437531 - raise non-CJK 12px monospace defaults to 13px on *nix to match Mac & Win

Status: NEW

(Core :: CSS Parsing and Computation, enhancement)

Description

[Felix Miata]

I spent a lot of time searching Bugzilla looking for the rationale for the 12px monospace default used for *nix without success. My guess is it is a holdover from pre-xft/fontconfig/pango days, when most installed *nix fonts were non-scalable, and odd pt sizes often did not exist. I surmise that in such cases a 13px default would often or usually fall between two even pt sizes and round up to a larger than desired pt size if 13px was specified.

Regardless how close my guess may be, it isn't like that any more. The best fonts used by modern web browsers on *nix are all scalable, often the exact same fonts used on the other platforms. With this change, Gecko users running the same DPI and screen sizes for multiple platforms would no longer see inexplicable differences in monospace sizing among the platforms.

On Mac & Win, 96 is the most common DPI. At 96, closest match to 10pt is 13px. That seems to be the indirect rationale for the existing Mac & Win 13px specification, with the direct rationale being that 13px/10pt is what IE does on Win. Since we floor *nix releases at 96 DPI, it now makes better sense to specify the same default there instead of only 12px/9pt. That would leave web pages viewed using unmolested Gecko profiles to look more alike cross-platform. It should also make life easier for for the many site stylists who refuse to adjust their development browser defaults to use *nix as their base development platform.

cf. bug 380915

Comment 1

[Felix Miata]

Attachment: testcase of commonly available monospace fonts

Comment 2

[Felix Miata]

Attachment: testcase on openSUSE 11.0rc2 using FF3, AA & byte code interpreter

Comment 3

[Felix Miata]

Attachment: testcase on Kubuntu 8.04 using FF3, AA & autohinter

Comment 4

[Felix Miata]

Attachment: patch

Comment 5

[Gérard Talbot]

Just curious: why the default font-size is not 16px for monospace font for western on all os-es ... just like it is for serif? 

Gérard