If the gradient has constant alpha, then we can express it as a flattened
linear gradient. Otherwise, should the opacity vary across the gradient we
need to fallback.
This reverts commit 85ed37da33.
Adrian Johnson pointed out that iff the gradient has constant alpha then
it can be flattened. Reverting this commit in order to restore the
capability to handle gradient flattening.
Quick summary of changes:
- Move list of cairo source files out of src/Makefile.am and into
src/Sources.mk,
- Generate files src/Config.mk and src/Config.mk.win32 that choose
the right set of source files and headers based on configured
backends and features. This drastically simplifies building
using other build systems. The src/Makefile.win32 file needs
to be updated to reflect these changes.
- Add README files to various directories,
- Add toplevel HACKING file.
Be explicit about handling cached FAIL images, instead of relying on the
sequences of failed matches as the files are an external resource and we
can not guarantee their individual accessibility.
Note this also changes the filename, so you may want to run:
$ find -name '*-last.*' -print | xargs rm
after this checkout.
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'.
Having included some extra details in the test output PNG filename, we
need to pass the extra information to
cairo_ref_name_for_test_target_format() in order to find the match.
In order to achieve substantial speed improvements the external conversion
utilities are rewritten as a daemon that communicates with the test suite
over a local socket. This is faster as it avoids the libtool and dynamic
linker overhead for each invocation, the caches persist between tests and
we no longer require a round trip through libpng.
The daemon is started automatically by the test suite and if communication
cannot be established then it falls back to using a pipe to a normal
conversion utility. The daemon will then persist for 60 seconds waiting
for further connections.
Of course any memory leak (stares at poppler) is exacerbated.
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.
By keeping a static reference to the user font face, it is erroneously kept
alive during a call to cairo_debug_reset_static_data(). (A violation of
the caller's contract to ensure that no active reference to a cairo object
is held by the caller.)
When cleaning files, limit the glob to only match *-out.{pdf,ps,svg} in
order to distinguish the current practice of naming vector output files
from possible future vector target/reference files.
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.
Currently fallback-resolution is included in the test suite if we have all
of the vector surfaces available. This commit enables individual support
for the vector surfaces, so that the test can be run even if one or more
of the surfaces are not available.
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/.
And update user-font text_to_glyphs() method to match.
Currently disable the win32-font text_to_glyphs(), until that one
is updated. Or better yet, remove it and implement ucs4_to_index().
It's the toy font API afterall.
The init func does not actually need to draw anything, but having a cairo_t
similar to that passed to render_glyph is handy for computing font extents.
This is because cairo makes doing some things really hard (if not impossible)
without a cairo_t.
The user-font-proxy test case is a great example of how the added cairo_t
makes life much easier.
