206975 - Mozilla renders point-size specified fonts too small

Status: RESOLVED WORKSFORME

(Core :: CSS Parsing and Computation, defect)

Description

[Mitsu Hadeishi]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.2) Gecko/20030208 Netscape/7.02
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.2) Gecko/20030208 Netscape/7.02

In general, Mozilla renders fonts with specified point sizes (as opposed to
"small," "x-small", etc.) unreadably small.  This is a problem since, as we all
know, the vast majority of users now use IE, and IE renders fonts larger, so a
lot of sites now end up unreadable.  The URL specified here is just one of many
examples.


Reproducible: Always

Steps to Reproduce:
1.Go to an URL such as
http://www.philly.com/mld/inquirer/news/local/states/pennsylvania/counties/bucks_county/5933814.htm
2. Try to read the page using the default settings, 100% text zoom.
3.

Actual Results:  
The text is unreadable.

Expected Results:  
I propose that Mozilla should render all fonts larger, because that's the way IE
does it, and I don't think this could possibly hurt.  Many websites now only
test against IE.  Yes, I realize that IE does a lot of things in a quirky way,
but font size I don't think is a "quirk".

Comment 1

[Mitsu Hadeishi]

Additional note: a text zoom setting of 110% seems to approximate readability in
my cursory tests, without making larger font sized sites look too big.

The particular problem, of course, is with the smallest point size fonts --- IE
tends to do a reasonable job of always rendering these readably, and Mozilla
often renders them unreadably.  This is perhaps more to the point of this bug.

Comment 2

[Felix Miata]

Web sites should not be sizing display text in points, but many do it anyway.

The meaning of a point is dependent on DPI setting. If your system DPI setting
produces unacceptably small fonts on web pages in Mozilla, you can set Mozilla
to use a larger DPI setting via prefs. The UI to choose a particular DPI value
is clunky, but you can put the override setting into user.js in your profile
directory thus: 

     user_pref("browser.display.screen_resolution", 144);

144 is 150% of the Windows system default of 96, usually suitable for display
resolutions around 1280 or 1400 wide. 120 (125%) is typically appropriate for
1024 wide resolution.

Comment 3

[Felix Miata]

I failed to include http://members.ij.net/mrmazda/auth/PointsDemo.html in my
previous comment, which can help you decide upon a suitable Mozilla DPI.

What DPI are you using now?

Comment 4

[Mitsu Hadeishi]

This doesn't really address the core of the problem, which is not that it is
impossible to adjust Mozilla in some way to read the text, but that the average
user is never going to find out about that file.  More likely the average user
will try out Mozilla and see that some sites come up with unreadable text and
just conclude that Mozilla isn't for them, and give up. This is really a
usability issue: you shouldn't have to change any configuration whatsoever in
order to get readable pages.

There are really two issues here: one, Mozilla ought to be configured by default
to display the vast majority of websites with readable fonts, and two, even when
the font size is very small, the text should render readably (which it doesn't
now).  Very small text invariably comes out unreadable.  It is, I believe, a
design flaw: web browsers are not typesetting systems, and readability should
take precedence over making the font come out precisely the "correct" size.

Comment 5

[Hixie (not reading bugmail)]

By default we use the system default DPI or 96dpi, I believe. Unless you have
done something to your Mozilla or X configuration, it should be fine. However,
if you (or your distribution manufacturer) have set an incorrect DPI, all bets
are off. Go to Edit > Preferences > Appearance > Fonts > Display Resolution.
What value do you have set?

Comment 6

[Mitsu Hadeishi]

Okay, I checked and the DPI was set to "system setting".  I have no idea what
that setting is, but I am running Red Hat 9 with a Radeon 9000 Mobility driver
with all default settings.

Forcing it to 96dpi does solve the readability problem on some of the sites I
examined.  So, the question then becomes: does Mozilla default to "system
setting", and if so, is that a good idea?  It seems to me that it might be
better if Mozilla defaults to force it to 96dpi, since at least some system
default settings lead to unreadable text.

Comment 7

[Hixie (not reading bugmail)]

bz: how does one find the current system dpi, and, on linux, do we / should we
default to that, or 96dpi?

Comment 8

[Felix Miata]

try this to find system DPI: 

     xdpyinfo -display :0 | grep resolution

Comment 9

[Christopher Blizzard (:blizzard)]

Red Hat has forced using 96 dpi for text measurement, and if you're using an xft
build, that _should_ be what ends up being used.  The URL that you mention looks
fine on this display, as a side note.

Comment 10

[Mitsu Hadeishi]

Using xdpyinfo I get a resolution of 75dpi.  So this must be what is being used
(again, Red Hat 9, fully updated, using Radeon 9000).

Comment 11

[Christopher Blizzard (:blizzard)]

Both Xft and gtk2 have a hard coded (ok, not hard coded, more like a pref) value
of 96.  Are you using either of those?

Comment 12

[Felix Miata]

Class .body-content {font-size:9pt;line-height:13pt;} is applied to the main
content in the center. 16px is the Mozilla default. 9pt @ 75 DPI is 9px, @ 96
DPI 12px, @ 120 DPI 14.4px. I'm using 120 DPI on 19" CRT, and find the page most
comfortable at 112% or more zoom.

Comment 13

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

"System setting" shouldn't be the default, but prefs don't reflect what the real
default is, which is unfortunate.  Anybody want to figure out what it takes to
change the pref from the default to "System setting" because of the prefs
front-end brokenness?

