Stephen's Weblog

Hey, it’s been a while. I’ve taken a few minutes (well an hour or two) to upgrade wordpress and check/tweak my site’s links – I’d like to use this blog more often

Since I’ve gone through all that effort, I should probably write something…

I’ve been involved in a lot lately,

• Work – Eats a lot of my time – I really like what I do. I actually have an office job now, never would have imagined that :)
• Personal projects – Still doing stuff all over the place. I may link these from time to time but mostly keep them to myself
• XNA games – Have a big  project or two in progress. Also not saying much about this, but I may link something from time to time…

Also, I have a lot of plans for the future,

• DS Wifi project – Reverse engineering the hardware again, more thoroughly – Completely rewriting the 802.11 and TCP/IP stacks. Not going to start for a few months at least, and it will probably take a few more months when I do get started.
• Some hardware ideas have been brewing, but I won’t say much about these…
• Some emulation ideas have been brewing, but I won’t say much about these…
• There are always far more ideas than I can imagine having time for.

I’ve decided I will post interesting milestones of large projects or interesting completed small projects here when I have spare time to do so- It shouldn’t be hard to keep this blog more active than it has been :)

I’m also currently playing with Twitter, so some additional information about what I’m doing is available there – http://twitter.com/sgstair/

One other thing: I’m toying with the idea of writing an article every week or two, but I haven’t decided what exactly to write about yet. If you have ideas I’d appreciate if you tell me, in the comments or otherwise. Currently I’m considering writing a series of articles on building a software rendering 3D engine from scratch.

Well, that’s all  for now. Maybe I’ll manage to post here more often :)

Hi! Well, the Opti compo has ended. I haven’t got around to judging cause pepsiman probably won, and I’ve been really short on time, and tied up in other things.

I’m not sure just how much I want to say yet, but I have moved (I’m in the Seattle area now), and have an office job now – which is new for me. I’m still working out how much I’ll be able to continue working on my personal projects, but I will post more on that when I know for sure. I’m not sure how things are going to unfold yet but I will certainly post more when I do know.

And then, I’ll try to clean up the pieces of all the stuff I dropped in the process of moving out here and getting started in a new place.

I continue to fail to post weekly; all the fun stuff I would want to say, I don’t think I should talk about, though.

Anyway, the Opti compo is still going along, but it’s getting close to the end – right now there are 11 days before the compo ends. I’m adding this informational post to remind people and also to alert people to a new revision of the test system, better rules for whether an entry will be accepted or not, and various other things. I’ll reiterate  the important parts on the competition page.

Firstly, the test system update: this update will probably be the final update of the test system code for this competition. Unfortunately I didn’t get all the stuff I wanted in it, I’ve been short on time and have had more than enough stress to go around :) So, this update does not contain the statistical time-sampling profiler that I wanted to add to the test app. It also doesn’t include a fractal explorer section which I had wanted to add. But on to the features that I did get around to adding: There is now a new default test set of 6 tests, they zoom in quickly on a specific point in the fractal, and are pretty complex areas to render (the number for max_iterations on the 6th image is 1400, and the horizontal and vertical steps are in units of 2^-44). I’ve included a modified example that is designed to serve as a lower bound for correctness – passing implementations should have a smaller amount of error than the lower bound. I don’t think this will be too hard, the lower bound currently exists as a modification to the multiply code that loses 3.5 bits of precision with each multiply. This actually caused less difference from the reference implementation than I had thought; currently across the 6 tests, there is a total difference of 7044 iteration counts, notably the 6 tests render a total of 147456 pixels, so this value is really barely even noticeable.

There was also a bug in the test app that caused it to only display the last test’s cycle count rather than the sum of all of them, this has also been fixed, and (in no$) the cycle count for the “lower bound” test is 0x0004CC483E1E cycles – which is 307 seconds of cputime, about 5 minutes. As the default test behavior also runs the example code alongside it, this means a test run of the lower bound takes about 10 minutes; not very good for repeated testing. I’ve added a way to start the tests without checking them, by pressing start instead of A, so the code execution time you have to sit through is purely your own fault ;) It will be pretty obvious if there are big errors, but it will still take a long time to check results against the reference function.

Ok, that’s all I have for now; I’ve been working on my own implementation just lately in assembly, but I really have no idea how well it will perform just yet. I’ll post some numbers in the comments on the Opti site once I get them.

So, the Ludumdare 11 competition is over (as of 2 weeks ago), and voting has completed (as of yesterday)- it’s been a while since I last posted.

You can see the competition results Here  - I got first place in the timelapse video, and third in the technical category – participating was a lot of fun.

Things are moving really slowly here lately, I’m trying to get a job, trying to get varioius odd projects done in the meantime… Haven’t really started on any of the big things I want to do, due to lack of time. I do hope I can get all of these things sorted out  soon.

The First Opti Competition is still moving along – in hindsight it’s really not doing as well as I’d like, and that’s mostly due to the theme. Well. I do have ideas on how to fix that – after this first compo I’ll be starting some more useful / reasonable / interesting competitions that will hopefully involve a wider array of people and won’t be quite so technically involved. I’m also going to add some more categories to the site, so there should be something for everyone.

