This commit expands on the prior commits to introduce the concept
of per-window configuration overrides.
Each TermWindow maintains json compatible object value holding
a map of config key -> config value overrides.
When the window notices that the config has changed, the config
file is loaded, the CLI overrides (if any) are applied, and then
finally the per-window overrides, before attempting to coerce
the resultant lua value into a Config object.
This mechanism has some important constraints:
* Only data can be assigned to the overrides. Closures or special
lua userdata object handles are not permitted. This is because
the lifetime of those objects is tied to the lua context in which
they were parsed, which doesn't really exist in the context of
the window.
* Only simple keys are supported for the per-window overrides.
That means that trying to override a very specific field of
a deeply structured value (eg: something like `font_rules[1].italic = false`
isn't able to be expressed in this scheme. Instead, you would
need to assign the entire `font_rules` key. I don't anticipate
this being a common desire at this time; if more advance manipulations
are required, then I have some thoughts on an event where arbitrary
lua modifications can be applied.
The implementation details are fairly straight-forward, but in testing
the two examplary use cases I noticed that some hangovers from
supporting overrides for a couple of font related options meant that the
window-specific config wasn't being honored. I've removed the code that
handled those overrides in favor of the newer more general CLI option
override support, and threaded the config through to the font code.
closes: #469closes: #329
`wezterm`, `wezterm-gui` and `wezterm-mux-server` now all support
a new `--config name=value` CLI option that can be specified
multiple times to supply config overrides.
Since there isn't a simple, direct way to update arbitrary fields
of a struct in Rust (there's no runtime reflection), we do this
work in lua.
The config file returns a config table. Before that is mapped
to the Rust Config type, we have a new phase that takes each
of the `--config` values and applies it to the config table.
For example, you can think of configuration as working like this
if wezterm is started as `wezterm --config foo="bar"`:
```lua
config = load_config_file();
config.foo = "bar";
return config;
```
The `--config name=value` option is split into `name` and `value`
parts. The name part is literally concatenated with `config` in
the generated lua code, so the name MUST be valid in that context.
The `value` portion is literally inserted verbatim as the rvalue in the
assignment. Not quoting or other processing is done, which means
that you can (and must!) use the same form that you would use in
the config file for the RHS. Strings must be quoted. This allows
you to use more complicated expressions on the right hand side,
such as:
```
wezterm --config 'font=wezterm.font("Fira Code")'
```
The overrides stick for the lifetime of the process; even if
you change the config file and reload, then the value specified
by the override will take precedence.
refs: https://github.com/wez/wezterm/issues/469
refs: https://github.com/wez/wezterm/issues/499
This is defined as a trait method on Pane (default: false), and has the
obvious transitive equivalent methods in Tab and Window (eg: if all
contained items are `can_close_without_prompting`, then that container
is also `can_close_without_prompting`).
The intent is to avoid bothering the user to confirm closing a window
when the content is not stateful and doesn't warrant it.
For example: the window that is displayed in the event of a
configuration error really shouldn't prompt to the user to confirm
closing it.
All termwiztermtab panes are `can_close_without_prompting==true`
to effect this policy.
In the future, we could teach LocalPane to lookup the session leader
process against a list of "uninteresting" or "stateless" processes
and return an appropriate result (as suggested in
https://github.com/wez/wezterm/issues/280). That functionality
is NOT part of this commit.
`exit_behavior = "Hold"` will keep the pane alive until explicitly
closed. More details in the docs that are part of this commit.
refs: https://github.com/wez/wezterm/issues/499
The Cascadia Code font has ligatures for `---` that consist of
a triple wide glyph followed by two zero-width glyphs. Rewrite
that into a single glyph that spans three cells and remove the
zero-width glyphs from the shaped info.
refs: https://github.com/wez/wezterm/issues/478
for fonts located by core text, if they are singular TTF files rather
than TTC files, and the font doesn't exactly match the search critiera,
we could loop forever re-parsing the same file over and over again.
This commit restructures the logic to definitively check the number
of contained font entries and constrain the loop to that number.
In addition, it adjusts the name matching, as macos can return
names like "Cascadia Code Roman" when the underlying font is named
"Cascadia Code".
refs: https://github.com/wez/wezterm/issues/475
Connect the gui to the new shaping logic; this means that we
can now correctly render fg/bg color when the cursor moves
through the cells that comprise a ligature.
refs: https://github.com/wez/wezterm/issues/478
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
Refine the colorization logic to make it more of a blending operation.
Previously, we were relying on opengl to carry out blending between
layers on our behalf, but that wasn't perfect.
This commit is inspired by this post:
https://www.puredevsoftware.com/blog/2019/01/22/sub-pixel-gamma-correct-font-rendering/
and factors in the background color when computing the colorized
glyph.
This appears to reduce the dark fringes/edges that we were seeing
before, without noticeably changing the brightness of the result.
refs: #491
https://learnopengl.com/Advanced-Lighting/Gamma-Correction suggests
some good practices:
* Only enable SRGB output on the final draw call, so that all prior
stages can operate on linear values and avoid converting to/from
linear multiple times.
* The SRGBA textures automatically linearize when sampled, but:
* The RGB data must be SRGB (non-linear)
* The A channel is assumed to be linear!
This commit nudges us closer to that by:
* Converting the freetype coverage map from its linear value to
non-linear when rasterizing.
* Splitting the shader files into one per stage (background, lines,
glyphs) and only setting outputs_srgb for the glyph stage
refs: #491
In the earlier times wezterm supported different font rasterizers,
and the configuration was a bit vague and generic to accomodate
differences in how the rasterizers worked.
Since then, we've standardized on freetype.
One of the things that's been bothering me for a while is that
we have some fiddly logic to transform from the config to the freetype
flags.
This commit does away with the transformation and simply exposes
the two sets of freetype options.
The main thing that I expect people to play with is
`freetype_load_target` which can have one of the following values:
```
pub enum FreeTypeLoadTarget {
/// This corresponds to the default hinting algorithm, optimized
for standard gray-level rendering.
Normal,
/// A lighter hinting algorithm for non-monochrome modes. Many
generated glyphs are more fuzzy but better resemble its original
shape. A bit like rendering on Mac OS X. This target implies
FT_LOAD_FORCE_AUTOHINT.
Light,
/// Strong hinting algorithm that should only be used for
monochrome output. The result is probably unpleasant if the glyph
is rendered in non-monochrome modes.
Mono,
/// A variant of Normal optimized for horizontally decimated LCD displays.
HorizontalLcd,
/// A variant of Normal optimized for vertically decimated LCD displays.
VerticalLcd,
}
```
I expect most people will want to set this to one of `Normal`, `Light`
or `HorizontalLcd`. `HorizontalLcd` is what `font_antialias=Subpixel`
used to select.
refs: #491
