Scale plugin causes windows to change transparency over time

[Bogdan Butnaru]

Binary package hint: compiz

Hello! I'm running up-to-date Jaunty on a machine with a GeForce 9600 GT video card. I'm currently using nvidia-glx-180 version 180.44-0ubuntu1, however the problem described below has been occurring for a while.

The scale plugin behaves strangely when transparency is involved. When I activate it, first everything is displayed correctly. Then the parts that are transparent (either because of windows' alpha channels or because of the scale plugin's opacity setting) become less so, in steps about a second apart. It looks a bit of it the transparent parts are redrawn without erasing their old images (thus the transparency is effectively reduced each step).

There are some delays between the effect of this on different windows, but less than the “step” delay. I'll attach below two screenshots showing the difference.

In addition to this, other operations, e.g. moving the mouse to focus different windows while in the scaled mode, cause a kind of “flickering” of the windows, as if they switch between different transparencies and can't decide. In all cases, if I leave the scale mode active for a few seconds without any activity all windows will become opaque.

[Bogdan Butnaru (bogdanb)]

The two screenshots above show the difference between two steps of “opacification”, as described above. I just held the button that activates scale, then pressed print screen a few times.

As you can see, the windows in the second are visibly more opaque than in the first. Also, it's noticeable that the bottom windows are slightly more opaque than the top ones. I haven't included the final state, it's exactly the same but with every window completely opaque.

By the way, the “redraws” between the steps are easily visible (like a “swipe” that takes about a tenth of a second; however, all the animations are smooth.), and, strangely enough, come from the physical bottom of the screen. (Since my monitor is pivoted to the right, this means left-to-right relative to the images. In case you're wondering, this bug manifests itself without rotation.)

[Bogdan Butnaru (bogdanb)]

I've just noticed another strange behavior:

If there is exactly one window on the screen that is full-screen (not maximized), then this bug doesn't affect it, it's shown correctly.

If there are two, it seems to affect them both.

If there are three or four full-screen windows, then exactly one of them is transparent at the final “steady-state”, though it has a bit of flickering on the way.

I've tried with five and six, and all were affected. With eleven, only two were left transparent. Weird.

[Bogdan Butnaru (bogdanb)]

This seems to have gone away at some point.

[Bogdan Butnaru (bogdanb)]

Nope, sorry. It doesn’t happen on my work computer, but it still happens on my home machine. They both have nVidia cards, running the same drivers AFAIK.

[jhfhlkjlj (fdsuufijjejejejej-deactivatedaccount)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to look at all reported bugs in a timely manner. There have been many changes in Ubuntu since that time you reported the bug and your problem may have been fixed with some of the updates. Compiz, in particular, is in heavy development and this bug may have been fixed in the development version of Ubuntu (12.04) if not on your current version. If you are able, it would be of great help if you could confirm if the bug still exists by testing a livecd (available at ubuntu.com). When you test it and it is still an issue, kindly upload the updated logs by running apport-collect <bug #> and any other logs that are relevant for this particular issue. If you are unable to test the development version, please let us know if you are able to reproduce this issue on Ubuntu 11.10.

Thank you for your help and patience.

[Launchpad Janitor (janitor)]

[Expired for Compiz Core because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for compiz (Ubuntu) because there has been no activity for 60 days.]