Hacker Newsnew | past | comments | ask | show | jobs | submitlogin
Writing a Vi-like Graphics Editor in Racket (jeapostrophe.github.io)
88 points by p4bl0 on May 14, 2013 | hide | past | favorite | 22 comments


I'm not sure why, but I love that Racketeers write their docs in Scribble. The application docs look like the platform docs... it makes everything have a very cohesive feel. So much more powerful than something like JavaDocs, too, since you get the full power of the language.

http://docs.racket-lang.org/scribble/


Scribble is excellent.

My favorite part about Scribbled documentation is that everything from code samples to function names in text is clickable. Even the function names in the five-line code samples on the front page of http://racket-lang.org/ are clickable; you can just jump straight to any function's documentation from the home page of the language.


I missed screenshots, it seems this editor has a fairly unique (or at least unusual) concept but it's much harder to quickly get it from the textual description.

It's intriguing that it talks about very simplistic sprite definitions (8 colors), but yet seems to expect the sprites to be rendered using 3D hardware (talk of normal maps and lighting).


Same here. And it's even more intriguing for me that it seems to match a lot of my own current game design aesthetics (namely the idea of simple, very low pixel graphics but with high-end light and particle effects). What's more, when browsing for the simplest (yet powerful) sprite editor for my own use, I found Pixen to be the best available option but still I dreamed of a vi-like pixel pusher (I was thinking in terms of having buffers with, say, small reusable sprites which then I could compound to make variations and animations, all accessible through a CtrlP inspired browser.)


This is the author.

I agree very much with both of you. I assemble all the tiles into texture atlases (and earlier post discusses the technique) and then use a fairly simple shader to render. If you look in the gb/graphics directory [1], then you can see the GLSL code. It was originally coded for OpenGL 3.3 with geometry shaders but I switched to OpenGL 3.00 as a stepping stone to ES 2.

The whole model is based on the concept of "SNES Unbound": I want to have effectively infinite numbers of sprites with many layers and any Mode 7 effects with arbitrary scaling and rotations. This is a very small level of expectation of a modern GPU, so I can get about 1,000 FPS on my laptop with millions of sprites, because I only use a single OpenGL draw call per layer.

Anyways, I'd be happy to comment or chat more with you. Maybe I should post some screenshots of the editor.

Jay

1. https://github.com/get-bonus/get-bonus/tree/master/gb/graphi...


Dr. Racket is one hell of a development environment. The things we could do if we were using Scheme+Racket instead of Java+Eclipse ...


Racket is a Scheme dialects that adds quite a lot to vanilla scheme as far as I know. The racket IDE is not praised that much and the lispers/schemers I know prefer Emacs/SLIME (though I believe you that it's better than Eclipse).

...so saying "Scheme+Racket vs Java+Eclipse" is really comparing apples to pineapples :) (maybe Clojure+Lighttable is closer to what you'd mean...)


I'm a grad student that works in Racket and fwiw I find that I prefer emacs for editing but DrRacket for testing and debugging. It has great tools for documentation, locating errors and macro expansion and of course it all works out of the box. I also use Geiser, but I've found it buggy and unreliable (including instantly shutting down my OSX machine if I tell emacs to kill it when I quit, plus I still haven't figured out how to limit its memory consumption).


Just to be nitpicky, Racket is not a Scheme dialect (hence the name changing from PLT Scheme to Racket a few years ago (already!)). It's not because it not only adds a lot to Scheme but also has somewhat important differences. For instance, `cons` pairs are immutable in Racket: there's no `set-car!` or `set-cdr!` as in Scheme (you can have mutable cons pair using `mcons`, `set-mcar!`, and `set-mcdr!` though). Also the macro systems that Racket uses (`syntax-parse` and co) is quite more advanced than the current Scheme rNrs one.


Well, #lang racket is not scheme, but one can run rnrs in the racket runtime. There are many languages that run on the racket runtime.


IIRC, Arc/HN runs on mzscheme because they rely on mutable cons cells that newer versions (racket) don't provide. Could they run under new rackets by just telling racket to use a proper scheme?


As a Racket author, I can tell you that we provided them with a hack to enable mutation on arbitrary conses, so they can upgrade whenever they wish, and I don't know whether they have or not.


There is an mzscheme language mode, but it specifically does not include set-car! and set-cdr!.


Why don't you? It's easy enough to pick up. I was doing C# for quite a long time (and actually liking it), and just decided to start doing Racket. I've got a project going right now that is 100% custom racket. Once you get the macros down, the code flies. It's pretty amazing.


You have a client project in Racket? Cool! Care to share what area / what are you using it for?


Well, I can only share a little. It's a web app built around a large, temporal knowledge base, with a proprietary data analytics engine that we develop in-house. The engine generates metrics and alerts that give our users decision-making insights. Gads, this sounds like the worst shit-head MBA project ever, but there is a lot I'm leaving out.

In the process, it's also a major test bench for a number of development tools we're building. This is where Racket pays dividends: it has a lot of the simple web-dev stuff in a good-enough state to get you off the ground fast, but doesn't pin you down to any one thing, leaving you wide open to rip out and replace whatever you want. Don't like how the HTML templating engine works? If you're good at macros (and Racket's macros are relatively easy), it's a simple job to roll your own.

