Environment

Cascadia Code version number: 2009.22
Application (with version) used to display text: Windows Terminal dev branch
OS platform and version: 10.0.19042.804
Screen resolution (i.e. 220dpi):  4K @ 200% 

Any other software? No

Steps to reproduce

Running cmatrix in Windows Terminal with no font specified (fallback to Cascadia Mono, I think) & Hack.

Expected behavior

The performance should be about the same.

Actual behavior

This is the CPU usage breakdown:

Cascadia:

Hack:

A significant more amount of CPU is consumed with Cascadia.

The reason behind this is that for some reason, analyzer->GetTextComplexity() gives unexpected result for pure ASCII strings when using Cascadia.

For example, take a random string produced by cmatrix:

r   8   1   z $   J   p `   X \ M   o ;             E   o d A G 9   O                       T

With Cascadia GetTextComplexity reports this result:

• Pos 0 - 17 : Simple
• Pos 18 : Complex
• Pos 18 - 97 : Simple

However with Hack, the entire text is reported as simple so that we can optimize the layout process.

I've seen a dozen of examples. The letter J seems to be the cause. I have no idea why the letter J is so special.