Glyph struct
#include <Jazz2/UI/FontFormat.h>
Metrics of a single glyph.
X, Y, Width and Height bound the inked pixels inside the atlas. BearingX and BearingY place that box relative to the pen position, and Advance is how far the pen then moves - so a trimmed glyph draws exactly where a fixed-cell one used to.
A glyph with no ink at all (a space) has a zero Width and Height and is never drawn, only advanced over.