Tablet PCs – a chance for Maemo?

I just have watched the Apple iPad announcement and I have to say that I am quite impressed by the Apple marketing team. Before the film I could not think of a good use case for a oversized iPod, but after the film I have to say that Apple greatly refined the use case of the netbooks as a second PC.

Instead of putting an ordinary OS into a differently shaped device, like Microsoft is seemingly doing with the Slate, Apple adjusted the OS to the new use case.

If you have a much smaller screen and a much smaller keyboard, like you have on netbooks, you don’t want to write long articles or aim for the tiny buttons of ordinary user interfaces. Instead one should of a netbook like a playback device, which only requires rudimentary interaction.

As apple is great at streamlining stuff, they simply left out the keyboard and used a modified version of the iPhone OS, which is optimized for easy usage and – voilla here comes the computer you actually want to use in your living room, to quickly peek on facebook or your mail inbox.

But there are two big disadvantages that come with using the iPhone OS. First it is stripped down to much; there is no multitasking and no system clipboard which takes a lot of the convenience you have when using a real OS.

And second you are again locked-in by apple. If you use the iPad, you are also more or less forced to use iTunes for your music, iBook Store for your eBook and the AppStore if you want new Software.

Of course you might be able to Jailbreak the device and use third-party software but this will be nowhere as convenient as using the defaults. This is Apples Achilles heel and where Maemo can triumph.

With Maemo you basically have a full-fledged Linux with a easy to use UI. You have multitasking, you have a system clipboard and most importantly you have an open software repository – and all of this very well integrated in the UI.

You can freely choose your email provide, your music player and even the format you save your music in. And even though Nokia does not support OGG by default, the open nature of the OS allows it to be just as integrated as everything else.

Actually Nokia only has to build a Internet Tablet with the size of the iPad…

ArtoolkitPlus for Maemo

I just uploaded the latest version of ArtoolkitPlus to Frementle devel, so you can start playing around with it soon. Artoolkit is a marker tracking library which allows Augmented Reality applications similar to ARhrrr possible. I am currently working on a AR application for the N900 as part of a project work for the university. Of course it is not quite as advanced as ARhrrr, but it certainly runs better than this demo on the iPhone 🙂

PowerVR SGX 530 does NOT support Depth Textures

If you download the PowerVR SDK for the TI OMAP3430 which is used in the N900, you will find a nice shadow mapping example which uses the OES_depth_texture extension. You can even run this example using the included emulator using the SGX 530 profile.

However if you try to run your code on the actual device you will soon find out that it does NOT support OES_depth_texture. This is quite surprising as the device supports OES_texture_float and OES_depth24, so depth_texture should be not too hard to implement.

But the situation is the same on the iPhone 3GS, which uses the same hardware. This leads me to believe that this is not just a driver limitation.

However here is a workaround using a ordinary RGBA texture and byte packing:

const highp vec4 packFactors = vec4(256.0 * 256.0 * 256.0, 256.0 * 256.0, 256.0, 1.0);
const highp vec4 cutoffMask  = vec4(0.0, 1.0/256.0, 1.0/256.0, 1.0/256.0);

void main() {
    highp vec4 packedVal = vec4(fract(packFactors*gl_FragCoord.z));
    gl_FragColor = packedVal - packedVal.xxyz*cutoffMask;
}

the packFactors vector basically contains the 3 necessary byte wise shifts to the left. The call to fract() cuts off anythig which is to the left of the byte we want to save and subtracting packedVal.xxyz*cutoffMask cuts off anything to the right of the byte.

The cutting is necessary as we are dealing with floating-point here and we dont know how the hardware selects the value that should go in.

The future of the radeon OSS driver is bright

recently I had to switch to the gallium based r300g driver to get GLSL support, which I need for a project. And I must say I am quite impressed. It exposes all extensions necessary for OpenGL 2.1 and already seems quite stable. Although some extensions are not implemented properly yet like NPOT as they need special workarounds I think this will eventually become the most feature complete driver for radeon hardware.

