The code definitions Tom is referring to are at https://travellermap.com/doc/secondsurvey - I missed why they were being referenced, though.

On Sat, Jun 4, 2016 at 4:27 PM, Christopher Hilton <xxxxxx@vindaloo.com> wrote:

Thanks, The tile based screen at travellermap.com is definitely a feature I want in the web based map viewer. I’m not sure how that one works. I’d have to use an image generating program to generate the subsector map form and then fill it in from the database. Those two things shouldn’t be that hard but I’ve underestimated the scale of a task before.

At this point I wouldn't bother with generating the bitmap tiles on the server. Deliver system descriptions down to the web app as JSON and render them directly to canvas, or generate SVG either client side or server side.

The reasons I don't do this for TravellerMap are (1) I wrote most of the code before canvas or SVG were widely supported and (2) the server code uses a graphics library that can generate both bitmaps and PDFs.