This commit makes some adjustments to FontConfiguration and LoadedFont
such that it the shaper is unable to resolve a (non-last-resort) font
for a set of codepoints, the locator can be used to try to find a
font that has coverage for those codepoints.
At the moment this is a bit limited:
* Only the font-config locator implements this function
* The directory based locator isn't actually an implementor of the
locator trait and doesn't have a way to be invoked for this.
Make an effort to explain what failed to load and where it came from,
and funnel users to the documentation on font configuration.
The message presented is slightly different depending on whether
we think that the font was their primary font, an explicitly
specified font_rule or an implicitly synthesized font_rule.
refs: #340
Use the scaling factor between the font metrics for the base font
and those of the fallback font selected for a given glyph.
The scenario is this: the base font is typically the first one selected
from the font configuration. There may be multiple fallback fonts that
are different sizes; for instance, the Font Awesome font has glyphs that
are square in aspect and are thus about twice the width of a typical
textual monospace font. Similarly, Noto Color Emoji is another square
font but that has a single set of bitmap strikes at a fixed 128 px
square.
The shaper returns advance metrics in the scale of the containing font,
and the rasterizer will target the supplied size and dpi.
We need to scale these to match the base metrics.
Previously we used a crude heuristic to decide whether to scale,
and that happened to work for Noto Color Emoji but not for Font Awesome,
whose metrics were just inside the bounds of the heuristic.
This commit allows retrieving the metrics for a given font_idx so
that we can compute the correct scale factor without any heuristics,
and applies that to the rasterized glyph.
refs: https://github.com/wez/wezterm/issues/342
Don't short circuit on just the family portion of the name;
if the criteria don't match there, we should fall back to
test against the full font name.
closes: https://github.com/wez/wezterm/issues/341
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.
Bundle the *Last Resort High-Efficiency* font from
https://github.com/unicode-org/last-resort-font/
version 13.001 (Oct 22 2020).
This provides a more useful fallback glyph than we'd otherwise
produce if there is no matching glyph in any of the fonts.
Its license is OFL-1.1 which is compatible with the other
bundled fonts.
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
9892b16d40 adjusted how the text
colors are produced; it resulted in some ugly dark edges, especially
on lighter backgrounds.
This commit routes that tint via an alpha compositing helper which
produces smoother edges.
refs: #320
This commit more cleanly separates the load from the render flags,
and fixes up the render call; at some point this got messed up such
that we'd never end up with freetype returning subpixel format data
(LCD) and instead we'd only ever get grayscale data.
With that fixed, it's apparent that the colorization of the glyph
data was wonky in the shader so this commit also cleans this up.
refs: #320
refs: #121
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
