terminal/.github/actions/spelling
Dustin L. Howett 4b7d955012
dx: add support for inverting all types of cursor (#9665)
This commit introduces support for inverting all types of cursor.

To invert the display without re-rendering any text, we draw the cursor
into a command list and then compose the command list with the existing
renderer using the MASK_INVERT composition flag.

This wouldn't normally work with our renderer because there is no
_background_ color to invert in some cases (such as when acrylic is in
use.)

To work around that, we're taking advantage of @zadjii-msft's two-pass
cursor renderer.

To properly invert the cursor over a transparent background:
(Examples are given below for two cursor types, but this applies to all
of them.)

First, we'll draw a "backplate" in the user's requested background color
(with the alpha channel set to 0xFF). (`firstPass` == true)

    EMPTY BOX  FILLED BOX
    =====      =====
    =   =      =====
    =   =      =====
    =   =      =====
    =====      =====

Second, the glyph is drawn (outside of the cursor renderer).

    EMPTY BOX  FILLED BOX
    ==A==      ==A==
    =A A=      =A=A=
    AAAAA      AAAAA
    A   A      A===A
    A===A      A===A

Last, we'll draw the cursor again in all white and use that as the
*mask* for inverting the already-drawn pixels. (`firstPass` == false) (#
= mask, a = inverted A)

    EMPTY BOX  FILLED BOX
    ##a##      ##a##
    #A A#      #a#a#
    aAAAa      aaaaa
    a   a      a###a
    a###a      a###a

Related to #9610

## Validation Steps Performed
Manual visual validation in all configurations.
2021-04-02 11:18:06 +00:00
..
dictionary Implement Default Terminal (#7489) 2021-03-26 17:09:49 -05:00
expect dx: add support for inverting all types of cursor (#9665) 2021-04-02 11:18:06 +00:00
patterns Spec for Windows Terminal Process Model 2.0 (#7240) 2021-02-05 06:19:32 -06:00
advice.txt ci: update to Spell check to 0.0.17a (#9014) 2021-02-03 11:17:38 -08:00
excludes.txt Auto-format our XAML files and enforce in CI (#9589) 2021-03-29 17:09:38 -05:00