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how Google Maps works [Wed, 9-Feb-2005 1:26 PM]
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[music |Recoil -- Stalker]

If you haven't seen Google Maps yet, check it out: it's pretty impressive! If, like me, you're too lazy to read the source to figure out how they accomplished it, that's fine, because this guy has posted an analysis. Short version: lots of transparent PNG overlays, and communication with the server by treating a hidden IFRAME as a socket.

linkReply

Comments:
[User Picture]From: [info]parkrrrr
Wed, 9-Feb-2005 1:42 PM (UTC)

(Link)

I don't know if it's interesting to anyone but me, but the encoded string in the <points> element for a route contains actual latitudes and longitudes for the entire route, suitable for munging and uploading to a GPS receiver. I posted some Perl to decode it over on Slashdot (same username.)
[User Picture]From: [info]zenmonkeykstop
Wed, 9-Feb-2005 1:45 PM (UTC)

(Link)

And if you pan all the way out you get to see the world map as displayed in US highschool textbooks!
From: [info]michaeljgrasso
Wed, 9-Feb-2005 4:33 PM (UTC)

"the world map"??!!!!

(Link)

Some clown wrote: 

  And if you pan all the way out you get to see the
  world map as displayed in US highschool textbooks!


As far out as I can zoom I can only see North America - is the limits of the known world for you?
[User Picture]From: [info]rosefox
Wed, 9-Feb-2005 6:04 PM (UTC)

Re: "the world map"??!!!!

(Link)

Wow, and you even quoted the joke before completely missing it. Impressive, in a sort of bemusing way.
[User Picture]From: [info]balloonist
Wed, 9-Feb-2005 6:23 PM (UTC)

Re: "the world map"??!!!!

(Link)

It Appears to be Australian, so sadly its not that impressive... just typical.
From: [info]michaeljgrasso
Wed, 9-Feb-2005 7:48 PM (UTC)

Re: "the world map"??!!!!

(Link)

Almost true...
[User Picture]From: [info]fatalfury
Wed, 9-Feb-2005 2:00 PM (UTC)

(Link)

thanks for the heads up.
[User Picture]From: [info]bitwise
Wed, 9-Feb-2005 2:06 PM (UTC)

(Link)

It's pretty clear the map chunks are all prerendered and use easily-understood URLs, so who's going to be first to write an app that will stitch together a map of any size?

Failing that, I seem to recall somebody here wrote a script that used VNC+mozilla to take long, tall "screenshots" of an entire web page. Any chance of redoing that to capture a massively huge Google Map? I wonder if their code is smart enough to stop loading tiles if your screen appears to be 20,000 pixels square...
[User Picture]From: [info]bitwise
Wed, 9-Feb-2005 3:24 PM (UTC)

(Link)

Oh well, guess it'll have to be me.



(crappy jpeg because photobucket doesn't allow bigger than 250k images)
[User Picture]From: [info]taffer
Thu, 10-Feb-2005 11:16 AM (UTC)

(Link)

Now we need a program to convert that into a SimCity map.
[User Picture]From: [info]corneliusagain
Wed, 9-Feb-2005 2:32 PM (UTC)

(Link)

Very cool, but I do like the way that the rest of the world is just kind of missing...
[User Picture]From: [info]duskwuff
Wed, 9-Feb-2005 3:59 PM (UTC)

(Link)

Google's new US-centric view of the world.
From: [info]zhixel
Wed, 9-Feb-2005 4:22 PM (UTC)

(Link)

I'm having a hard time determining whether or not you two are serious.
[User Picture]From: [info]jwz
Wed, 9-Feb-2005 4:47 PM (UTC)

(Link)

Everybody knows Europe is just a less hygienically sophisticated version of Canada.
[User Picture]From: [info]zenmonkeykstop
Wed, 9-Feb-2005 8:38 PM (UTC)

the middle country

(Link)

I thought it was a more socially responsible version of the US?
From: [info]zhixel
Wed, 9-Feb-2005 10:55 PM (UTC)

Re: the middle country

(Link)

OH MAN America sucks SO MUCH doesn't it?? Man, why do I even live here!
[User Picture]From: [info]zenmonkeykstop
Thu, 10-Feb-2005 7:50 AM (UTC)

I'm guessing...

(Link)

Your debased savings wouldn't even buy you an espresso somewhere with a real currency?
From: [info]panda_boner
Wed, 9-Feb-2005 5:55 PM (UTC)

(Link)

Shut up.
[User Picture]From: [info]corneliusagain
Thu, 10-Feb-2005 8:01 AM (UTC)

(Link)

For the record, I really meant I did like the style of it - the way you pan off the US expecting to find other countries, but you just get ocean... endless blueness... it doesn't stop you, and it knows where you are because you can go back the same distance or even circumnavigate the US without seeing it, but it's just blue.

Cool.
[User Picture]From: [info]imperator_mei
Wed, 9-Feb-2005 5:31 PM (UTC)

(Link)

Doesnt' support Safari. Grumble, mutter.
[User Picture]From: [info]mackys
Wed, 9-Feb-2005 5:47 PM (UTC)

Or Opera...

(Link)

That one still has me scratching my head. Are these browsers so different (or is Google maps doing things that are so browser dependant) that they can't support anything except IE and Moz derivatives?

I guess I should be happy they bothered to make it work in anything else besides IE. Most websites these days don't seem to even bother with that much.

-Ben
[User Picture]From: [info]jwz
Wed, 9-Feb-2005 5:49 PM (UTC)

Re: Or Opera...

