main/src/georegression/geometry/UtilPolygons2D_F64.java
public static void convert( Polygon2D_F64 input , Quadrilateral_F64 output ) {
		if( input.size() != 4 )
			throw new IllegalArgumentException("Expected 4-sided polygon as input");

		output.a.set(input.get(0));
		output.b.set(input.get(1));
		output.c.set(input.get(2));
		output.d.set(input.get(3));
	}
public static void convert( Polygon2D_F64 input , Quadrilateral_F64 output ) {
		if( input.size() != 4 )
			throw new IllegalArgumentException("Expected 4-sided polygon as input");

		output.a.set(input.get(0));
		output.b.set(input.get(1));
		output.c.set(input.get(2));
		output.d.set(input.get(3));
	}
Converts a polygon into a quadrilateral

@param input polygon.
@param output Quadrilateral.  Modified.