digital home of MacSlow

… so… I wrote my first particle-system ever. It does not look photorealistic - by far not *g* - but implementing something like that is great fun! You see a cluster of 5000 particles in the screencasts below. Right now I’ve two emitters (a “singularity” one and a rectangle one) with a gravity force-field being applied to the particles. WASD/Quake-like camera-navigation I implemented too, so one can “walk around”. From here numerous things could be added: wind, general turbulence, attraction-/repulsion-forces between particles, collision-detection with obstacles… the visualization could be improved with motion-blur, lighting, shadows etc. Rendering- and simulation-loop are coupled and run at 60 Hz. Screencasts were recorded with 30 Hz.

I hooked up the cubic curve patch rendering to the preliminary cairo-path drawing. With it fonts look better now (compared to the first try).

The same clip on YouTube.

I feel happy now for the weekend

That’s what I did over the last couple of days. The reason was following the Loop/Blinn paper on “Resolution Independent Curve Rendering using Programmable Graphics Hardware” turned out to be harder than I first thought. Implementing just quadratic curves segments is a piece of cake compared to cubic cuves (read: Bézier curves). The dynamic generation of 3D texture-coordinates to feed the fragment-shader evaluating the cubic curve inequality v³ - wt > 0 is nasty. But I’m seeing a light at the end of the tunnel… or rather this:

There’s still much left to be done (and many bugs to fix), but piece by piece it’s getting there. The same clip on YouTube.

While working on this I also had a look at what a cairo rendering-backend actually needs to implement. Sofar I did not find hooks in a backends callback table to just hand over paths from cairo. That’s a bit unfortunate, because that’s what I want to be able to grab from cairo. I don’t want the decomposition to triangles/trapezoids to happen in cairo itself (on the CPU). That’s meant for the GPU. Well, it’s still a good stretch to go before it is time to thoroughly think about such issues. I assume folks on the cairo mailing-list help me sort things out, once the time has come.

I still have a few (vacation) days left before work starts again on monday. Let’s see what I can motivate myself to accomplish until then.

feedback:
I did not get much proposals for the theming/branding of the GTK+-hackfest interviews. It was just one. But that single one is very impressive, I believe. Take a look at this example:

It was done by a very close friend of mine, Blasius “Milho” Floch, who happens to study communication-design. Furthermore a colleague at Canonical David “komputes” Bensimon, GStreamer/pitivi-overlord Edward “bilboed” Hervey and a few others offered help with encoding and compressing the videos. I’ll get back to you all once I’ve the raw intros and outros for every interviewed person.

more help needed:
To continue the work on the GTK+-hackweek interview editing, I need to collect a bit more info about a few interviewed people. In the following list you see the people I don’t know or remember either their exact nickname and/or company-affiliation at the time of the GTK+-hackweek 2008. It would be nice if these people could drop me a brief eMail with the missing information. Thanks in advance!

• Alberto Ruiz
• Alex Larsson
• Alp Toker
• Andrew Cowie
• Carlos Garnacho
• Cody Russell
• Dennis Oliver Kropp
• Hans Petter Jansson
• Johan Dahlin
• Juerg Billeter
• Kris Rietveld
• Lennart Pöttering
• Mathias Hasselmann
• Richard Hult
• Rob Taylor
• Ryan Lortie
• Tor Lillqvist
• Torsten Schoenefeld

Right now I’m doing my best to coordinate the editing and encoding work for the GTK+-hackfest interviews (some volunteers I still have to answer). What I’m looking for at the moment is GTK+-ish branding for the videos. All interviews should share the same look and feel in terms of branding. Everybody with some (or a lot) of experience in these regards is welcomed to send in suggestions (e.g. templates as SVG would be great). Try to stick as much as you can to established cues from GTK+ (read: don’t go for MTV-like graffiti-style… while that by itself might look stylish, that’s just not GTK+… you get the idea).
I’ll collect your submissions for a week and then let a vote on the top 5 (depending on how much material I get) happen on my blog here.
Here are a couple of guidelines to consider:

• branding-overlay using GTK-logo, name of interviewed dev, main project/company affiliation of dev
• intro- and outro-screen
• provide templates of screen-layout as SVG
• have 4:3 and 16:9 aspect-ratio versions
• PAL 720×576 (4:3 aspect)
• your work has to be CC-SA-BY

Add anything you’d find helpful or missing from the above list.

general request:
Everybody who is a sophisticated/seasoned/established/*insert.favourite.buzzword* video-editor and would like to help the GTK+-community should email me, if they want to help with beating GTK+-hackfest interviews into shape.

requirements:

• have good skills with editing raw DV-files
• have an artistic eye for spicing up my boring recordings
• use of OpenSource tools prefered, but commercial tools are ok too
• have a “get the job done”-attitude
• do volunteer work
• have high-speed internet access
• stick to branding/artwork to be provided by GTK+-community

task:

• cut out boring parts of interviews
• interact with interviewed develeopers about technical/content-questions
• cut together a teaser/sampler of key moments of all interviews
• encode final cut of each interview to theora/vorbis in ogg-container
• stuff interviews also on YouTube/Vimeo/*your.favourite.video.site*

Any further information should be exchanged via eMails. Thanks in advance for your consideration!

