Zynga Ports Cocos2D-X to Emscripten | Zynga Engineering

If I could snap my fingers and wake up the following morning with any one problem at work just solved, you know what it would be?

No, not the stock price.

Without a doubt — it would be the problem of deploying our games concurrently to mobile and web. At Zynga we’ve tried just about every approach out there — written games with Adobe’s Air, used manual ports, and evaluated several proprietary solutions. They have all been valiant efforts, but have fallen short of our expectations.

Most people would throw up their hands in frustration over this problem. However, these kinds of problems are the reason that being an engineer is the coolest job in the world. In Apollo 13 (one of my favorite movies ever), there is this scene where a group of nerdy-looking scientists tackle the problem of fitting a square air-filter into a round hole. Whenever I watch that film, I always walk away thinking that the engineers were the heroes — they solve a tricky problem that saves lives. And while people generally don’t live or die as a result of my work, I do occasionally get the opportunity to save a lot of time for other engineers.

Emscripten is a hot new piece of technology from Mozilla that uses the popular LLVM toolchain to compile C++ code down to JavaScript, which can be executed directly in your web browser. In addition,  Emscripten translates OpenGL calls into WebGL calls. Given that many of our games are built using the popular Cocos2D-X C++ framework, I started wondering if there was a way we could MacGyver together Emscripten and Cocos2D-X to build a way to get our mobile games to deploy straight to the browser.

It turns out that my inclination was correct.

Last week, the Cocos2D-X team merged some of my changes into their master branch. The changes, in short, get Cocos2D-X to compile and run using Emscripten. Now, this is an alpha version, at best. However, it’s proven robust enough that we’ve been able to get some of our simpler mobile games up and running using this port, and, given these patches, it was a matter of a couple of days to get those games working.

If you want, you can checkout Cocos2D-X from the usual location, then follow these instructions to get it up and running. Unfortunately, we’re changing the code rapidly so we don’t yet have a demo online, but we hope to have one very soon.

This is hugely exciting.

Zynga, like many other companies, has pivoted to developing games mobile-first. But we think about it more as a “ubiquity strategy” than a mobile strategy — we definitely want you to play our games on mobile, but we also want to see you on Zynga.com.

However, we’ve learned that the successful teams develop for mobile first, thus building code around the assumption that resources will be limited. They also build on mature (read: “old, creaky”) technologies, because you want to spend time making the game fun, not trying to get the latest and greatest development tool to work.

What’s exciting about this approach is that it fits these priorities hand-in-glove. Whilst Emscripten itself is a new tool, the fact that it can be retrofitted to existing mobile games and their workflows is very appealing.

Before I end this blog post, I wanted to mention why Zynga is choosing to open-source this technology, rather than keep it to ourselves.

One of the great things about working at a company like Zynga is that we’re not just trying to build the best games — we’re trying to build an ecosystem of developers and a network of players. We want to be the best place to play games, and we know we can’t do that alone. We hope that by releasing this exciting new technology to the world we can help you build better games, which will be better for everyone.

Please, check it out! I’ll be blogging more about technical aspects of how we did it, how you can start using it, and get a demo online so you can try it for yourself.