main/src/georegression/geometry/UtilPolygons2D_F64.java
public static void shiftUp( Polygon2D_F64 a ) {
		final int N = a.size();

		Point2D_F64 first = a.get(0);

		for (int i = 0; i < N-1; i++ ) {
			a.vertexes.data[i] = a.vertexes.data[i+1];
		}
		a.vertexes.data[N-1] = first;
	}
public static void shiftUp( Polygon2D_F64 a ) {
		final int N = a.size();

		Point2D_F64 first = a.get(0);

		for (int i = 0; i < N-1; i++ ) {
			a.vertexes.data[i] = a.vertexes.data[i+1];
		}
		a.vertexes.data[N-1] = first;
	}
Shifts all the vertexes in the polygon up one element.  Wraps around at the end
@param a Polygon