Fix RTL regression (fixes #4779)

[schorrm]

Summary of the Pull Request

This fixes the RTL regression caused in #4747. We create the rectangle taking the direction (through the BiDi Level) into account, and then the rendering works again. The GlyphRun shaping could still probably use some work to be a polished thingy, and there are still issues with RTL getting chopped up a lot when there's font fallback going on, but this fixes the regression, and it's now functional again.

References

#4779 #4747

PR Checklist

• Closes RTL is worse after #4747 #4779
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Detailed Description of the Pull Request / Additional comments

The baseline is actually direction dependent. So when it was being initialized, the unconditional baseline as left broke it, setting the box off to right of the text. We just check if the GlyphRun->bidiLevel is set, and if so, we adjust it so that the baseline lines up with the right, not with the left.

Validation Steps Performed

[zadjii-msft]

This seems totally reasonable to me, but I want to make sure this gets the renderer-guru's approval

[zadjii-msft]

@msftbot make sure @miniksa signs off on this

[ghost]

Hello @zadjii-msft!

Because you've given me some instructions on how to help merge this pull request, I'll be modifying my merge approach. Here's how I understand your requirements for merging this pull request:

• I'll only merge this pull request if it's approved by @miniksa

If this doesn't seem right to you, you can tell me to cancel these instructions and use the auto-merge policy that has been configured for this repository. Try telling me "forget everything I just told you".

[zadjii-msft]

uhg github, trim the whitespace plz

[miniksa]

Huh. Alright then. Looks good to me. Thank you.

[DHowett-MSFT]

@msftbot merge this in 3 minutes

[ghost]

Hello @DHowett-MSFT!

Because you've given me some instructions on how to help merge this pull request, I'll be modifying my merge approach. Here's how I understand your requirements for merging this pull request:

• I'll only merge this pull request if it's approved by @miniksa
• I won't merge this pull request until after the UTC date Mon, 04 May 2020 16:14:08 GMT, which is in 3 minutes

If this doesn't seem right to you, you can tell me to cancel these instructions and use the auto-merge policy that has been configured for this repository. Try telling me "forget everything I just told you".

[DHowett-MSFT]

Thank you, @schorrm!

[ghost]

🎉Windows Terminal Release Candidate v0.11.1251.0 (1.0rc1) has been released which incorporates this pull request.:tada:

Handy links:

• Release Notes
• Store Download

[DHowett]

🎉 Once again, thanks for the contribution!

This pull request was included in a set of conhost changes that was just
released with Windows Insider Build 20161.