Red Hat Bugzilla – Bug 60327
XFree with Xinerama misscalculates DPI
Last modified: 2007-04-18 12:40:37 EDT
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User-Agent: Mozilla/5.0 Galeon/1.0.3 (X11; Linux i686; U;) Gecko/20020205
Description of problem:
XFree86 fails to calculate DPI correctly when using Xinerama
example: two monitors, each has 1600x1200 resolution and each of them is
e.g. xdpyinfo shows:
dimensions: 3200x1200 pixels (372x271 millimeters)
resolution: 245x131 dots per inch
IMHO that means when calculating the "dots per inch" it uses the total
resolution but only the size of the first monitor.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. config X to use xinerama with 2 monitors (horizontally)
2. start X
3. launch xdpyinfo to see it
Actual Results: DPI are set incorrect.
Many apps look really ugly, because the true type fonts are rendered much too
big, e.g. surfing on redhat.com with mozilla or galeon is really a pain..
Expected Results: It should calc it correctly, as it does when running with
only one monitor. Probably the best solution would be to use only 1 monitor when
calculating the DPI of the display.
a) using -dpi as X server option does not work very good, because somehow X
seems two change the value even if u specify it (but it is slightly better than
b) use DisplaySize to specify some dimension of the first monitor, so that the
wrong calculations lead to correct DPI settings - works, but is not very nice
This problem should be reported directly to XFree86.org upstream via
the email@example.com mailing list, and the firstname.lastname@example.org bug
report address. We provide Xinerama as a convenience, however we do
not officially provide support for it. When possible, when we can
track down an upstream bug fix for such an issue, they are generally
applied to our future erratum however.