[cairo] Discussion: LCD Filtering API

[Brandon Wright]

On Thu, Jan 29, 2009 at 4:30 AM, Behdad Esfahbod <behdad at behdad.org> wrote:
> Sure.  Very good point.  The main reason I have to start rasterizing fonts in
> cairo itself is to get truly linearly scalable fonts.  See:
>
>  http://lists.cairographics.org/archives/cairo/2008-May/014149.html
>
> Currently, the win32 and quartz backends do the show_glyphs() operation
> natively so they don't even rasterize glyphs and pass them to cairo.  I
> imagine in the future we will be going through the cairo rasterizer and
> filtering if and only if any of the font options is set to anything other than
> DEFAULT.  Something like that.  That will keep both fronts happy.  Or I hope
> so :).

Linearly scaling fonts need to be unhinted to work (many users would
complain of "fuzzy" fonts if were the default), and the only situation
I can think of where they're useful is for scaling animations (feel
free to provide more examples). I think most cairo users would be
smart enough to follow your third column and generate the outline at
the final size of the text when it is static, and scale the result,
which provides smooth scaling and a well-hinted end image.

Are you planning to have linearly scaling fonts by default? What will
cairo users have to do to get results that are native to the platform?