[cairo] text on win32

[Vladimir Vukicevic]

----- "Behdad Esfahbod" <behdad at behdad.org> wrote:
> On Mon, 2007-02-12 at 19:43 -0500, Daniel Amelang wrote:
> > 
> > So some quick fix needs to be applied so that 1.4 doesn't ship with
> > broken win32 font code. Does Jordan's patch solve the problem well
> > enough for now? Should we just define WIN32_FONT_LOGICAL_SCALE to 1
> > like in the mozilla code? 
> 
> Owen already commented on why we use a larger LOGICAL_SCALE.  From what
> I understood, that is necessary for subpixel positioning of rotated text.

Yes, because IIRC, the idea is to render the glyph N times bigger than it needs to be, then scale it down to get correct subpixel behaviour.  However, the problem with LOGICAL_SCALE is that it's applying a very big hammer to a small (and infrequently hit, compared to the common case) problem.  I believe it should only be used to generate glyph images, and those images should then have a scale set in their surface device transform matrix.  (I don't think that functionality existed when the code was originally written.)

    - Vlad