = point;
						//while (point.next !== head && poly.vertices.length) {
						do {
							i = poly.vertices.indexOf(point);
							poly.vertices.splice(i, 1);
							newPoly.edges.push([point, point.next]);
							newPoly.vertices.push(point);
							point = point.next;
						} while (point !== head);
					} while (poly.vertices.length);

					//remove original polygon from list
					i = polygons.indexOf(poly);
					polygons.splice(i, 1);

					//add new polygons to list
					for (i = 0; i < newPolygons.length; i++) {
						polygons.push(newPolygons[i]);
					}
				} else {
					poly.simple = true;
				}
			}