PlayFab Game Jam Postmortem

A couple of weeks ago I participated in a 48-hour game jam hosted by PlayFab here in Seattle, with fellow procedural planet veteran Alex Peterson, my good friend and composer Leo Langinger, and the fortunate last minute addition of artist Brent Rawls.

We were both surprised and excited to have won this game jam, especially given the number and quality of competing entries.

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Permanence (or a lack thereof)

When Google VP Vint Cerf warned that increased dependence on technology could lead to a ‘digital dark age’, he merely echoed the concern of everyone involved in the preservation of information in a digital world. While it is expedient to dismiss his claim as sensationalist and/or paranoid, Google’s announcement yesterday that they are closing down the Google Code source code repositories provides an unfortunate echo to his cries.

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Approaches to Resource Disposal

I’m working on developing a novel programming language, working title ‘aevum’. As part of that process, I’ll be writing a series of articles about various aspects of language design and development.

Every long running computer program is going to need to obtain a variety of resources, and those resources are almost always finite. Memory, file handles, threads, GPU resources – all of these are relatively scarce, and exhausting the available supply will have dire consequences, anywhere from killing the program, to crashing the computer on which it runs.

Given this scarcity, it is essential that we can dispose of these resources as soon as we are finished using them (or at least, before they are needed elsewhere). Although that sounds simple enough, it turns out that there are a couple of hurdles to overcome.

The first hurdle relates to ownership. As long as every resource is owned exactly once (i.e. a member variable of one object, or a local variable to one function), then disposal is trivial – a resource is disposed of as soon as it’s parent is disposed of. But requiring single ownership of every object comes with disadvantages of its own: with strict single ownership you can’t easily maintain cyclic data structures such as bi-directional lists, graphs or trees.

On the other hand, if you elect to allow multiple ownership, you are then faced with the problem of how to determine when a resource is actually no longer being used. Obviously you can’t dispose of it as long as even a single owner still exists, but how do you determine that the last owner is gone? You can explicitly keep track of the list of owners for each resource (a la reference counting), at the expense of both storage and performance, or you can at regular intervals scan the entire system to determine objects without owners (a la tracing garbage collectors), at the cost of determinism and performance.

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Fun with commas

This thread over at GameDev got me thinking, “can one assign Python-like tuples in C++?”

I don’t want to pollute the thread in For Beginners with that discussion, but the answer is yes, even without C++11 initialiser lists:


#include <iostream>

struct A {
    A &operator = (int i) {
        std::cout << "A = " << i << std::flush;

        return *this;
    }

    A &operator , (int i) {
        std::cout << ", " << i << std::flush;

        return *this;
    }
};

int main() {
    A a;

    a = 10, 20, 30;

    std::cout << std::endl;
}

Should you ever do this? Probably not. Though I’m guessing one of Boost’s container libraries is doing exactly this.

Bidding a Freelance Contract

Although I am gainfully employed at present, in the past I have made a good portion of my living in freelance work: websites, Facebook applications, database tools – even the odd carpentry project. The most essential skill involved in freelancing any field? Communication. But the next most important skill is the ability to accurately estimate and bid for a contract.

If you’re working a regular job, you are almost always paid by the hour. Freelance work is sometimes paid by the hour, but more often the client will want you to bid a fixed price for the entire project: a ‘contract price’. And even if it is paid by the hour, the hourly rate isn’t generally a pre-determined constant – you will have to get in there and negotiate the hourly rate you deserve.

So how does one estimate a fair bid for a contract? Continue reading →

The price of progress

I recently installed the beta of Microsoft Office 2010, and the first thing that struck me is how it performs noticeably worse on my 3.0 GHz quad-core AMD gaming rig, than Office ’98 performed on a now 12-year-old PowerBook G3, powered by a little 250 MHz PPC processor.

You can probably guess the next stage of this little anecdote… Office ’98 on that G3 performed ever-so-slightly worse than Office 4.0 on a truly antediluvian PowerBook 180, which sported a fantastic (for the time) 33 MHz Motorola 68030 CPU.

Now, I am not being entirely fair here – the spellchecker is much faster, the grammar checker didn’t even exist back then, and various other ancillary features have been added and improved. But the core issue remains, Office 2010 (or 2007, which is not in beta) running on a very decent gaming rig, takes longer to launch and is less responsive to keyboard input than Office 4.0 on an 33 MHz 68k.

And the problem isn’t restricted to Microsoft products alone, as many pieces of software have suffered the same sort of creep, not least among them the Mac and Windows operating systems.

