An OpenSeadragon plugin for updating the zoom/pan in the page URL.
Create your OpenSeadragon viewer and then:
It'll take the viewer to wherever the page's hash parameters point, and it'll update the page URL with hash parameters.
See demo.html for an example. You can also see it in the wild here: https://minecraft.greener.ca/byblos/map/overworld/
Thanks to @jason-green-io for the generous support!