According to "man setjmp", one possible way to avoid variable clobbering
is to declare them as volatile. Thus, this commit turns the variables
that are changed between setjmp() and longjmp() and whose values are
still needed after setjmp() returned the second time into volatile
variables.
The warning in cairo-bentley-ottmann-rectangular.c is worked around by
not initializing the variable before setjmp(). To be honest, I don't
understand why the compiler warns here at all since the value of update
is clearly not used after setjmp()'s second return.
This commit re-fixes the warnings that were reintroduced in commit
82f40285 which reverted b092b63.
Signed-off-by: Uli Schlachter <psychon@znc.in>
Acked-by: Bryce Harrington <bryce@osg.samsung.com>
This reverts commit b092b63119 which
introduced a wrapper function around setjmp(). To quote from man setjmp:
If the function which called setjmp() returns before longjmp() is
called, the behavior is undefined. Some kind of subtle or unsubtle
chaos is sure to result.
Since after the above commit setjmp() is called from the wrapper
function, the result might or might not work, depending on compiler
settings. If the setjmp() wrapper is not inlined, then the state of the
stack after longjmp() will likely be garbage.
returned traps will have their left edge to the left of their right
edge, but if only one trap is passed in then the function always returns
without doing anything. This results in incorrect rendering of SVG
paths with more than one subpath.
Currently calls to _cairo_bentley_ottmann_tessellate_rectangular_traps
are guarded by traps.has_intersections checks, so this is only a
theoretical bug. But we'll eliminate the potential of the bug by
making the left side to be left of the right side, similar to what was
done in _cairo_bentley_ottmann_tessellate_boxes (commit 11b6c49c).
Patch authored by Tom Klein for Mozilla.
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=90984
Ref: https://bugzilla.mozilla.org/show_bug.cgi?id=853889
Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
Having spent the last dev cycle looking at how we could specialize the
compositors for various backends, we once again look for the
commonalities in order to reduce the duplication. In part this is
motivated by the idea that spans is a good interface for both the
existent GL backend and pixman, and so they deserve a dedicated
compositor. xcb/xlib target an identical rendering system and so they
should be using the same compositor, and it should be possible to run
that same compositor locally against pixman to generate reference tests.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
P.S. This brings massive upheaval (read breakage) I've tried delaying in
order to fix as many things as possible but now this one patch does far,
far, far too much. Apologies in advance for breaking your favourite
backend, but trust me in that the end result will be much better. :)
Saves having to fixup the pointers afterwards by only having to update
them on the list boundaries during merge.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
However, this is only useful for inserting multiple boxes within the
pixel, so we maintain the cached insert cursor as this speeds up the
general case (and aides this optimisation as well).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Since we only allocate a pointer to the rectangle after it is started
and so decoupled from the start queue, we reuse the memory allocated for
the start queue for the stop binary heap.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Bucketing the rectangles together on their top-scanline and then sorting
within that scanline is significantly faster for dragon despite the extra
passes.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Step 1, fix the failings sighted recently by tracking clip-boxes as an
explicit property of the clipping and of composition.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Winding of a box is toggled by swapping x1, x2 coordinates. So
we have to swap those coordinate rather than just copying.
Many routines assume that boxes are left-top to right-bottom
convention. So tessellator should produce such output boxes.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
We cannot assume that parameter 'out' is empty. So we should make it
empty before returning CAIRO_STATUS_SUCCESS when 'in' contains no boxes.
When 'in' contains a single box, we should copy 'in' to 'out' rather
than just returning CAIRO_STATUS_SUCCESS.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
I updated the Free Software Foundation address using the following script.
for i in $(git grep Temple | cut -d: -f1 )
do
sed -e 's/59 Temple Place[, -]* Suite 330, Boston, MA *02111-1307[, ]* USA/51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA/' -i "$i"
done
Fixes http://bugs.freedesktop.org/show_bug.cgi?id=21356
Benjamin Otte tracked down an invalid read triggered by WebKit. The
cause is that we attempt to dereference the list_head as an edge as we
failed to check that during the skipping of colinear edges we advanced
to the end, under the false assumption that there would always
be a closing edge in a rectangle. This assumption is broken if the tail
rectangles having colinear right edges.
We remember the location of the last insert as the next edge is likely to
be nearby. However, we need to be careful when the pointer rests upon the
HEAD and ensure that we begin the search from the appropriate end.
Add an even simpler sweep-line tessellator for rectangular trapezoids (as
produced by the rectilinear stoker and box filler).
This is so simple it even outperforms pixman's region validation code for the
purposes of path-to-region conversion.
