Dirty Coding Tricks
August 20, 2009 Page 1 of 4
[When the schedule is shot and a game needs to ship, programmers may employ some dirty coding tricks to get the game out the door. In an article originally published in Gamasutra sister publication Game Developer magazine earlier this year, here are nine real-life examples of just that.]
Programmers are often methodical and precise beasts who do their utmost to keep their code clean and pretty. But when the chips are down, the perfectly-planned schedule is shot, and the game needs to ship, "getting it done" can win out over elegance.
In a case like this, a frazzled and overworked programmer is far more likely to ignore best practices, and hack in a less desirable solution to get the game out the door. We have here compiled nine testimonials from working developers, which chronicle times when they weren't quite able to follow the script and had to pull some tricks to save a project.
- Brandon Sheffield
[If any readers have any dirty coding tricks of their own to share, please email them to Brandon Sheffield at [email protected] Illustrations for this article by Jonathan Kim.]
Shoot Me From My Good Side
Around four years ago I was working as a programmer on a multiplatform PlayStation 2, Xbox, and GameCube release. As development was coming to a close it should come as no surprise that some code hacks started creeping into the game to get the title shipped. The PS2 version in particular had a late, extremely hard-to-track-down issue: A long soak test of the player character standing still in the first level of the game would cause it to periodically crash. Unfortunately, the crash was limited to disc-only retail builds that included no debugging information. With fears of a Sony technical requirement check (TRC) failure looming we worked hard to find a solution.
To narrow down the issue we continuously rendered a border around the edge of the screen with a different color for different sections of the code. For example, blue represented render setup, and green was the player control update. Because the crash was intermittent, the lead engineer on the title and I would manually burn a bunch of discs and start them up on an array of PS2s. (Keep in mind this was an independent developer, with no IT team or fancy disc burning machines.) The test cycle -- between making a code change, burning discs, deploying, and waiting to whittle down some approximation of where the crash was -- took hours. It was the eleventh hour of development and there was a fixed number of these test cycles we could conduct.
Between stretches of passing the time over the weekend in the office with World of Warcraft while waiting for a crash, someone noticed that the game didn't crash if you rotated the camera 90 degrees to the right. Initially, the programming team correctly waved this off as some kind of fluke that was masking the underlying bug. This isn't the type of "fix" that would repair the root cause of a crash. That didn't stop us from shipping it though! As we ran out of time, we created the final PS2 disc with a rotated camera at level start -- the other two platforms were already on track -- and submitted everything. The game passed all the platform holders' TRC tests and was shipped to market on time.
I wouldn't call this a "coding trick," but it was definitely "dirty." The mysticism of the fix is disconcerting to this day, but thankfully I never heard of any reported user issues.
- Mark Cooke
This scene is familiar to all game developers: It's the day we're sending out the gold candidate for our Xbox 1 game. The whole team is playtesting the game all day long, making sure everything looks good. It's fun, it's solid, it's definitely a go in our minds.
In the afternoon, we make the last build with the last few game-balancing tweaks, and do one last playthrough session when disaster strikes: The game crashes hard! We all run to our workstations, fire up the debugger, and try to figure out what's going on. It's not something trivial, like an assert, or even something moderately hard to track down, like a divide by zero. It looks like memory is garbage in a few places, but the memory reporting comes out clean. What's going on?
One dinner and many hours later, our dreams of getting out on time shattered, we manage to track it down to one data file being loaded in with the wrong data. The wrong data? How's that possible? Our resource system boiled down every asset to a 64-bit identifier made out of the CRC32 of the full filename and the CRC32 of all the data contents. That was also our way of collapsing identical resource files into a single one in the game. With tens of thousands of files, and two years of development, we never had a conflict. Never.
Until now, that is.
It turns out that one of the innocent tweaks the designers had checked in that afternoon made it so a text file had the exact same filename and data CRC as another resource file, even though they were completely different!
Our hearts sank to our feet when we recognized the problem. There's no way we could change the resource indexing system in such a short period of time. Even if we pulled an all-nighter, there was no way to know for sure that everything would be stable in the morning.
Then, as quickly as despair swept over us, we realized how we could fix this on time for the gold candidate release. We opened up the text file responsible for the conflict, added a space at the end, and saved it. We looked at each other with huge grins on our faces and said:
- Noel Llopis
Driving Under the Influence
I've been tasked with taking care of a system dealing with vehicles, which is a fairly major part of our current game. Fortunately, we were able to grab the majority of the code from another studio. Unfortunately, the code isn't always perfect or well written, as is the perception with most code you don't write personally. I happened to find this nice bit of code that was simply trying to get a variable from the engine loop, but was going about it in the most backward way possible (See Listing 1).
Listing 1: Driving Under the Influence
// Function: AGameVehicle::Debug_GetFrameCount
//! A very hacky method to get the current frame count; the variable is protected.
//! \return The current frame number.
BYTE* pEngineLoop = (BYTE*)(&GEngineLoop);
pEngineLoop += sizeof( Array<FLOAT> ) + sizeof(
INT iFrameCount = *((INT*)pEngineLoop);
The funniest part about this chunk of incredibly gross code is that there was a simple function on that object to get the frame count. Even if there weren't, the person who wrote this code could have easily added one himself! Needless to say, this code was not added to my game, nor to the game this code was taken from, as soon as I pointed it out. If this isn't an example of why code reviews are good, I don't know what is.
- Austin McGee
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