1. News from Marble: Planets

    Hey, folks!

    A few days ago we posted about new functionality added to the Virtual Globe - support of the Sun and the Moon (with appropriate phases support). Today we want to introduce planets!

    In KStars you can observe any real object in the sky, starting from the Moon, finishing with Deep Sky Objects. As well as in KStars, we want alike support in Marble, so you can go deeper and try to explore not the world only, but the Sky also.

    To show what Marble can do, I’d like to talk about planet conjuction in June 7: the Moon and Mars (The Moon will pass within two degrees of the the planet Mars in the evening sky. The gibbous moon will be at magnitude -12.2 and Mars will be at magnitude -0.8). Conjunctions are rare events where two or more objects will appear extremely close together in the night sky. The two bright celestial bodies will come unusually close to each other (like planets or moon), only a quarter of a degree, in the early morning sky. This rare, double-object event is definitely one not to miss. Look for the bright planets in the east just before sunrise.

    In case of the Marble, you don’t need to wait until June 7, to see, how does it look like. You may just change the time control, by specifing this to correct time (in our case it is 7.6.2014).

    Marble view

    There is also another conjuction this year: of Venus and Jupiter. It’s date is August 18. But we won’t talk about it in terms of this article. Instead, you will have a chance to play around and experiment, as soon as we have this feature tagged and released (you will have it in master, if building from sources)! As said above: start Marble (which you can get on marble.kde.org), set Time Control in Edit menu entry to 7 Jun 2014 and find the Moon there. You’ll find Mars as well!

    You easily can turn off all or specific planet. To do such, you should find an empty space on the Sky, right-mouse click and you see context menu with all features (e.g. disabling/enabling all planets). To control specific planets, go to Configure… dialog.

    We also added proper sunshading for all Planets (previously, we had it only for the Earth). For example, it’s supported by Mars. In order to prove it, we will show you two screenshots. From the Mars24 application and from the Marble (both in Flat projection). Compare them.






  2. 25 posts!

    (Source: assets)


  3. News from Marble: Introducing Sun and the Moon

    Happy New Year, folks!

    Here, in Marble we work a lot on new cool features, so you can play around with the Globe and explore the world more and more. Not a secret, that each minor release Marble shows great improvements in performance and features. Today I want to show you our new previously missing feature - enhanced Sun and absolutely cool support of the Moon.

    For lazy people, who don’t really like reading all this news posts here is a quick overview of added stuff:

    • Gerhard Holtkamp’s astrolib is bundled to Marble core
    • Sun texture is scaled according to its real size (thanks, astrolib!)
    • Moon is rendered, moon phases are shown

    Marble provides a nice opportunity to observe eclipses without even standing up from your sofa. You just go for View -> Eclipses and choose the right one (only works in master now, sorry). Here is an example of Tue Apr 29 2014:

    Tue Apr 29 2014 eclipse

    A quick example of moon phases support in the Marble is 23 Jan 2014, when we have the Moon, Spica and Mars around!

    marble view

    You would probably like to compare this to what KStars gives as output:

    kstars view

    Note: distances to Mars are different, because in Marble, the Moon is 4x times bigger than it should be (otherwise it’s too small and makes no sense, however this can be changed in preferences).

    **Few words about moon phases (bonus) **

    Moon rendering becomes not so trivial as soon as you need to reflect moon phases. It should be rotated according to its actual position also, so that’s where comes astrolib (thanks, Gerhard Holtkamp!). Final rendering process looks similar to this:

    • Rotation (Moon is rotated relatively to its current position to the Earth)
    • Scaling (by default, in Marble we use 4x aspect ratio to “real” Moon size, but you possibly would like to turn it off)
    • Moon phases overlay rendering

    Let’s stop on the last step. Astrolib provides API to get information about the Moon phase in the specific moment of time:

    void SolarSystem::getLunarPhase(qreal &phase, qreal &ildisk, qreal &amag)

    Outputs are actual phase, illuminated disk and the apparent magnitude of the Moon reffered to the center of the Earth.

    Moon phases picture

    There are 8 different phases (from 1 to 8 on the picture): New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, Wanning Crescent and then it’s New Moon again. Actual rendering process is about drawing two arcs, which is not complicated, but still needs to cover all cases and calculate angles neatly. An exported paste is published here. You also can observe it right in the source code (StarsPlugin.cpp:1130; line may be different later).

