Hello Kusanagi-san,
I am trying to do more testing with tategaki and i am finding that your original tests are incorrect because of the vertical.ttf font you have build.
Windows appears to be very very picky about when it will to a vert or vrt2 replacement. I have run the test with MS UI Gothic, and i get behavior where "@MS UI Gothic" of U+2025 is a different glyph than for just "MS UI Gothic" contrary to your tests.
I have spent a day or so trying to get fontforge to build a ttf font that windows will do vrt2 or vert glyph replacements on and I cannot get it to work. Nothing I build seems to meet the requirements.
I am thinking of abandoning the vertical.sfd and ttf and instead just running the test with MS UI Gothic or something else that is a font that Microsoft properly does vert replacements on.
Do you have any insight or help here that we could do to make these tests function properly?
thanks! -aric