There a many, many, e-book reader devices available these days, and they're quickly becoming pretty affordable. The currently cheapest device in Germany (that I know of) is the TrekStor eBook Reader 3.0, model number EBR30-a, at 59.- Euros via Weltbild or Hugendubel. The device has an 800x480 7" TFT (yep, no e-ink), 2100mAh battery, it can display PDFs, EPUB, and TXT files (and Adobe DRM crap, which I don't really care about), it has an accelerometer which allows for landscape/portrait switching, it can play MP3, OGG, WAV, and WMA audio files (headphone jack), it can display pictures (BMP, GIF, JPG, even PNG, though that's not mentioned in the vendor's specs), and it has 2GB internal storage for books/music/pictures. Uploading of (non-DRM) content is done by a simple file copy, it enumerates as a standard USB mass storage device with FAT filesystem. It's a relatively nice reader for the price, I've read a few PDFs (datasheets, presentations) on it in the subway/train while listening to music from the device and it's quite OK for my purposes. So much for the review part. However, I didn't really buy it for reading books on it, I was more interested in taking it apart, of course ;-) My hope was that it would turn out to be a really cheap device running Linux/U-Boot which would be perfect for playing around with embedded Linux stuff. Unfortunately, I wasn't so lucky (it seems). I've posted a few photos of the device and its hardware components on my flickr account and over at randomprojects.org, together with all the information I was able to find out so far. Here's a quick summary:

• Main CPU/SoC: FI E200 B6077BA 26P1
• RAM: MIRA P3S12D40ETP (512MBit / 64MByte DDR SDRAM, max. 200MHz)
• NAND flash: Samsung K9GAG08U0E (16GBit / 2GByte, x8, 3.3V)
• Battery management: KrossPower AXP199 A5004AB 36G
• RTC/clock/calender chip (I2C): H8563S
• Some accelerometer (to switch between landscape/portait mode), model unclear so far, maybe the chip labeled 605 132?

There are public datasheets for most of the hardware components (see randomprojects.org for links), but unfortunately the most important one (for the CPU) is not yet found/identified. I was told that the CPU/SoC is probably based on an ARM9 (ARM926EJ-S) core and the firmware running on it seems to be some uCos-based RTOS (not Linux, unfortunately). So far I was not able to find out the vendor name or website of the "FI E200" CPU/SoC (let alone any datasheets), any hints would be highly appreciated. I checked arm.com: Processor Licensees, but the only two companies whose name starts with "F" having licensed an ARM9 core are Fujitsu and Freescale, which doesn't fit, I think? I could (and probably will) check the PCB for RX/TX lines on an UART and/or JTAG pads (none are obviously labelled), and given that it's and ARM9 core there is a good chance that OpenOCD can be used and that a standard cross-gcc for ARM will work. However, that is all pretty pointless until it's clear which SoC exactly is used, and thus whether there is already Linux and/or U-Boot support for it and/or whether datasheets are available so that the respective code could be written. Without datasheets, this is going to be a pretty painful experience, not really worth investing much time, IMHO. If anyone knows more about the vendor/device and respective datasheets, please let me know. Thanks!

Valve's Portal game introduced an innovative teleporter system - where you basically can see through the teleporter and even walk seamlessly through it. Ever wondered how this is implemented? Check this Mini-Portal demo, along with its companion tutorials!

http://en.wikibooks.org/wiki/OpenGL_Programming/Mini-Portal

In this first part, we cover a basic working version that we will improve over the next few days. [Find more tutorials at the OpenGL wikibook.]

