It is the code used in the excellent article Character Formatting Extensions with DirectWrite from Charles Petzold.
Just wanted to make sure that it doesn't get lost (Capture on web archive here in case the link above doesn't work anymore)
NOTE
The project does not compile.
If you want to make a PR to make it working, fair enough, but it might be quite some work to revive a project that is using 10 years old VC++/Windows 8.1 API! 😅
The code didn't have a license, so I picked up MIT with Charles Petzold in its copyrighter. Hope it is ok!