There is the Gosper curve : http://www.toroidalsnark.net/mkss3-pix/CalderheadJMM2014.pdf http://www.toroidalsnark.net/mkss3-pix/CalderheadJMM2014.pdf https://en

There is the Gosper curve : http://www.toroidalsnark.net/mkss3-pix/CalderheadJMM2014.pdf http://www.toroidalsnark.net/mkss3-pix/CalderheadJMM2014.pdf https://en.wikipedia.org/wiki/Gosper_curve https://en.wikipedia.org/wiki/Gosper_curve