A few months after Zoe was born, it hit me that we didn't just have to raise a baby to grow up happy and healthy, we were raising a girl, and had to worry about making sure she had a healthy self-image and mind as well, and having to worry about how the world she was coming into was going to have an impact on that. I think it might have been around the time that I became aware of the book Cinderella Ate My Daughter that I had this realisation. I started taking more of an interest in, what I guess I'd call feminist issues. I became a seed funder for the Ada Initiative, and I tend to prick my ears up when I hear about feminist issues. So when an email went by on the parents list at work about a screening of an independent documentary film called Miss Representation, I watched the trailer, and since I'm currently swanning around sans wife and child, ponied up the $10 to go and see a screening of it in Palo Alto, which was followed by a Q&A session with the writer/director/producer. I basically went along on the strength of the trailer, and being a father of a daughter, and didn't do much more reading into the who the writer/director/producer was. It turns out that Jennifer Siebel is Gavin Newsom's wife. I didn't figure that out until I got home and did my homework, so some of the references she made in the conversation after the screening didn't make a lot of sense to me at the time. The documentary itself was very poignant, but I found that after about 40 or 50 minutes, I felt that the point was made, and I would have preferred to see more about what to do about it. But I guess what to do about it is to be aware of the problem. I had some trouble accepting the statistic quoted at the beginning of the film that the average teenager spends more than 10 hours each day consuming media. If they sleep for 8 hours, and go to school for 6 hours, that means they're spending every other waking minute consuming media, and I just don't buy that. Apparently Jennifer is working on a couple of related follow-up documentaries, so it'll be interesting to see what they're about and what they're like, and how they're presented to the viewing public. One of the things that disappointed me a bit was this film doesn't look like it's going to do any sort of mainstream theatre run. I'm not sure why, but it seems like the way they're going is for more of a grassroots, small screening thing, possibly as a way of trying to get it added to (I presume private) school curricula. It is getting a couple of showings on Oprah Winfrey's cable channel OWN, but that doesn't seem like enough to me. I think it'd really cause people to sit up and take notice if it got half-decent box office numbers and a bit more press coverage as a result. It's the kind of thing I could see going viral if it gets more exposure. The other thing that really disappointed me was the lack of men in the audience. I think I could have counted on both hands the number of men there. But I have to say that I wouldn't have heard about it (yet, anyway) if it weren't for that email that went by on the mailing list at work, so maybe it just doesn't have much of a profile yet. I view this documentary in the same calibre as Super Size Me, or anything that Michael Moore has put out. It's a documentary trying to highlight an issue with American culture. It should get as widespread a viewing as possible to get the conversation going. Instead, as best I can tell, there's two DVDs billed as "educational material", with what I consider prohibitive pricetags. I want to purchase a copy of the film for posterity (if nothing more, it'll be interesting to show Zoe a snapshot of American culture from around when she was born), but I'd also like to get my hands on the age-appropriate educational stuff so that I can use it with Zoe. The likelihood of Zoe going to a school that incorporates the material into its curriculum is slim (she'll be educated in Australia), so I'd really like to be able to use it at home. I'll end with this thought provoking article that also did the rounds of the parents list at work a few months ago.

Looking through the Libravatar access logs, I found that most of the traffic we currently serve consists of 302 redirects to Gravatar. Optimising that path is therefore very important.

While Apache allows admins to provide custom error pages for things like 404 or 500, it's not quite that straightforward for 30x return codes.

Standard 301 / 302 responsesBy default, Apache (and most web servers out there) returns a fairly large HTML page along with a 30x redirection. Try it for yourself by disabling automatic redirections in Firefox (Preferences Advanced General Accessibility) or by installing the Request Policy add-on.

The 302 responses sent by Libravatar looked like this:

$ curl -i http://cdn.libravatar.org/avatar/12345678901234567890123456789012
HTTP/1.1 302 Found
Date: Wed, 21 Sep 2011 01:51:52 GMT
Server: Apache
Cache-Control: max-age=86400
Location: http://www.gravatar.com/avatar/12345678901234567890123456789012.jpg?r=g&s=80&d=http://cdn.libravatar.org/nobody/80.png
Vary: Accept-Encoding
Content-Length: 310
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="http://www.gravatar.com/avatar/12345678901234567890123456789012.jpg?r=g&s=80&d=http://cdn.libravatar.org/nobody/80.png">here</a>.</p>
</body></html>

As you can see, the body of the response is just as large as the headers and isn't really necessary.

Body-less 301 responsesAfter reading about the ErrorDocument directive, I created an empty file called 302 in the root of the web server and included this directive in my vhost configuration file:

ErrorDocument 302 /302

which made the responses look like this:

$ curl -i http://example.com/redir
HTTP/1.1 302 Found
Date: Wed, 21 Sep 2011 03:39:26 GMT
Server: Apache
Last-Modified: Wed, 21 Sep 2011 03:39:17 GMT
ETag: "8024d-0-4ad6b52201036"
Accept-Ranges: bytes
Content-Length: 0
Content-Type: text/plain

This one does have a completely empty body, however, there's an important problem with this solution: the Location header is missing! Not much point in reducing the size of the redirect if it's no longer working.

