code: public static Point inverseTransform (double x, double y, double sx, double sy, double rotation,
                                            double tx, double ty, Point result) {
          x -= tx; y -= ty; // untranslate
          double sinnega = Math.sin(-rotation), cosnega = Math.cos(-rotation);
          double nx = (x * cosnega - y * sinnega); // unrotate
          double ny = (x * sinnega + y * cosnega);
          return result.set(nx / sx, ny / sy); // unscale
      }
docs: Inverse transforms a point as specified, storing the result in the point provided.
  @return a reference to the result point, for chaining.