439194 - simple glyph matching across all installed fonts on OS/2

Status: VERIFIED FIXED

(Core :: Graphics, defect)

Description

[Steve Wendt]

The default font configuration does not display the Unicode dash used in Bugzilla, as can be seen in attachment 319725 [details].  Apparently, some kind of glyph matching for Unicode characters was implemented for Win32 and Linux, and it needs ported to OS/2.

Comment 1

[Peter Weilbacher]

Unicode and user-defined font matching is already implemented on OS/2, very similar to what was available on the 1.8 branch, so I'm changing the title to reflect what needs to be done. What we need to do is similar to what was implemented on Mac in bug 396137, bug 409342, bug 419757, and bug 416946.

Comment 2

[John Daggett (:jtd)]

You might want to wait a week or two on this, I think work for bug 437356 will probably help you, I'm going to fold the glyph matching code into gfxFont/gfxFontGroup, in which case you'll only need to implement the code that connects it to platform-specific font data.

Comment 3

[Peter Weilbacher]

John, thanks for the pointer. I will take a closer look at your work there. But from a quick look it seems to be a large overhaul, that I guess will only be put in 1.9.1.

But this OS/2 problem is something that I think I should even fix for 1.9.0.x, so I spent some time on it today. What I managed to do quickly is far from elegant but seems to improve things a lot.

Comment 4

[Peter Weilbacher]

Attachment: simple glyph matching across all good installed fonts

OK, this really seems to work. On pages with lots of missing glyphs it of course still slows down loading a tiny bit and then also uses a few MB more RAM than without the patch (depending on the number of fonts installed) but I guess for the benefits that is OK.

For testing, I uploaded a DLL with this change to
   http://temp.weilbacher.org/sm200807181122_thebes.zip
it goes with the latest SeaMonkey 1.9.0 nightly.

Comment 5

[Steve Wendt]

Thanks, Peter - looks good!

Comment 6

[Peter Weilbacher]

Thanks for testing, Steve!

One more effect that I noticed with this patch, is that one notices much more, if one has a broken font or ugly Unicode font installed, especially if its name is early in the alphabet... (Like Code2002 or Athena.ttf which report weird metrics, at least for some glyphs, and manage to frequently destroy the layout.)

But if that becomes a problem for more people then there could be other solutions. So I'm going to check this in soon.

Comment 7

[Dave Yeo]

It also looks good here, much fewer bad glyphs at wikipedia.org and no noticeable performance hit on my relatively slow machine
 

Comment 8

[Peter Weilbacher]

OK, I have checked this into CVS. I also pushed it into mozilla-central, I think that will make it easier to later make use of John's cross-platform font work.