Custom 302 response pageThe next thing I tried (and ended up settling on) is this:

ErrorDocument 302 " "

which results in a 1-byte response (a single space) in the body:

$ curl -i http://example.com/redir
HTTP/1.1 302 Found
Date: Wed, 21 Sep 2011 03:37:50 GMT
Server: Apache
Location: http://www.example.com
Vary: Accept-Encoding
Content-Length: 1
Content-Type: text/html; charset=iso-8859-1

There is still a little bit of unnecessary information in this response (character set, Vary and Server headers), but it's a major improvement over the original.

If you know of any other ways to reduce this further, please leave a comment!

Even though some three months have passed since DebConf11 has successfully ended, I still wanted to give you just a glimpse on how some parts were played through the eyes of a lunatic (read: organizer). Of course, blog post can t come close near of explaining anything but at least it should give some insight and hopefully some pointers to the future DebConf organizers. If you don t feel like reading this much text you can listen to last episode of This Week In Debian podcast and after it just head to Beginning of the end part. DebConf11 First of all I d like to apologize if I offended or hurt anyone in this whole process as it wasn t my intention and during DebConf organization this is nothing irregular, for you to get hurt or you hurting somebody else. One thing that got stuck with me this whole time is when Mart n Ferrari approached me after I did bid proposal of Bosnia/Herzegovina for DebConf11 back on DebConf9 and told me you have no idea what you just got yourself into I played cool and said something along the line of coure I do and boy did I lie. During DebConf organization you re bound to make some of your decisions instantaneously in which you ll lose something, the most you can do is assess what s the thing you can cut the cord on, even though if that thing or a person for that matter might have meant something to you. You ll lose things, relationships, friendships, contacts at the times sense of humor and maybe even common logic. Some of it comes back to you, some the very next day and for some it may take longer. Some of it was lost irreversibly, but even in that case it wasn t lost and could even be traced to some other cause. One thing that I m thankful for is that I didn t lose, not lose but even get distanced from those close to me, and that I didn t lose guy who was with me in this from very first day, my right hand, my partner in crime Velimir ( aroundthfur ). It s not even losing I m talking about here, because even by losing you re gaining something and this is part of your everyday life, it s just that your life frame kinda gets stuck on fast forward button. So once the ride s over you may feel bit dizzy asking yourself what just happened. During this time I was also contacted by Google recruiter regrading software engineer internship but to make a long story short I didn t make it due to my heavy involvement and my lack of time (read: fail). But I don t find this as losing either, first time I was contacted by them, next time they ll be contacted by me maybe even for different position this time (project manager? . Even this DebConf wasn t our first bid we lost DebConf7 bid to Edinburgh, but it is perseverance that got us here. The moral I m trying to tell here is if you have a goal never back down from it. What I found to be our biggest problem and what I personally found as most painstaking in all of this was having and reporting to so many different sides and different groups while trying to keep them in same communication channel. Even my right hand (Velimir) was apart from me (Vienna), then place where two of us are coming from is not the place where DebConf is getting organized in. As in the end we ended up having all the parties separated and pulling to their own side, from Government of Republika Srpska to NGO to Debian to local team and to those who remained as undeclared . Option of cutting the cord in this case was missing as these were the components that DebCon11 was made of. Of course this meant you ll be missing workforce and there were days you d wake up driving >= 200 km/h (literally) with one hand on the wheel, other on the phone and your other right hand (Velimir) holding your RedBull. But you wouldn t do this just because you had to and there was no one else to do it, you d do it because you re responsible for the sake of the project and won t be just sitting there because by some unwritten hierarchy rules you re supposed to sit and supervise things. I d advise you do the same thing when you see there s no one else to do something, even if it means making coffee for one of the teams. I m not trying to scare you away from organizing your own DebConf, on the contrary after all I ve been through in past two years if someone asked me would I do it if I knew it was like this, without a doubt my answer would still be fsck yea . All the previous DebConf organizers told me about all of this, but why didn t I give up? For the same reason you won t give up and for the same reason why we believe in the same goal. If anything this is one of the stories you ll want to tell your kids about so When I was your age I used to sleep naked in the snow would turn to When I was your age I organized DebConf11 in Maybe this blog post wasn t even necessary and some things weren t supposed to be said, I guess sometimes I just can t shut up For those who