This gets the matching time down below 110+ms to around 70ms
in release mode, which may not sound like a huge amount, but 100ms
is on the cusp of perceivable latency, so getting below that is
desirable.
Freetype's support for colr is relatively rudimentary, which is fine,
but we want more control, so we probe a bit harder to figure out
whether a glyph has colr information before allowing freetype
to rasterize it, so that we have the opportunity to reroute
that rendering to our own logic.
Weirdly, the rust compiler is suddenly complaining about this,
when this file hasn't changed.
```
error[E0283]: type annotations needed
--> window\src\os\windows\window.rs:2398:26
|
2398 | if vk <= u8::MAX.into() {
| -- ^^^^
| |
| type must be known at this point
|
= note: cannot satisfy `u32: PartialOrd<_>`
help: try using a fully qualified path to specify the expected types
|
2398 | if vk <= <u8 as Into<T>>::into(u8::MAX) {
| ++++++++++++++++++++++ ~
error[E0283]: type annotations needed
--> window\src\os\windows\window.rs:2415:32
|
2415 | if leader.1 <= u8::MAX.into() && key.1 <= u8::MAX.into() {
| -- ^^^^
| |
| type must be known at this point
|
= note: cannot satisfy `u32: PartialOrd<_>`
help: try using a fully qualified path to specify the expected types
|
2415 | if leader.1 <= <u8 as Into<T>>::into(u8::MAX) && key.1 <= u8::MAX.into() {
| ++++++++++++++++++++++ ~
```
Now we can optionally skip loading svg fonts, making our default
to continue to try to use them.
We don't actually support interpreting svg data, but we do now
support COLR v1 data which is found in some of those same fonts.
refs: https://github.com/wez/wezterm/issues/4148
The harfbuzz driven rasterization of COLR glyphs is superior to
my attept at a freetype driven rasterizer, so let's default to
the harfbuzz version.
This change means that the default for most regular glyphs is
freetype, but we'll use harfbuzz for COLR glyphs.
Popping open the char selector could result in comedy-sized emoji
that dramatically overflow the bounds.
The reason for that is that glyphcache isn't smart enough to notice
when the glyph.height exceeds the cell_height and allows the glyph
bitmap to be rendered at the rasterized size.
The reason for that glyph being so huge is that freetype is producing
outlines that are too large. The font metrics have the requested
x and y ppem values (eg: the nominal font size in pixels), but also
x and y scaling values that are not set to 1. The result is that
the produced extents are too large by those x and y scaling values.
I'm not sure why that is, but it is simplest and most self-contained
to adjust for that scale factor when we rasterize via cairo, so that
is what we do here.
When using the harfbuzz rasterizer with a bitmap glyph, the result
is a rasterized glyph that is pre-scaled to the cell dimensions.
We need to tell glyphcache that that has happened, otherwise it
will apply the same scale factor again.
I think I've got the right values going in and out, so I think
it's ok to turn this on, but I'm worried about legacy non-opentype
formats that freetype supports but harfbuzz doesn't.
Let's stick with ft's metrics until I find time to validate
the behavior.
This isn't fully baked, but it looks mostly ok.
The ghost emoji has a weirdly positioned white patch; there's
something funky with its positioning that needs to be investigated.
There's some copypasta here; a bunch of the cairo related stuff
was copied and adapted from the harfbuzz impl.
I plan to refactor the latter in terms of the former to reduce
the amount of code overall.
fixup colors and excessive clipping.
This now looks decent. Still don't support sweep gradients;
those look complex and I'm not sure that I have a font to
test that against.
This meshes well with the sequence of instructions that we
get from harfbuzz.
This will need some vendoring to integrate with wezterm's build
on all platforms; that can come later.
Still need to hook up gradients.
We need to make a couple of passes over the paint instructions,
and making a nice interface around FontFuncs and DrawFuncs was
taking up a lot of boilerplate.
Adjust so that we accumulate parsed PaintOps and DrawOps instead.
This makes the code smaller and easier to grok.
Still has trouble rasterizing the new noto color emoji font though.
I think this fixes up the discrepancy I had in metrics with images.
The "solution" is to tell harfbuzz to scale to the selected
bitmap strike size instead of the the computed pixel size for
the current settings.
I'm experimenting with using cairo's 2D graphics for glyph related
drawing operations, and perhaps more stuff in the UI in the future.
The challenge is that no one has yet encapsulated its build in a
cargo-friendly way.
This commit is that attempt.
The strategy is this:
* `deps/cairo` is ostensibly the same thing as https://github.com/gtk-rs/gtk-rs-core/tree/master/cairo/sys
which is the cairo-sys-rs crate
* Its build.rs has been replaced with a version that builds from the C
sources that are found in-tree; it will never look for the system
cairo library
* A pair of scripts to import pixman (a required dep of cairo) and
cairo itself in a repeatable way are include, for if/when we need
to update the vendored sources
Cairo is a mature library and doesn't release very often.
* The workspace sets a patch for crates.io so that cairo-rs has
its cairo-sys-rs dep redirected to the local build.
I'm not planning to upstream this stuff to gtk-rs-core as full cairo
depends on a lot more things than are dealt with here, so it would be a
PITA to handle that generally.
This vendoring strips out things that are not used, so the cairo
library that remains:
* Is not internally thread safe; no TLS or mutex support is enabled
in either of them. That's fine because the high level cairo-rs
wrapper is not Send+Sync, which means that rust will only allow
it to be used single threaded anyway.
* Only has the basic recording and image surfaces
* No platform support for win32/xlib/xcb and so on
* Allow set_environment_variables to set the SHELL.
Previously, we'd always set it to the shell from the password
database. Now we do that by default, but if set_environment_variables
has been used, we'll preserve that value for the environment
of the to-be-spawned process
* Clarify the docs:
* Remove the confusing version dependent sections that started
with old behavior and rewrite in terms of the behavior that
has been true for the past year
* I've heard from a few people that they tried to change COMSPEC
on Windows and pain ensued. Try to nudge them to read the
next paragraph that tells them what they are actually supposed
to change.
refs: https://github.com/wez/wezterm/issues/4098
refs: https://github.com/wez/wezterm/issues/4168
closes: https://github.com/wez/wezterm/issues/3816
refs: https://github.com/wez/wezterm/issues/3317
The vertical alignment is wonky, and some glyphs have the wrong
aspect and are missig colors. eg: the watermelon glyph in Noto Color
Emoji (U+1f349).
Turn this off by default, and skip loading fonts that have svg by
default.
The warnings were not noticed in the original PR.
Those warnings were actually errors.
Promote warnings to error in the mapping logic to prevent
this sort of thing from slipping through in the future,
and fixup the errors.
refs: #3935
refs: #3937
