An issue occured when using subpixel antialiasing with user-fonts and
XRender - the glyphs were transparent, as demonstrated by the font-view
example.
The problem lies in that enabling subpixel antialiasing triggers use of an
ARGB32 image surface for rendering the glyph, but the default colour is
black (so the only information is in the alpha-channel). Given an ARGB32
glyph XRender treats it as a per-channel mask, but since the R,G,B
channels were uniformly zero, the glyph is rendered as transparent.
Fix this by setting the initial colour to white before rendering the image
surface for a user-font glyph, which generates the appropiate gray-level
mask by default.
The PDF surface now keeps track of all the patterns it is embedding in
a hash table keyed by the unique_id returned by the
_cairo_surface_get_unique_id().
This patch adds more implementation of the snapshot method. For
surface types where acquire_source_image is already making a copy
of the bits, doing another one as is the case for the fallback
implementation is a waste.
Provide a mechanism for backends to attach and remove snapshots. This can
be used by backends to provide a cache for _cairo_surface_clone_similar(),
or by the meta-surfaces to only emit a single pattern for each unique
snapshot.
In order to prevent stale data being returned upon a snapshot operation,
if the surface is modified (via the 5 high level operations, and on
notification of external modification) we break the association with any
current snapshot of the surface and thus preserve the current data for
their use.
Use 'cairo-perf -v -r' to have both the summary output along with the raw
values. This gives a progress report whilst benchmarking, very reassuring
with long running tests.
There are synchronisation issues with similar surfaces (as only the
original target surface is synced) which interferes with making
performance comparisons. (There still maybe some value should you be aware
of the limitations...)
Use the new API Behdad exposed in 1.8 to precompute a glyph string using
Cairo and then benchmark cairo_show_glyphs(). This is then equivalent to
the text benchmark but without the extra step of converting to glyphs on
every call to cairo_show_text() i.e. it shows the underlying glyph
rendering performance.
The glyph advance cache was only enabled for glyph indices < 256,
causing a large number of misses for non-ASCII text. Improve this by
simply applying the modulus of the index to select the cache slot - which
may cause some glyph advances to be overwritten and re-queried, but
improves the hit rate.
Allow the caller to choose whether or not various conversions take place.
The first flag is used to disable the expansion of reflected patterns into a
repeating surface.
We can defer taking the cairo_scaled_font_map_lock until we drop the
last reference to the scaled font so long as we double check the reference
count after waiting for the lock and not making assumptions about
unreferenced fonts during construction. This is significant as even
acquiring the uncontended cairo_scaled_font_map_lock during
cairo_scaled_font_destroy() was showing up as a couple of percent on text
heavy profiles (e.g. gnome-terminal).
When observing applications two patterns emerge. The first is due to
Pango, which wraps each glyph run within a context save/restore. This
causes the scaled font to be evicted after every run and reloaded on the
next. This is caught by the MRU slot on the cairo_scaled_font_map and
prevents a relatively costly traversal of the hash table and holdovers.
The second pattern is by applications that directly manage the rendering
of their own glyphs. The prime example of this is gnome-terminal/vte. Here
the application frequently alternates between a few scaled fonts - which
requires a hash table retrieval every time.
By introducing a MRU slot on the gstate we are able to directly recover
the scaled font around 90% of the time.
Of 110,000 set-scaled-fonts:
4,000 were setting the current font
96,000 were setting to the previous font
2,500 were recovered from the MRU on the cairo_scaled_font_map
7,500 needed a hash retrieval
which compares to ~106,000 hash lookups without the additional MRU slot on
the gstate.
This translates to an elapsed time saving of ~5% when replaying a
gnome-terminal trace using the drm backend.
The structure is already exposed, so just expose the
constructors/destructors in order to enable caches to be embedded and
remove a superfluous malloc.
By simply iterating over the array cairo_trapezoid_t, converting each one
separately to a pixman_trapezoid_t and rasterizing each one individually
we can avoid the common heap allocation. pixman performs exactly the same
iteration internally so there is no efficiency loss.
Make the treatment of replacing the NULL source pattern with WHITE
consistent. As it is a solid pattern, we can skip _cairo_pattern_fini()
and so make the code more readable, and consistent along the error paths.
The number of mime-types attached to a surface is usually small,
typically zero. Therefore it is quicker to do a strcmp() against
each key in the private mime-data array than it is to intern the
string (i.e. compute a hash, search the hash table, and do a final
strcmp).
Record the current working directory and pass that along to cairo-trace so
that the trace output is local to the user and not the application. This
is vital if the application is called via a script that changes directory.
Some backends are quite constrained with surface sizes and so trigger
fallbacks when asked to clone large images. To avoid this we attempt
to trim ROIs (as these are often limited to the destination image, and
so can be accommodated by the hardware). This patch allows trimming
REPEAT sources both horizontally and vertically independently.
As the number of places where we add valgrind client requests grows, it
becomes imperative that we should be able to disable them with a simple
configure time option.
Jeff Muizelaar noted that the treatment of edges differed with firefox's
canvas definition, which considers a point on any edge as inside. The
current implementation has a similar definition to that of flash, for
which the top and right edges are outside. Arguably, firefox has the more
intuitive definition here...
If the backend cannot create a similar surface to hold the image, then
report back the failure before embarking upon an infinite recursion.
The UNSUPPORTED return should percolate up through the call stack and
trigger a fallback.
Bug 19251: --enable-win32=yes and --enable-win32-font=no causes
compilation failure
[https://bugs.freedesktop.org/show_bug.cgi?id=19251]
Wrap use of the win32 font backend within win32-printing-surface within
CAIRO_HAS_WIN32_FONT ifdefs to prevent compilation failure if the user
explicitly disables the win32 font backend.
