* 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.
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).
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 ?
Replace character indices with UTF-8 byte offsets throughout the code dealing
with text shaping and breaking. This eliminates a lot of complexity when
converting from one to the other, and interoperates better with the rest of
the Rust ecosystem.
This is a no-op, since a "non-glyph" is simply `GlyphEntry(0)`. This is the
same as `GlyphEntry::initial()`, which all the entries are already initialized
to.
Shaper::save_glyph_results incorrectly starts its loop by setting glyph_span
to a length of 1. This means that the `if glyph_span.len() == 0` test in the
inner loop will never succeed.
Instead the glyph span should start out empty, and a glyph should be added only
as the corresponding char is found. For comparison, see the Gecko code this
was ported from:
https://hg.mozilla.org/mozilla-central/file/ab0044bf/gfx/thebes/gfxHarfBuzzShaper.cpp#l1682
