Box drawing characters are not antialiased

[armak]

Environment

Windows build number: Microsoft Windows [Version 10.0.18362.592]
Windows Terminal version (if applicable): Version: 1.0.1401.0
Any other software? No.

Steps to reproduce

1. Install the latest 1.x version of Windows Terminal and open a WSL terminal.
2. Download and display the UTF-8 Demo Text, for an example
   $ curl https://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-demo.txt

Expected behavior

The box drawings are properly rasterized with antialiasing in similar fashion to the rest of the text. Here is an example from Fluent Terminal using the Inconsolata font:

(Note: I'm not necessarily saying this is perfect either, but it's at least closer to what would be an acceptable and more consistent result.)

Actual behavior

The box drawing glyphs are severely aliased, unlike any other text, with visible pixel gaps in diagonal elements, and generally just look really bad. Rendered in the latest stable Windows Terminal version using the Inconsolata font (size 10pt):

This behavior is not just limited to Inconsolata, but happens with every font, and every size. Here is for an example Cascadia Mono in different sizes:
8pt

10pt

12pt

This behavior was introduced recently in the RC versions, and I assume 0.11.1333.0 in specific since it included #5743 which altered the way box drawing glyphs were handled. Prior versions had alignment issues with these glyphs that the PR aimed to fix, but at least the glyphs were still rendered nicely individually, with a similar, comparable output to what Fluent Terminal produces.

[j4james]

I think this is will probably be covered by issue #5897.

[DHowett]

Linking, but not closing this. Thanks.

[oising]

I add that utf8 file to the repo last year some time: https://github.com/microsoft/terminal/blob/master/doc/reference/UTF8-torture-test.txt

[oising]

It's not too bad at all with Fira Code:

[j4james]

The diagonals are terrible though (U+2571, U+2572, and U+2573). These are "box drawing" characters - they're meant to connect together.

[armak]

@oising Definitely doesn't look like that for me. This is Fira Code at 10pt:

[zadjii-msft]

From #8614

Steps to reproduce

Start Windows Terminal (defaults to PowerShell) and Windows PowerShell (that runs in Windows Console) and log in using ssh in PowerShell to a Raspberry Pi with BOINC and boinctui and run that in each.

Expected behavior

That the scrollbar should be without gaps in Terminal like it is in Console. Console here:

(The Xbox Game Bar using Alt+Win+PrtSc cut out the lower part of the Window with the status bar, but it is there in reality.)

Actual behavior

The scrollbar has gaps in Terminal. Terminal with original settings (generated by Windows Terminal 1.4.3141.0) here:

[leduyquang753]

With the new code-driven box-drawing character rendering feature, the rectangles are also not antialiased. This column has 8 steps and with the column width being 6 pixels here it appears there are only correspondingly 6 steps.

Not sure if this should be made a separate issue.