[cairo] a couple requests from Inkscape

[Carl Worth]

On Tue, 2008-09-02 at 12:43 -0300, bulia byak wrote:
> we at Inkscape have some feature requests for cairo - I had talked to
> Carl and would like to discuss them here as well.

Hi Bulia,

Thanks for bringing this to an open discussion on the list!

> - inversion operator, i.e. rendering an object by inverting what is
> below it in z-order. With the existing operators it's impossible,
> although it is no less (and probably more) useful than e.g. xor. In
> SVG, inversion can be done by a filter; in other vector backends, it
> will need rasterization (but you use rasterization anyway for other
> operators).

Benjamin Otte is currently working on significantly extending the set of
cairo operators, (adding the blend modes from PDF, Flash, SVG, etc.).
Benjamin, is there an effective invert in any of those? Or would it be
reasonable to add?

> - a new moveto method which does not start a new subpath, so we could
> skip some parts of the path during rendering (e.g. those that don't
> fit the render area, for speed) and still use the closepath correctly,
> i.e. close the real subpath regardless of these interruptions.

This one Chris proposed as cairo_set_current_point I think---and I think
he had it all coded up too. Maybe it's just waiting for 1.8 to go out
the door and then it will land.

Keep those inkscape requests coming! And if you want, you can list any
pie-in-the-sky ideas here, for example:

	http://cairographics.org/missing [*]

Have fun!

-Carl

[*] But "missing" is a rather strange name for this---maybe we should
rename that to "wishlist" or so?