Avoid calling libtool to link every single test case, by building just one
binary from all the sources.
This binary is then given the task of choosing tests to run (based on user
selection and individual test requirement), forking each test into its own
process and accumulating the results.
If the filter mode is anything other than DEFAILT, FAST or NEAREST set the
Interpolate flag in the image dictionary so that a smoothing filter is
applied when rasterising the vector file.
As we have no control over the implementation of the Interpolate filter
(the PS/PDF specifications leave it undefined) we need to capture the
output of poppler/GS and update our reference images. (For a couple of
tests, the filtering is irrelevant so for those we set the filter to
NEAREST.)
Note that GhostScript's Interpolate filter does not work on rotated images
(and a variety of other transformations) so several of the PS reference
images have use nearest-neighbour sampling instead of a bilinear filter.
In order to run under memfault, the framework is first extended to handle
running concurrent tests - i.e. multi-threading. (Not that this is a
requirement for memfault, instead it shares a common goal of storing
per-test data). To that end all the global data is moved into a per-test
context and the targets are adjusted to avoid overlap on shared, global
resources (such as output files and frame buffers). In order to preserve
the simplicity of the standard draw routines, the context is not passed
explicitly as a parameter to the routines, but is instead attached to the
cairo_t via the user_data.
For the masochist, to enable the tests to be run across multiple threads
simply set the environment variable CAIRO_TEST_NUM_THREADS to the desired
number.
In the long run, we can hope the need for memfault (runtime testing of
error paths) will be mitigated by static analysis. A promising candidate
for this task would appear to be http://hal.cs.berkeley.edu/cil/.
The 5 additional bugs that will be shipped with 1.4 are
ft-text-vertical-layout-type1
radial-gradient
surface-pattern
surface-pattern-scale-down
surface-pattern-scale-up
Most of these are non-issues, (unbundled font for
ft-text-vertical-layout-type1), or very minor issues (radial-gradient
and surface-pattern). The only things in here that look like a real
bug are the surface-pattern-scale-down and surface-pattern-scale-up
tests where the xlib backend results have some non-1.0 alpha that is
very unexpected.
with surface patterns. One test scaled the pattern up, another scales
down. We observe that both PS and PDF are broken when scaling down.
This is the reason that PDF is failing in the fallback-resolution test
too.
