Clip text to within the row we expect

[miniksa]

Summary of the Pull Request

Adjusts DrawGlyphRun method inside DirectX renderer to restrict text
to be clipped within the boundaries of the row.

PR Checklist

• Closes Certain characters taking up more than one line in height #1703
• I work here.
• No tests.
• No docs.
• I am core contributor.

Detailed Description of the Pull Request / Additional comments

For whatever reason, some of these shade glyphs near U+2591 tend to
extend way above the height of where we expect they should. This didn't
look like a problem in conhost because it clipped every draw inside the
bounds. This therefore applies the same clip logic as people don't
really expect text to pour out of the box.

It could, theoretically, get us into trouble later should someone
attempt zalgo text. But doing zalgo text is more of a silliness that
varies in behavior across rendering platforms anyway.

Validation Steps Performed

• Ran the old conhost GDI renderer and observed
• Ran the new Terminal DX renderer and observed
• Made the code change
• Observed that the height and approximate display characteristics of
  the U+2591 shade and neighboring characters now matches with the conhost
  GDI style to stay within its lane.

[ghost]

Hello @miniksa!

Because this pull request has the AutoMerge label, I will be glad to assist with helping to merge this pull request once all check-in policies pass.

Do note that I've been instructed to only help merge pull requests of this repository that have been opened for at least 8 hours, a condition that will be fulfilled in about 7 hours 44 minutes. No worries though, I will be back when the time is right! 😉

p.s. you can customize the way I help with merging this pull request, such as holding this pull request until a specific person approves. Simply @mention me (@msftbot) and give me an instruction to get started! Learn more here.

[miniksa]

@msftbot merge in 1 minute

[ghost]

Hello @miniksa!

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 won't merge this pull request until after the UTC date Fri, 21 Feb 2020 00:24:12 GMT, which is in 1 minute

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".