Based on the work by Øyvind Kolås and Pierre Tardy -- many thanks to
Pierre for pushing this backend for inclusion as well as testing and
reviewing my initial patch. And many more thanks to pippin for writing the
backend in the first place!
Hacked and chopped by myself into a suitable basis for a backend. Quite a
few issues remain open, but would seem to be ready for testing on suitable
hardware.
When converting a grid pixel area into the range [0,255] the
GRID_AREA_TO_ALPHA() macro would truncate extra bits off the result
rather than rounding. This could cause seams between abutting
collinear edges of separately rendered polygons even when the
coordinates of the abutting edges were the same.
Reported by Soeren Sandmann on the cairo mailing list:
http://lists.cairographics.org/archives/cairo/2009-May/017043.html
As we don't strictly use the current-point in comparing paths, exclude it
from the hash. Similarly use the path content flags as a cheap means to
differentiate contents.
Use the cairo_list_t and its style of iterators to improve the readability
of the cairo_path_buf_t management. Note the complications that arise from
the embedding of the initial buf -- however the macros do help make the
unusual manipulations more identifiable.
Whilst constructing the path, if the operations continue to be
axis-aligned lines, allow the is_box and is_region flags to persist. These
are set to false as soon as a curve-to is added, a diagonal or in the case
of is_region a non-integer point.
Use the cow-snapshotting mechanism to store the meta surface replay (either
to an image inside acquire_source_image() or to a similar surface during
clone_similar()).
Fixes Bug 17971 -- Extreme slowdown for manual convolutions in most
vector backends.
https://bugs.freedesktop.org/show_bug.cgi?id=17971
The meta-surface is a vital tool to record a trace of drawing commands
in-memory. As such it is used throughout cairo.
The value of such a surface is immediately obvious and should be
applicable for many applications. The first such case is by
cairo-test-trace which wants to record the entire graph of drawing commands
that affect a surface in the event of a failure.
Remove some redundant defining of surfaces and contexts and of setting
defaults. In order to reduce the number of defines, we need to operate on
the operand stack more frequently - though in practice those operations
are quite rare.
Requires hooking into test-meta-surface currently. Export meta-surface!
The idea is that on detection of an error, we can reconstruct a minimal
trace from the meta-surface. The first step is to simply dump the trace
for the failing meta-surface. Later, we should automatically minimise
this further.
Before attempting to even set the attributes on the source Picture, we
ensure that it exists. So remove the redundant safe-guards to do nothing
if it doesn't exist.
We are expected to return a new reference from get_implementation(), and
failing to do so was causing use-after-frees (detected by the reference
counting checks).
Observe that patterns are not altered during an operation and so we are
safe to use the data from the original pattern without copying. (This is
enforced through the declaration that the backends operate on constant
patterns which are not allowed to be referenced or destroyed.)
Keep the resolved font face alive whilst the default FcConfig remains
identical i.e. resolve the pattern again if the system configuration
changes (e.g. a new font is added or the rules are updated). This should
retain the benefits of lazily resolving font patterns whilst improving
performance by reducing the number of calls to FcFontMatch().
A trivial fix to reset the original surface size after emitting the group.
The annoying aspect is that this should have been caught by the test suite.
Alas, no. A gentle reminder that simple line coverage is insufficient. :(
Evaulate the integer sizes during configure to find one of the exact same
size as a void* to use in the conversion of the atomic ptr cmpxchg to an
atomic int cmpxchg.
Fix an implicit pointer/integer cast in _cairo_atomic_ptr_cmpxchg()
when building with LLVM/clang.
The Intel synchronization primitives __sync_val_compare_and_swap()
are only defined by Intel for types int, long, long long and their
unsigned variants. This patch uses one of those for
_cairo_atomic_ptr_cmpxchg() instead of relying on a gcc extension of
__sync_val_compare_and_swap() to pointer types.
