[cairo] Re: "retained" surface for cairo

Carl Worth cworth at east.isi.edu
Tue Jul 20 14:00:10 PDT 2004

On Tue, 20 Jul 2004 21:10:29 +0200 (CEST), =?iso-8859-1?q?Jost=20Boekemeier?= wrote:
> I must confess I haven't looked at the code close
> enough.  I have only looked at the vtable which has a
> _cairo_xlib_surface_set_matrix for the xlib backend.
> Isn't that the transformation matrix that applies to
> all following I send to the server?

Not exactly.

This function is used when transforming an image used as a source
pattern for compositing. This function doesn't make sense for
destination surfaces.

There was a time when source patterns and destination surfaces were
conflated within cairo and used the same datatype, (cairo_surface_t).
This cause some confusion. Now, we have a much cleaner interface with a
separate cairo_pattern_t. With this, the function above will likely go

But even with this function still present, it has nothing to do with the
transformation applied to geometry within cairo.


More information about the cairo mailing list