public SvgPathBuilder append(final SvgPoint controlPoint1, final SvgPoint controlPoint2, final SvgPoint endPoint) {
        mStringBuilder.append(makeRelativeCubicBezierCurve(controlPoint1, controlPoint2, endPoint));
        mLastPoint = endPoint;
        return this;
    }
Build a SVG path as a string.

https://www.w3.org/TR/SVGTiny12/paths.html
signature-pad/src/main/java/com/github/gcacace/signaturepad/utils/SvgPathBuilder.java