This change adds support for `white-space-collapse: break-spaces` and
adds initial parsing support for `overflow-wrap` and `word-break`. The
later two properties are not fully supported, only in their interaction
with `break-spaces`. This is a preliminary change preparing to implement
them.
In addition, `break_and_shape` is now forked and added to Layout 2020.
This function is going to change a lot soon and forking is preparation
for this. More code that is only used by Layout 2013 is moved from `gfx`
to that crate.
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
- Better detect situations where emoji is necessary by looking ahead one
character while laying out. This allow processing Unicode presentation
selectors. When detecting emoji, put emoji fonts at the front of
fallback lists for all platforms.
This enables monochrome emoji on Windows. Full-color emoji on Windows
probably needs full support for processing the COLR table and drawing
separate glyph color layers.
- Improve the font fallback list on FreeType platforms. Ideally, Servo
would be able to look through the entire font list to find the best
font for a certain character, but until that time we can make sure the
font list contains the "Noto Sans" fonts which cover most situations.
Fixes#31664.
Fixes#12944.
This allows sharing font templates, fonts, and platform fonts across
layout threads. It's the first step toward storing web fonts in the
layout versus the shared `FontCacheThread`. Now fonts and font groups
have some locking (especially on FreeType), which will probably affect
performance. On the other hand, we measured memory usage and this saves
roughly 40 megabytes of memory when loading servo.org based on data from
the memory profiler.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Mukilan Thiyagarajan <mukilan@igalia.com>
* Simplify `FontHandle` and rename it to `PlatformFont`
Rename it to `PlatformFont` and move the `FontTemplate` member to
`Font`, because it's shared by all platforms.
* Update components/gfx/platform/freetype/font.rs
Co-authored-by: Mukilan Thiyagarajan <mukilanthiagarajan@gmail.com>
* Fix build for MacOS and Windows
---------
Co-authored-by: Mukilan Thiyagarajan <mukilanthiagarajan@gmail.com>
Now that `FontTemplateData` is more or less the same on all platforms,
it can be removed. This is a preparatory change for a full refactor of
the font system on Servo. The major changes here are:
- Remove `FontTemplateData` and move its members into `FontTemplate`
- Make `FontTemplate` have full interior mutability instead of only
the `FontTemplateData` member. This is preparation for having these
data types `Send` and `Sync` with locking.
- Remove the strong/weak reference concept for font data. In practice,
all font data references were strong, so this was never fully
complete. Instead of using this approach, the new font system will
use a central font data cache with references associated to layouts.
- The `CTFont` cache is now a global cache, so `CTFont`s can be shared
between threads. The cache is cleared when clearing font caches.
A benefit of this change (apart from `CTFont` sharing) is that font data
loading is platform-independent now.
The old logic was assuming that all whitespace was a break opportunity,
and that no newlines would be preserved.
Note that text shaping considers the advance of a newline to be the same
as a space. This was problematic because if we have a segment with a
preserved space and newline, only the advance of the space should
contrinute to the size of the block container. Therefore, I'm changing
the breaker logic in other to have newline characters in their own
segment.
Then glyph_run_is_whitespace_ending_with_preserved_newline can just be
renamed to glyph_run_is_preserved_newline.
This patch is still not perfect because it doesn't check allow_wrap(),
so `nowrap` is treated like `normal`, and `pre-wrap` like `pre`.
* clippy: fix warnings in components/gfx
* refactor: switched the order of impl so that its intent is clearer
* fix: add font context default in other platforms
Synthetic small caps is supported by the font subsystem, but this is
disabled in Layout 2020. We can turn this on to bring support to parity
with the old layout system.
In addition to turning on synthetic small-caps this change also improves
the way that they work. Before, synthetic small caps meant that every
character was a small version of capitalized character. After this
change, capital letters are larger than small caps versions of small
letters -- matching other browsers and the common expectation of how
small caps works.
We can use stable rust if we pass the unstable configuration as
command-line arguments to rustfmt itself. This prevents needing to
install an unstable rust toolchain.
The one downside here is that it doesn't seem that "ignore" is
supported so we have to start formatting the files in "third_party."
This shouldn't be a huge issue because we don't plan to check much more
rust code into those directories.