But although currently compiz works as do most of the OpenGL programs, I would not reccomend using r300g for production use as it is still really slow. I know glxgears is not a benchmark, but these numbers represent the impression I got quite well

  • 8200 frames in 5s (no kms + classic mesa)
  • 5140 frames in 5s (kms + classic mesa)
  • 2431 frames in 5s (kms + gallium)

But as r300g exposes GLSL and the adobe flash player uses that if available, HD flash movies seem smoother now. And considering that using gallium not only provides better OpenGL, but eventually also VDPAU, OpenVG, OpenCL etc. the r300g driver does a good job already. And remember all AMD cards starting from r300 will get this stuff – I hope you now see why open source drivers are important 😉

GLUT for C++ and OpenGL ES

did you ever try to use GLUT with C++? Do you remember the pain of having to make you member function static, so they can be used as a callback? Maybe you also want to create a OpenGL ES2 context if you develop for mobile devices. But although the latest freeglut supports OpenGL3 contexts, you are still out of luck using GLUT here. But there is rescue:

#include <QGLWidget>

class View : public QGLWidget {
public:
 View();  // glutInit
protected:
 void initializeGL();
 void paintGL(); // glutDisplayFunc
 void resizeGL(int width, int height); // glutReshapeFunc
 void keyPressEvent(QKeyEvent *event); // glutKeyboardFunc
};

and thats it. Works with OpenGL2 and OpenGL ES2 and integrates nicely with the Object Oriented approach. As Qt is LGPL today you can also use it in closed source projects and as you see, you can easily migrate from GLUT without changing all your code 🙂

E-Mail backup in 2009

Are you still one of those using POP to pull E-Mails and save them locally? Are you then using some kind copy to back-up the local mails? At least so did I until recently… But welcome to 2009!

Today the serious e-mail providers also offer IMAP access and pulling e-mails from other servers using POP. Furthermore you get about 7GB(at gmail at least) of online storage and you can configure IMAP to maintain a full local copy. (hint: default of Thunderbird 3)

So instead of fiddling with some local back-ups you can just let gmail pull and save your mail in one place. Then you can clone all your mail locally with thunderbird and you have a reasonable backup. (also recommended for offline usage)

But what to do with your mail collection from the last years? Luckily IMAP has also push support, so you can upload them to gmail and maybe to a bunch of other email providers if you feel safer. 🙂

YouAmp 0.6 has grown

After several betas the final release of YouAmp 0.6 is almost there. You can find the current versions in the launchpad PPA for Ubuntu and in maemo-extras for N8x0.

YouAmp DesktopYouAmp Maemo

the new features are:

  • Playlists
  • Automatic Cover Download
  • Adding Files from anywhere, not just the music library (just drag and drop in Desktop version)
  • you can pay for YouAmp now

I would like to emphasise the last feature: make me a millionaire! No seriously – if you like YouAmp consider a small donation > 0,30€ (otherwise everything goes to paypal) which will help developing the program in my free-time. 😉

As I did not get into the Developers programme for the N900, I also accept unused discount codes – in case you would like to see YouAmp on the N900.

First serious YouAmp release for Desktop

YouAmp is yet another music player for Linux. But it is different than the other players as it is written by me! Here is a screenshot

youamp-0.6

if you are convinced by these outstanding features you can give it a try here. Do not be afraid if nothing happens on first startup as it will index your whole home directory which takes a while.

Basically this re-implements Tracker for music files – and indeed one of the features of this release is that I throw away Tracker. Although the Tracker devs never get tired of praising the cool new features they are implementing, their last stable release Tracker 0.6 is an unusable piece of crap. But I am actually looking forward to try out Tracker 0.7 once it gets an stable release for using it with YouAmp.

For those waiting for playlist in YouAmp on maemo: this release means they are not far away. The main purpose of the last release on maemo was basically to sync the code with the desktop version. Now it only needs some polish and UI love, so it works well on the small screen.

ARToolkitPlus 2.1.3

I just released ARToolkitPlus 2.1.3 based on the new development on launchpad. While the last official release 2.1.1 was back in 2006 and the intermediate release 2.1.2 just contained some build fixes, this version is actually useful.

It has the following features/ fixes:

  • build fixes with GCC 4.4
  • allow build with -std=c++0x
  • allow system-wide installation (allows packaging)
  • add debian packaging information

therefore you can find some ARToolkitPlus packages in my PPA now.

In case you wonder about the differences between ARToolkit and ARToolkitPlus or you are searching for more documentation, I also set up an FAQ.