Avahi to be considered harmful

Let me paint a picture as it's come into focus for me recently. Apple develops a protocol called mDNS for zeroconf via multicast DNS. They call it Bonjour and are serious enough about making it a standard they release a free software library called mDNSResponder to support it which runs on GNU/Linux, OSX, and Windows.

A community project, Avahi, implements their own mDNS suite for GNU/Linux. Avahi adds some nice features, such as dbus support. To help apps use either option they support compatibility with mDNSResponder's API.

It's great to have this sort of cooperative-competition, but they took this a bit too far by printing a nag warning when their mDNSResponder compatibility API is used by an application and otherwise pressuring mDNS-using apps to drop support for mDNSResponder.

I sincerely hope Python projects aiming to implement mDNS build against the mDNSResponder API, for cross platform support if nothing else, and encourage their users to avoid using Avahi when questions about this nag page come up.

Concordance register.py

I have the main Python callback in Concordance working now to handle <iq/>, <message/>, and <presence/> elements. Eventually it'll only handle these elements when they're directed to the server, otherwise the server will route the message to it's destination without Python needing to process it first.

examples/register.py demonstrates user registration handling using ElementTree (or at least the start of the process for now). The result is shown here.

Concordance lives

Concordance-XMPP now listens and responds to new XMPP connections with basic XML parsing via expat.

David has been working with me to maintain Windows compatability. I'm working on SASL support and the Python callback API.

With luck the first (very early) release will be ready this weekend which can handle logging in and intra-server routing between users.

Python 3.0 - first extension module

After hours of hunting down docs and debugging my build environment (turns out I had a 3.0-alpha5 lurking around mucking up setup.py)..

Python 3.0 (r30:67503, Jan  2 2009, 00:20:15) 
[GCC 4.3.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import concordance
>>> concordance.__file__
'/usr/lib/python3.0/site-packages/concordance.so'
>>>

New Year, New Project

The first day of 2009, PySoy's copyright notices updated and a few tickets closed, I hit a point where I really need a decent XMPP server.

I've started a new project called Concordance, a XMPP/Jingle server written in C (message routing and RTP mixing) and Python 3.0 (authentication, login, MUC handling, etc).

The goal is a framework giving Python full control over the server, for nearly unlimited configurability, while having the speed to serve a large user base with a minimal of CPU use.

great cheese frustration

I overall like Gnome, but the guys working on Cheese appear to be making some horrible design choices.

Such as, they've removed any possible way to set the video input device, either via gstreamer's properties, or command line, or within the cheese app itself.

Now I'm hunting for another app that does video capture from a video4linux device, or possibly writing one using PySoy.

Beta3, new features on Ohloh

So we're trying to get Beta3 out the door. No date yet, there's still a lot of cleanup work to do.

For smaller updates, Ohloh has a new "Journal" feature that resembles Twitter. What's really cool is once you associate your XMPP id with your Ohloh account you can use XMPP (via your normal IM client) to post to your journal.

Check PySoy's journal for smaller, more frequent updates on what we're doing.

bike accident

I got side-swiped by a car Tuesday. Only injuries are some scraped skin and sprained wrist (I'm either really lucky or all too experienced in surviving bike accidents), but the latter has dramatically slowed by dev pace due to having to type with only one hand.

The sprain is mending well and i should be able to do light stuff (like typing) with it this weekend, provided I keep it immobile.

In other news, bump mapping is working again, but our blocks.py lacks proper normals, texcoords, and tangents. If anyone is willing to spend an hour or two working out the calcs for these please get in touch.

hacking at 3am, seeing rainbows

There are some real advantages to hacking into the wee hours of the morning, this gem of a screenshot is one of the best of late.

Thing is, I'm sitting here after refactoring several hundred lines of code and fixing two typos that was causing our normalisation cubemaps to be bugged, staring at this window, and unable to understand why.

The rainbow effect is obviously from the normalisation cubemap, a data construct that maps tangent-space bumpmaps to object-space on the video card (without shaders). I just can't determine at this late hour why it's showing up instead of rendering the bumpmap as it used to.

I'm sure it'll make much more sense after 8 hours sleep. In the meantime, enjoy the screenshot, or compile PySoy from subversion and run TexBlocks.py yourself!

Mesh code refactoring

I spent most of the day fixing, shifting, folding, documenting, and otherwise refactoring soy.models.Mesh and it's related datatypes and atoms. I'll likely spend most of tomorrow finishing this up.

In short, the render process we used was crude, lacked some really easy features, looped through 6 different classes for each Mesh (Mesh, MaterialList, Material, Texture, FaceList, VertexList) and had data management code in these plus the two related atom classes (Face and Vertex).

In short, not only was the code difficult to grok (even for me and I wrote much of it) but was slower that need be and increasingly difficult to expand. Game engines need both rendering speed (fps) and easy expandability, so this is a high priority ticket.

The new structure moves all of the actual Mesh data into the Mesh objects themselves; MaterialList is gone (to be replaced by MaterialDict later), FaceList and VertexList will now only store a reference to their parent Mesh to draw data from.

I'm going to be centralizing data management functions in Mesh as well, so the atoms can be much simpler and we can actually talk about optimizing the VBO layout. We'll also be doing dynamic passes, based on how many textures/pass a GL implementation supports, and supporting more textures targets (ie, specularity, emissive)

Again, sprint via IRC this weekend complete with remote peer programming via Gobby. Join us in #PySoy on irc.freenode.net