(Link)

This question is, of course, answered in the link you didn't click...
[User Picture]From: [info]mackys
Wed, 9-Feb-2005 6:08 PM (UTC)

For anyone else lazy...

(Link)

The reason why Google Maps doesn't work in alternative browsers is because XSLTProcessor is an invention of Microsoft which was picked up by the Mozilla team at some point, just like XmlHttpRequest.
From: [info]wilecoyote
Thu, 10-Feb-2005 5:10 AM (UTC)

Re: For anyone else lazy...

(Link)

So let me get this straight: all these incredibly cool things that Google is doing with the browser (not just maps, but also Google Suggest) are possible thanks to non-standard technologies first introduced by Microsoft?

Great. That's some cognitive dissonance for you. Let's see how the Google fanboys (who usually tend to be open source/anti-M$/W3C standard zealots too) react.
[User Picture]From: [info]fgmr
Thu, 10-Feb-2005 4:12 PM (UTC)

Re: For anyone else lazy...

(Link)

Netscape had some pretty fancy stuff (e.g. javascript "style sheets," which could change the html document), but it got stomped as "nonstandard" in favor of things like CSS. I remember an intern at netscape wrote a FPS in browser-side javascript. (I don't know if that was with a released version of the client, or an ill-fated version.) So I wouldn't say microsoft is "first" introducing such technology; if anything, they set things back half a decade.
[User Picture]From: [info]flipzagging
Wed, 9-Feb-2005 6:21 PM (UTC)

google draw

(Link)

To do driving directions, they let your browser request a line drawing with coordinates. This means Google will draw you any line drawing, (well, in that semi-transparent blue) as long as you know how to encode the URL.

Here's a little Perl program to make your own.

For instance, here's Google drawing a circle.
[User Picture]From: [info]jwz
Wed, 9-Feb-2005 7:04 PM (UTC)

Re: google draw

(Link)

I am experiencing a strange kind of cognitive dissonance here. One the one hand, that's really cool, and on the other, I can't think of a single thing to do with it. I mean, it's less useful than ringing the bell on a teletype. It's pulling my brain apart.
[User Picture]From: [info]flipzagging
Wed, 9-Feb-2005 7:16 PM (UTC)

Re: google draw

(Link)

Yeah. I guess they did it this way because their cluster is way too big to do something secure-ish like generating the image server-side, and handing the user an opaque ID.

Perhaps some dumbass could make a genuine Google URL that displayed some crude graffiti? Well, I've given them the tools now.
[User Picture]From: [info]zarex
Thu, 10-Feb-2005 8:34 AM (UTC)

Re: google draw

(Link)

My prediction is a google-drawn goatse.
[User Picture]From: [info]thaths
Wed, 9-Feb-2005 6:52 PM (UTC)

(Link)

So, jamie, when can we expect a xscreensaver module that grabs pre-rendered blocks of map images and does a flyby? I will start my coding today. There are faster coders than I that will likely get this done quicker.
[User Picture]From: [info]jwz
Wed, 9-Feb-2005 7:01 PM (UTC)

(Link)

If you can find a way to incorporate porn, you may have something.

(All screensavers that involve taking images off the web must eventually show you porn. It's a rule.)
[User Picture]From: [info]benfrantzdale
Wed, 9-Feb-2005 8:33 PM (UTC)

(Link)

That solves your cognitive dissonance. Use google to draw porn to create map-based screensavers.
[User Picture]From: [info]taffer
Thu, 10-Feb-2005 11:13 AM (UTC)

(Link)

Display random map co-ordinates/zoom level, then draw bewbie-styled "driving directions" on top. Voila.

SMOP.
From: [info]grayscalewolf
Wed, 9-Feb-2005 8:59 PM (UTC)

(Link)

it's the Obscene Driving Directions game. find two addresses give you a route that has two round bulges, shaped like breasts. bonus points if they include nipples. triple-x bonus if you can make the shape of an erect cock
From: [info]treptoplax
Wed, 9-Feb-2005 9:09 PM (UTC)

law of software envelopment, revised

(Link)

``Every program attempts to expand until it can display porn. Those programs which cannot so expand are replaced by ones which can.''
From: [info]wilecoyote
Thu, 10-Feb-2005 5:06 AM (UTC)

(Link)

[User Picture]From: [info]jwz
Thu, 10-Feb-2005 12:18 PM (UTC)

settle down, beavis

(Link)

The detail that guy left out is that webcollage is disabled by default, so he had to explicitly (heh heh, heh heh) turn it on (heh heh, heh heh.)

But a much better whine is this one.
[User Picture]From: [info]srcosmo
Wed, 9-Feb-2005 9:16 PM (UTC)

(Link)

Finally I can reenact the satellite zoom-in scene from every thriller movie!
[User Picture]From: [info]dym
Thu, 10-Feb-2005 2:13 PM (UTC)

(Link)

Try keyhole (also from Google) -- it does very impressive zooms.
From: [info]srmanek
Thu, 10-Feb-2005 9:01 AM (UTC)

SimCity

(Link)

The map looks a lot like simcity. Now we know what game the google developers like to play.
[User Picture]From: [info]d1663m
Mon, 14-Feb-2005 11:06 AM (UTC)

I gave mapquest the idea

(Link)

About a two years ago, I gave Mapquest the idea in a suggestion, even went into some detail how it could be pulled off. My idea involved a java thin-client, not sure how much more elegant that would be. This one seems to be (mostly) AnyBrowser(tm) friendly anyway.

Nice to see somebody put "my" ideas into action! :) Maybe google hired up the dude at Mapquest who read my note? It could happen!