    Find your way and explore the world!


  4. KDE is the best open-source org… ever

    Hello, blogey!

    Today I’d like to tell you about KDE (K Desktop Environment) and how I started working on some projects there. I first met KDE 2-3 years ago when I was moving from Windows to Linux (one of the most important moments of my life, as developer). Choosing desktop environment was challenging and I thought about GNOME, which I was using for few month. Finally, I totally moved to KDE 4. I was using some nice applications, like Kate, KDevelop, Telepathy.

    In the past year I heard about Google Code-In 2012. After thinking for a while I chose KDE, because it’s the most suitable organisation for me (I was working with Qt 4 smth like a year-1.5). I started working for Marble/Telepathy and that was extremely interesting. Few days later I got my KDE developer account, so I made my first commit to KDE these days.

    Already, I have done relatively big amount of coding mostly for Marble - my favorite and onelove KDE application. I am participating in GCI-2013 this year also and I will do my best to improve quality of KDE in terms of UI, core stuff, user support and everything :)

    For newcomers, I created a list of things you should/shouldn’t do, anyway:

    1. Don’t be aware of asking - ask as much as you need and try not to be anoying.
    2. Be creative - it’s extremely important to show yourself as creative person
    3. Try hard

    P.S. I really wanna say many thanks to Dennis Nienhüser, Torsten Rahn, David Edmundson, Claudia Rauch, Lydia Pintscher and to all kde people, all gci mentors!


  5. Sup, journal.

    A few days ago I was lucky enough to attend “Premier Event of The Year”… Qt… Developer… Days!!1 In this report I’d like to express how was it and why is it great to visit such a conference. Who doesn’t wanna read the whole report: organisation was excellent, we missed Thiago this year and Cafe Moskau. Day 1. Trainings

    Firstly, when you arrive to Cafe Moskau, which located just in the downtown of Berlin you would get a badge and a goodie pack with guides, bucklets, some KDAB stuff, 2 free drinks tickets and a voting form (about it later). I am KDE volunteer, that’s why I should have done some job in cloakroom. Basically, it was something like getting clothes and hanging it on the hook. Amazing work, but that’s not essential.

    What is training? There are 5 (could be 6, I am not sure abt it) different traineys. You choose one, that fits more up to you and sit in corresponding room the whole day. Sure, it’s possible to jump between trainings, but it’s a bad idea, at least because they are sequental. So, you can miss a lot of pretty nice stuff. Actually, in each auditory there are lots of tables and you can put your laptop there and it’s possible (even a good practice) to do some coding during training.

    I chose the one which I am the worst at. I chose “Advanced OpenGL with Qt 5”. Why? I really wanna create a 2d videogame with Qt and all that old opengl stuff can’t be a suitable solution for me. I thought that this one is the best opportunity to start all that “shader-based” things. (Spoiler: I am working on one now :D)

    It was incredible. Sean and James are great guys and their speech was enough light for me to get it almost 100%. Thank you, that was an amazing experience and source given is extremely helpful, I’d say.

    Day 2. Sessions & Keynotes

    The day started with opening keynote in the building of “Kino International” by Kalle Dalheimer. Then Tommi Laitinen, Digia SVP was talking a bit about how Qt is “breaking down”. Kevin Franklin replaced him with a Qt Insights statistics. (British people are cool!). I even got a Qt Insights badge just yesterday. Then, there was Lars Knoll. As usually, he was talking a lot about what we did this year and what we are going to do forwarding year. By the way, Qt releases are time-based now (each 6-7 months minor version incremented). Dan Dodge told, how Qt is important for QNX and what is Q Unix (tricky you, Dan) is about. Amazing speech, fun jokes.

    Then there are some sessions. Rooms full of chairs (tables removed), people are listening to speaker and making notes. Again, there are 5 different streams, so you can’t be in 2 places at the same time. I was on “Qt for Android”, “3D OpenGL scenes with QML under Qt 5”, “Qt for iOS”. Each talk I chose was awesome, informative and really helpful.


