Peter Velichkov's Blog

To fix the recent bug with VMware Player 2.5.3 and Workstation 6.5.3 Build 185404 under Karmic Koala Ubuntu just paste this line in your console before launching vmplayer/vmware:

export VMWARE_USE_SHIPPED_GTK=yes

you may also modify the VMware starting script so you don’t have to export it every time.

If you get this error on each frame then you have probably moved the camera to the same position as the object (camera.z = 0). Change it a bit and the error should be fixed.

First of all let me apologize for not blogging in a while but I’ve been working on couple of interesting projects after which it was time for deserved vacation on the BlackSea’s beaches.

Anyway I needed a better looking horizontal slider for one of the projects and all of my googling got me nothing reasonable (most of the tutorials were for changing the Thumb and leaving the default TrackHighlight) so I had to figure out something. Here is my horizontal slider, it is pretty basic but you can use it as a base for your needs. Corner Radius and Background Gradients are set via CSS, width and height are flexible too. Check the example and get the source code.

With no surprise the update from Interpid Ibex to Jaunty Jackalope was not as easy as I hoped. After booting the fresh 2.6.28 kernel I was welcomed with “Press enter for maintenance (or type Control-D to continue)” and errors when trying to mount my RAID0. After some investigations found that the devices are now named md_d* and there are some devices in /dev/md/.  Because of this change I had to do the following things to get my raid up and running:

1. Reassemble the raid (check if it is inactive with less /proc/mdstat) – in my case the command looked like this: mdadm --assemble /dev/md_d1 /dev/sdb2 /dev/sda5
2. mdadm --detail --scan >> /etc/mdadm/mdadm.conf and comment your previous ARRAY definition in the config file
3. Modify /etc/fstab if needed

Also if DKMS fails to build the new NVIDIA driver be sure to check that you have installed the headers files (the upgrade process did not install them for me).

Again : I’m NOT responsible for any damage or data loss you might experience. Backup often, backup soon!

One not-so-beautiful morning I woke up just to find out that my Seagate 7200.11 500GB hard drive is not detected from my BIOS. Unfortunately it was a well know problem which have three solutions:

1. Replace the hard drive with new one from where you got it and lose your data
2. Send it to Seagate for data recovery and wait a month or more
3. Fix (or totally screw) it yourself

Of course as some-kind of geek I chose the last option and successfully repaired my drive following the MSFN forums guide. Check the photos for more details of the process.

Summary:

1. If you have Seagate 7200.11 be sure to  check if it is affected and if is still running flash it with the latest firmware
2. If you are planning to repair it yourself be sure to know how to solder
3. You will need quite a few parts and tools. It took me two days to prepare
4. Most of the cellphone cables have what you need inside. I used a Nokia datacable.

PS: I’m NOT responsible for any damage or data loss you might experience

PS2 (in Bulgarian): Ако ви трябва помощ при възстановяване на данни от 500/750/1000GB хард диск Seagate 7200.11, който не се появява в БИОС-а или е с размер 0, драснете ми едно писъмце и ще се опитам да помогна.

For one of my recent Wordpress projects I needed an easy way for the client to organize and display videos. Unfortunately my hope that NextGen Gallery plugin, which I already used for the images, will do the trick vanished after couple of clicks and I started googling for a solution. Since neither google nor Worpdress Plugins page gave me anything reasonable I started rethinking the situation:

1. I was already using Shadowbox which allows displaying videos
2. I already had jQuery enabled in my Wordpress Theme
3. I can use the alt field in the NextGen options for the url of the video

So what I needed was to modify the generated from NextGen anchor (the href attribute) and somehow to distinguish if the  thumbnail is for image or video.

Here is the script I wrote which does both things:

jQuery(document).ready(function($){
  $(".ngg-gallery-thumbnail a").each(function (arr){
    if ($(this).attr("title").substr(0,5)=="Video"){
      $(this).attr("rel","shadowbox;width=405;height=340");
      $(this).attr("href",$(this).children("img").attr("title"));
    }
  })
});

All you have to do to make it work is:

1. Include this Javascript somewhere on your page
2. Put the url for your video in the alt textfield
3. Start your descriptions with “Video”

In the past couple of weeks I’ve been working on couple Augmented Reality (AR) projects for row27 Studios including the newly released “Oski on your Desk” mini site dedicated to the Californian Golden Bears’ mascot Oski.

It was quite interesting to see Papervision3D’s superpowers combined with FLARToolkit with all the limitations and difficulties connected with it.

If you don’t have a webcam or printer you can check out the video bellow. It lacks sound and is looking a lot worse than the real experience because of the low quality webcam and the screencapturing process.

Stay tuned for more AR projects from me.

After completing my personal website I started considering the idea of recording some video tutorials and as a result I have just done my first Papervision3D screencast. One thing I am very pleased with is the technical part of this task. Since I’m not a big fan of Camtasia and other propriatery software this time I used VirtualDub with x264 codec instead of Camstudio and flashsv. This way the quality of the video and the file size came out amazingly well (less than 1mb per minute of recording).

Moving to what the tutorial includes:

1. Downloading and installing Tortoise SVN
2. Downloading (check out) the Papervision3D SVN repository
3. Setting up Flex Library Project (in Adobe Flex Builder) for the code downloaded at step 2.
4. Setting up Flex Project (in Adobe Flex Builder) for our first Papervision3D attempt
5. Writing and testing very simple AS3 Class CoolCube for getting started with PV3D
6. Having fun!