were on DebConf11 I hope you enjoyed and had a great time, otherwise I m saying all of this in vein. As organizer all you see is problems and you miss most of the confrence, but by what I know there are 11 candidate bids for DebConf13 and for me hearing that tells me the results of our efforts. DebConf11 after effects I could write a whole novel about this, but to keep it as short as possible, for last two years as a side project I was working on an idea of Government or some of its institutions migrating to Linux. At first I was somewhat loud about it, then after Microsoft heard about it and after they tried stopping the idea by trying to scare me by trying to interfere with my private life; as that didn t work its lobbyist came even near of obstructing the whole conference within the Government. For the sake of the conference, I convinced the Government that by supporting DebConf it doesn t mean they need to move to Linux and publicly stopped talking about it. I also convinced them that our only goal was to have successful conference and promote alternative options and open ideas. I wasn t lying as I saw this as new opportunity of them concluding on their own why they should or shouldn t not move, the better conference was the more chances of success we had. That s why I tried pushing as many representatives from various companies as in this case we would use reverse psychology where basically no one or few know what Linux or Debian for that matter is, but everybody knows who Google is, so if you have participants from i.e: Google or Austrian E-Health care system talking about how they are using your technology is better way to explain what s it all about really. Eventually Microsoft even had their first ever conference in Bosnia/Herzegovina and you wanna take a wild guess where it was held? In the end we had a great conference, after the conference we were the ones that were approached by some big local companies interested in future co-operation and in the end a meeting with Mark Shuttleworth and President along with the core of Government was scheduled. Topic? Migration to Linux. For me personally this meeting went better then I could possibly even picture it, many topics were discussed and basically it was up to us/me to make a draft of the project plan and submit request for proposal to the Government. There was still some lobbying but it seemed as it all disappeared, runway was clear and open for the lift off. Necessary contacts with potential future partners were made and before any meetings were scheduled I announced I ll be taking a short break. I missed this years vacation, for matter of a fact I missed going to a vacation for last two years. I decided going to Dubrovnik for few days, just to recollect my thoughts, recompile my kernel and switch to lower gear as I was stuck in 6th gear for way too long. Beginning of the end Being on this vacation , even if it was only for few days this gave me an opportunity to look at it all from a different prospective, different angle and that s when it came to me. I realized that even before I was finished with one project without even realizing I was already involved with another one, one that would take much more time and one that might leave me wondering ~5 years later with question what if? After all if get involved with something I m not going to back out, it s either failure is not an option or I won t start doing it at all. Even if it brought me everything I wanted, how would you know if that s what you wanted if you haven t thought about it first? Having DebConf for the first time in this region already showed some (positive) results, but for seeing the actual results it may take a bit longer. We sowed the seeds now the best thing we can do is leave them as it is and see if anything grows out. Of course I could lean over them and protect them from any natural or any other type of hazards, this would also mean when I m not around it wouldn t know how to protect itself on its own. Besides all, interfering with natures way of doing things is rarely a good option. I consider myself to still be relatively young and threatening my well being over safe keeping some seeds and watching over if they grow into something or not doesn t really seem that attractive to me. Maybe one day I ll decide to leave the land, maybe I won t even get to see if anything grows out after all. Maybe some day someone will find this fruit, recognize its worth and claim it as it s own, maybe over time everybody forgets everything and even that this land once was a fertile ground. Maybe, maybe not. I m still a student, I was supposed to graduate last year but I took less classes last year so I wouldn t snap under all the pressure. That s why this year I have less classes and am supposed to graduate in May, that s less then a year until then and I just want to devote some time to myself, figure out what I want with me life, learn the things I want to learn, do the things I want to do. I want to turn back to working on Eclipse, I have some good plans for Eclipse and Android developers, lately I ve been slacking off way too much but I think I have a good excuse In the end, all I know is that I still want to change the world, whether it s doing that inside of Google or in my own company, or some third place; or I ll just be laughing at this statement only time will show. I m hoping that now with all of this out of me I can finally finish the DebConf11 chapter of my life.