Some time ago - around the beta period in the intrepid cycle - I’ve found a nice mockup of a window on deviantart by willwill100. While that was an idea for the gdm-login, which as such I did not like within the login-scope, I liked the style of the window itself. Fast forward to the present days. I found some time here and there and in between to hack a bit on this. What I got so far looks like this:

(click for full size)

On the left you see the mockup-image in eog and on the right the implemented thing. There are remaining issues to be solved and fixed, but it’s getting there. Once I’ve found some more time to finish it, I’ll put it somewhere at a publicly accessable spot.

The nicest bit about this kind of look is the fully outline-less border and the artefact-free wobbling (if you happen to have that enabled). The end of the story is: client-side drawn window-decorations is the next big thing imo. The idea is not new and I did not come up with this concept (krh did). More and more I run into situations, where I wish we already had those in gtk+ and Qt.

Ubuntu:
The heron took off… nuff said! It’s running on all of my machines for quite some time now… I’m happy! I leave the marketing-talk to the people that know this kind of business *g*

gdm-face-browser:
A first look at what will become the OpenGL/clutter-based face-browser for the new gdm…

With still a lot of work left on the graphics-side, it will take some time until I can start integrating it into gdm. But it’s rather weeks than months.

clutter:
During my ongoing entanglements with clutter I deeply miss support for mipmapping. But that will land in a patch I’m writing atm. It will do wonders to the nasty shimmering during scaling and zooming of text and images (well, textures really) in the gdm-face-browser. Check this stand-alone example-screencast…

Thanks to a tip from Matthew Allum I grabbed Ivan’s current clutter-branch, which offers a rewritten cogl (clutter’s core GL-abstration if you will), that will make written the patch a lot easier. Sofar I worked against clutter-0.6.2.

Big Buck Bunny:
Not really news anymore, but still impressive none the less was watching “Big Buck Bunny” at its world-premiere in Amsterdam. I don’t want to give away anything or provide spoilers for the people that still have not seen it. But let me say this… it is cute and funny short-film, which showcases blenders capabilities wielded by capable artists. The whole atmosphere of seeing and hearing this second OpenMovie as a 35mm print in a cinema gave me goose-bumps! It was a wicked feeling being aware of the fact that I was witnessing a small part of movie-history in the making there at the Studio-K cinema. Also seeing “Ubuntu” being explicitly mentioned in the movie-credits gave me a cozy feeling. Thanks so much to the whole blender-community and the foundation for producing something so cool that once more is a shining example of OpenSource. I can’t wait to get the DVD of the movie and the game! After the movie I had the chance to talk a bit with Andreas Goralczyk, Brecht Van Lommel, and Ton Roosendaal… a 10 on the OpenSource-rock-star-scale *g* What a terrific experience all this was!

gtk+-hackweek interviews:
This weekend I should get the time - finally - to edit and upload the first bunch of interviews from the gtk+-hackweek in Berlin. Big big sorry for the delay! Anybody who wants to offer hosting- and/or mirror-space?

I’m doing interviews with all gtk+ upstream-hackers during the gtk+-hackweek here in Berlin. Please send me the questions you would like to ask the people behind the toolkit used in GNOME. And please hurry with sending me those questions via email. But keep it brief, three questions at maximum and stick to questions about gtk+-features you would like to see (or rather their feasibility) and future-development. For example avoid overly generic questions like “What’s the next big thing coming in gtk+?” or “Why isn’t my favourite bug XYZ in current gtk+ fixed?”. Remember this is about gtk+’s future. I will take the liberty to pick a subset from all the questions send to me. This week is mainly about planning and hacking and not about asking these folks a 1000 questions. If you want you can add a hint about the person I should ask a particular question.

I just arrived in Berlin for the gtk+-hackfest after maning the GNOME-booth at CeBIT for a week. Gosh do I feel exhausted right now! Reporting about that is something I do later, after I had a good sleep!

So the gtk+-hackfest is about to start. Too bad that there was no reliable wifi in the Linux-park at CeBIT. At least not when the room allocation was put up on live.gnome.org. It’s a bit unfortunate that I was not able to directly place myself in the appartment with the folks behind cairo, clutter, X11 etc.