Blue Lotus Blog

Spencer Nielsen

Language Aid is a system-wide text lookup tool I developed and sold for the past couple of years. I recently decided to make it free and release the source code. This is the story behind it.

Rewind to 2006, I was just winding down active development of Vision, my OpenGL Window Sever/UI Framework. I had started work on Vision in college 3 years earlier and had been churning on it full-time for the previous 2 years. I had decided that it was finally time to get a job and so I interviewed around and accepted a position at Apple. I had two weeks until my start date and I wanted to do some programming for fun that was completely different from what I had been doing.

Iron Coder[0]

It was during that two week period of not yet working for Apple that Wolf Rentzsch started the (now defunct) Iron Coder contest. The way it worked was that the organizer announces an API that each of the contestants must use somehow in their entry and then 24 hours later a theme is announced that entries must also somehow incorporate. I thought it was just what I needed. A fun, small-scoped project with a little bit of competition. So the day of the very first Iron Coder arrived and the contest API was announced: The Accessibility API. Accessibility API? What’s that? Until that moment I had not been aware of it but it was actually just what I had been looking for to solve a different problem I had. I started researching it and immediately there were portions of it that were very interesting to me. Specifically, the ability for programs to inspect and copy data (like displayed text) out of other running applications was of particular interest to me.

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Spencer Nielsen

Language Aid version 1.2 is out! The big feature of this release is that it is free and open source! This will also be the last release supported by Aoren Software. Development has pretty much wound all the way down at this point and the source has experienced some code rot as Core Foundation has progressively become more and more obsolete and Mac OS X has marched forward.

So it occurred to me that the time has come to set Language Aid free. Anyone care to take the code and modernize it? Maybe even release it on the Mac App Store? Let me know and I can work with you to make that happen. Be sure to check out my tell all Language Aid postmortem.

Spencer Nielsen

AirPlay Mirroring was without a doubt one of the coolest iOS 5 features announced to the public at the 2011 WWDC Keynote. This amazing technology allows you to display the screen of your iOS device on an Apple TV 2. At the moment, the only supported mirroring device is the iPad 2 and the receiving device is limited to only the Apple TV 2. Airplay Mirroring is the latest in a pedigree of Apple media streaming technologies. The previous entry in the family was Airplay Video and is a slightly different technology that allows specific content to be broadcast from a variety of iOS devices and iTunes to an Apple TV 2. The precursor to that technology was originally called AirTunes and is used to broadcast audio content from iOS devices and iTunes to the AirPort Express and Apple TV (either 1 or 2). One peculiar thing that people noted about AirPlay Video was that it was wide open and unencrypted! This was surprising in light of the fact that AirTunes was most definitely not. Because of AirPlay Video’s relatively easy hackability, there quickly sprang up all manner of apps for both Mac OS X and iOS which would act as an AirPlay Video consumer.

So my thought process went like thus:

• AirTunes – Encrypted
• AirPlay Video – Unencrypted
• AirPlay Mirroring – ???

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Spencer Nielsen

 

As a partial follow up to my previous article “Play SNES Games On Your iPad Without Jailbreaking” I have now made a similar patch to the imame4all project which will allow it to build for non-jailbroken iOS devices. Everything appears to be in order except that I havn’t figured out a way to get the BTDaemon to run on a non-jailbroken device. This means that it can’t currently use Bluetooth controllers like the Wiimote. Digging into the btstack source it looks like you can configure it to talk with a BTDaemon process even if it is running on another machine like a Mac. I havn’t had time to fully investigate that yet though.

How To Get It Working Yourself

I have created a patch and script that will create everything for you automatically and set you up so that you can just build, run and go. Like the SNES-HD- patch before, you are going to need a current copy of Apple’s Developer Tools (tested with Xcode 3.2.6) and a copy of the iOS SDK (my changes assume the 4.3 SDK). You will need to be a paid iOS developer with Apple and have correctly configured your development machine and iOS device so that you can sign code and run said code on your device.

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Spencer Nielsen

Top-down view of the Aoren Software datacenter in the living room corner.

Why, you might ask? In my case the answer is simply because it is my only alternative. In development of my game Cannonade there quickly arose a need to be able to replay my user’s completed games and validate the results with exactness. In order to obtain that level of exactness, my games must execute with complete determinism. Unfortunately the implementation of floating-point match according to IEEE754 can actually vary somewhat between x86 and ARM processors. This means that if I replayed a game that two of my users played using iOS devices on an x86-based server, the results of the replay would very quickly diverge. Thus I am left with no choice but to set up a dedicated iOS device to wait for notifications of the matches that it needs to replay and validate (a process I call judging). An iOS server you might say.

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Spencer Nielsen

Apple gets a lot of flack over its curated app distribution model. No matter what your opinion on the subject is there is no doubt that for Apple’s model to have any sort of success it needs to be the only commercially realistic distribution avenue on the platform. This leads many people to jailbreak their devices for a variety of different reasons. Lets examine just the motivation of wanting to personally use non-App Store approved apps. The argument is then almost always framed as a dichotomy. I can jailbreak and get access to apps that Apple cannot or will not approve but risk damaging the device, violating warranty/support expectation, losing the ability to directly update to the latest OS version and introducing instability. Or I could keep my device in a stock configuration that will ensure stability and a clean upgrade path but miss out on some truly awesome and useful jailbroken apps out there. People don’t often remember that there is actually a third way to load apps onto your iOS device that has its own set of unique pros and cons. Apple fully supports loading apps on stock devices outside of the App Store through its developer program.