Lindsay Holmwood has written about the benefits of a standing desk and how to buy one [1]. The case for avoiding sitting is strong, but I couldn t stand up all day. One thing that s been on my list of things to do if I had an unreasonably large amount of spare time or money is to make a reclining computer station. The idea would be to take a bed and mount a TFT display above it so that it can be viewed while lying down. Then a split keyboard would be required so that each hand can be used for half the keys (this would be difficult or expensive). If the keyboard halves were aligned correctly then it would reduce the carpal tunnel problems associated with computer use (which has been a big problem for me in the past and is something that I will probably never fully recover from [2]). As far as I am aware the risk of back problems is eliminated when lying down, so two of the major problems with regular computer desks would be avoided. I don t think that lying down all day would be that great and it wouldn t work for collaborative projects. But as monitors are so cheap nowadays it would be viable to have a second monitor at a desk connected to the same computer. Then I could spend about half my computer time lying down.

• [1] http://holmwood.id.au/~lindsay//2011/10/03/standing-desk-adventures/
• [2] http://etbe.coker.com.au/2010/06/16/carpal-tunnel-getting-better/

The Occupy Wall St blog has an informative summary of attempts to reclaim the American political process which has been pwned badly by financiers in recent times [1]. The basic concept is that people who represent the 99% of the population who aren t super rich have protests in Wall St and now other business areas. Care2 has an interesting article about US marines opposing the brutal actions of police against Occupy Wall St protesters [2], apparently they treated Iraqis better than US police are treating Americans. The movement has spread to other locations, the OccupyTogether.org site has information on related events all around the world [3]. We have an ongoing event in Melbourne, Australia. It s been going for a week and yesterday Robert Doyle (the Mayor of Melbourne) ordered police to disperse the protest, so riot police and mounted police forced the protesters out of the city square [4]. According to the news reports there were only 100 people there at the time, here is a Google Maps link to the location, as you can see 100 people would not take up much of that space, not even with banners etc. The smart move would have been for the government to ignore it all until the protesters got bored. Now of course we will have more and bigger protests. The use of riot police will probably be considered as a good thing by some of the more aggressive protesters, but anyone who doesn t want to make the government (and the corporations that control it) look bad would consider it a gross error. Robert Doyle needs to be replaced, the liberal reason for replacing him is that we just don t want unnecessary force used against peaceful protesters. The conservative reason for replacing him is that he s grossly incompetent, he transformed a small protest that wasn t getting much media attention and appeared to be losing interest into a large protest with a lot of media attention. It will be interesting to see what happens next.

• [1] http://occupywallst.org/
• [2] http://www.care2.com/causes/u-s-marines-protect-occupy-wall-street-protesters-video.html
• [3] http://www.occupytogether.org/
• [4] http://www.theage.com.au/victoria/doyle-accused-of-heavyhandedness-in-halting-occupation-20111021-1mck9.html

