In step 1 of speeding up stroking, we introduce contours as a means for
tracking the connected edges around the stroke. By keeping track of
these chains, we can analyse the edges as we proceed and eliminate
redundant vertices speeding up rasterisation.
Coincidentally fixes line-width-tolerance (looks like a combination of
using spline tangent vectors and tolerance).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
We refactor the surface fallbacks to convert full strokes and fills to the
intermediate polygon representation (as opposed to before where we
returned the trapezoidal representation). This allow greater flexibility
to choose how then to rasterize the polygon. Where possible we use the
local spans rasteriser for its increased performance, but still have the
option to use the tessellator instead (for example, with the current
Render protocol which does not yet have a polygon image).
In order to accommodate this, the spans interface is tweaked to accept
whole polygons instead of a path and the tessellator is tweaked for speed.
Performance Impact
==================
...
Still measuring, expecting some severe regressions.
...
To build, do:
make malloc-stats.so
inside util/, and to use, run:
LD_PRELOAD=malloc-stats.so some-program
For binaries managed by libtool, eg, cairo-perf, do:
../libtool --mode=execute /bin/true ./cairo-perf
LD_PRELOAD="../util/malloc-stats.so" .libs/lt-cairo-perf
The code also includes Jeff Muizelaar's libbacktracesymbols that
is a much better implementation of backtrace_symbols() than what
is provided by glibc. That can be built by:
make backtrace-symbols.so