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Spencer Nielsen

One day while I was hard at work a couple weeks ago I hit a really difficult technical snag. I stood up from my desk, let out a sigh and declared to the other person working in the office that “I’ve lost my determinism!”. He then inquired how I had lost my motivation while visibly wondering if I had used the word correctly. Although I had hit a significant roadblock, my determination to overcome it and make progress on my game was higher then ever. The “determinism” of my game however, had been lost. Now I needed to take it back.

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Spencer Nielsen

The biggest problem I see with the current implementation (iOS 4.x) of Game Center is that there is no way for Game Center users to authenticate themselves to 3rd-party servers. Let me explain from the top. Game Center is Apple’s new games oriented social network and infrastructure on iOS devices. It has a lot of great features like leaderboards, achievements and matchmaking. Once a user creates an account on an iOS device they are perpetually signed in at the operating system level. This is great because it means that all existing and future Game Center games can take full advantage of its features, social connectivity and never have to make users create an account (users HATE creating new accounts) or even sign in again (unless of course they explicitly sign out). From the game developer perspective, Game Center is really awesome. There are a lot of developers (myself included) who do not want to have to:

• Create a complete login infrastructure
• Store and handle people’s passwords safely
• Figure out some sort of account confirmation
• Implement password recovery
• Encourage users to start building YET another social graph on your service/game
• Handle other support related support requests

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Spencer Nielsen

Deadlock is the name for my copy-protection/registration framework that I have been using in Language Aid since version 1.0. It has worked faithfully for me since then and I have have decided to share it with other developers who might be looking for such functionality or looking to bump up their protection a little.

I have long heard many developers argue that most of the time pirates wouldn’t purchase your software anyway and so you shouldn’t bother putting that much effort into fighting it except for the most basic and obvious of protections. In most cases it just isn’t economical. I generally agree with this but the reason that I put so much effort into Deadlock to protect a $20 program was more personal education and entertainment than anything else. I must admit that I had a lot of fun thinking of how to hack the program, come up with a countermeasure, then come up with a circumvention of that countermeasure and then engineer a protection against that back and forth over and over again. I mostly just thought of the kinds of reverse-engineering that I have performed on other software for entertainment and then researched methods to prevent such fun. In the end I thought I had a pretty good setup of minimally invasive mechanisms to prevent piracy for my software.

Deadlock has been refined over the course of Language Aid releases and as of Language Aid 1.1.1 it was built out as its own separate product. I have wanted to refine it and add more diverse functionality to it for a long time. To accomplish this Deadlock needs more clients, preferably applications outside of Aoren Software. In the future I also plan on productizing my payment processing engine (works hand in hand with Deadlock) that makes paying for and registering Language Aid easy, fast and instant (no serial numbers, no confirmation emails, just instant gratification). I wanted to end this post by citing one of the many insightful quips from Bruce Schneier in order to emphasize that security invasion is inevitable and that defenses are simply deterrents. Instead I give you this:

The user’s going to pick dancing pigs over security every time.

— Bruce Schneier

Spencer Nielsen

I actually had a very hard time thinking of a name for this project. Nothing really seemed to fit too well or sound that good. But I needed some sort of name for my new project. You have to call it something… I finally settled on “Razor”. What does it mean? Nothing. What does it have to do with the project? Nothing other than now that is what the project will be known by. After not being able to think of a name for a while and itching to just start coding on the darn thing I just picked the name and it has just kind of settled.

Ok, so what is it? On the Google Code page that it is hosted at I wrote:

Razor is a strategy game engine which is oriented around programming the AI of the units rather than direct control by humans. The idea is that human players compete by engineering the intelligence of the units under their control in order to fulfill an objective. The game world is in 3D and will employ some basic physics. Units, AI, physics models and many other aspects are extensible through a plugin system.

Razor is for Mac OS X Leopard only due to leverage of certain Leopard exclusive features such as dynamic loading/unloading of Objective-C, Garbage Collection and more as time goes on.

This is an idea I have had banging around in my head for a long time. Ever since I worked on an AI lab in college where the final semester objective was to program the AI of 5 tanks to play capture the flag against 5 other tanks controlled by one of the AIs of my many classmates. At the end of the semester the class had a tournament in which the prize was an instant ‘A’ in the class and didn’t have to take the final! My lab partner and I won the tournament and even though we both had As in the class at that point, not having to take the final exam was a big time relief at the end of a very busy semester. Perhaps I will make a blog post on our winning strategy later.

Along with that, I have always loved the great strategy involved in RTS games like Starcraft (which in my opinion is the best RTS ever made). I loved thinking of crazy new strategies that would find kinks in established defenses or play with the psychology of the other players. The only thing that prevented me from pulling off my grand designs was the limitations of my own reflexes. Some people just have the twitch and can bounce from scene to scene, keep everything in their heads at once and make lightning fast and precise mouse movements. But if the Korean Starcraft scene is any indicator, these cyber-athletes like gymnasts have a limited lifespan. Once you hit the ripe old age of 22 your reflexes aren’t what they used to be and some pretty young 16 year old is going to take your spot. What I want in some respects is AI programmable Starcraft.

Now the project is only in its infancy and is nowhere near doing anything of significant interest at this point but I decided that I wanted to get the code into an initial functional state that would at least be worthy of initial check-in. Because the project is open source I will be commenting here about the work that I am doing on it, future feature additions and other issues with great openness and frequency unlike my closed projects.

Below is a screenshot of the Simulation Viewer app that you can build and run right now from the source that is posted on the project page. It is not much but it is a start.