A common question about hosting is whether to use a dedicated server or a virtual server. Dedicated Servers If you use a dedicated server then you will face the risk of problems which interrupt the boot process. It seems that all the affordable dedicated server offerings lack any good remote management, so when the server doesn t boot you either have to raise a trouble ticket with the company running the Data-Center (DC) or use some sort of hack. Hetzner is a dedicated server company that I have had good experiences with [1], when a server in their DC fails to boot you can use their web based interface (at no extra charge or delay) to boot a Linux recovery environment which can then be used to fix whatever the problem may be. They also charge extra for hands-on support which could be used if the Linux recovery environment revealed no errors but the system just didn t work. This isn t nearly as good as using something like IPMI which permits remote console access to see error messages and more direct control of rebooting. The up-side of a dedicated server is performance. Some people think that avoiding virtualisation improves performance, but in practice most virtual servers use virtualisation technologies that have little overhead. A bigger performance issue than the virtualisation overhead is the fact that most companies running DCs have a range of hardware in their DC and your system (whether a virtual server or a dedicated server) will be on a random system from their DC. I have observed hosting companies to give different speed CPUs and for dedicated servers different amounts of RAM for the same price. I expect that the disk IO performance also varies a lot but I have no evidence. As long as the hosting company provides everything that they offered before you sign the contract you can t complain. It s worth noting that CPU performance is either poorly specified or absent in most offers and disk IO performance is almost never specified. One advantage of dedicated servers in this regard is that you get to know the details of the hardware and can therefore refuse certain low spec hardware. The real performance benefit of a dedicated server is that disk IO performance won t be hurt by other users of the same system. Disk IO is the real issue as CPU and RAM are easy to share fairly but disk performance is difficult to share and is also a significant bottleneck on many servers. Dedicated servers also have a higher minimum price due to the fact that a real server is being used which involves hardware purchase and rack space. Hetzner s offers which start at E29 per month are about as cheap as it s possible to get. But it appears that the E29 offer is for an old server new hardware starts at E49 per month which is still quite cheap. But no dedicated server compares to the virtual servers which can be rented for prices less than $10 per month. Virtual Servers A virtual server will typically have an effective management interface. You should expect to get web based access to the system console as well as ssh console access. If console access is not sufficient to recover the system then there is an option to boot from a recovery device. This allows you to avoid many situations that could potentially result in down-time and when things go wrong it allows you to recover faster. Linode is an example of a company that provides virtual servers and provides a great management interface [2]. It would take a lot of work with performance monitoring and graphing tools to give the performance overview that comes for free with the Linode interface. Disk IO performance can suck badly on virtual servers and it can happen suddenly and semi-randomly. If someone else who is using a virtual server on the same hardware is the target of a DoS attack then your performance can disappear. Performance for CPU is generally fairly reliable though. So a CPU bound server would be a better fit on the typical virtual server options than a disk IO bound server. Virtual servers are a lot cheaper at the low end so if you don t need the hardware capabilities of a minimal dedicated server (with 1G of RAM for Hetzner and a minimum of 8G of RAM for some other providers) then you can save a lot of money by getting a virtual server. Finally the options for running a virtual machine under a virtual machine aren t good, AFAIK the only options that would work on a commercial VPS offering are QEMU (an x86 CPU instruction emulator), Hercules (a S/370 S/390, and Z series IBM mainframe emulator), and similar CPU emulators. Please let me know if there are any other good options for running a virtual machine on a VPS. Now while these emulators are apparently good for debugging OS development they aren t something that are generally useful for running a virtual machine. I knew someone who ran his important servers under Hercules so that x86 exploits couldn t be used for attacking them, but apart from that CPU emulation isn t generally useful for servers. Summary If you want to have entire control of the hardware or if you want to run your own virtual machines that suit your needs (EG one with lots of RAM and another with lots of disk space) then a dedicated server is required. If you want to have minimal expense or the greatest ease of sysadmin use then a virtual server is a better option. But the cheapest option for virtual hosting is to rent a server from Hetzner, run Xen on it, and then rent out DomUs to other people. Apart from the inevitable pain that you experience if anything goes wrong with the Dom0 this is a great option. As an aside, if anyone knows of a reliable company that offers some benefits over Hetzner then please let me know. What I would Like to See There is no technical reason why a company like Linode couldn t make an offer which was a single DomU on a server taking up all available RAM, CPU, and disk space. Such an offer would be really compelling if it wasn t excessively expensive. That would give Linode ease of management and also a guarantee that no-one else could disrupt your system by doing a lot of disk IO. This would be really easy for Linode (or any virtual server provider) to implement. There is also no technical reason why a company like Linode couldn t allow their customers to rent all the capacity of a physical system and then subdivide it among DomUs as they wish. I have a few clients who would be better suited by Linode DomUs that are configured for their needs rather than stock Linode offerings (which never seem to offer the exact amounts of RAM, disk, or CPU that are required). Also if I had a Linode physical server that only had DomUs for my clients then I could make sure that none of them had excessive disk IO that affected the others. This would require many extra features in the Linode management web pages, so it seems unlikely that they will do it. Please let me know if there is someone doing this, it s obvious enough that someone must be doing it. Update: A Rimuhosting employee pointed out that they offer virtual servers on dedicated hardware which meets this criteria [3]. Rimuhosting allows you to use their VPS management system for running all the resources in a single server (so no-one else can slow your VM down) and also allow custom partitioning of a server into as many VMs as you desire.

• [1] http://www.hetzner.de/
• [2] http://www.linode.com/
• [3] https://rimuhosting.com/order/vps-on-dedicated.jsp

Quickie OpenGL wikibook tutorial to show how to display a bounding box around your object

http://en.wikibooks.org/wiki/OpenGL_Programming/Bounding_box

I'm building a debian package, CDAT. The latest version 6.0.alpha uses CMAKE to build, rather than configure. The trouble is that CMake doesn't build. It doesn't even fail.

$ mkdir build
$ cd build
$ cmake ..
()-- Configuring done
-- Generating done
-- Build files have been written to: /home/amckinstry/deb-packages /cdat/cdat-6.0.alpha/build
$ make
$

The problem is, 'make' does nothing. A Makefile is generated by CMake, which calls cmake which calls make again on ./CMakeFiles/Makefile2 ... which does nothing useful. Apparently the CMake is supposed to put useful stuff in there, but doesn't. What puts stuff into Makefile2, and where should I pick up the bugs trail? Tags lazyweb, cmake, debian

