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Just a quick note… in order to get nice things like sync-to-vblank, fsaa and anisotropic-texture filtering for Xgl/compiz have a little script like this…

#!/bin/sh

export __GL_FSAA_MODE=4
export __GL_LOG_MAX_ANISO=3
export __GL_SYNC_TO_VBLANK=1
sudo Xgl :1 -fullscreen -ac -accel glx:pbuffer -accel xv:fbo &

… to start Xgl. If you have Xgl setup to be started via gdm you’ll need to place the exports for the env-vars in a different file of course.

NOTE: This only applies to nvidia-cards running on the closed-source driver!

Furhtermore you should have a beefy card (something with a 256-bit wide memory-bus and much RAM), because this can get really stressing for the card, if you drive the values for fsaa and filtering up high. The meaning of the number-values for each env-var is described in the documentation shipping with the driver. It gets usually installed somewhere like /usr/share/doc/nvidia-glx/README.txt. Exact path and capitalization may vary from distro to distro. If your card is to weak for running fsaa and/or texture-filtering at least give the sync-to-vblank a try. Trearing, during cube-rotation, will be a thing of the past. The nvidia-driver has more settings you can tweak, but unfortunately not all of those are controlable via env-vars.

I just got an AMD64 Dapper Drake .deb for cairo-clock 0.3.1 from Andrew Sawyer. Thanks Andrew! You can grab it here.

It’s true. It exists. It has a strange genesis. About three weeks ago, when I initially started with the skydome-extension to the cube-plugin for compiz, I had the skydome animated right from the start. But I had the feeling it was to heavy on the eyes and would annoy people with “to much polygons in your face”. Therefore I didn’t include it in the first patch I sent to David Reveman. But this one reply by bobmitch from the ubuntu-forums made me dust of the old code. After foolishly underestimating the issues of ABIs, I beat the patch into a little better shape and sent it to the ubuntu-forums (David also received this one). DeeZiD made a tarball of a new set of .debs for Dapper-users within an hour or so and people could try out the visual “crack”. There are currently two small cosmetic issues pending, which I will fix and offer in an updated patch to David as well.

Some remarks about using it to clarify things. Skydome is not a seperate plugin for compiz, but an addition to the normal cube-plugin for compiz. Thus you don’t need to load a “libskydome.so” explicitly, the normal “libcube.so” will do. In contrast to the very first version I did (I only blogged about it, but never made it publicly available), the current version only a accepts PNG-images as textures. You should be able to load images with arbitrary dimensions. This means that there is no need to scale the image to have power-of-2 width and height (e.g. 1024×1024 will work, but 1000×932 should too). Although some people reported to have problems with non-power-of-2 textures. The reason for this I currently don’t know. At the moment the best guess is that some cards may have a limit of 1024×1024 to be the maximum texture-size supported. Modern cards like e.g. a GeForce 5×00/6×00/7×00 for sure have a maximum texture-size limit of 4096×4096. Here’s a little tip for you… try this in a shell:

  $ glxinfo -l | grep GL_MAX_TEXTURE_SIZE  

Here I would like to offer you a screencapture of the animated skydome in action, but gvidcap just isn’t made for grabbing fast moving stuff under Xgl. It drops too many frames. I tried it and the resulting video is acid to the eyes. The least I can present you is a screenshot of the new option available via the gconf-editor.

@DeeZiD: Das ist ja mal albern… Du wohnst hier ja fast direkt um die Ecke *g*

Ok, I’ve checked out compiz 0.0.5 and adjusted my skydome-patch to integrate with the newest version of the cube-plugin. David Reveman also did some fine polishing here and there, e.g. he added lighting for the cube (so I can remove that from my own source) and tuned the window for the switcher. My skydome-patch will allow you to set any power-of-2 image (e.g. 1024×1024) to be used as texture for the background (that empty void of space behind the cube, only visible when you rotate the cube). Filetypes like .png, .jpg, .tga and .bmp can be used. You can set the image on the fly via gconf-editor. If you enter an invalid filename a fallback color-gradient will be used. No more black backgrounds. Have a look at the screenshots below.

the fallback color-gradient (click for high-res)	background-image and gconf-editor (click for high-res)
the new switcher in compiz 0.0.5 (click for high-res)

Let’s keep fingers crossed David accepts my patch