Darkradiant: fixing font problems and crashes on Linux

[rand0m]

Hi guys,

the recent version of darkradiant (1.7) is unable to display the grid numbers in the ortho view due to use of the deprecated "gdk::gl::font::use_pango_font" function. When switching between editor layouts, crashes can occur.

I rewrote the broken code with the use of the ftgl-library, freetype and fontconfig. If you are interested in the code, pm me. Unfortunately I don't have permission to upload diff-files.

The only problem with my "solution" is that fontconfig is only available on *nix systems. I use it to get the path to the appropriate font files. A similar mechanism for Windows is missing since I'm not familiar with the internals of the windows font support.

[OrbWeaver]

Feel free to send the patch to the maintainer email address in the debian/changelog, and I will have a look at it.

 

If there are complications with trying to load a system font on different platforms, would it make more sense to include our own font file and load that one specifically using FTGL? It would be a known quantity in that case, and ought to work the same way on all systems.

[PranQster]

Is this only an issue with Ubuntu or Debian? I have no problems with grid numbers displaying in Mageia 2alpha 64-bit, or any release of Mageia or Mandriva since 2010.0 (when I started using DR).

pango1 libraries version 1.29.5-1mga2

pangomm2.4 libraries version 2.28.4-1mga2

gdk libraries version 2.25.0-1mga2

 

I do get an occasional rare crash when pressing a key (can be any key) command in DR. Sometimes when pressing 'S' to bring up the surface inspector... most frustrating when pressing 'Esc' to de-select an object or 'Back space' to delete an object.

Edited December 22, 2011 by PranQster

[rand0m]

Feel free to send the patch to the maintainer email address in the debian/changelog, and I will have a look at it.

 

If there are complications with trying to load a system font on different platforms, would it make more sense to include our own font file and load that one specifically using FTGL? It would be a known quantity in that case, and ought to work the same way on all systems.

 

I'll look out for that email address. Including the fonts with the sources would of course solve the issue. But that would be a decision for the maintainers. I'll send the diff file for review and you guys can decide.

 

PranQster:

The problem is that the aforementioned function uses a deprecated gdk-backend. The gdkmm version on my system is 2.4 respectively 3.0. My guess is that most updated systems will have troubles. Personally, I'm working on Xubuntu 11.10.

If you google "gdk_gl_font_use_pango_font" you can find discussions on the topic.

As far as the crashes go: after my code changes DR ran crashfree.

Edited December 22, 2011 by rand0m

[rohezal]

Maybe try to use it kvm and Ubuntu 10.4 or 90.10 or something?

[greebo]

Thanks for bringing that to our attention and thanks for working on a patch, too. I'll see what I can do.

 

As for the Windows platform, we do have fontconfig available in the Win32/Win64 builds.

 

edit: I don't seem to see the use_pango_font being deprecated in the docs? There isn't a newer version of gtgklext(mm) than 1.2.0 available, is there?

[greebo]

I checked out your fix and got it working by building the most recent FTGL library from source (FTGL 2.1.3 RC5). It seems to work but I noticed a few things:

 

- The grid font is rendered (even with anti-aliasing), but it's very small and hard to read. I guess that can be fixed.

- The numbering of the clip points is missing, I haven't investigated why this is yet.

- The first startup of DarkRadiant takes ages. I first thought it was caught in an infinite loop, but it was just fontconfig building its font cache, obviously.

- Fontconfig is writing its cache to C:\Temp (which didn't exist on my system, so it cluttered my root folder with that one). That one can possibly be fixed by hacking the Fontconfig library we're using for DarkRadiant, something that would need to be re-hacked everytime we upgrade the fontconfig package. It would be nicer if Fontconfig wrote to the user folder or something.

 

The only major problem I have with that situation is the long UI disruption on the first startup. Maybe this is only on first startup and maybe only in debug builds, I'll have to check that out.

[greebo]

I worked around the application hang by packaging two fonts with DarkRadiant, as OrbWeaver suggested. I already changed the code in the Windows implementation to pick up these two fonts instead of looking through patterns and replacements by means of fontconfig. The make/install scripts have not been adjusted yet, maybe OrbWeaver has a few minutes to spare on that to get them installed? Once that's done, the Linux implementation of GLFont can use these TTF fonts too.

 

There is still the issue of the disappearing clip point numbers to be fixed though. (edit: found it, this is fixed now.)

[OrbWeaver]

The Linux changes are committed now as well.

[rand0m]

The use_pango_font-function itself is not marked as deprecated. But the backend it uses is. The documentation is a little behind on that. The discussion about that took place in a mailing list. Unfortunately the link to the original discussion doesn't seem to work atm. Here is link to a related mailing list conversation concerning GtkRadiant:

http://icculus.org/pipermail/gtkradiant/2010-November/011336.html

 

Since I never had a correctly working version of darkradiant, I wasn't aware that there were clip point numbers. But it seems like you guys got that worked out.

 

 

Glad I could help at least a little.