Re: [ft-devel] Peculiar Hinting / Rendering Behavior

[Alexei Podtelezhnikov]

> Here's another recipe to see the artifact even better (I'm using
> msmincho.ttc from Windows 7):
>
>   ftgrid -f 4420 19 msmincho.ttc
>
> (value 4420 is the glyph index of U+56DB in this font).  After
> pressing key `a', a vertical line on the left is missing in the
> outline.  Interestingly, this happens at 100% zooming only.

This is a typical dropout situation. The following minute patch
"fixes" it. I am actually surprised that this does not happen more
often. The left edge line happens to cover two adjacent pixels at less
than 50%, which is also surprising. Deep inside, this is probably a
stroker rounding issue.

diff --git a/src/ftgrid.c b/src/ftgrid.c
index 55489b6..b4ac1a4 100644
--- a/src/ftgrid.c
+++ b/src/ftgrid.c
@@ -538,7 +538,7 @@
     {
       FT_Stroker_New( handle->library, &st->stroker );

-      FT_Stroker_Set( st->stroker, 32, FT_STROKER_LINECAP_BUTT,
+      FT_Stroker_Set( st->stroker, 33, FT_STROKER_LINECAP_BUTT,
                       FT_STROKER_LINEJOIN_ROUND, 0x20000 );
     }