    Here is one essential thing about devdays. I am talking about exhibition area. Sponsors (KDAB, Digia, ICS, KDE and others) had some stands on the second floor. I spent most time around KDE one, talking with some e.V. people, like John. Pity that David haven’t arrived this year, it could be great :(. Actually, afaiu, all these amazing stands are just showing off. Each company wanna show that they are better and their technologies/products are more innovative/etc. Funny thing is KDE does more stuff than all these companies taken together but we had the smallest stand (no one cares, that we are non-profit organisation, so we couldn’t have better).

    Anyway, I found some bugs in ICS and Digia applications :P (saying hello to Denis and the whole Digia team). Ubuntu (Canonical?) stand was kinda interesting, maybe at least because I tried Ubuntu Touch (or how this OS called?) on Nexus 4. People there are really nice and doing a lot of amazing applications with QML.

    Day 3. Sessions

    This report will be too big if I leave feedback about all sessions too. So, it was just a regular sessions’ day + some additional events. Niceeee! I left at 5 PM, so missed cool parties, etc.


    In this chapter I’d like to leave some specific notes about talks and training I attended. Let me start from the training called “Advanced OpenGL with Qt 5”. Speakers are: Sean Harmer & James Turner (both from KDAB). It was super nice, specially for me, because I am not so good at OpenGL. The only one problem, which I thought that would be better to spend more time on GLSL. Actually, GLSL is not a trivial thing, we don’t have even good guides with working and well-commented examples. If they showed us how to do all that shader magic, like in real life…

    Then I attended almost all “platforming” and some “qml” talks. Bogdan’s “Qt on Android” was really nice, after it I even managed to create working Android application I was trying to build maybe 3-4 weeks. Richard’s “Qt on iOS” was nice too. No idea how, but I lost that news, about working Qt Quick 2 on this platform. Anyway, embedding Objective-C code, all that states, accelerometer stuff, etc is incredible.

    Generally, all QML talks I attended were quite good, but I am newbie at this UI field, so smth was unobvious. Keynotes were also impressive + jokes.


  6. Akademy 2013: Report with blackjack


    Previous week I have attended Akademy 2031 conference. This year they joined forces with Qt Contributors’ Summit 2013, that’s why I am so lucky to attend even two global events the same time. In this report I would like to say about how it was. Seems like these keywords will fit theme of the whole report: kde, community, I, love, you.

    Let’s start then. Day 1. It was kinda greeting party with some free wine and awesome music, which attendee and organisators were playing themselves. Greet music and paid Coke for me were great! :D I also got my badge (mum got her one next day).

    day 1

    I also had a conversation mostly with Kevin Krammer (thanks, Kevin!)

    Day 2. Sessions started. It was great, a lot of new knowledge, etc. I listened everything and got a lot of important experience. Sessions are great, only one remark is I would like to have a bit more technical talks.

    After that we had a party at the night, that was unfortuntely, great also. We had nice music of two terrific spanish groups and I had some new contacts. Here is a photo of our conversation group during the party:

    day 2

    Day N

    My memory is so bad, I can’t remember everything in the right order, that’s why I am going to mention only the most significant events, okay.

    There are no sessions about KDE. Qt Contributors’ Summit startes. Actually, it happend that the most important Qt CS talks were going the same time the most interesting BoF’s were running, that’s why I missed a lot of BoF’s (sorry KDE). Only one excuse I can list - Qt support is extremely critical for me now, it was too important.

    I had some new contacts during QtCS also:

    Thanks to BlackBerry, they gave us a new BlackBerry Z10 as a gift!

    Also, I had some time for relax and just hanging out there, in Bilbao. Some photos about that:

    The most philosophical one (:D)

    At the end of the day before the last one we had an amazing dinner with some alcohol drinks (sure I had no alcohol). Anyway, the dinner was great, great and great again. A photo from our conversation there:

    Tadam. Looks like it’s the end of my story at Akademy 2013. The only one thing: Thank you, KDE. You organised one of the most exciting experiences in my life. Hope to meet you guys again


  7. Impossibly cool, cool, cool and again. Cool.

    (Source: Spotify)


  8. lipstobone:

    Doctor Who: 50th Anniversary Special Trailer - in 3D! (by John Smith)


    (via vegaslights212)


  9. Yet another hipster look.


  10. Anonymous asked: What is your opinion on the Raspberry Pi computer for just 25$ ?

    Thumb up!