Changing the "maximum_fps" parameter in "config.ini" doesn't work

[Lavatyper]

GREETINGS!!
I am in the process of learning to use Stellarium. I have a Macbook and am using Mac OS X 10.8.4. My "config.ini" file is located at:

~/Library/Application Support/Stellarium/config.ini

BACKGROUND: Stellarium processes the sky display on my computer at approximately 50 frames per second, with higher peaks. During this time, Stellarium uses about 20%-50% of my CPU, which makes my computer run very hot. I have tested this on 3 different Macs and I get the same thing. This behavior is present even when I freeze the time. After reading that Stellarium has a frame rate limiter in place, I decided to edit the "maximum_fps" parameter, in "config.ini," to reduce the number of frames that Stellarium processes, so that my computer would not get so hot.

PURPOSE: I want to I lower the "maximum_fps" parameter from its default.

TROUBLESHOOTING: I changed the value of "minimum_fps" to 1 and the value of "maximum_fps" to 15. I would expect, then, that when I re-launch Stellarium, my display would process at no more than 15 frames per second. Unfortunately, when I saved the "config.ini" file and re-launched Stellarium, my highest frame was just as high as it was before (about 50 frames per second), which means that lowering the value of "maximum_fps" didn't work. I was able to confirm, however, that changing the value of "minimum_fps" seems to work.

SUMMARY: Lowering the maximum frames per second parameter "maximum_fps" doesn't work.

[Alexander Wolf (alexwolf)]

Just for understanding: maximum fps sets maximal value for FPS for sky frames. FPS on yours screenshot displays FPS for GUI.

[Lavatyper (lavatyper)]

Alex, I am confused. Your post suggests that there are two FPS parameters that I can change: one for the "sky frames" and one for the "GUI" - How would I limit the FPS for sky frames?

[Alexander Wolf (alexwolf)]

maximum_fps in the config.ini file limited FPS for sky.

[Alexander Wolf (alexwolf)]

Hmm... looks like we broke that feature.

[William Formyduval (wlformyd)]

Greetings! I believe I have fixed this issue. It appears that the maximum_fps item was not being honored, and this was causing too many scene updates.

Apologies, but this would be my first patch to stellarium--the first of many I hope. I've created a branch with the fix here:

https://code.launchpad.net/~wlformyd/stellarium/bug1210510

What should I do next to move this along? Can I go ahead a propose a merge, and if so who should be the reviewer?

[Alexander Wolf (alexwolf)]

Yes, you should propose this patch for merge. For current patch you can set Fabien Chéreau (~xalioth) or Guillaume Chereau (~guillaume-chereau), or both brothers as reviewers, because brothers Chereau wrote original code for scene updates.

Not for future: you can don't set reviewer - any developer from core team can take patch for review.

[Guillaume Chereau (guillaume-chereau)]

Hello William, thanks for the fix. I just had a look at your branch and it fixes the issue indeed. I merged it into the trunk.

For future improvement, I thought maybe there is a way to make the code simpler by using the same QTimer for both min and max FPS, instead of using QTimer::singleShot for maxFPS. Does it make sense to you?

[Alexander Wolf (alexwolf)]

A fix has been committed as revision 6676 of the trunk branch in Stellarium's Bazaar repository at Launchpad: http://bazaar.launchpad.net/~stellarium/stellarium/trunk/revision/6676