Comment 23 for bug 589485

(In reply to comment #22)

> While there can obviously be rasterisation differences (the higher
> resolution display will look better), this is not merely a theoretical
> issue.

I guess I could have done a better job of making my point. Basically what I meant was because of rasterization differences, there is less practical consistency than ideal, and thus practice in fact falls short of theoretical. Still, the results aren't all that different from ideal, and using actual DPI in practice is much better than an inane assumption of 96 without regard to actual.

> Firefox has the ability to render based on a fixed DPI (which indeed
> solves the problem with broken websites not rendering correctly).

By default, FF uses the greater of actual DPI as reported to it by the environment, or 96. As a practical matter this infrequently makes much difference on web sites, as sites styling in such DPI-dependent physical measurements as mm, in or pt aren't particularly common, and FF's defaults are set in px, which is not affected by DPI.

> I'm not sure why we need the feature in X.org as well.

IMO Xorg has no business making that inane assumption. Nevertheless, there is some rationale to do it that results in some distros doing it, e.g. http://wiki.mandriva.com/en/2009.0_Notes#Font_size_and_physical_DPI