I was watching a video about vectorized instructions and I wanted to
try out some new things, as I had never written AVX code before.
This commit is the result of this tiny Thursday morning detour into
AVX land. It improves performance of `TextColor::GetColor` by about 3x.
## Validation Steps Performed
* Default colors are still properly shifted +8 ✔️
We were using std::basic_string_view as a stand-in for std::span so that
we could change over all at once when C++20 dropped with full span
support. That day's not here yet, but as of 54a7fce3e we're using GSL 3,
whose span is C++20-compliant.
This commit replaces every instance of basic_string_view that was not
referring to an actual string with a span of the appropriate type.
I moved the `const` qualifier into span's `T` because while
`basic_string_view.at()` returns `const T&`, `span.at()` returns `T&`
(without the const). I wanted to maintain the invariant that members of
the span were immutable.
* Mechanical Changes
* `sv.at(x)` -> `gsl::at(sp, x)`
* `sv.c{begin,end}` -> `sp.{begin,end}` (span's iterators are const)
I had to replace a `std::basic_string<>` with a `std::vector<>` in
ConImeInfo, and I chose to replace a manual array walk in
ScreenInfoUiaProviderBase with a ranged-for. Please review those
specifically.
This will almost certainly cause a code size regression in Windows
because I'm blowing out all the PGO counts. Whoops.
Related: #3956, #975.
## Summary of the Pull Request
This PR adds support for the `SGR 8` and `SGR 28` escape sequences,
which enable and disable the _concealed/invisible_ graphic rendition
attribute. When a character is output with this attribute set, it is
rendered with the same foreground and background colors, so the text is
essentially invisible.
## PR Checklist
* [x] Closes#6876
* [x] CLA signed.
* [x] Tests added/passed
* [ ] Documentation updated.
* [ ] Schema updated.
* [x] I've discussed this with core contributors already. Issue number
where discussion took place: #6876
## Detailed Description of the Pull Request / Additional comments
Most of the framework for this attribute was already implemented, so it
was just a matter of updating the `TextAttribute::CalculateRgbColors`
method to make the foreground the same as the background when the
_Invisible_ flag was set. Note that this has to happen after the
_Reverse Video_ attribute is applied, so if you have white-on-black text
that is reversed and invisible, it should be all white, rather than all
black.
## Validation Steps Performed
There were already existing SGR unit tests covering this attribute in
the `ScreenBufferTests`, and the `VtRendererTest`. But I've added to the
`AdapterTest` which verifies the SGR sequences for setting and resetting
the attribute, and I've extended the `TextAttributeTests` to verify that
the color calculations return the correct values when the attribute is
set.
I've also manually confirmed that we now render the _concealed text_
values correctly in the _ISO 6429_ tests in Vttest. And I've manually
tested the output of _concealed_ when combined with other attributes,
and made sure that we're matching the behaviour of most other terminals.
## Summary of the Pull Request
This PR adds support for the `SGR 2` escape sequence, which enables the
ANSI _faint_ graphic rendition attribute. When a character is output
with this attribute set, it uses a dimmer version of the active
foreground color.
## PR Checklist
* [x] Closes#6703
* [x] CLA signed.
* [x] Tests added/passed
* [ ] Documentation updated.
* [ ] Schema updated.
* [x] I've discussed this with core contributors already. Issue number where discussion took place: #6703
## Detailed Description of the Pull Request / Additional comments
There was already an `ExtendedAttributes::Faint` flag in the
`TextAttribute` class, but I needed to add `SetFaint` and `IsFaint`
methods to access that flag, and update the `SetGraphicsRendition`
methods of the two dispatchers to set the attribute on receipt of the
`SGR 2` sequence. I also had to update the existing `SGR 22` handler to
reset _Faint_ in addition to _Bold_, since they share the same reset
sequence. For that reason, I thought it a good idea to change the name
of the `SGR 22` enum to `NotBoldOrFaint`.
