The Microsoft C Compiler does not accept empty-initialized arrays:
cairo-boilerplate-win32-printing.c(373) : error C2059: syntax error : '}'
cairo-boilerplate-win32-printing.c(374) : warning C4034: sizeof returns 0
A deficiency of cairo-perf-trace is that it currently always uses similar
surfaces for new surface which are kindly cleared by Cairo. This does
not accurately reflect the captured trace and introduces large bandwidth
overheads that distort the profiles.
So we introduce a new boilerplate hook so that the targets can create a
surface without incurring additional overheads.
[Fixes the broken partial commit of bf1b08d066e.]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This function is supposed to describe the backend in use. The describe
function is optional - and therefore initialized as NULL everywhere.
Note:
It is well known that the xlib backend uses X. What is not known is what
version the server supports or what graphics card it is running on. That
is the information the describe vfunc is supposed to provide.
For the purposes of benchmarking it is useful to run cairo-perf against a
different library from the one it was compiled against. In order to do so,
we need to check that the runtime library contains the required entry
points for our targets - which we can check by using dlsym.
By moving the backend target definition out of the massive amlagamated
block in cairo-boilerplate.c and into each of the
cairo-boilerplate-backend.c, we make it much easier to add new targets as
the information need only be entered in a single file and not scattered
across three. However, updating the target interface means trawling across
all the files -- except given that I found it difficult maintaining the
single massive array I do not see this as an increase in the maintenance
burden.
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.
For this we extend the boilerplate get_image() routines to extract a
single page out of a paginated document and then proceed to manually
check each page of the fallback-resolution test.
(Well that's the theory, in practice SVG doesn't support multiple pages
and so we just generate a new surface for each resolution. But the
infrastructure is in place so that we can automate other tests,
e.g. test/multi-pages.)
Compare the current output against a previous run to determine if there
has been any change since last time, and only run through imagediff if
there has been. For the vector surfaces, we can check the vector output
first and potentially skip the rasterisation. On my machine this reduces
the time for a second run from 6 minutes to 2m30s. As most of the time,
most test output will remain unchanged, so this seems to be a big win. On
unix systems, hard linking is used to reduce the amount of storage space
required - others will see about a three-fold increase in the amount of
disk used. The directory continues to be a stress test for file selectors.
In order to reduce the changes between runs, the current time is no longer
written to the PNG files (justified by that it only exists as a debugging
aid) and the boilerplate tweaks the PS surface so that the creation date
is fixed. To fully realise the benefits here, we need to strip the
creation time from all the reference images...
The biggest problem with using the caches is that different runs of the
test suite can go through different code paths, introducing potential
Heisenbergs. If you suspect that caching is interfering with the test
results, use 'make -C test clean-caches check'.
As Behdad suggested, we can dramatically speed up the test suite by
short-circuiting the write to a png file, only to then immediately read it
back in. So for the raster based surfaces, we avoid the round-trip through
libpng by implementing a new boilerplate method to directly extract the image
buffer from the test result. A secondary speedup is achieved by caching the
most recent reference image.
Construct the test name to pass to the boilerplate creation routines such
that it uniquely identifies the test in terms of test, target, content and
pass (similar, offset, thread). This allows the vector targets to create
output different output files for each test, whereas before, later tests
would overwrite existing files making debugging more difficult.
Testing win32-printing requires setting the default printer to
a PostScript level 3 color printer. The PostScript output is
saved to a file and converted to png using ghostscript.