We've got a data comprehension system that has its own pseudo-byte code that treats SQL like a machine-language in need of a VM that gives us a lot of static checking of our queries. We have a migration system that can rebuild the schema and restore data as easy as compiling your application, with reversible data translations between schema versions (so that we often do. Setting up a new developer-machine/test-environment/culster-node/what-have-you is a snap). Some of this stuff would have been damn costly to not just build without Racket's macros, I shudder to think what the changes we've had to make along the way would have been like.

Racket lets us take DRY to the extreme. Almost nothing in this project has been difficult to change, or at least no more difficult than the initial effort to develop it, because there is almost never a reason to change the interface to anything, and if it does need changing, the human-readable-code level has so few interaction points it's trivial to change interfaces. Hell, even in the case where a lot of interface changes would be necessary, we could probably just write a Racket program to chop up the S-expressions for us.

The mathematics library is also very good, providing a lot of intuitive, high-performance primitives that fit our data crunching needs. And we're currently investigating using the Prolog-like Datalog language mode

And the performance is extremely good, especially if you're coming from the Python/PHP/Ruby world. I find it as expressive as Python (actually, translating Python programs is nearly 1-to-1) but with performance more like static C#. The optimizer is very good and there is a typed version of Racket that gets optimized even more. Yeah, you should use Racket even if you don't plan on learning macros, because it's as easy as Python and its a lot faster.

All along the way. Graphics primitives: standard library feature. Parallel code: super-simple, very solid, and built in. Linear algebra: very solid, very easy to use (almost as easy as basic primitives) and again, built in. Distributed package management: built-in, it's part of the regular import syntax. Racket-to-JavaScript translator: well, not quite built in yet, but the package manager might as well let you treat it as so. Cross-platform compatibility: haven't had a single issue getting people on Linux, OS X, and Windows up and running with development yet.

If you've ever tried getting Scala or Clojure or Ruby setup on your own, Racket blows them out of the water.

I'm not terrible certain the fundamental premise of the project is sound, but at the end of the year we're going to have something of value on our hands, whether it's the raw data of the knowledge base or the development tools. Racket doesn't just let us build proof-of-concepts fast, it lets us expand them into heavy-lifting mode pretty quick, too.


Thank a lot for sharing what you can! Just out of curiosity, have you decided to use Racket because you already knew it well, or have you also considered Clojure? If you did, what were the advantages of Racket over Clojure (as far as I see, there's a bigger community and more learning resources around Clojure, but the JVM related setup complications may outweight the benefits)


No, didn't know Racket first, though I had a little experience with it, it really only translated to a general comfortablness with higher-order functions and the S-expression syntax (which I now find as transparent as curly-brace syntax).

I did try to go with Clojure at first, but found the entire ecosystem to be very haphazard. I already knew that Racket was easy to install and easy to use, so when I started running into trouble with getting Clojure to run on Windows and Linux (it seems it is super easy if you're on OS X, but eff that noise). Also, there was no one setup with Clojure. It was clear that Clojure without Leiningen was half a product, and I consider Leiningen to be a terrible piece of software.

As for learning resources for Clojure, that was another area where I felt like Racket won out. The Racket community is very, very friendly and extremely knowledgable, and the documentation at racket-lang.org is (mostly) extremely good. The sections on macros and continuations seems like they were written by someone with intimate mathematical knowledge of the issues, but not a lot of understanding of what beginners go through, but there are other sites (Scribble-based, even!) that do a better job of explaining the features.

And yeah, I didn't want to be tied to the JVM. Clojure ends up slightly slower than raw Java because of the need to emulate certain Lispy features, and years of Java AND C# development have given a very poor opinion of the JVM. Sure, there are more libraries available, but just how many do you need? There are some holes in Racket's library ecosystem, but it's been fun trying to fill them in and I think it's a site better scenario than having 15 different ORMs to choose from, and none of them are very good.

With Clojure, I had to install a JVM, then Clojure, then Leiningen, then plugins for Vim or Emacs or whatever, then a dozen and a half dependencies for the web framework, a lot of which are still in beta, have interface-breaking changes, and the documentation hasn't kept up. It was a nightmare of poorly executed distribution, something that drives me up a wall.

With Racket, you install Racket. It has other dependencies that it needs, but it handles it because it has a real installer. You can use Vim or Emacs if you want, but you don't have to right away. You import web-based dependencies in almost the exact same way you import standard libraries. In fact, you can even do it in the same require statement:

  (require net/smtp ;; standard library for interfacing with a sendmail server
         (planet mordae/couchdb:1:11) ;; a reference to a specific version of a CouchDB API from a specific user
         (planet xtofs/firmata/firmata)) ;; a reference to whatever is the latest version of "Firmata", a library for Arduino programming.


Very cool thread which definitely piqued my interest. Do you have a blog or a github repository somewhere online? I've had a try building a simple racket web app following the documentation online, and found it fun but went no further. The docs for the language are wonderful though.

If you do write or have written more about your experiences, please let me know .. my username at gmail . com


I'm lobbying very, very hard to get our code open sourced, but it's going to take some convincing. I do, however, have one Racket project on GitHub right now, though I haven't touched it in a while and it is very simple:

https://github.com/capnmidnight/philly_mud

I don't really blog that much, and when I do it's not usually about programming. Maybe I should...


Good luck! Let me know if you do write more.


Follow me on Tumblr, then! http://moron4hire.tumblr.com

or G+: https://plus.google.com/u/0/100282968888030008096/posts

The posts will show up on Tumblr and get linked on G+, but I'm not a huge fan of Tumblr's dashboard system.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: