Tuesday, December 30, 2008

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.

Saturday, September 13, 2008

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.

Thursday, May 22, 2008

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.

Tuesday, May 20, 2008

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!

Saturday, May 17, 2008

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

why can't XMPP keep their website up?

Several times this month I've found www.xmpp.org/, the organization responsible for the Jabber protocol and it's many extensions, non-responsive. Their site has been down for at least 7 hours tonight, the longest yet (to my knowledge).

For our purposes I'll be mirroring their XEP's on pysoy.org as soon as they're back up. It's seriously frustrating to be working on this when the documents you need are often unavailable.

If anyone knows of an existing mirror we could use, please reply to this posting.

Friday, May 16, 2008

some real progress toward beta-3

With Pyrex 0.9.8 released yesterday, including a number of key changes we needed to move forward, we're back in action for PySoy belated Beta-3 release.

The new forward declarations are a bit kludgy (example), and I don't think it'll be very maintainable in the long term. I think changing a class's inheritance should require editing one file, not two (the .pxd) or more (every .pxd that uses it).

It works for now, until we can wipe out the entire include/ directory, and to be fair it's only so cumbersome due to PySoy's size and how the classes are interconnected.

The nogil allowance for cdef methods is a massive step toward stomping out the multicore race conditions. One of the developers testing just the fixes to soy.bodies noticed the examples often running longer than before, though there's a lot more cleanup to be done before this is package-wide.

One of the roadblocks I hit is the nogil fix can't be used with our Children class, which stores pointers to Python objects of the same type and uses those pointers (through a typecast) to access their cdef methods in a for loop.

While our usage is GIL-safe, the current version of Pyrex still wants to throw in an INCREF just to be extra-cautious, which makes it not. I've let Greg know about this, we'll see if it can't be fixed soon.

In the meantime, I've called for an IRC sprint this weekend for the pending cleanup, refactoring, documentation, and testing that needs doing before beta-3. Join #PySoy on irc.freenode.net if you want to pitch-in!

Tuesday, May 13, 2008

Building a better Pyrex - part 1

With our recent decision to drop the Pyrex codebase and start from scratch, we find ourselves repeating a process from 2 years ago;

When PySoy first forked off of Soya, we had a small list of things that needed to be fixed based on our negative experiences working with that project. The API needed to be cleaned up, pydocs added, Shape needed to be mutable and implemented with vertex arrays or VBOs rather than display lists, etc.

As we worked on it, that list grew longer, including rewriting large parts of the codebase, until we found ourselves at a point where starting over would be more expedient. Of course now there's little doubt that was a good move, learning from both Soya's mistakes and our own failed early attempts we now have a pretty rocking architecture.

The first and most foundational change we're making from Pyrex, as previously stated, is in the lexical scanner and parser. Both Pyrex and Cython are based on Plex, which was Greg's answer to processing a Python-like language.

In contrast, we'll be using Python's own tokenize module for our lexical scanner and an ASDL-based parser akin to the parser used in Python 3.0. We're extending Python.asdl with cdef, ctypedef, cimport, cinclude, etc.

This way we have less code to debug and a solid foundation to start with. With lexing and parsing almost "for free" we'll be able to focus on the important bits and get the platform able to support the kind of features we need quickly.

We've also reached a rough consensus on the following syntax changes from Pyrex:
  • unicode, generators, decorators, etc will be supported
  • all custom for syntaxes dropped in favor of Python's standard
  • with nogil: replaced with full with support
  • special methods will always have self as first argument (ie, both __sub__ and __rsub__ used)
  • cinclude added for direct C header parsing

There's more to come, which I'll post in additional installments as work progresses on this project.

setup-pyrex.py works with

Greg fixed the latest bug that caused PySoy to raise a dict assignment error on import with 0.9.7.

Pyrex was released a few hours ago with this fix, and I've updated setup-pyrex.py to work with either or >=

Beta-3 is still blocked by the multicore race condition caused by redundant incref/decref calls on Python arguments to class methods in this latest version of Pyrex.

Monday, May 12, 2008

setup-pyrex.py now requires EXACTLY Pyrex

16:02 < maacl> import soy
16:02 < maacl> File "LoopThread.pym", line 51, in
16:02 < maacl> TypeError: 'dict' object does not support item assignment
16:03 < Arc> from threading import _active, _active_limbo_lock
16:03 < Arc> self._active = _active
16:03 < Arc> [...] and line 51:
16:03 < Arc> self._active[self._threadID] = self

I'm not going to even look into this further. Pyrex 0.9.7, for a reason I'm not going to even contemplate, raises an error about dict item assignment on the last line. None of us use it due to it's barfing of depreciated lines for all our for statements, but this brave tested did and reported the problem today.

I just committed an update to setup-pyrex.py that fails when any Pyrex version besides is used.

Sunday, May 11, 2008

subversion vs git

I stayed up late last night working to install a shared git repository for the Pyrex replacement project. First of all, copious thanks to johnw and Ilari on #git for their help on this.

I'm very much an enthusiast of Trac, it's an excellent engine for project websites and has all the essential tools, builtin and via plugins, that any project should need. Ok, so there's a few things a project could need that isn't already written, but new plugins are easy enough (it's all Python, after all).

As such, I like to leave user administration to Trac, and it maintains a .htusers and .access file local to each project for that purpose. Likewise, for SVN, we use WebDAV on Apache, whereas the ssh+svn method would require adding those users to the local system or PAM hacking.

Thus, the most direct path would seem to install GIT via WebDAV and run it from there. As Ilari pointed out, GIT's DAV has many problems over SVN, from lockups to a failed push sometimes corrupting the shared repository. I tried anyway, with hours of help from joshw, and at 5am I had to throw in the towel. I'm sure it's possible, but not with my current lack of GIT knowledge.

The other available solutions could work, but first I'd want to write some new Trac plugins for accepting developer ssh keys and using these on the backend to govern access or figure out the PAM configuration for .htusers to have restricted SSH access for GIT pushes.

There are certainly advantages to GIT, but server setup difficulty and added complications for Windows developers leads me to sticking with subversion servers with git-svn client-side for now.

Saturday, May 10, 2008

a radical redirection

We've been at a deadlock for a few weeks now, our previous coding pace has turned into a lot of contemplation and side discussions about the greater issues with the PySoy codebase.

I think we have a roadmap forward, or enough of one to post these in a blog entry:

First, PySoy 1.0 will not be released until after Python 3.0 this Fall, and it would be pointless to continue developing with 2.x in target. Python 3.0 also has a large number of useful changes for our project. Our target platform should therefore be 3.0 (and it's alpha/beta's for now).

Second, with the release of Pyrex 0.9.7 Greg has, once again, introduced a major language change (the "for" statement) without even soliciting input from the community. This has sealed the deal for us, even if our immediate issues are fixed we cannot continue to subject ourselves to a language that changes in incompatible ways between 2 micro versions (0.9.6 -> 0.9.8, when the old syntax will not be supported).

We earlier started a Cython variant to support PySoy's codebase, but given recent developments in their community, the timelines of our projects, and their choice to stick with Python 2.x for now, we're moving forward on a Pyrex replacement written from scratch and targeting Python 3.0.

We're going to use a similar language style to Pyrex, Greg certainly had some good ideas, and will keep language porting in mind, but there will be changes. We will also not be using any of his code including his Plex module, Pyrex and Cython's lexical analyzer which is the core of those packages.

PySoy Beta3, earlier aimed for release in "early Spring", has been indefinably postponed as we work on that. The subversion repository is of course open, and development can and will continue, but we cannot release until the new build system is complete.

Friday, May 02, 2008

initial impressions of Trac 0.11

Trac 0.11rc1 was released this week, marking a feature freeze for 0.11.

One of the major improvements over 0.10.4 is the Genshi template system allowing complete control over a site's HTML. For example, you can copy the default layout.html to your site's templates/ directory to remove the obnoxious "Trac" string at the end of every page's title and the other Edgewall advertising splayed all over a default Trac site.

Of course, this is also means a Trac site can be radically redesigned in structure without editing the source code. Hopefully this leads to a greater diversity in project site design.

Another major feature is ticket workflows are now customizable, allowing projects using Trac to decide how their tickets will be processed. For example, a "testing" state could be added to signify a ticket as "though to be complete, but waiting for verification".

I plan on upgrading pysoy.org this weekend along with a few new Trac plugins and a minor site redesign.

Wednesday, April 02, 2008

some race conditions found

Well after many weeks we found the source of the race conditions on multicore CPUs; they were not in PySoy at all but in the Pyrex compiler.

Throughout the generated .c we found INCREF/DECREF where it didn't belong, namely in every cdef method for __pyx_v_self. In other words, even though the calling function must already hold a reference to instance in order to access it's C methods, thus preventing the instance from being garbage collected during method execution, the Pyrex.Compiler inserts redundant INCREF/DECREF calls.

These would normally just waste CPU cycles, but since our 3d engine has non-GIL background threads these refcount adjusting calls are accessed in a thread-unsafe manner and will inevitably cause either a segfault or a memory leak.

The solution is to not consider "self" a normal Python argument, which would also allow these C methods to be called with nogil: set, provided checking is done to ensure no Python methods, properties, or variables of self are accessed.

We'll be fixing this problem with our new source compiler, to be announced soon.

Friday, March 21, 2008

1.0_beta3 release and a Sprint this weekend

There is a rumor going around that because our 1.0_beta3 milestone is marked as due today (3/21) we're planning a release today. This is false, we'll be releasing sometime in early spring as advertised - the due dates marked for our milestones are our preferred date only.

We're still tracking down one or more nasty race conditions which only show up on multicore systems, we still have a bit more work to do before the next release, and a good deal more testing is needed after these bugs are found to demonstrate stability. If you're experience with debugging we could use some help - some of our tests seem to indicate mutex locks being ignored.

This weekend is a good time, too. Starting today (Friday) we're running a pre-Beta3 online sprint. In our IRC channel (#PySoy on irc.freenode.net) you can find a good number of developers working almost around the clock on various parts of the 3D engine and a few working in Gobby for remote pair programming.

If you're not into debugging, or don't have a multicore system, there are many other tasks - large and small - that need doing.

Wednesday, February 27, 2008

State of the Soy @ r1000

Last night our humble 3D game engine reached 1000 commits to it's Subversion repository.

PySoy has been contributed to by 20 developers, 7 of which are currently active. The project's IRC channel is in nearly constant use by developers working on different tasks.

The external API has drawn considerable praise by users, despite it's state as beta, and the constructive feedback we've received has led many of the post-Beta2 API changes.

The internal API, while having some rough edges, has been commented on by several new developers as remarkably clean. We've passed the point which the COMPLETED list exceeds the TODO list, despite the latter constantly growing, and focus has largely shifted toward debugging, documentation, and polish.

Most notably, we've reached the point of needing a legal entity for the project. Using the Software Freedom Conservancy as a rough template, we've started the process to form a non-profit corporation with a focus on copyleft game projects. An announcement about this will be posted as more details are firmed up.

Tuesday, February 26, 2008

PySoy goes from 3 threads to 5

We're doing the final work now to replace CoreLoop with TransportLoop, WindowLoop, and SceneLoop. All three are instances of soy._internals.LoopThread which (should) play well with Python's threading system and should never hold the GIL.

The increased performance this has brought for multi-core users is amazing, some have reported more than twice the framerate!

To be fair, an equal number of subversion Trunk users are experiencing frequent segfaults since we've not finished adding mutexes and rearranging the internal API post-move. Obviously these issues are being resolved prior to the Beta-3 release next month.

Wednesday, February 20, 2008

why we're blocking Microsoft Live

While going through server logs I noticed something funny, Microsoft Live has surpassed Google in the number of hits we've received. Weird, eh? I didn't think anyone actually used it.

The terms people arriving at our site through search.live.com are just... weird, though. Most are outright vulgar, searching for obscure pornography or celebrity names, drugs, sex aids... Here's an few examples: http://search.live.com/result.aspx?q=valtrex&mrt=en-us&FORM=LVSP
/log/trunk Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2; .NET CLR
1.1.4322) http://search.live.com/result.aspx?q=breast+enhancement&mrt=en-us&FORM=LVSP /
Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; Win64; x64; SV1) http://search.live.com/result.aspx?q=ferarri&mrt=en-us&FORM=LVSP
/browser/media/tutorials Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2;
.NET CLR 1.1.4322)

These hits were to small obscure pages on our site, such as svn changelogs, and then I noticed the source IP addresses were in just a few IP ranges, so I ran a whois to see if one ISP tied connected them all;

arc@sobek ~/work/pysoy $ whois

OrgName: Microsoft Corp
Address: One Microsoft Way
City: Redmond
StateProv: WA
PostalCode: 98052
Country: US

NetRange: -

You read that correctly. Microsoft, in a desperate attempt to make themselves seem more important, or perhaps just to flood free software project's websites with unwanted traffic, is running bots which act like normal web crawlers. Indeed, over 97% of the hits we got from search.live.com were from Microsoft's own IP subnets. Searching Google, I found this story was previously covered by others more observant of their logs.

