fn font_or_actual(
font_value: f64,
font_metric_name: &str,
actual_value: f64,
actual_metric_name: &str,
) -> Result<f64, KeyPaintError>Expand description
Return the distance between the baseline of some measured text and the bottom of whatever would be avove it. We use font ascent instead of actual ascent, so that we get an appropriate amount of space between lines. This also gives us some consistency of appearance. However, if the font ascent metric is not available, we use the actual ascent with a “fudge factor”.