Font

A GlyphMeasurer can compute line metrics from a font. Implementations of this trait are specific to a rendering context

Holds line metrics data

For the meaning of the members see https://docs.oracle.com/javase/tutorial/2d/text/fontconcepts.html

Ascent is the distance from the baseline to the typical highest point of the letter (ascender line). Descent is the distance from the baseline to the typical lowest point of the letter (descender line). Leading is the gap between lines, i.e. distance from the descender line to the next line's ascender line.