Which side of pos the query point fell on: 0 upstream (the end of
the preceding glyph), 1 downstream (the start of the following one).
It is what decides where a caret sits at a line wrap.
pos
pos:number
Offset into the paragraph's text, in UTF-16 code units.
A text position, as returned by Paragraph.getGlyphPositionAtCoordinate.
🧪 Not in the HTML Canvas standard.