This function is intended to deal with certain kinds of ligatures
and certain combining sequences that don't have corresponding glyphs.
It isn't hooked up to the gui yet, but does have unit tests that
are probably mostly correct.
refs: https://github.com/wez/wezterm/issues/478
My original goal was to update to allsorts 0.5 but the API
changes are significant and not clearly described.
To make that transition easier, the prior commit moved the shaping
logic into our allsorts shaper module, leaving the name parsing
here in parser.rs.
This commit now replaces that logic with ttf_parser, which is
potentially faster (there's more emphasis on optimal code in that
crate than in allsorts) but definitely simpler.
It's not a slam-dunk transition: ttf_parser doesn't know how to
decode MacRoman encoded text, so there's a bit of logic borrowed
from allsorts here to handle that.
This tidies up the font-dir and built-in font management a little
bit and paves the way for codepoint -> font resolution for fonts
discovered in font-dirs.
This commit uses a bit of DirectWrite to discover which font(s)
can be used to render a set of codepoints.
While hooking this up, I found that the method we were using
to extract the font data didn't handle TTC data so this commit
improves some parser diagnostics and handling for that.
refs: https://github.com/wez/wezterm/issues/299
98f289f511 causes more metrics retrieval
than in earlier versions; each unchached glyph render would trigger
a metrics recompute for the relevant font.
Add a simple cache for this.
refs: #353
This is one of those massive time sinks that I almost regret...
As part of recent changes to dust-off the allsorts shaper, I noticed
that the harfbuzz shaper wasn't shaping as well as the allsorts one.
This commit:
* Adds emoji-test.txt, a text file you can `cat` to see how well
the emoji are shaped and rendered.
* Fixes (or at least, improves) the column width calculation for
combining sequences such as "deaf man" which was previously calculated
at 3 cells in width when it should have just been 2 cells wide, which
resulted in a weird "prismatic" effect during rendering where the
glyph would be rendered with an extra RHS portion of the glyph across
3 cells.
* Improved/simplified the clustering logic used to compute fallbacks.
Previously we could end up with some wonky/disjoint sequence of
undefined glyphs which wouldn't be successfully resolved from a
fallback font. We now make a better effort to consolidate runs of
undefined glyphs for fallback.
* For sequences such as "woman with veil: dark skin tone" that occupy a
single cell, the shaper may return 3 clusters with 3 glyphs in the
case that the font doesn't fully support this grapheme. At render
time we'd just take the last glyph from that sequence and render it,
resulting in eg: a female symbol in this particular case. It is
generally a bit more useful to show the first glyph in the sequence
(eg: person with veil) rather than the gender or skin tone, so the
renderer now checks for this kind of overlapping sequence and renders
only the first glyph from the sequence.
There are a number of cases where font-loader might panic on windows,
and the optional font-loader dep causes problems with `cargo vendor`
in #337, so this is a step to removing that dep.
This commit makes direct GDI calls to enumerate monospace truetype
fonts from the system and then applies our normal matching on the
result.
The current master of allsorts supports color fonts in both bitmap and
svg varieties. I'm interested to see if I can teach wezterm to render
the svg based variety in a subsequent diff.
First though, it's times to dust off our allsorts shaper logic.
This commit updates to point to the current master of allsorts at the
time of writing; there's a little bit of API fanout that makes it a bit
easier to manage font fallback.
The fallback logic has been improved so that we can now successfully
fall back to the emoji font.
The shaping logic has been improved so that we turn on the options that
enable ZWJ for combining sequences of emoji, such as "man health
worker".
Running with the allsorts shaper enabled produces generally superior
emoji/ligature substitution results compared to harfbuzz with Noto Color
Emoji; the "man health worker" and the flags (eg: `flag: England`) from
the subdivsion-flag section don't get substituted at all with harfbuzz,
but do produce appropriate glyphs with allsorts.
refs: https://github.com/wez/wezterm/issues/66
This wasn't used by anything and the version was getting pretty stale.
Upgrading is awkward because newer versions pull in an incompatible
freetype library version.
This commit moves a bunch of stuff around such that `wezterm` is now a
lighter-weight executable that knows how to spawn the gui, talk to
the mux or emit some escape sequences for imgcat.
The gui portion has been moved into `wezterm-gui`, a separate executable
that doesn't know about the CLI or imgcat functionality.
Importantly, `wezterm.exe` is no longer a window subsystem executable
on windows, which makes interactions such as `wezterm -h` feel more
natural when spawned from `cmd`, and should allow
`type foo.png | wezterm imgcat` to work as expected.
That said, I've only tested this on linux so far, and there's a good
chance that something mac or windows specific is broken by this
change and will need fixing up.
refs: #301