In the open-source world and among smaller developers this phenomenon is far less common: a well configured linux or BSD installation boots in a handful of seconds, Blender (sporting most of the features of expensive software such as 3DS Max and Maya) launches immediately and always remains responsive, and Maxis’ Spore takes minutes to start up and load a game while Eskil’s Love throws you into the game in under 10 seconds.

My current computer is many thousands of times faster than that PowerBook 180, so in theory at least, we should be able to do far more, and do the same old things much faster. Why then the slowdown?

It can’t be lack of resources – we are talking about companies such as Microsoft, Apple and Adobe, all with enormous R&D and development budgets, and teams of experienced programmers and engineers. Besides, the open-source guys manage just fine, some with just a handful of programmers, and most with no budget whatsoever.

It has been argued that programmer laziness (a.k.a. badly educated programmers) are to blame, but I am not sure this can be the entire story. Certainly the ‘dumbing down’ of University-taught computer science hasn’t helped, nor has the widespread rise of languages that ‘protect’ the programmer from the hardware, nor the rise of programming paradigms that seek to abstract away from low-level knowledge. But that is the topic of another rant, and is somewhat tangential to the topic at hand. Companies can afford to hire the best programmers, and could if they wanted to, create the demand necessary to reform education practices.

And that brings us to the real heart of the issue: software developers measure success in terms of sales and profit. As long as your software sells, there is no need to spend money on making the software perform better. And if you happen to have a virtual monopoly, such as Microsoft’s Office or Adobe’s Photoshop, then there is no incentive to improve the customer’s experience, beyond what is needed to sell them a new version each year.

However, when you lose such a monopoly, the game changes, and it generally changes for the better. When FireFox, Opera and later Safari started cutting a swathe into Microsoft’s Internet Explorer monopoly, Microsoft was forced to adapt. The latest version of Internet Explorer is fast, standards compliant, and relatively free of the virus infection risks that plagued earlier versions.

This outcome of the browser war has led at least a few to the conclusion that open-source is the answer, and that open-source will inevitably recreate what has been developed commercially, and either surpass that commercial product, or force it to evolve. Sadly, I don’t see this happening particularly quickly, or on a wide scale – OpenOffice is playing catch-up in its efforts to provide an out-of-the-box replacement for Microsoft Office, GIMP lags far behind Photoshop, and linux, despite widespread adoption in a few key fields (namely budget servers and embedded devices) still lags far behind Windows and Mac in many areas.

For many years this wasn’t a problem – every few years you would buy a new computer, typically an order of magnitude faster than the computer it replaced. If new versions of your software consumed a few million more cycles, well, there were cycles to burn, and besides, the hardware companies needed a market for faster computers, didn’t they?

Nowadays the pendulum is swinging in the opposite direction. Atom powered netbooks, Tegra powered tablets, ARM powered smartphones – all of these promise a full computing experience in tiny packages with minimal power consumption. Even though the iPhone in your hand is considerably more powerful than that 33 MHz PowerBook 180, it doesn’t have even a fraction of the computing power offered by your shiny new laptop or desktop. And users expect a lot more than they did in the early nineties – animated full colour user interfaces, high definition streaming video and flash applications, oh, and don’t drain the battery!

CPU cycles today are becoming as precious as they ever were, only now many of our programmers have no experience of squeezing every last drop of performance out of them. Has the business of software development come full circle, and once again become the territory of the elite ‘low-level’ programmer?

RFC 1149 implemented

This one goes out to all the networking students in the house:

Wired reports that a firm in South Africa successfully demonstrated that data transmission via flash drive equipped carrier pigeon is faster than their existing internet service (source).

Of course, any networking student worth his salt should know that this approach dates back to 1990, in the form of RFC 1149…

simplui 1.0.4 released

New in this version:

  • Support for multiple windows
  • Java-style flow layout
  • Full batching
  • Numerous performance enhancements and bug fixes
  • Minor theme tweaks
  • setuptools/easy_install support

Given the speed of development, simplui has moved to its own googlecode project:

http://simplui.googlecode.com

You can obtain the source from Mercurial, or download the binary package there.

In addition, simplui has been integrated with setuptools/easy_install. You can find the package listing in the PyPI directory (here), or you can install immediately with easy_install:

easy_install simplui

(note that easy_install will not install the demo application and themes)

This release does come complete with a few of caveats:

  • simplui is only compatible with pyglet 1.1 maintenance – not the experimental version in trunk
  • There is a bug in pyglet 1.1.3 which can cause crashes if un-patched.
  • On Mac OS X, you may need to upgrade setuptools (sudo easy_install -s /usr/bin setuptools)