PS. Sorry for the lag of outline around the captions but  I was informed that I have to buy a license for JW Player (which supports outlines). This forced me to use Flowplayer which has insane set of features but is nightmare to configure.

If you have any other player in mind (or hosting which will not recompress the video), please drop me a line.

Update (02-03-2009):

Recently things are going a bit beyond the healthy conversations and various people are taking the whole “which-is-the-fastest-framework” idea way too seriously. The most important thing in any benchmarking process is not to compare apples to oranges, which unfortunatelly happens too often. After jQuery adopted Sizzle (a selector engine) many people started comparing it directly to Mootools (a framework).  As a result Aaron (Clientcide) posted Sizzle and MooTools by the Numbers as an answer to the recent flame-wars on the Javascript Frameworks scene. Apart from only testing and comparing the selectors engines (which is what Slickspeed does) I suggest checking out another post on Clientcide – Comparing Frameworks with Inheritance Benchmarking.

/update end

As my previous post comparing Dojo vs JQuery vs MooTools vs Prototype got quite popular and was included in the Wikipedia’s Comparison of JavaScript frameworks article I decided it is about time to update it with some fresh data and browsers.

For the performance part I used the same tool as before – Slickspeed. If you have forgotten, it tests the selectors which are essential part of any Javascript framework. Currently Slickspeed includes the following frameworks: MooTools 1.2, JQuery 1.2.6 (1.3 see bellow), Prototype 1.6.0.2, YUI 2.5.2 Selector beta and Dojo 1.1.1. Unfortunately some of those are not the latest versions but still are quite recent and I am sure the guys will update it soon. The good news is, as you can see from the list, now it includes YUI which is really strong competitor.

Performance comparison done as following:

1. All tests were done under OS with latests updates applied (Windows XP SP3, Ubuntu 8.10, Windows 7 Beta 1)
2. Slickspeed was run three times per browser with emptied cache and restart between each iteration.
3. The average from all tests results rounded to integers were taken in account for the chart.
4. Nothing else was running during the tests.

Results per browser:
Results per framework:

Since this time the comparison includes a lot more browsers and frameworks the raw data table is in separate html file.

Remarks:

• FF refers to Mozila Firefox, IE is Internet Explorer and Win7 is Microsoft Windows Seven
• 3 Dojo selectors failed under both Mozilla Firefox 3.1 Beta2 and Safari 3.2.1
• 11 Dojo selectors and 4 YUI returned invalid results (failed) under Internet Explorer 8

Failed tests mean lower final time under the listed above browsers which was especially valid for Dojo under IE8 where the summary time was around the obviously impossible 1ms .

Update (jQuery 1.3): When I started writing this post the latest jQuery version was still 1.2.6 but on January 14-th they released 1.3 with lots of performance changes. The dev team have replaced the whole selector engine with Sizzle which gave a noticeable performance boost to the framework.  The official jQuery website is providing Slickspeed test results which indeed show big improvement among the other interesting changes in this release.

Summary:

I have done my best to be as objective as possible. As you can see I have tested twelve browsers and for each I ran Slickspeed three times. However those benchmarks are very hardware dependent so on different computers the results may vary. Still the chart (proportions) should look quite similar to the ones above. If you have very different times please contact me so I can double check again and update if needed.

Since performance should not be the only criterion for choosing a Javascript framework here are couple thoughts on the design differences between some of them.

Glenn Vanderburg does great comparison between Prototype and JQuery code design in his Why I still prefer Prototype to jQuery blog post.

And here’s the capsule summary: jQuery is a very nice piece of work, and makes some common tasks easier than their Prototype equivalents. Where it’s good, it’s very good indeed. But its design is uneven, and its scope is limited. For me, at least, Prototype is still the tool of choice. I think it’s a richer, more thorough, and overall better designed library.

A good resource on Dojo is Dylan Schiemann’s post Debunking Dojo Toolkit Myths were he addresses file size, performance, documentation, usage and bunch of other topics.

And ofcourse no comparsion is complete without my favourite JS framework Mootools. When it comes to What’s Moo I am a big fan of Aaron Newton and his blog Clientcide (was previously Clientside when he worked for CNet). On several occasion Aaron wrote about differences between jQuery and Mootools:

When I wrote that post, I went out of my way to make the point that jQuery is different than MooTools, but not, in my view, either inferior or superior. Just different.

I suggest to read those posts jQuery, MooTools, the Ajax Experience, Programming to the Pattern, and What Really Makes One Framework Different From Another and How Many Flavors of Linux Are There?. A good thing to do is subscribe to his RSS feed since apart from the strictly Mootools topics there are many general ones which will help anyone using whatever framework.

Another good piece of information that may affect your choice is that Microsoft and Nokia are adopting jQuery and will be integrated in Visual Studio. However if you are using Aptana there is already support for most of the frameworks including Mootools.

The point of this post is not to start another flame war on which JS framework is better. Each one does what it was supposed to do and has its supporters.

I am open to any reasonable suggestions about the above content.

One issue that was bugging me for a while was the different font size (after adjusting it) on couple applications (including Adept) under my fresh installation of Kubuntu Interpid. After investigating and Google-ing I found out that it was due to running those proccesses as “root” which had different fonts and GTK+  settings.

Solution:

$ kdesudo systemsettings

After running the command above setup the font size as you like it. Working as normal user is something new to me and I’m not sure I like. Needing to write my pass to many times and having to chown my old files is just not that pleasant.