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
▏
Test case for:
Bug 22441 -- Unexpected shift with push_group and pop_group
https://bugs.freedesktop.org/show_bug.cgi?id=22441
This is a test that demonstrates the error in the pdf backend when using
groups on surfaces with non-integer sizes. In order to create such a
surface, we need to update the boilerplate to use doubles instead of
integers when specifying the surface size.
Quite an expensive test that converts an image into a distorted array of
glyphs, using a perspective transformation taking the intensity of the
pixel as depth. This generates a pretty picture and many overlapping
glyphs.
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.
Eliminate the need for a runtime test on the sizeof the private structures
by performing the check at compile time. This was provoked by Ginn Chenn
noting that the test was including a private header.
Jeff Muizelaar found a regression in commit 005436 and submitted this
little test to exercise it. The essence of the bug appears to be wrt to
the product of the CTM and device transform matrices.
