
Mapping Mountains - samsolomon
https://mapzen.com/blog/mapping-mountains
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ryansouza
Neat!

Annoyingly it seems every time you scroll pass one of the maps a browser
history entry is pushed

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tantalor
They always keep 2 iframes loaded; when you scroll down (or up) the old
iframes are unloaded by setting their src="" and the new ones are loaded by
setting their src attribute to the correct URL (kept the "source" attribute of
the iframe).

However, when you change the src attribute of an iframe, for some reason your
browser creates a new history frame. I suppose so you can navigate inside of
an iframe and go back/forward as expected.

The correct solution is to create/remove the entire iframe element instead of
reassigning the src attribute.

See discussion at [http://stackoverflow.com/questions/14737365/modify-iframe-
sr...](http://stackoverflow.com/questions/14737365/modify-iframe-src-without-
entry-to-history-object)

You can see it in the HTML source of the page around the "check visibility
every half-second, hide off-screen demos to go easy on the GPU" comment.

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iamleppert
Super awesome writeup and use of leaflet, very pretty maps! I work for a drone
company and we deal with DEM data all the time, I recognized your first image
of the clamped PNG.

Here's one of our office: [http://kespry-
experiments.s3.amazonaws.com/elevation/valueFo...](http://kespry-
experiments.s3.amazonaws.com/elevation/valueForPixel.html)

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tricolon
The author keeps referring to "Gak", with which I'm unfamiliar. Is it this?
[https://en.wikipedia.org/wiki/Nickelodeon_Toys#Gak](https://en.wikipedia.org/wiki/Nickelodeon_Toys#Gak)
Is it just because of the color?

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majewsky
Yes, it's most certainly that. See also
[http://knowyourmeme.com/memes/events/gak](http://knowyourmeme.com/memes/events/gak)

~~~
zachrose
But also the freeform sprawling shape that Gak was packaged in:
[https://i.ytimg.com/vi/MSDVImHZsFU/hqdefault.jpg](https://i.ytimg.com/vi/MSDVImHZsFU/hqdefault.jpg)

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micro_cam
I'm really glad someone is producing a service like this and will start using
it as soon as coverage is at least national!

I wrote a webapp hillmap.com that does client side slope shading for travel in
avalanche terrain a few years ago using a usgs webservice that has since
broken. I've looked into building a replacement but it is amazing how hard it
is to find consistent elevation data across the globe.

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outworlder
That's cool. It's amazing how much overlap there is with gamedev concepts.

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davidw
It'd be cool if there were more maps you could play with on their site.

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maaku
Back button breaks (Firefox).

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EwanG
From the article: "Fly with me now, on a tour through the world of elevation
data"

Basically a nice article talking about how the data is gathered, stored, and
sometimes used.

~~~
dandermotj
The article has nothing to do with how the data is gathered, stored and
sometimes used. It's about real-time rendering of elevation maps in the
browser. It's really impressive work.

