[cairo] newbie question - fill pre-existing png polygons?

[Alexander Shulgin]

On Mon, Aug 9, 2010 at 20:30, Daniel Goldman <dagoldman at yahoo.com> wrote:
> Hi,
>
> I use GD to make maps with labels and color fills. To add pdf output, I've
> started
>
> using cairo / pango. The pdf is looking great so far.
>
> To make it easier to keep label placement consistent between png and pdf,
> I'm working on switching the png maps to also use cairo.
>
> With GD, I would import a png outline of the map that has been generated before,
>
> and use gdImageFill () to fill a polygon. With cairo, it's easy to get the
> outline map
>
> in with cairo_image_surface_create_from_png (). But I'm getting the feeling that
>
> is not a helpful step under cairo, that cairo does not fill existing png
> polygons.

Are you asking for a 'Flood Fill' tool in cairo?  If so, I think
there's none and it's not going to happen.

May be you can turn to use cairoscript backend to record your polygons
into a file.  Then load them and fill the path using cairo_fill().

--
Alex