GNOME Bugzilla – Bug 124175
Thai combining characters shifted in framebuffer
Last modified: 2004-12-22 21:47:04 UTC
GTK+ on framebuffer mode renders Thai combining characters shifted to the left of its base consonants. I have verified that pango-thai-ft2 was loaded to do the job, both by checking /proc/<pid>/maps and by printing some debug messages. It's weird that the same logic works on X, but fails on FB backend. So, I'm not sure if this is the bug in Pango or GTK+. But the attached patch just makes it work. (P.S. This requires Bug #121488 to be fixed first. I have applied Owen's patch before checking this bug.)
Created attachment 20582 [details] [review] Possible Pango patch
I've applied this patch in CVS, and it looks reasonable to me. But I don't undderstand why it would make a difference to the displayed output. So there might be a bug somewhere else we should track down. Can you provide an example of the text and font that was giving problems? Mon Jan 26 10:30:06 2004 Owen Taylor <otaylor@redhat.com> * pango/modules/thai/thai-c: Fix up glyph addition code so that it works properly with the typical TrueType fonts that have 0 width for combining characters. (#124175, Theppitak Karoonboonyanan)
Created attachment 23829 [details] Example Thai TTF
Created attachment 23830 [details] A Thai test message
Created attachment 23831 [details] A shorter test message
Please find test font and texts above. Note, however, that I have already lost my previous configuration for testing framebuffer. So, I haven't verified yet if the problem remains in recent CVS head.
Hmm, with that font and that text I get identical results for pangoft2topgm with and without the patch. So I don't know what was going on. Looks like I accidentally committed a revert of the patch earlier, so fixed that up now: Mon Jan 26 10:30:06 2004 Owen Taylor <otaylor@redhat.com> * pango/modules/thai/thai-shaper.c: Reapply the patch from #124175 that somehow got reverted.