Since the 3.5.0 release, Openbox automatically starts applications with .desktop files in /etc/xdg/autostart. This was already the case with previous releases when setting the . $GLOBALAUTOSTART instruction in the autostart script. This instruction is now deprecated. This has puzzled me as some applications were started twice in my Openbox session: those launched via my ~/.config/openbox/autostart script which are also launched through xdg autostart. I also like to use notify-osd when in openbox, but it seems the new gnome-fallback session requires notification-daemon. In my Openbox session, I have noticed that notification-daemon was launched whereas my autostart script specifies to use notify-osd. I then discovered that /etc/xdg/autostart/notification-daemon.desktop was the cause of this. I had to drop a notification-daemon.desktop file in my ~/.config/autostart/ directory with the following contents: The last two lines allow me to not start notification-daemon only when using Openbox ie. it still starts automatically when launching a GNOME session. You can check what applications are automatically started through xdg with: The results are quite amazing, most applications being only configured to start in GNOME or KDE, but nothing seems to be very coordinated amongst maintainers. I find this quite misleading, and would prefer openbox to stick with the previous default behaviour. Who said diehard ?!

A couple of times I have written code which basically does this:

1. accept() an incoming connection
2. do some magic to get another socket
3. start passing bit between the two sockets
4. perform a correct close down sequence

An example use case of this is a proxy implementing the HTTP CONNECT method, but in for some known hostnames it will log a message and mangle the hostname before proceeding. This has been used as a legacy fall back solution while changing a network setup. But my uses are not restricted to HTTP proxies I have done the same for a few legacy protocols where the magic has been of different complexities. The two final steps are quite general and it would be nice to have a module doing just that. Take two sockets and make it easy (or even automatic) to pass bytes between them. The na ve non-blocking solution would use a scalar string buffer for each direction and perform a select loop while maintaining the write vector depending on which buffers contain data. I have written this code multiple times. In development this is usually quite successful, in production less so. While Perl might be quite suited for the magic in step 2, the na ve way of passing bytes have quite an overhead for the buffer management. A less na ve way would use a array of strings for buffers, but I m not quite sure if this would be a win in all cases. You might be able to get away with some string operations on the read side of the buffer, but it might be more expensive on the write side. I have not benchmarked this. Most of the time I don t care about Perl level IO handles. I know that there is a real C level file descriptor beneath. So an even better POSIX compliant solution might be to use XS to have plain C strings and use readv()/writev() and a iovec structure as buffer. Can we do even better? At least on Linux we can. With the Linux splice() specific system call it is possible to us a pipe as buffer and never to have to copy data from and to user space. I have not been able to find any off the shelf solution on CPAN. So I think I need to write it myself, but what would the nice and general API be? I guess the basic interface would be something like:

    my $chain = IO::Splice->new($fh1, $fh2);
    $chain->pump(); # read and write from both handles if possible and needed
    $chain->read($fh1);  # read to buffer from one specific handle
    $chain->write($fh2); # write from buffer to one specific handle
    $chain->can_write(); # returns the handles it needs to write to

but it might be simpler to have two callbacks for setting a file handle in write or no-write state:

    my $readset  = IO::Select->new( $fh1, $fh2);
    my $writeset = IO::Select->new();
    my $chain = IO::Splice->new( $fh1, $fh2,
        writable => sub    $writeset->add( shift )  ,
        unwritable => sub   $writeset->remove( shift )  
    );
    while ( ... select ... )  
        $chain->pump();
     

As said, I think I have plenty of implementations of the na ve way but before releasing some code it would be nice to get some input on the API. But the best feedback would be a module that already have a usable API but might not implement the Linux specific way. That would allow me to steal the interface