Before counting whitepsace-only `GlyphStore`s where counted as a single
justification opportunity when trimming whitespace from the front and
back of lines. This isn't correct, instead count the actual number of
word seperators of the trimmed `GlyphStore`s.
These two counts can be different in the case where whitespace collapse
isn't happening yet (flexbox). In addition, using word seperators means
the code is making less assumptions about the contents of the line and
is more robust.
This fixes some crashes in flexbox tests on debug builds.
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
We previously sent a " " to the linebreaker in order to ensure that the
next text had a soft wrap opportunity at the start. Calling `next(" ")`
without waiting until the returned index was 1, violated some
invariants of linebreaker ultimately causing a panic.
Instead of using the linebreaker for this, simply keep a flag in the
IFC layout state, which avoids the problem entirely.
Fixes#30703.
It's not possible anymore, in the presence of min() / max(), to split a
<length-percentage> value into a <length> and a <percentage> component.
Tweak word_spacing to do what Gecko does (resolving it in advance).
This crate takes about 40 seconds to build of a fast desktop,
and was used in exactly one place. Additionally, that use was previously
accidentally disabled (a553964123)
and we only noticed more than a year later when the build broke
(d1efad6763).
There are a few canvas2d-related dependencies that haven't updated, but they
only use euclid internally so that's not blocking landing the rest of the
changes.
Given the size of this patch, I think it's useful to get this landed as-is.
`hb_font_funcs_set_glyph_h_kerning_func` is gone but I couldn't find any
replacement. Kerning tests are passing and kerning seems fine on my
computer so I guess it's useless now ?
Use line comments instead of block comments
as block comments contain trailing whitespace
after formatting with rustfmt.
Skip tests for malloc_size_of and script_plugins
with rustfmt as they have many block comments.
Prior to this change, if none of the fonts specified in CSS contained a
glyph for a codepoint, we tried only one fallback font. If that font
didn't contain the glyph, we'd give up.
With this change, we try multiple fonts in turn. The font names we try
differ across each platform, and based on the codepoint we're trying to
match. The current implementation is heavily inspired by the analogous
code in Gecko, but I've used to ucd lib to make it more readable,
whereas Gecko matches raw unicode ranges.
This fixes some of the issues reported in #17267, although colour emoji
support is not implemented.
== Notes on changes to WPT metadata ==
=== css/css-text/i18n/css3-text-line-break-opclns-* ===
A bunch of these have started failing on macos when they previously
passed.
These tests check that the browser automatically inserts line breaks
near certain characters that are classified as "opening and closing
punctuation". The idea is that if we have e.g. an opening parenthesis,
it does not make sense for it to appear at the end of a line box; it
should "stick" to the next character and go into the next line box.
Before this change, a lot of these codepoints rendered as a missing
glyph on Mac and Linux. In some cases, that meant that the test was
passing.
After this change, a bunch of these codepoints are now rendering glyphs
on Mac (but not Linux). In some cases, the test should continue to pass
where it previously did when rendering with the missing glyph.
However, it seems this has also exposed a layout bug. The "ref" div in
these tests contains a <br> element, and it seems that this, combined
with these punctuation characters, makes the spacing between glyphs ever
so slightly different to the "test" div. (Speculation: might be
something to do with shaping?)
Therefore I've had to mark a bunch of these tests failing on mac.
=== css/css-text/i18n/css3-text-line-break-baspglwj-* ===
Some of these previously passed on Mac due to a missing glyph. Now that
we're rendering the correct glyph, they are failing.
=== css/css-text/word-break/word-break-normal-bo-000.html ===
The characters now render correctly on Mac, and the test is passing. But
we do not find a suitable fallback font on Linux, so it is still failing
on that platform.
=== css/css-text/word-break/word-break-break-all-007.html ===
This was previously passing on Mac, but only because missing character
glyphs were rendered. Now that a fallback font is able to be found, it
(correctly) fails.
=== mozilla/tests/css/font_fallback_* ===
These are new tests added in this commit. 01 and 02 are marked failing
on Linux because the builders don't have the appropriate fonts installed
(that will be a follow-up).
Fix build errors from rebase
FontTemplateDescriptor can no longer just derive(Hash). We need to
implement it on each component part, because the components now
generally wrap floats, which do not impl Hash because of NaN. However in
this case we know that we won't have a NaN, so it is safe to manually
impl Hash.
