(mouse press restarts the program)
This online version is a restoration port by @dribnet. The initial port that resulted directly from the original processing code produced a version which - like the original - generates the image all at once. Subsequent revisions show the drawing being built up incrementally - Manolo gratiously allowed these embellishments and also provided feedback and guidance. The original code and both ports can be found in the accompaning github repository which also includes the git history for all changes.