Fixed cache-control headers for images

If you use IE you may have noticed that when zooming in then back out the map image tiles would re-load from the server (that is, it'd be slow). Firefox (or another Mozilla-derived browser) were zippy. I was generating the HTTP headers incorrectly which caused IE (compliant) to re-request the images each time.

FYI, the fix was in the ASP.NET code for Tile.aspx:

Response.Cache.SetCacheability( HttpCacheability.Public ); // was doing this
Response.Cache.SetExpires( DateTime.Now.AddDays( 1 ) ); // was doing this
Response.Cache.SetValidUntilExpires( true ); // wasn't doing this

I was also misinterpreting the meaning of Response.Cache.VaryByParams (which populates the HTTP "Vary:" header). I was interpreting the semantics as "re-request if these params are different" rather than correct semantics: "re-request even if these params are the same". So I removed calls to that, and everything appears happier now.

So what does that mean? In IE, try zooming all the way in to 64 pixels/parsec then out to 1/32 pixels/parsec, using the mouse wheel. Then, once all the tiles are cached, you can repeat the zoom in/zoom out without waiting for the images to re-load. Makes a great demo! Ω


Blog is live!

If you’re reading this, you can tell that I’ve moved the changelog from the Traveller Map site to a blog. Sorry about the “type the characters in the image” thing (HIP/CAPTCHA) – within one minute of setting up the blog I had spam. I’d rather have a HIP test than make everyone register to post.


Traveller Galaxy vs. the Milky Way

If you zoom out far enough in the map, you'll see Marc Miller's depiction of the Traveller galaxy (c/o The Core Route Projects). You might want to compare that with this recent depiction of the Milky Way, using the most up-to-date data: http://www.spitzer.caltech.edu/Media/mediaimages/sig/sig05-010.shtml Ω

Fixed Search Display in Opera

I think I've fixed the search display in Opera. IE handles dynamic heights just fine, but Mozilla and Opera need special work. Mozilla needs to have the height calculated by script. That works in Opera too, but some layout calculations are done asynchronously so it needed a little more working around.
Also, Opera doesn't like xml elements for data islands, so the default search wasn't working.

Mouse Wheel in Mozilla

The mouse wheel should now work for zooming in Mozilla/Firefox; this uses the "DOMMouseScroll" event. I'm not sure if Safari implements this. Anyone out there want to be my volunteer Mac test buddy? (I can’t quite justify springing for a new box just to test this page.)
Also, I tossed in Alt+Double-click to zoom out.


Added Content: Solomani and Aslan

With the help of an awesome tool by John G. Wood I've reconstructed the dotmaps for "missing" sectors in Aslan space (far spin-rimward) from DGP's Solomani and Aslan, plus the sector Theron.
Note that the worlds outside of known domains are marked as "Na", but otherwise are randomly generated, which is bogus - there shouldn't be a lot of class A starports in the middle of nowhere. But at least the dotmaps are now salvaged!


New Feature: Animation

Added animation between search points - feedback appreciated. Refactored script code. Control panel now updates when a permalink is followed or the page is refreshed. Ω