In response, I'm adding a special rule to block all future traffic from the offending netblocks, including MICROSOFT - and MICROSOFT-1BLK -

Thursday, February 14, 2008

libjingle disappointments

Last year we chalked libjingle as our choice for a XMPP library, since it handled all the networking we needed (ICE-UDP, HTTP, etc) tightly integrated with XMPP through a standard protocol.

On closer inspection, we found why libjingle hasn't really been adopted by the community yet. For starters it requires patches to build the latest release with GCC 4, and no release has been made to include these patches in months. Not a good sign.

Next we find there are no dynamic libjingle libraries, it builds as static only, and doesn't build for C programs (only C++). Unless we transformed our project to build as C++ this isn't an immediate option.

Looking over the libjingle code structure, it's in a severe state of poor maintenance. The internal name for it appears to be "libcricket", with naming confusion all over the place, code format inconsistencies, and extremely poorly documented.

Thus, libjingle integration is unlikely until after PySoy's Beta-3 release when we'll have time to write the C shim code as a dynamic library.

All this said, libjingle appears to have great potential for us and the entire free software community, it's just in need of attention from a few detail-oriented developers.

Monday, February 11, 2008

consolidated _core-*/ to _core/

Last year Pyrex, then version, did not support compile-time conditions for things such as platform specific code. To work around this used different _core directories, one for each platform, and a platform test in setup.py would determine which directory soy._core was compiled from.

While functional, this created duplicated work and a fairly messy source tree with four different _core-* directories. With Pyrex 0.9.6 release came support for code such as this:

IF UNAME_SYSNAME == "Windows":
include "icky_definitions.pxi"
include "nice_definitions.pxi"
include "penguin_definitions.pxi"
include "other_definitions.pxi"

... and, thus, we could finally merge those _core-* directories into src/_core and remove kludge from setup.py. Tonight that's exactly what I did. Behold, http://svn.pysoy.org/trunk/pysoy/src

Wednesday, February 06, 2008

website makeover and new logo

We've been working with the same website design (www.pysoy.org) for a year now. While it got the job done, we're in need of a makeover - and that's exactly what's going on. The basic layout from Planet PySoy is going site-wide with a new docs section, info on how to get involved with development, separate bug and task/idea/etc filing forms, and a ton of new features that will make the site more community-oriented.

In the spirit of community inclusion, I'm also opening the new logo for collaboration and competition for. Draft logos can be worked on in http://svn.pysoy.org/media/logos with the final designs voted on by all active developers near the end of this month. We'll aim to include this in the beta-3 release next month as a special mesh and texture.

Friday, February 01, 2008

normals (dot3) texture

PySoy Dot3 Bump MappingWith a few minor bugs left to be worked out, we now have normals mapping. This was written by Jaroslaw Tworek, a high school student in Poland who also added recently volumetric fog and billboards. These features and more will be included in the Beta-3 release next month.

Bump Mapping; yet another feature PySoy has over it's predecessor.

downtime and new server

As many people have noticed, *.pysoy.org was down yesterday. Since our former server is still offline (thanks, Verizon) I've paid out of pocket for a new colocated server hosted at ServerBeach.

After an all-nighter getting it setup, www.pysoy.org is back up, as is svn, and hopefully everything else. I'll resolve any problems tomorrow, as I'm in serious need of sleep now.

Wednesday, January 02, 2008

PySoy Beta-2 response!

12 hours after the PySoy Beta2 release we've had over 120 downloads, about half of which for Windows.

Some users were quick to point out we forgot three dll's in the installer; glew, iconv, and zlib1. We're rebuilding the installers for Windows to include these and testing to ensure we didn't forget anything else.

PySoy Beta-2 Released!

We finished up the spit-n-polish work tonight and shipped the second "beta" of our 3D game engine for Python!

Included is support for Microsoft Windows (with nice bdist graphical installer), keyboard input and an early draft of the controller-action system, text rendering thanks to Cairo, support for Joints, and other enhancements and fixes too numerous to list.

While over a dozen developers contributed to this release I'd like to especially thank Kirk McDonald for porting the engine to Windows API, Derek Rhodes for getting the Cairo support in, Eric Stein for his work from Summer of Code and since, and Piet Delport who provided countless hours of help to all of us with Pyrex-related issues.

We're far from done so please download, enjoy, give feedback, and if so inspired help us reach 1.0!