Typography Line Terms

See: https://en.wikipedia.org/wiki/Typeface#Font_metrics

Windows terminology is slightly different:

/* Example em55x55 H1 font @ 192dpi:
    _   _                   _              ___    <- y:0
   (_)_(_)                 | |             ___ /\    "diacritics circumflex"
     / \   __ _ _   _ _ __ | |_ ___ _ __       ||
    / _ \ / _` | | | | '_ \| __/ _ \ '_ \      ||    .ascend:30
   / ___ \ (_| | |_| | |_) | ||  __/ | | |     ||     max extend above baseline
  /_/   \_\__, |\__, | .__/ \__\___|_| |_| ___ || <- .baseline:44
           __/ | __/ | |                       ||    .descend:11
          |___/ |___/|_|                   ___ \/     max height of descenders
                                                  <- .height:55
  em: 55x55
  ascender for "diacritics circumflex" is (h:55 - a:30 - d:11) = 14
*/