wplace clone, but without building upon map and introduced a new form of saving stuff.
Pixels are saved in integers in any mainstream format. I want to save it by double so one could place more pixel in the same pixel place.
Have a manual set of coordination systems, store it in a state. drag or zoom it in canvas. Give the state a side effect that will run every time the capturable area changes, then send the capturable size to the server. Server returns a JSON with every pixel in it, the canvas redraw it.
Fairly simple enough.