For the purpose of rendering, I've updated the
`TextAttribute::CalculateRgbColors` method to return a dimmer version of
the foreground color when the _Faint_ attribute is set. This is simply
achieved by dividing each color component by two, which produces a
reasonable effect without being too complicated. Note that the _Faint_
effect is applied before _Reverse Video_, so if the output it reversed,
it's the background that will be faint.
The only other complication was the update of the `Xterm256Engine` in
the VT renderer. As mentioned above, _Bold_ and _Faint_ share the same
reset sequence, so to forward that state over conpty we have to go
through a slightly more complicated process than with other attributes.
We first check whether either attribute needs to be turned off to send
the reset sequence, and then check if the individual attributes need to
be turned on again.
## Validation
I've extended the existing SGR unit tests to cover the new attribute in
the `AdapterTest`, the `ScreenBufferTests`, and the `VtRendererTest`,
and added a test to confirm the color calculations when _Faint_ is set
in the `TextAttributeTests`.
I've also done a bunch of manual testing with all the different VT color
types and confirmed that our output is comparable to most other
terminals.
This is a refactoring of the renderer color calculations to simplify the
implementation, and to make it easier to support additional
color-altering rendition attributes in the future (e.g. _faint_ and
_conceal_).
## References
* This is a followup to PRs #3817 and #6809, which introduced additional
complexity in the color calculations, and which suggested the need for
refactoring.
## Detailed Description of the Pull Request / Additional comments
When we added support for `DECSCNM`, that required the foreground and
background color lookup methods to be able to return the opposite of
what was requested when the reversed mode was set. That made those
methods unnecessarily complicated, and I thought we could simplify them
considerably just by combining the calculations into a single method
that derived both colors at the same time.
And since both conhost and Windows Terminal needed to perform the same
calculations, it also made sense to move that functionality into the
`TextAttribute` class, where it could easily be shared.
In general this way of doing things is a bit more efficient. However, it
does result in some unnecessary work when only one of the colors is
required, as is the case for the gridline painter. So to make that less
of an issue, I've reordered the gridline code a bit so it at least
avoids looking up the colors when no gridlines are needed.
## Validation Steps Performed
Because of the API changes, quite a lot of the unit tests had to be
updated. For example instead of verifying colors with two separate calls
to `LookupForegroundColor` and `LookupBackgroundColor`, that's now
achieved with a single `LookupAttributeColors` call, comparing against a
pair of values. The specifics of the tests haven't changed though, and
they're all still working as expected.
I've also manually confirmed that the various color sequences and
rendition attributes are rendering correctly with the new refactoring.
Essentially what this does is map the default legacy foreground and
background attributes (typically white on black) to the `IsDefault`
color type in the `TextColor` class. As a result, we can now initialize
the buffer for "legacy" shells (like PowerShell and cmd.exe) with
default colors, instead of white on black. This fixes the startup
rendering in conpty clients, which expect an initial default background
color. It also makes these colors update appropriately when the default
palette values change.
One complication in getting this to work, is that the console permits
users to change which color indices are designated as defaults, so we
can't assume they'll always be white on black. This means that the
legacy-to-`TextAttribute` conversion will need access to those default
values.
Unfortunately the defaults are stored in the conhost `Settings` class
(the `_wFillAttribute` field), which isn't easily accessible to all the
code that needs to construct a `TextAttribute` from a legacy value. The
`OutputCellIterator` is particularly problematic, because some iterator
types need to generate a new `TextAttribute` on every iteration.
So after trying a couple of different approaches, I decided that the
least worst option would be to add a pair of static properties for the
legacy defaults in the `TextAttribute` class itself, then refresh those
values from the `Settings` class whenever the defaults changed (this
only happens on startup, or when the conhost _Properties_ dialog is
edited).
