Re: Drawing antialiased shapes with alpha transparency

[Samuel Abels <newsgroups debain org>]

On Wed, 2005-01-05 at 11:40 -0300, Daniel Serpell wrote:
> You could try cairo: www.cairographics.org

Now I am probably going completely off topic, but I can't think of a
better place right now...

It seems that libart does not support rendering into RGBA buffers, but
only renders into RGB buffers using a given alpha value, which is not an
option if I want to cache an item in a buffer and then copy it to the
final surface.

Unfortunately libcairo is poorly documented. The examples look fairly
simple, but are also incomplete (where is the pixmap created, what is
cr, etc.); most of the documentation links on the cairo homepage are
broken either.
Do you know whether this supports rendering into an RGBA buffer, thus
preserving the alpha? I haven't found any information on this.
I like the general idea of cairo and though I would probably have to
rewrite some parts of the canvas I would like to use it if it supports
this.

Also, I don't know which of

  cairo_t*         cr;
  cairo_surface_t* surface;

is the buffer. And is it a standard RGBA buffer that can be drawn using
Gdk::Pixbuf::create_from_data()?

Thanks,
-Samuel
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