The rule is: cairo_glyph_t* is always passed as const for measurement
purposes. This was not reflected in our public api previously. Fixed
Showing glyphs used to have cairo_glyph_t* always as const. With this
changed, it is only const on cairo_t and cairo_gstate_t operations.
cairo_surface_t, cairo_scaled_font_t, and individual backends receive
cairo_glyph_t* as non-const. The desired semantics is that they may modify
the contents of the array as long as they do not return
CAIRO_STATUS_UNSUPPORTED. This makes it possible to avoid copying the glyph
array again and again, and edit it in-place. Backends are in fact free to use
the array as a generic buffer as they see fit.
This fixes a huge performance bug (entire image was being pushed to X
server in order to copy a tiny piece of it). I see up to 50x improvement
from subimage_copy (which was designed to expose this problem) but also
a 5x improvement in some text performance cases.
xlib-rgba subimage_copy-512 3.93 2.46% -> 0.07 2.71%: 52.91x faster
███████████████████████████████████████████████████▉
xlib-rgb subimage_copy-512 4.03 1.97% -> 0.09 2.61%: 44.74x faster
███████████████████████████████████████████▊
xlib-rgba subimage_copy-256 1.02 2.25% -> 0.07 0.56%: 14.42x faster
█████████████▍
xlib-rgba text_image_rgb_over-256 63.21 1.53% -> 11.87 2.17%: 5.33x faster
████▍
xlib-rgba text_image_rgba_over-256 62.31 0.72% -> 11.87 2.82%: 5.25x faster
████▎
xlib-rgba text_image_rgba_source-256 67.97 0.85% -> 16.48 2.23%: 4.13x faster
███▏
xlib-rgba text_image_rgb_source-256 68.82 0.55% -> 16.93 2.10%: 4.07x faster
███▏
xlib-rgba subimage_copy-128 0.19 1.72% -> 0.06 0.85%: 3.10x faster
██▏
New internal function _cairo_surface_set_font_options is used to set them.
cairo_surface_create_similar propagates the font options of the other
surface into the newly created surface. Fixes bugs with font options in
fallback images and bug 4106.
Fixes the bug that paginated backends had font-matrix translation
applied twice, AND removes a second copy of the glyphs. It's
essentially similar to what cworth did for stroke/fill/clip in
this commit: bd92eb7f3c
Reviewed by: Carl Worth
As the font matrix includes translation, which is otherwise unused for glyph
transformation, the interpretation of translation is fairly arbitrary. For
1.2.0, we choose to have this translation affect the glyph advance with the
thought that it could be used to do letter spacing/kerning. That is fairly
useless in practice, and a far more useful interpretation is to relocate
the origin of each glyph.
This patch uses the translation in the font matrix as an offset for the
glyph origin in user space. It turns out glyph extents were already correctly
shifted.
The end result with this patch is to have cairo match the 1.0 behaviour for
font matrix translations, but now we know why :-)
Explanation above courtesy of Keith Packard.
This is an attempt to fix the following bug:
http://bugzilla.gnome.org/show_bug.cgi?id=332266
With the recent rewrite of the device-offset code, which pushed things
from the gstate to the surface layer, the 16-bit limitations on coordinates
which previously applied to device space only, have lately been applying to
user space. This commit moves the device_transform back up above the conversion
from floating-point to fixed-point values so that once again the limitation
only applies to device space.
Previously this function was attempting to return values in surface
space, (but even then it was doing it wrong). However, all callers
actually expect values in backend space. Fixing this cleans up bug
7268 quite nicely.
The aliases should allow binaries with the old symbols to continue to run.
Meanwhile, the macros in cairo.h prevent any code from being compiled without
using the new, future-proof function names.
This is a temporary, transition strategy and the aliases will be dropped
before the next major release.
The old behavior of returning "infinite" extents is inconsistent with
the current usage of meta-surface where it is always created for
replay against a particular (sized) target surface and that size is
passed to _cairo_meta_surface_create.
Also clarify documentation of _cairo_surface_get_extents to eliminate
the possibility of inifinite extents.
(This is covering up my mistake from the last batch of 12 commits which
wasn't ready to be pushed yet. This fixes some of the crashes which
were introduced, and is a good thing to do regardless.)
The trick is to create a new scaled_font with the device_transform
multiplied into the CTM within _cairo_surface_show_glyphs before
calling into the backend. The fallback-resolution test shows that
the font size is now correct.
The trick is to simply multiply the device_transform into the CTM
within _cairo_surface_stroke before passing the CTM down to the
backend. The fallback-resolution test shows that the stroke width is
now correct.
Add new, private _cairo_surface_set_device_scale for getting at the
scaling components of device_transform. Use this in paginated surface
when replaying to an image surface. The fallback-resolution test now
clearly shows that image fallback resolution can be controlled by the
user. Hurrah!
This is a step toward allowing device scaling in addition to device offsets.
So far, the scale values are still always 1.0 so only the translation is
actually being used. But most of the code is in place for doing scaling as
well and it just needs to be hooked up.
There are some fragile parts in this code, all of which involve using the
translation without the scale, (so grep for device_transform.x0 or
device_transform->x0). Some of these are likely bugs that will hopefully
be obvious once we start using the scale. Others are OK if only because
we 'know' that we aren't ever setting device scaling on a surface that
has a device offset (we only set device scaling on surfaces we create
internally and we don't export device scaling to the user).
All of these fragile parts in the code have been marked with comments of
the form: XXX: FRAGILE.
This just provides the mechanics for storing the value and removing the old
function calls. The new value is still not used anywhere (though nor where
the old values), so there should be no functional change (other than forcing
any programs calling the old API to be updated).
This rectangle has regular integer values, not fixed-point values.
So the old name was horribly wrong and misleading, (and yes I think
it was even I that had suggested it).
This patch was produced with the following (GNU) sed script:
sed -i -r -e 's/[ \t]+$//'
run on all *.[ch] files within cairo.
Note that the above script would have also created all the changes
from the previous commits to remove trailing whitespace.
This patch was produced with the following (GNU) sed script:
sed -i -r -e '/^[ \t]*\/?\*/ s/[ \t]+$//'
run on all *.[ch] files within cairo, (though I manually excluded
src/cairo-atsui-font.c which has a code line that appears as a comment
to this script).
Specifically, device offsets now affect using the offset surface in
a source pattern as well as drawing to the surface. This behavior
os also verified with a new test case: test/device-offset.c
This is a mega-patch that has the advantage that the entire test suite
passes both immediately before and immediately after this commit.
The disadvantage of the mega-patch is that it does not reflect the
development history of the device-offset branch, (with its various
fumblings and flailings). To capture that history, we will next merge
in that branch.
