ink_rect, logical_rect = pglyphstring:Extents(font)
x, y, width, and height fields initialized.
See the documentation for pfont:GetGlyphExtents() for details
about the interpretation of the rectangles.
Examples of logical (red) and ink (green) rects:
- font
- a Pango font
- ink_rect
- table containing the extents of the glyph string as drawn
- logical_rect
- table containing the logical extents of the glyph string