The loop between texture_setup() and clone_similar() should be
impossible, since every compositing backend should know how to clone an
image surface. cairo-gl is no longer an exception and so this code can
safely be removed.
When creating the trapezoid mask, avoid having to allocate a temporary
array to hold the converted pixman trapezoids by instead rasterizing each
trapezoid separately into the mask.
In order to make the initial context current we need a Drawable that
matches the context. In general, the RootWindow may not match the desired
context so we need to query the context and construct an appropriate
Drawable.
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.