Comment 14

[Felix Miata]

Reporter, xdpyinfo does not display the DPI setting that is used by xft apps.
Check /etc/X11/Xresources for a setting 'Xft.dpi:'. You'll find probably either
90 or 96 there. I don't know what is supposed to replace xdpyinfo for xft, but
you can take your xft Mozilla to http://www.gemal.dk/browserspy/resolution.html
and find out what resolution it is seeing. It won't likely be the same as what
xdpyinfo reports, which is probably computed from the display size setting in
/etc/X11/XF86Config if there is one in there. Changing in Mozilla's about:config
browser.display.screen_resolution to 0 and adjusting the Xft.dpi setting should
get you an acceptable rendering of pt sized text on web pages. The problem you
may see as a result of adjusting Xft.dpi is that Mozilla chrome text will be
changed as well, plus you'll see changes in other xft apps.

Comment 15

[Gervase Markham [:gerv]]

This is an automated message, with ID "auto-resolve01".

This bug has had no comments for a long time. Statistically, we have found that
bug reports that have not been confirmed by a second user after three months are
highly unlikely to be the source of a fix to the code.

While your input is very important to us, our resources are limited and so we
are asking for your help in focussing our efforts. If you can still reproduce
this problem in the latest version of the product (see below for how to obtain a
copy) or, for feature requests, if it's not present in the latest version and
you still believe we should implement it, please visit the URL of this bug
(given at the top of this mail) and add a comment to that effect, giving more
reproduction information if you have it.

If it is not a problem any longer, you need take no action. If this bug is not
changed in any way in the next two weeks, it will be automatically resolved.
Thank you for your help in this matter.

The latest beta releases can be obtained from:
Firefox:     http://www.mozilla.org/projects/firefox/
Thunderbird: http://www.mozilla.org/products/thunderbird/releases/1.5beta1.html
Seamonkey:   http://www.mozilla.org/projects/seamonkey/

Comment 16

[Felix Miata]

In Knoppix 3.9 started up totally default except to specify screen=1152x864 on
the kernel line, kinfocenter reports 75 DPI and 1152x864 resolution, the same as
xdpyinfo, which also claims my 327mm X 245mm Sony 200GS CRT display is 390mm X
293mm. Starting Firefox 1.0.4 (with
user_pref("browser.display.screen_resolution", 0); assumed)
http://members.ij.net/mrmazda/auth/dpi-screen-window.html reports 76 DPI. On my
327mm X 245mm CRT @ 1152x864, actual DPI computes to about 90, which makes the
75 DPI used make the FF UI (and fonts on
http://members.ij.net/mrmazda/auth/PointsDemo.html) small and for me marginally
usable.

In Fedora Core 4, with nothing in /etx/X11/xorg.conf or/etc/X11/Xresources to
specify system DPI, kinfocenter reports 75 DPI and 1280x960 resolution for my
nominal 19" Dell P991 CRT, the same as xdpyinfo, which also claims my 365mm X
274mm Dell display is 433mm X 325mm. Starting Firefox 1.0.4 with
user_pref("browser.display.screen_resolution", 0);
http://members.ij.net/mrmazda/auth/dpi-screen-window.html reports 76 DPI. When X
is restarted with Xft.dpi: set in /etc/X11/Xresources to e.g. 96, then Firefox
shows that setting on that page, even though xdpyinfo still reports 75. On my
19" CRT, actual DPI computes to about 90, which makes the 75 DPI used without a
system DPI forced make FF UI (and fonts on
http://members.ij.net/mrmazda/auth/PointsDemo.html) small, and for me, too small.

In SuSE 10.0, with nothing in /etx/X11/xorg.conf or/etc/X11/Xresources to
specify system DPI, the KDE applet Xserver (as kinfocenter) reports 75 DPI and
1400x1050 resolution (same Sony as above), the same as xdpyinfo . Starting
Firefox 1.0.6 with user_pref("browser.display.screen_resolution", 0);
http://members.ij.net/mrmazda/auth/dpi-screen-window.html reports 76 DPI. When X
is restarted with Xft.dpi: set in /etc/X11/Xresources to e.g. 120, then Firefox
shows that setting on that page, even though xdpyinfo still reports 75. On my
nominal 17" CRT, actual DPI computes to about 109, which makes the 75 DPI used
without a system DPI forced make FF UI (and fonts on
http://members.ij.net/mrmazda/auth/PointsDemo.html)  tiny, and for me unusable.

In Mandriva 2006, with nothing in /etx/X11/xorg.conf or/etc/X11/Xresources to
specify system DPI, kinfocenter reports 123x126 DPI and 1792x1344 resolution
(same Dell CRT as above), the same as xdpyinfo. Starting Firefox 1.0.6 with
user_pref("browser.display.screen_resolution", 0);
http://members.ij.net/mrmazda/auth/dpi-screen-window.html reports 131 DPI. When
X is restarted with Xft.dpi: set in /etc/X11/Xresources  to e.g. 144, then
Firefox shows that setting on that page, even though xdpyinfo still reports
123x126. On my CRT, actual DPI computes to about 125, which makes the 123x126
apparently used make FF UI (and fonts on
http://members.ij.net/mrmazda/auth/PointsDemo.html) reasonable, though I prefer
a slightly larger size forced via an explicit Xft.dpi setting.

So, with xft builds at least, pt sized fonts may not be too small, but likely
will be, depending on whether Gecko is able to find a reasonable system DPI, at
least for users who don't know how to correctly configure system DPI.

Comment 17

[Boris Zbarsky [:bzbarsky]]

At this point we use the bigger of the system DPI and 96, so this bug should be fixed.