usage: gftools-render-text [-h] {proof,diff} ...

Render strings from a font as a waterfall PNG, or diff two fonts. Subcommands: proof Render a
single font as a waterfall PNG. diff Render before+after waterfalls plus difference image and
animated GIF. Backend defaults to the platform-native rasterizer (CoreText on macOS, DirectWrite
on Windows, FreeType on Linux). Override with ``--backend``.

positional arguments:
  {proof,diff}
    proof       Render a font as a waterfall PNG.
    diff        Render before+after waterfalls plus a difference image and animated GIF.

options:
  -h, --help    show this help message and exit