I’m going to try to continue with weekly updates, because I know you all have nothing better to do than read about the trivialities of my life ;) yes, I’m being facetious. Sometimes I wonder why I write this at all; I do hope someone finds it interesting, but if nothing else it’ll give me something to laugh at many years down the road.

I’ve decided to enter the LudumDare 48 hour competition (#11) – it should be a lot of fun – 48 hours to develop a game completely from scratch! I’ll be sure to post here with the outcome, good or bad. Though I suspect the outcome will be good ;)

Ok, Finally – after a lot more effort than I thought it would take – the akkit.org optimization contest (for DS) is up and running, with it’s first competition!

Although the competition technically started a day and a half ago, I haven’t posted it yet because I didn’t have the test package ready, but is ready and posted now.

So, it is with great anticipation that I submit it to you, for review: Opti’s First Competition

Anticipation like, waiting for a pie to hit me in the face, or be run over by a car, or something similar ;) I do however want to see what level of interest there is, and try to make this into something that more people will be more seriously interested in next time (I am highly curious about how many people will be interested this first time) – So, to that end I am very interested in any sort of feedback. Anyway – That’s all I want to say for now, I’ll shut up before I ramble on about it for a very long time; Thanks for looking :)

So, I was holding off on posting until I had the optimisation contest site ready – but that didn’t work very well, it’s run a lot longer than I had planned for it to (oh, only a few months longer :P), but it’s finally getting to a usable state!

Currently, all of the public-facing user interface magic is done, I’m just wrapping up a few admin pages and testing things, but it’s looking very good! I’m going to aim to finish it up and get a proper competition started this weekend. However, if you want to get started and have some time to tinker around with the site first, have fun! The site is at http://opti.akkit.org/ – there is an IRC channel set up for support and general discussion (#opti on Blitzed). Also, please note the site still contains remnants from testing, that will all be swept under the metaphorical electronic rug when I get a real contest started but for now it serves to be some data to test with and show how things work. Comments and bug reports will be most welcome, as will suggestions for improvement – a design overhaul is planned for the near future as well (well, I like the design pretty well, but it’s functional rather than elegant, and it will be better if it’s both)

Since I’m not really in the business of detailing my life’s complexities in my blog (which, well, is what everyone else seems to use them for), the title of this post really sums up all I’m really going to say; Ordinarily I think life being complicated and interesting is a good thing, but it has it’s down sides too, and I’ve run into that lately.

That being said, I strive to not let things like life’s trivial and big problems bother me, and I’m continuing to work on entirely too many projects. Some things are making progress, others not so much. I’m prioritising Opti, followed by the logic analyzer, and I’ll decide what to do next when those are ready. I’ve picked up a few more smaller projects lately, tinkering around with graphics effects, video capture and image recognition, and I still have a stack of books to read.

I’m trying to decide whether I should disclose some of the smaller projects I’m tinkering around with and release binaries / possibly source / other information about them, I don’t really see this stuff being very useful to many people, and it does take time to document, depending on what level of disclosure I go with – but I think it’s generally pretty neat stuff – jury’s still out on this one but if you have an opinion I’d like to hear it.

Some of you might have been following this, but recently I’ve completed some DS homebrew code to make it simple to send data between processors; This took a good bit longer than it probably should have but it is done now, and being integrated into libnds as part of our plans for world domination, er, our plans to make homebrew easier. The basic idea behind the system is to take the single pipe between the processors (the IPC FIFO) and use a system wrapped around it to create a set of virtual channels, through which you can send data from one processor to the other. The system is set up with the ability to use callbacks, which will automatically dispatch the message on the receiving end to a user function, or the receiving code can just check the incoming queue occasionally. As it was designed, the system will pipe one of 3 types of value through to the other processor – it can either send a mainram address, a 32bit data value, or a sequence of 32bit values. It’s designed to be very fast and efficient about this sort of thing, the latency to send a value through is very low, and it’s all interrupt driven to receive data as soon as it comes in.

For now, the code is not available to the general public, right now it’s intended to be used as a low-level communication layer and currently the plans are being made to integrate it into the libnds examples as a way to quickly get information (buttons, touch, rtc) from arm7, and  provide a channel for controlling the arm7 (i.e. sound, power control, others) – the hope is to have a more solid interface for this sort of thing to help people who don’t really want to deal with the hardware directly but still want to play sound and things like that. I expect that some level of access to all this will also be provided for people who want to do their own thing on arm7, and this code I hope (and expect) will help provide a better environment for developing applications across both CPUs.

Well, some days I feel like I’m getting a lot done…. Some days I feel like there’s a lot going on but nothing’s getting done… And yet other days I don’t feel like doing anything at all.

I’ve been having a lot of that second type lately- sometimes making progress, sometimes not, but lots of things going on and not really apparently getting anywhere.

Here’s hoping next week will be different…