code: public static Point transform (float x, float y, float sx, float sy, float sina, float cosa,
                                     float tx, float ty, Point result) {
          return result.set((x*cosa - y*sina) * sx + tx, (x*sina + y*cosa) * sy + ty);
      }
docs: Transforms a point as specified, storing the result in the point provided.
  @return a reference to the result point, for chaining.