function intersectsPolygon(a, b) {
	    var p = a;
	    do {
	        if (p.i !== a.i && p.next.i !== a.i && p.i !== b.i && p.next.i !== b.i &&
	                intersects(p, p.next, a, b)) return true;
	        p = p.next;
	    } while (p !== a);
	
	    return false;
	}
// check if a polygon diagonal intersects any polygon segments
check if a polygon diagonal intersects any polygon segments
check if a polygon diagonal intersects any polygon segments
function intersectsPolygon(a, b) {
	    var p = a;
	    do {
	        if (p.i !== a.i && p.next.i !== a.i && p.i !== b.i && p.next.i !== b.i &&
	                intersects(p, p.next, a, b)) return true;
	        p = p.next;
	    } while (p !== a);
	    return false;
	}
function intersectsPolygon ( a , b ) { var p = a ; do { if ( p . i !== a . i && p . next . i !== a . i && p . i !== b . i && p . next . i !== b . i && intersects ( p , p . next , a , b ) ) return true ; p = p . next ; } while ( p !== a ) ; return false ; }
check if a polygon diagonal intersects any polygon segments
check if a polygon diagonal intersects any polygon segments