Pixel fonts

FONTS (pxart help fonts)
  export FONT.px[:SEL] --font F.woff2|F.woff|F.ttf [--kern K.kern]
      A pixel font from one file: each frame is a glyph, the frame's width its advance (the
      blank columns on its right space it from the next), and every pixel that isn't
      transparent is ink. Each glyph's ink is traced into its union outline (closed loops
      around the pixels, no seams), crisp at any size that makes 1 px whole screen pixels
      (an em of 10 rows: 10px, 20px...). Every glyph is the same height; a .notdef (a
      hollow box) comes first. The same source writes the same bytes.
      A frame's id is its glyph's name, and the name says the character: a name from
      Adobe's glyph list (A, a, zero, period, comma, quoteright, eacute, space), uniXXXX or
      uXXXXX (uni00A0, u1F600), or any name an @font 'map' line gives code points. A frame
      with no character, of another height, or claiming a character another frame has is
      E_GLYPH; FILE:SEL exports only the glyph frames.
      An @font section sets the font's metrics, a line each, all optional:
          @font
          family Tiny Sans          the family name (default: the file's stem)
          weight 600                the weight (400); style: its name (from weight: SemiBold)
          baseline 8                rows above the baseline (the frames' height: none below)
          unit 100                  font units per pixel (100); upm: the em (unit x height)
          ascent 9                  the line box above the baseline, in px (baseline)
          descent 3                 and below it (the rows under the baseline)
          cap 7                     cap height in px (H's ink); xheight: x's
          map bullet U+2022         a name's code points (one or more)
      and version (1.000), vendor (4 letters), license, psname (family-style, no spaces).
      Kerning: lines 'LEFTS RIGHTS PX' in an @kern section, or in --kern K.kern ('#' starts
      a comment line; its lines come after the section's, and a later line wins a pair):
      every character in LEFTS followed by every one in RIGHTS moves PX pixels (negative:
      closer). 'T aceo.,: -2' tucks them under T's bar. A pair that would make its glyphs
      touch, even at a corner, is E_KERN.
      In the .px, a run can't start with '#' or '@' (a comment, a section).
      Put @font and @kern after the palette, between frames or at the end (edits write them
      last); check --strict takes them. Errors are said all at once, at file:line, and
      nothing is written: E_FONT (an @font line), E_GLYPH, E_KERN.
      Needs fontTools, and brotli for .woff2: pip install fonttools brotli.