Re: Unicode rendering problems

[Patrick McCarty]

On 2010-05-05, Didi Kanjahn wrote:
> 
> Khmer Unicode does not get rendered correctly #1.
> 
> A major bug in the rendering of Khmer Unicode was fixed in version
> 2.13.3. 
> With 2.13.3 the first glyph-sequence of each line (also line 6) was
> now rendered as can be seen in line 1, 3 and 4 of 'test Khmer
> Unicode 2-13-3.pdf'. Before version 2.13.3 all Khmer fonts rendered
> those lines as in line 2 and 6.
> 
> However, in version 2.13.19 there is a new problem with rendering
> Khmer Unicode (it started at an earlier version, but I don't know
> when exactly), leading to many dotted circles. From that ensuing
> result, it can be assumed that the instructions of the Unicode
> rendering engine (not part of the font) are being carried out (in
> particular the shifting of certain glyphs/symbols within a cluster),
> but the instructions of the OpenType tables that are part of the
> font are not being carried out. Please see 'test Khmer Unicode
> 2-13-19.pdf'.
> 
> Please disregard the last dotted circle in each line for this
> particular bug report. See below under 'Khmer Unicode does not get
> rendered correctly #4' for details.
> 
> All fonts and other files can be made available.
> All of the above was done under Windows XP.
> 
> The font 'Khmer OS' can be downloaded at:
> http://sourceforge.net/projects/khmer/files/Fonts%20-%20KhmerOS/KhmerOS%20Fonts%205.0-%20LGPL%20Licence/KhmerOS_.ttf/download
> 
> Unfortunately it was not possible to attach any files, the other
> fonts and sample pdf files.
> 
> The lilypond code to illustrate the problem can be found in my post
> on 'Font selection problem'. I don't know yet whether the Unicode
> characters came across intact.

Yes, the Unicode characters were not mangled.

I suspect that the bug was introduced after we upgraded Pango to
version 1.26.0.  There are some major problems rendering Syriac glyphs
as well, as compared to 1.24.* versions.

If you would like to send me all of these test PDFs you've created, I
would be happy to look at them.

Thanks,
Patrick