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mirror of https://github.com/wez/wezterm.git synced 2024-12-24 13:52:55 +03:00
wezterm/termwiz
Wez Furlong 0324ff66f0 wezterm: add experimental_bidi config option and very basic bidi
This commit is larger than it appears to due fanout from threading
through bidi parameters.  The main changes are:

* When clustering cells, add an additional phase to resolve embedding
  levels and further sub-divide a cluster based on the resolved bidi
  runs; this is where we get the direction for a run and this needs
  to be passed through to the shaper.
* When doing bidi, the forced cluster boundary hack that we use to
  de-ligature when cursoring through text needs to be disabled,
  otherwise the cursor appears to push/rotate the text in that
  cluster when moving through it! We'll need to find a different
  way to handle shading the cursor that eliminates the original
  cursor/ligature/black issue.
* In the shaper, the logic for coalescing unresolved runs for font
  fallback assumed LTR and needed to be adjusted to cluster RTL.
  That meant also computing a little index of codepoint lengths.
* Added `experimental_bidi` boolean option that defaults to false.
  When enabled, it activates the bidi processing phase in clustering
  with a strong hint that the paragraph is LTR.

This implementation is incomplete and/or wrong for a number of cases:

* The config option should probably allow specifying the paragraph
  direction hint to use by default.
* https://terminal-wg.pages.freedesktop.org/bidi/recommendation/paragraphs.html
  recommends that bidi be applied to logical lines, not physical
  lines (or really: ranges within physical lines) that we're doing
  at the moment
* The paragraph direction hint should be overridden by cell attributes
  and other escapes; see 85a6b178cf

and probably others.

However, as of this commit, if you `experimental_bidi=true` then

```
echo This is RTL -> عربي فارسی bidi
```

(that text was sourced from:
https://github.com/microsoft/terminal/issues/538#issuecomment-677017322)

then wezterm will display the text in the same order as the text
renders in Chrome for that github comment.

```
; ./target/debug/wezterm --config experimental_bidi=false ls-fonts --text "عربي فارسی ->"
LeftToRight
 0 ع    \u{639}      x_adv=8  glyph=300  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
 2 ر    \u{631}      x_adv=3.78125 glyph=273  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
 4 ب    \u{628}      x_adv=4  glyph=244  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
 6 ي    \u{64a}      x_adv=4  glyph=363  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
 8      \u{20}       x_adv=8  glyph=2    wezterm.font("Operator Mono SSm Lig", {weight="DemiLight", stretch="Normal", italic=false})
                                      /Users/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontDirs
 9 ف    \u{641}      x_adv=11 glyph=328  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
11 ا    \u{627}      x_adv=4  glyph=240  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
13 ر    \u{631}      x_adv=3.78125 glyph=273  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
15 س    \u{633}      x_adv=10 glyph=278  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
17 ی    \u{6cc}      x_adv=4  glyph=664  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
19      \u{20}       x_adv=8  glyph=2    wezterm.font("Operator Mono SSm Lig", {weight="DemiLight", stretch="Normal", italic=false})
                                      /Users/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontDirs
20 -    \u{2d}       x_adv=8  glyph=276  wezterm.font("Operator Mono SSm Lig", {weight="DemiLight", stretch="Normal", italic=false})
                                      /Users/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontDirs
21 >    \u{3e}       x_adv=8  glyph=338  wezterm.font("Operator Mono SSm Lig", {weight="DemiLight", stretch="Normal", italic=false})
                                      /Users/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontDirs
```

```
; ./target/debug/wezterm --config experimental_bidi=true ls-fonts --text "عربي فارسی ->"
RightToLeft
17 ی    \u{6cc}      x_adv=9  glyph=906  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
15 س    \u{633}      x_adv=10 glyph=277  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
13 ر    \u{631}      x_adv=4.78125 glyph=272  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
11 ا    \u{627}      x_adv=4  glyph=241  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
 9 ف    \u{641}      x_adv=5  glyph=329  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
 8      \u{20}       x_adv=8  glyph=2    wezterm.font("Operator Mono SSm Lig", {weight="DemiLight", stretch="Normal", italic=false})
                                      /Users/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontDirs
 6 ي    \u{64a}      x_adv=9  glyph=904  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
 4 ب    \u{628}      x_adv=4  glyph=243  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
 2 ر    \u{631}      x_adv=5  glyph=273  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
 0 ع    \u{639}      x_adv=6  glyph=301  wezterm.font(".Geeza Pro Interface", {weight="Regular", stretch="Normal", italic=false})
                                      /System/Library/Fonts/GeezaPro.ttc index=2 variation=0, CoreText
LeftToRight
 0      \u{20}       x_adv=8  glyph=2    wezterm.font("Operator Mono SSm Lig", {weight="DemiLight", stretch="Normal", italic=false})
                                      /Users/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontDirs
 1 -    \u{2d}       x_adv=8  glyph=480  wezterm.font("Operator Mono SSm Lig", {weight="DemiLight", stretch="Normal", italic=false})
                                      /Users/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontDirs
 2 >    \u{3e}       x_adv=8  glyph=470  wezterm.font("Operator Mono SSm Lig", {weight="DemiLight", stretch="Normal", italic=false})
                                      /Users/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontDirs
;
```

refs: https://github.com/wez/wezterm/issues/784
2022-01-25 09:00:53 -07:00
..
data Respect emoji-variation-sequences.txt 2021-11-25 14:37:24 -07:00
examples Fix typo in strip-ansi-escapes --help output 2022-01-18 06:18:15 -08:00
src wezterm: add experimental_bidi config option and very basic bidi 2022-01-25 09:00:53 -07:00
Cargo.toml wezterm: add experimental_bidi config option and very basic bidi 2022-01-25 09:00:53 -07:00
LICENSE.md restructure termwiz tree prior to merging into wezterm repo 2018-08-05 07:55:30 -07:00
README.md termwiz: cut 0.9.0 release 2020-05-17 12:05:46 -07:00

Terminal Wizardry

This is a rust crate that provides a number of support functions for applications interested in either displaying data to a terminal or in building a terminal emulator.

It is currently in active development and subject to fairly wild sweeping changes.

Included functionality:

  • Surface models a terminal display and its component Cells
  • Terminal attributes are aware of modern features such as True Color, Hyperlinks and will also support sixel and iterm style terminal graphics display.
  • Surfaces include a log of Changes and an API for consuming and applying deltas. This is a powerful building block for synchronizing screen instances.
  • Escape sequence parser decodes inscrutable escape sequences and gives them semantic meaning, making the code that uses them clearer. The decoded escapes can be re-encoded, allowing applications to start with the semantic meaning and emit the appropriate escape sequence without embedding obscure binary bytes.
  • Capabilities allows probing for terminal capabilities that may not be included in the system terminfo database, and overriding them in an embedding application.
  • Terminal trait provides an abstraction over unix style ttys and Windows style console APIs. Changes from Surface can be rendered to Terminals. Terminals allow decoding mouse and keyboard inputs in both blocking or non-blocking mode.
  • Widget trait allows composition of UI elements at a higher level.
  • LineEditor implements shell-like line editing functionality.

Windows Support

Termwiz understands how to work with both the legacy console APIs and the new PTY and virtual terminal features available in Windows 10, allowing for true color terminal applications on Windows 10.

Documentation

https://docs.rs/termwiz