Yes, another question about font size

[zepto]

I've read about 4-5 of the recent threads about screen resolutions, font configuration, using or not using XFS etc, but I'm hoping someone can explain something for me.

What does DPI (monitor/screen not printer) mean, or more to the point what does it affect?

I followed a poster's advice about setting DPI to 96 (some sort of windows 'standard' ) and confirmed that X was running at 96x96 using "xdpyinfo | more", then I removed this statement to have X calculate the DPI, with 147x145 the result. (In both cases the 'physical' screen size was set in xorg.conf)

I though that in the second case (147x145) my fonts would look larger than in the first(96x96) ... noticeably so, but there is no visible difference. Can anyone fill in the missing knowledge?

Thanks
fractoon

PS. Also, does anyone know how I can go about 'tuning' xorg.conf so that it doesn't 'test/enable' all the vesa default modes!? I've got 4 working modes and that is more than enough!

[catkfr]

dpi is dots per inch as for printers. Your screen also has a certain dpi which is the number of pixels per inch. This depends on your screen resolution and physical size of the screen.

Now going from font size (ie, the one you set when you want a size 10 for example) to actual rendered pixels, you obviously need a dpi setting (again the analogy with printing works great to understand this as font size corresponds to the size of the font once it's printed independantly of the printer's dpi). This is what makes the dpi setting central to font rendering.

Now when printing, you use higher dpi to get better looking fonts. On computer displays, most of the time, you use higher physical dpi (ie resolution) to display more info on a screen and not get smoother looking fonts. In order to determine that balance between amount of information and font aspect. you need to specify both resolution and dpi.

Unfortunately, not all programs get the dpi info from the same place. Xorg provides one, xfs also provides one, gnome can over-ride both with its own setting, firefox uses a custom one... For Kde, I'm not sure, but it probably can also. Thus, everything can work fine (uniform dpi setting on your desktop) in gnome for instance and look horribly wrong if you switch DE or WM.

It would probably help if their was a respected standard to set dpi independantly of Application-DE-WM but until then, fonts will always be a mess...

[pactoo]

How do you set DPI to some random value at all ? Just had a look at my xorg.conf and there was nothing referring to dpi at all (besides the 75/100dpi fonts, of course)