Bug 60327

Summary:	XFree with Xinerama misscalculates DPI
Product:	[Retired] Red Hat Linux	Reporter:	Heinz Deinhart <heinz>
Component:	XFree86	Assignee:	Mike A. Harris <mharris>
Status:	CLOSED WONTFIX	QA Contact:	David Lawrence <dkl>
Severity:	low	Docs Contact:
Priority:	medium
Version:	7.2
Target Milestone:	---
Target Release:	---
Hardware:	athlon
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
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Clone Of:		Environment:
Last Closed:	2002-02-26 06:48:18 UTC	Type:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Embargoed:

Description Heinz Deinhart 2002-02-25 16:35:40 UTC

From Bugzilla Helper:
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
372x271mm big.
e.g. xdpyinfo shows:
[..]
screen #0:
 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):


How reproducible:
Always

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.

Additional info:

Workarounds:

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
before)

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

Comment 1 Mike A. Harris 2002-05-21 05:42:36 UTC

This problem should be reported directly to XFree86.org upstream via
the xpert mailing list, and the xfree86 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.