I updated the Free Software Foundation address using the following script.
for i in $(git grep Temple | cut -d: -f1 )
do
sed -e 's/59 Temple Place[, -]* Suite 330, Boston, MA *02111-1307[, ]* USA/51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA/' -i "$i"
done
Fixes http://bugs.freedesktop.org/show_bug.cgi?id=21356
The device is a generic method for accessing the underlying interface
with the native graphics subsystem, typically the X connection or
perhaps the GL context. By exposing a cairo_device_t on a surface and
its various methods we enable finer control over interoperability with
external interactions of the device by applications. The use case in
mind is, for example, a multi-threaded gstreamer which needs to serialise
its own direct access to the device along with Cairo's across many
threads.
Secondly, the cairo_device_t is a unifying API for the mismash of
backend specific methods for controlling creation of surfaces with
explicit devices and a convenient hook for debugging and introspection.
The principal components of the API are the memory management of:
cairo_device_reference(),
cairo_device_finish() and
cairo_device_destroy();
along with a pair of routines for serialising interaction:
cairo_device_acquire() and
cairo_device_release()
and a method to flush any outstanding accesses:
cairo_device_flush().
The device for a particular surface may be retrieved using:
cairo_surface_get_device().
The device returned is owned by the surface.
Gah, that was a horrible mistake. It was a flawed hack to create Pixmaps
of the correct depth when cloning patterns for blitting to the xlib
backend. However, it had the nasty side-effect of discarding alpha when
targeting Window surfaces. The correct solution is to simply correct the
Pixmap of the desired depth and render a matching pattern onto the
surface - i.e. a reversal the current acquire -> clone. See the
forthcoming revised xcb backend on how I should have done it originally.
Handling clip as part of the surface state, as opposed to being part of
the operation state, is cumbersome and a hindrance to providing true proxy
surface support. For example, the clip must be copied from the surface
onto the fallback image, but this was forgotten causing undue hassle in
each backend. Another example is the contortion the meta surface
endures to ensure the clip is correctly recorded. By contrast passing the
clip along with the operation is quite simple and enables us to write
generic handlers for providing surface wrappers. (And in the future, we
should be able to write more esoteric wrappers, e.g. automatic 2x FSAA,
trivially.)
In brief, instead of the surface automatically applying the clip before
calling the backend, the backend can call into a generic helper to apply
clipping. For raster surfaces, clip regions are handled automatically as
part of the composite interface. For vector surfaces, a clip helper is
introduced to replay and callback into an intersect_clip_path() function
as necessary.
Whilst this is not primarily a performance related change (the change
should just move the computation of the clip from the moment it is applied
by the user to the moment it is required by the backend), it is important
to track any potential regression:
ppc:
Speedups
========
image-rgba evolution-20090607-0 1026085.22 0.18% -> 672972.07 0.77%: 1.52x speedup
▌
image-rgba evolution-20090618-0 680579.98 0.12% -> 573237.66 0.16%: 1.19x speedup
▎
image-rgba swfdec-fill-rate-4xaa-0 460296.92 0.36% -> 407464.63 0.42%: 1.13x speedup
▏
image-rgba swfdec-fill-rate-2xaa-0 128431.95 0.47% -> 115051.86 0.42%: 1.12x speedup
▏
Slowdowns
=========
image-rgba firefox-periodic-table-0 56837.61 0.78% -> 66055.17 3.20%: 1.09x slowdown
▏
Damian Frank noted
[http://lists.cairographics.org/archives/cairo/2009-May/017095.html]
a performance problem with an older XServer with an
unaccelerated composite - similar problems will be seen with non-XRender
servers which will trigger extraneous fallbacks. The problem he found was
that painting an ARGB32 image onto an RGB24 destination window (using
SOURCE) was going via the RENDER protocol and not core. He was able to
demonstrate that this could be worked around by declaring the pixel data as
an RGB24 image. The issue is that the image is uploaded into a temporary
pixmap of matching depth (i.e. 32 bit for ARGB32 and 24 bit for RGB23
data), however the core protocol can only blit between Drawables of
matching depth - so without the work-around the Drawables are mismatched
and we either need to use RENDER or fallback.
This patch adds a content mask to _cairo_surface_clone_similar() to
provide the extra bit of information to the backends for when it is
possible for them to drop channels from the clone. This is used by the
xlib backend to only create a 24 bit source when blitting to a Window.
Add a variation of test-fallback-surface that forces the use of a 16-bit
pixman format code instead of the standard 32-bit types. This creates an
image surface akin to the fallbacks used with low bit-depth xservers.
