code: function viewPoint2SvgPoint(props, clientX, clientY) {
    const svgPoint = props.svgPoint;
    svgPoint.x = clientX;
    svgPoint.y = clientY;
    return svgPoint.matrixTransform(props.svgCtmElement.getScreenCTM().inverse());
  }
docs: [SVG] 
  Get SVG coordinates from viewport coordinates.
  @param {props} props - `props` of instance.
  @param {number} clientX - viewport X.
  @param {number} clientY - viewport Y.
  @returns {SVGPoint} SVG coordinates.