Show HN: Globe visualizations in Golang

by mmcloughlin • 9 years ago

258 44 9 years ago

warent• 9 years ago

It's always nice seeing unique projects in Golang appear like this. Also worth noting that this includes the ability to upload directly to imgur via the github.com/mattn/imgur tool. Once thing that I particularly love about Go is the built-in testing suite which mmcloughlin makes good use of.

The only critique I have here is to see some benchmarks! :)

deckarep• 9 years ago

Hence the power of open source.

mmcloughlin8• 9 years ago

Thanks! I was really glad to find that imgur tool. I wanted to make sure the images in the README were kept in sync with the code.

Also credit has to go to https://github.com/tidwall/pinhole where all the actual rendering happens!

ivanbakel• 9 years ago

The map in the readme is puzzling me. It's almost like a riddle: what is there a lot of in the UK, east America, Portugal, and barely any of in Norway, Spain, and Belgium? It looks country-related, since you can see the borders defined pretty well. Is it the Starbucks data? It would explain why Finland appears to have a few, compared to its neighbours.

filleokus• 9 years ago

Probably not Starbucks, way to many mapped in Sweden. Starbucks is not that widely spread here.

mmcloughlin8• 9 years ago

Yes the top image in the README is cities. The Starbucks image is lower down in their distinctive green color.

ucarion• 9 years ago

There's a cities.go file in the examples, maybe it's that? But the relevant cities.json is not in this repo.

mbel• 9 years ago

Judging by used color, the picture might be a result of this demo: https://github.com/mmcloughlin/globe/blob/master/examples/ci...

I have no idea what kind of cities might be listed in 'cities.json'.

mmcloughlin8• 9 years ago

Yes, the first image in the README is from cities.go. The data file is too big so I didn't include it in the repo, but the Makefile will fetch it.

https://github.com/mmcloughlin/globe/blob/master/examples/Ma...

It came from this node package

https://www.npmjs.com/package/cities.json/

It looks like the dataset has more cities in some countries than others.

goblin892• 9 years ago

Does anyone know why isn’t it possible to get the same perspective (preserving scale, distances, areas) in Google Earth Web?

For example, you wouldn’t be able to get the shapes of continents along with the size of the whole globe in Google Earth visually match the projection under “line” example in README.

[0] https://earth.google.com/web/@54.45747286,-25.48168721,-8084...

dsl2• 9 years ago

There are lots of different map projections[1] and coordinate systems[2]. As the old joke goes, "the best thing about standards is there are so many to choose from!"

1. https://en.wikipedia.org/wiki/Map_projection

2. https://en.wikipedia.org/wiki/Geographic_coordinate_system

goblin892• 9 years ago

If you want to map whole planet’s surface onto a plane then sure, there’re tons of options (Dymaxion projection is my favorite). I can’t understand why areas and distances would be distorted if user manipulates a 3D globe though; yet it seems to be the case here.

Scirra_Tom• 9 years ago

This looks really cool! One comment, in this picture: https://camo.githubusercontent.com/16434461a69346de4ee07b950...

The left and right side of the rectangle are correctly bent around the shape of the globe. However, the top and bottom sides of the rectangle are not. Is this intention (or am I being stupid?)

panic• 9 years ago

The red lines are the shortest paths between the corners of the rectangle, not lines of constant latitude (which would follow the latitude lines drawn on the globe).

fogleman2• 9 years ago

Glad to see more graphics work being done in Go. This is built on `pinhole`, which is built on `gg`, a 2D rendering library that I wrote. How many layers deep can we get? :)

https://github.com/fogleman/gg

eternalban• 9 years ago

That looks great.

mmcloughlin8• 9 years ago

Standing on the shoulders of giants :)

gg and pinhole made this easy to write. The globe package really just deals with mapping (lat, lng) space to cartestian coordinates (and also includes some land/country datasets).

tidwall3• 9 years ago

Looks so good. The detail is just amazing!

This may or may not be useful, but here's a Go package containing a bunch of city data. It might be a good fit for people using your project.

https://github.com/tidwall/cities

tidwall3• 9 years ago

fwiw, I also created a javascript port of pinhole a few weeks back. https://github.com/tidwall/pinhole-js

shurcooL• 9 years ago

How many layers deep can we get? :)

Layers, visualized:

https://godoc.org/github.com/mmcloughlin/globe?import-graph&...

gciruelos• 9 years ago

I've been following you on github for a long time (since the minecraft clone you made in C was featured in /r/programming). You are insane man, I love your work.

Keep it up!

fogleman2• 9 years ago

Ha, thanks!

tidwall3• 9 years ago

Anyone wanting to whip up cool graphics with Go, definitely check out Michael's work.

https://github.com/fogleman

elcapitan• 9 years ago

Looks great!

Was there a particular reason why you chose Go to implement this? (strong side of the language or sth like that)

mmcloughlin8• 9 years ago

Thanks!

I guess I wanted to use it to visualize data coming from other Go projects I was working on, so it made sense. A tiny example of this is https://github.com/mmcloughlin/spherand which correctly generates random points on a sphere. I also had seen pinhole (https://github.com/tidwall/pinhole) and thought it would be fun to play around with.

sxv• 9 years ago

How possible / appropriate would it be to utilize this library to create an interactive version similar to this example using d3: https://www.jasondavies.com/maps/rotate/

mmcloughlin8• 9 years ago

Jason Davies has some beautiful maps!

Interactive would be hard. It would be relatively simple to output an animated gif though, as the pinhole library does here

https://github.com/tidwall/pinhole/blob/master/examples/eart...

I'm planning to add this feature.

newtem0• 9 years ago

I need to learn go

kmicklas2• 9 years ago

No you don't, it has no benefits relative to languages in its space of competition (Rust, D, various JVM/.NET languages, Haskell, ML, Nim, etc.).

xyproto• 9 years ago

Team friendlyness, simplicity, readability, tooling, native compilation, built in syntax for concurrency and really fast compilation times for large projects.

AYBABTME• 9 years ago

That's pretty cool! It would be nice if the API allowed writing to io.Writer instead of taking filenames.

mmcloughlin8• 9 years ago

If you'd like to output to an arbitrary writer, you can use the Image method.

https://godoc.org/github.com/mmcloughlin/globe#Globe.Image

This can be passed to an image encoder like

https://golang.org/pkg/image/png/#Encode https://golang.org/pkg/image/gif/#Encode https://golang.org/pkg/image/jpeg/#Encode

These functions take io.Writer objects. SavePNG was provided for convenience.

gravypod• 9 years ago

Are there any provisions for drawing a color mesh on something like this?

Thanks!

graetzer• 9 years ago

Looks really cool! How many points can one draw with this before it becomes too slow? I did a similar looking 3D globe animation with WebGL once and the total number of points was quite an issue

http://jsfiddle.net/go2t1r4q/2/

Show HN: Globe visualizations in Golang

Related Stories