Re: [ft] mis-rendered o when a j is near

[Behdad Esfahbod]

On 01/28/2010 11:18 AM, Werner LEMBERG wrote:

>> There are several GTK programs I am using (since I'm XFCE user) and
>> some situations when words like "projects" occur, e.g. when surfing
>> with Thunar through my $HOME directory which actually includes a
>> directory called "projects" and a symlink to this called "Projekte".
>> There is also Geany which has a menu entry "Projects".  With
>> settings 96dpi and a 8pt sans serif font, e.g. DejaVu Sans, the o
>> isn't correctly rendered.
> 
> IMHO, this can't be a FreeType issue since this library always renders
> a single glyph per call, not a glyph string, and it seems that a
> single `o' is rendered just fine, right?
> 
> Behdad, how do you come to this impression?

Humm, good point.  This looks tricky at best.  There are three components here:

  - Pango: can't be a pango bug since Pango doesn't draw anything whatsoever,

  - FreeType: unless the font is substituting a new 'o' glyph in that context,
it's unlikely to be a FreeType issue,

  - cairo: hard to imagining it being a cairo issue either, since cairo
composites glyphs and each individual glyph is rendered (by FreeType)
separately, so I can't see why the bounding box of the glyph may be cropped in
a specific context.

To summarize, someone who can reproduce this needs to debug it.  I couldn't
reproduce.  That said, the rendering looks to me like it's with patented
bytecode-interpretter enabled.  Not sure how that may make a difference.

behdad

>     Werner