bug#36315: 27.0.50; SVG transparency handling is inaccurate

[Alan Third]

On Tue, Jun 25, 2019 at 07:54:52PM +0300, Eli Zaretskii wrote:
> > 3. Image transformations can be applied when rendering to the cairo
> >    surface, not after generating bitmaps.  So we can take advantage of
> >    outline format and get better results of scaling.  This is not in
> >    the patch.  Probably it should be done by a separate commit after
> >    general image transformation code has been stabilized.
> 
> Maybe it's just me, but I'm uneasy to bypass librsvg and call Cairo
> directly for manipulating SVG images.  Why doesn't librsvg provide a
> way to do this via its own APIs?
> 
> Does anyone else think it's unusual to make such direct calls to what
> is essentially a lower-level library?

Librsvg doesn’t provide any way to modify the images. It loads them
into either ‘GIO’ format (whatever that is), Cairo, or a pixel buffer.
There are functions for use with a GDKPixBuf that allow scaling, but
they’re now deprecated in favour of using Cairo.
-- 
Alan Third