Re: [Plplot-devel] Release issues related to unicode fonts

[Arjen M. <arj...@wl...>]

Rafael Laboissiere wrote:
> 
> * Alan W. Irwin <ir...@be...> [2005-01-22 21:31]:
> 
> > + There are still problems with vertical alignment of characters.  See
> > example 6 line 100 where the characters move up or down depending on whether
> > they have an ascender, descender or neither.
> 
> No idea where this come from, but it is not really a showstopper.  If I find
> inspiration, I will take a look.
> 
> > + Rafael's recent changes did help the vertical alignment of full-scale
> > labels, but for smaller plots (e.g., the 4 subplots of example 1) the
> > vertical
> > alignment of labels is still off.
> 
> You have an eagle's eye!  The labels are verically misaligned by only one
> pixel.  Integer truncation is the root of the problem.  The characters have
> 12 pixels and the exact computation of vertical shift is around 5.93.
> However an integer shift operation (>> 6) yields 5 instead.
> 
> I do not know yet how I will cope with this.  The code in plfreetype.c is
> unfortunately heavily based on such integer truncation operations.
> 

Maybe we should use the "fuzzy" algorithms that were developed years ago
for this kind of things. I have got the code (Fortran) and it can be
easily 
converted to C. These algorithms come from the APL community and are
meant 
to help with such operations in a consistent way. No idea if it will
work,
though - that will require experimentation.

Regards,

Arjen