Good morning all! It feels like forever since I last blogged . Which is extremely bad of me *slaps own wrist*. However, I m been horrendously stupidly busy. As some of you may know, I m very much an Android fan. Recently, I ve gotten myself a shiny Galaxy SII. Given the fact that alongside my day job of being a Web Developer for an Online Retailer, I m also a Voluntary Ambulance Person I thought it d be useful to ask my current workplace if they d provide me a mobile phone cover for my new phone. Of course, work were more than happy to provide me with a shiny Samsung Galaxy S2 case (I actually went for the Case-Mate Barely There in brushed aluminium). Being a voluntary Ambulance Person, I regularly have to go to random places to pick up an ambulance/attend an event. Because of that I rely quite heavily on Google Maps and it s navigation features (Free Sat Nav in my opinion, the killer feature of Android). Having only had my phone a week, I started to find that there were a few problems with the GPS. Whereas previously, I d been able to lock on almost instantly, It d now take me about half an hour (literally) to get a lock on anything. I tried Googling, I tried everything I could think of, but to no avail. I downloaded GPS Test, and it was showing that while it was picking up a couple of sattelites, it wasn t picking up enough to get a decent lock The image above is a screenshot of the GPS test from directly outside my front door, taken after it had settled down. As you can imagine, I wasn t happy and was ready to send the phone back. Then, for some reason, a brainwave hit me (It doesn t happen often). What changed from when it was working to now? I know! The Case *takes case off, tries GPS test again* It can be amazing what happens when you realise that shiny case you have is mainly made of aluminium. Guess what works well at deflecting radio signals and the like You got it, aluminium. So now I need to decide whether to get another case or whether to just take the case off when I need to do sensible things. Other than the case problem, I m finding that the Samsung Galaxy SII is a great phone (as soon as I got rid of Touchwiz). I m not a fan of the OEM Samsung crap that s been bolted onto the phone, and will, as soon as there s a decent release, be putting a copy of CyanogenMod on the phone (I ve already made most of the tweaks I just want rid of SNS) In other news I ve started more and more gaming again. If you re interested in a couple of rounds of TF2 or some SC2 (or some Portal 2 Co-Op) then give me a shout with your Steam ID / Battle.net ID and I ll see what I can do. I m thinking of starting doing some Let s Play Videos, as my Youtube Channel is looking a bit sparse! I m going to try and start blogging a bit more aswell so if there s anything you want to see me blog about pop a post in the comments below! Till next time..

As you may have noticed, I'm testing DIASPORA* as a blogging platform. Its been working reasonably well recently for me, with friends and family; even though the "Main" platform joindiaspora.com is not giving general invites, the code works and a bunch of distributed 'pods' have been set up. You can make entries public, and I've tested a public address for this: http://diaspora.sceal.ie/u/amckinstry which looks ok, a bit plain for the moment, but I'll work on that later. The problem has been the atom feed is garbage. (It's putting the content into both the Subject line (as unadulterated MarkDown, no less), and into the content). So, I've put the old blog back up for the moment. While I debug some Ruby on Rails, not a language i'm too familiar with ... Note: only logged in DIASPORA users can leave notes on the Diaspora site, but go to the login page and registrations are open. At least until spammers notice... Tags diaspora, ruby, debugging, blogging

It'll be a week today since I assume Smudge disappeared. Still no sign of her. I got one call from my posters around the neighbourhood, but I'm now pretty confident that it was another black cat. I really got my hopes up on that one. I don't know what else to do. I could be out beating bushes every spare minute, but I feel like I'm chasing a potentially moving target around an unbounded space. I've had no bites in the cat traps out by the front door. Not even a skunk. The waiting game sucks. I have no idea if she's dead or alive.

Manipulating meshes and lights is nice, but sometimes we want to manipulate the good old pixels, in particular for post-processing effects such as blur. But how can we do that in OpenGL? In this new OpenGL wikibook tutorial, we'll explore a solution: render to a texture through a framebuffer object! http://en.wikibooks.org/wiki/OpenGL_Programming/Post-Processing For our first effect, we'll implement the wave system previewed a few days ago in the video capture tutorial.

Hello World,

I am very pleased to announce the release of Laptop Mode Tools, version 1.60.
This release includes lots of bug fixes and should make power savings much better on your machines.

The battery polling daemon now, more reliably, gets triggered and killed based on power states.

read more

Best said here Let not make the final statement and not a single newspaper cares " into a reality. PS: Do check out Against Nostalgia, a great jab at Jobs.

I m in Paris for the LibreOffice conference, but today after a random talk with a guy that had a Mozilla badge/pin, I found myself in a tour to the Mozilla Europe office (which is also in Paris). Thank you random guy David for the tour (: The office itself looks very nice, and reminds me of the work space of many software companies. But the unique part of the tour was David pointing to people and telling us what they are working on. It s interesting to see the people behind the sciences, although we didn t talk with them in order not to disturb the work. I remember most when we David pointed to a guy and said he s the one doing composer. Maybe because it s very clear what he doesn t, while some people work on more internal parts or more conceptual concepts like performance . After seeing some cool posters on the wall, I got a chance for a short chat with Tristan Nitot and ask him some questions about Mozilla Europe and the office. I m still trying to understand how Mozilla works (as an organization), and this was a good chance to get familiar with the European branch. For me, the highlight of the tour was the chance to say to the people at the office thanks for the software just before leaving and saying goodbye. Not in everyday you get a chance to see the faces behind the software you use daily.
Filed under: Mozilla