And once the `TextAttribute` class had access to those defaults, it was
fairly easy to adapt the constructor to handle the conversion of default
values to the `IsDefault` color type. I could also then simplify the
`TextAttribute::GetLegacyAttributes` method which does the reverse
mapping, and which previously required the default values to be passed
in as a parameter
VALIDATION
I had to make one small change to the `TestRoundtripExhaustive` unit
test which assumed that all legacy attributes would convert to legacy
color types, which is no longer the case, but otherwise all the existing
tests passed as is. I added a new unit test verifying that the default
legacy attributes correctly mapped to default color types, and the
default color types were mapped back to the correct legacy attributes.
I've manually confirmed that this fixed the issue raised in #5952,
namely that the conhost screen is cleared with the correct default
colors, and also that it is correctly refreshed when changing the
palette from the properties dialog. And I've combined this PR with
#6506, and confirmed that the PowerShell and the cmd shell renderings in
Windows Terminal are at least improved, if not always perfect.
This is a prerequisite for PR #6506Closes#5952
This is an attempt to simplify the SGR (Select Graphic Rendition)
implementation in conhost, to cut down on the number of methods required
in the `ConGetSet` interface, and pave the way for future improvements
and bug fixes. It already fixes one bug that prevented SGR 0 from being
correctly applied when combined with meta attributes.
* This a first step towards fixing the conpty narrowing bugs in issue
#2661
* I'm hoping the simplification of `ConGetSet` will also help with
#3849.
* Some of the `TextAttribute` refactoring in this PR overlaps with
similar work in PR #1978.
## Detailed Description of the Pull Request / Additional comments
The main point of this PR was to simplify the
`AdaptDispatch::SetGraphicsRendition` implementation. So instead of
having it call a half a dozen methods in the `ConGetSet` API, depending
on what kinds of attributes needed to be set, there is now just one call
to get current attributes, and another call to set the new value. All
adjustments to the attributes are made in the `AdaptDispatch` class, in
a simple switch statement.
To help with this refactoring, I also made some change to the
`TextAttribute` class to make it easier to work with. This included
adding a set of methods for setting (and getting) the individual
attribute flags, instead of having the calling code being exposed to the
internal attribute structures and messing with bit manipulation. I've
tried to get rid of any methods that were directly setting legacy, meta,
and extended attributes.
Other than the fix to the `SGR 0` bug, the `AdaptDispatch` refactoring
mostly follows the behaviour of the original code. In particular, it
still maps the `SGR 38/48` indexed colors to RGB instead of retaining
the index, which is what we ultimately need it to do. Fixing that will
first require the color tables to be unified (issue #1223), which I'm
hoping to address in a followup PR.
But for now, mapping the indexed colors to RGB values required adding an
an additional `ConGetSet` API to lookup the color table entries. In the
future that won't be necessary, but the API will still be useful for
other color reporting operations that we may want to support. I've made
this API, and the existing setter, standardise on index values being in
the "Xterm" order, since that'll be essential for unifying the code with
the terminal adapter one day.
I should also point out one minor change to the `SGR 38/48` behavior,
which is that out-of-range RGB colors are now ignored rather than being
clamped, since that matches the way Xterm works.
## Validation Steps Performed
This refactoring has obviously required corresponding changes to the
unit tests, but most were just minor updates to use the new
`TextAttribute` methods without any real change in behavior. However,
the adapter tests did require significant changes to accommodate the new
`ConGetSet` API. The basic structure of the tests remain the same, but
the simpler API has meant fewer values needed to be checked in each test
case. I think they are all still covering the areas there were intended
to, though, and they are all still passing.
Other than getting the unit tests to work, I've also done a bunch of
manual testing of my own. I've made sure the color tests in Vttest all
still work as well as they used to. And I've confirmed that the test
case from issue #5341 is now working correctly.
Closes#5341
Generated by https://github.com/jsoref/spelling `f`; to maintain your repo, please consider `fchurn`
I generally try to ignore upstream bits. I've accidentally included some items from the `deps/` directory. I expect someone will give me a list of items to drop, I'm happy to drop whole files/directories, or to split the PR into multiple items (E.g. comments/locals/public).
Closes#4294
