This function is supposed to describe the backend in use. The describe
function is optional - and therefore initialized as NULL everywhere.
Note:
It is well known that the xlib backend uses X. What is not known is what
version the server supports or what graphics card it is running on. That
is the information the describe vfunc is supposed to provide.
Text with size 0 has a singular scale matrix, thus requires special
handling to avoid invalidating the context where it is used.
Fixes pthread-show-text and text-zero-len (they failed with assertion
when ran using the user font backend).
Currently the translation component of the scaled_font scale matrix
is applied by gstate and only linear components should be applied in
font backends.
Fixes font-matrix-translation (when using user-font as font backend).
glyph_path was taking into account the translation (which currently
is already applied in gstate) and the sign of the elements of the
matrices was not explained.
Use scale instead of manually compositing font_matrix and ctm and
composite it with the context ctm, so that no workaround for clipping
is needed anymore.
On error, surface creation functions should always return a surface
created with _cairo_surface_create_in_error() instead of a new surface
in an error state. This simplifies internal code as no refcounting has
to be done.
Under the restrictive conditions where we are doing an untransformed
contained upload of an image into a matching surface, perform it in
place. The drivers will attempt to stream such uploads efficiently, far
more so than our code.
Previously, the code returned a status and required the caller to mangle
this status with his own status. Now, the function takes the previous
status ass an argument and does the mangling itself.
Also contains fixes for all the callers to actually check the return
value - which is now rather trivial as it just requires passing through
the status variable.
When acquiring the GL context, do not assert that the GL context is not
in an error state. Do not even call _cairo_error(). Handling GL errors
in other code is not Cairo's responsibility.
Instead just clear all previous errors so we don't accidentally set
surfaces into error states to unrelated errors.
Now that we probably call _cairo_error() on every GL error, there is no
need to use custom methods to catch those errors. The usual breakpoint
is enough.
As we transform the array of trapezoids into an array of boxes in-place,
we must take local copies of the coordinates before writing into the
boxes otherwise we may inadvertently modify the trapezoidal coordinates.
Fixes test/a1-bug.
This adds internal API to retrieve the LCD filtering parameters from
fontconfig, or as set on the Screen, and feed them to FreeType when
rendering the glyph.
References:
Bug 10301 - LCD filtering patch
https://bugs.freedesktop.org/show_bug.cgi?id=10301
Tested-by: Brandon Wright <bearoso@gmail.com>
Forward-ported-by: Robert Hooker <sarvatt@gmail.cm>
ickle: The API is clearly not ready for public consumption, the enum are
poorly named, however this stands by itself as enabling system wide
properties.
When checking if the traps are equivalent to a set of rectangles, we
need to use the same rounding mode as when converting the traps to a set
of boxes and then filling them. Failure to do leads to a situation where
(-127,-128) was thought to be equivalent to (0,0) but we attempted to
fill from 0 to -1 instead.
References:
http://lists.cairographics.org/archives/cairo/2010-June/020115.html
cairo_fixed_integer_round[_down] were adding an unsigned mask value
before shifting its result, causing the shift to be computed as
logical (unsigned) right shift, thus producing incorrect values for
negative inputs. Making the mask value signed fixes this issue.
Bug report by cu:
http://lists.cairographics.org/archives/cairo/2010-June/020115.html
