Re: GdkPixbuf vs. Cairo, new image library needed?

["BJörn Lindqvist" <bjourne gmail com>]

On 10/8/07, Kalle Vahlman <kalle vahlman gmail com> wrote:
> 2007/10/8, BJörn Lindqvist <bjourne gmail com>:
> > It feels like Cairo doesn't fit in. For example, GDK uses GdkColor to
> > represent colors but Cairo has no equivalent.
>
> There is gdk_cairo_set_source_color() though, which bridges the gap.
>
> > Same thing with
> > GdkRectangle, GdkPoint and a whole host of other types that becomes
> > much less useful in a cairo-world.
>
> There's also gdk_cairo_rectangle() and _region(), and I'm sure the
> rest (what they ever may be) could have similar bridging API if deemed
> necessary. Like forming a path from an array of GdkPoints etc.

Yeah, but those functions aren't substitutes for "native" Cairo
types. For example, gdk_cairo_set_source_color() as no matching
gdk_cairo_get_source_color(). It is not so strange because Cairo
handles an infinite amount of colors in the range 0..1 and has alpha
channels, GdkColor only has 0..65535 and no alpha channel. There is a
similar mismatch between GdkRectangle and cairo_rectangle_t.

I think that integrating Cairo with GDK involves much more work than
just replacing GdkPixbuf even if that is good first step.

> > So how about replacing gdk-pixbuf with something cairo compatible that
> > is also modern? 16 bits per sample is common these days. Support for
> > digital camera RAW images would also be nice. Is a completely new
> > image library worth pursuing? Are there maybe better ways to solve the
> > problems Cairo and GdkPixbuf have?
>
> Even having an additional API for things like
> gdk_pixbuf_cairo_load_from_file() would be a step forward I guess. I'd
> personally like to see all the useful pixbuf API (file loading/saving,
> possibly others) migrated to allow cairo usage and then deprecate
> PixBufs over cairo image surfaces, but YMMV.

I think that is out of the question. The Cairo developers are happy
with Cairo being "only" a drawing API and letting other libraries
handle loading and saving.


-- 
mvh Björn