I'm making a presentation mode where I want to vertically center some text in the window, which is the only window in the frame. I'm using a custom face so I can control how large the font is.
To horizontally center the text, I can use
window-max-chars-per-line with the
face argument, so I can get the number of characters put in a line.
But I also want to know how many lines are in the window. There's
window-body-height, but that doesn't let me specify a face.
How can I tell how tall a window is in lines of a specific face?