Older blog entries for alex (starting at number 14)

Visited the "Ballance lab" at the hospital today, but they couldn't really find anything. It seems I'll never know exactly what caused the problems I had, although everyone seems to think that its benign.

I asked for a copy of the MRI scan, they're gonna send it to me later. Having a picture of your brain will be cool.

Its getting better though. Hopefully it'll be mostly gone by the end of the week.

Spent all day today at the hospital, trying to figure out what is causing the dizziness. It doesn't seem to be Benign Positional Vertigo, since I don't have the characteristic eye movement. At least the MRI scan didn't show anything nasty, so its likely nothing too bad. The current theory is that its some form of inner-ear problem. Maybe I'll find out tomorrow.

And I even forgot to ask for a copy of the MRI scan. I have to ask for that tomorrow.

Some weekends are good, some are not. This one doesn't rank particularly high on the list.

This Saturday I was at a party at a friends place, I was feeling fine, and things were good. However, suddenly while I was standing up and talking to some people I got very very dizzy. I had trouble standing up and almost fell down while trying to get to a chair. I was sweating badly and had nausea.

My friends dad drove me to my parents place which was nearby, where my dad (who is a doctor) gave me the diagnose Benign Positional Vertigo. I don't see whats benign about it, I had to lie still the rest of the weekend and could hardly even walk without support.

I'm a little better now, but I still have trouble walking, and I get very dizzy when I move my head. I've gotten better at keeping my head very still, so I can cope with it a bit better. Hopefully it'll just go away eventually.

Experiencing something like this suddenly happening when you were feeling fine is pretty scary. It makes you think about the fragility and complexity of the human body, and how suddenly things can go bad.

I understand that ALSA is the Linux Sound system of the future. Its apparently really powerful, which the hard-core audio people like. However, somewhere along the way, it seems like the whole power thing went overboard.

Check out this screenshot of the volume control for my Trident 4D Wave card. Clearly someone should have been thinking a bit more about the user experience before exposing all that to the user.

Does anyone know what "Sigmatel Surround Phase Inversion Playback" is? Or what the various PCM sliders do?

We're deep into the Gnome 2.8 hard code freeze, and I really should be fixing bugs all day... However, I was talking to Joe Orton yesterday about webdav servers, and it made me very exited about a good idea for userlevel filesharing.

So, I spent some hours today hacking up an application that lets you share ~/Public as a webdav folder, using apache running in the desktop session. The webdav server then gets published via mDNS so that it immediately shows up in the "Network" location in Nautilus on all computers on the local network. As a user, all you need to do is to enable file sharing and everything magically works.

Enabling is done via gconf at the moment, although obviously there should be a user interface for this. It needs a user interface to edit the .htaccess file too.

Check out this screenshot from my test machine, showing how the local Public folder (for the gnome user) is shared, and how I'm browsing the share from another machine (alex's public files).

fejj: Check out libelf and libdwarf in uli's elfutils.

mrcsparker:

The reason the gnome-vfs ssh method doesn't work with ptys is because you didn't send us a patch to make it work.

There isn't any deep secret why this hasn't been done, just the normal reason: not enough time for the people working on it, not enough people working on it.

See also: http://bugzilla.gnome.org/show_bug.cgi?id=117633

badger: no

Got a new job since the last post, now I work at RedHat Labs doing Mozilla and Gtk+ work. These days I work remotely from Sweden, but as soon as possible (pending visa stuff) I will be moving to the states, just like everyone else.

Work is good. The commuting (about 2 hours a day) is a bit boring, but I get to read a lot.

I've been doing a lot of research for the vector drawing program. Yesterday i stumbled over a brilliant algorithm for calculating the intersection between bezier curves (curve/line and curve/curve) called bezier clipping. It is fast, numerically stable and uses little memory, but the real brilliance lies in its simplicity and versality.

Ahh, gotta implement this.

I've been hacking some C++ 2D vector and matrix classes in preparation for a vector drawing program I'm planning to do. They are template expression based and therefore totaly unreadable. But they do generate kick ass code using the latest g++ snapshot.

Using the online snapshot compile form at codesourcery this function:

double dotty(Vector &x, Vector &y, Vector &z)
{
  return dot(x, y+z);
}
compiles to this (x86) code (using -O2 -march=pentiumpro):
dotty__FR6VectorN20:
        pushl   %ebp
        movl    %esp, %ebp
        subl    $24, %esp
        movl    8(%ebp), %eax
        movl    12(%ebp), %edx
        movl    16(%ebp), %ecx
        movl    %ebp, %esp
        fldl    (%eax)
        fldl    (%edx)
        fldl    8(%eax)
        fxch    %st(1)
        popl    %ebp
        faddl   (%ecx)
        fmulp   %st, %st(2)
        fldl    8(%edx)
        faddl   8(%ecx)
        fmulp   %st, %st(1)
        faddp   %st, %st(1)
        ret
which is pretty damn good for that (very readable) sourcecode. There is none of the normal problems with temporary objects etc.

Unfortunately i had to fight quite a lot with the template syntax, so the code isn't very nice. It would be a lot nicer if convertion operators were actually used when matching arguments to template functions. I wonder why that isn't in the C++ standard?

5 older entries...

New Advogato Features

New HTML Parser: The long-awaited libxml2 based HTML parser code is live. It needs further work but already handles most markup better than the original parser.

Keep up with the latest Advogato features by reading the Advogato status blog.

If you're a C programmer with some spare time, take a look at the mod_virgule project page and help us with one of the tasks on the ToDo list!