## Open issues

- move these to GH issues

- documentation:
  - contrib (should all be function that works with no args and returns a gauge)
  - g3.config.debug.alignment placeholder gauge
  - double check and align tutorial, e.g. g3.panel()...grid(true).append(...)
  - common errors - create a panel but not draw it; forget () => in contrib;
  - create an observablehq demo
  - could add animated gifs in README via:
        https://superuser.com/questions/556029/how-do-i-convert-a-video-to-gif-using-ffmpeg-with-reasonable-quality

        ffmpeg -ss 0 -t 5 -i flightdemo.mov -vf "fps=10,scale=630:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" -loop 0 flightdemo.gif

- bugs:
  - fix drop-shadow for window cutout in altitudeDHC2 - apply to mask?

- improvements:
  - add gauge.instance(qualifier) which returns deferred drawing function setting local qualifiers []
  - change panel.url() => panel.source() and support a function or URL
  - switch to a recursive setTimeout rather than setInterval
  - more throw messages. e.g. for g.measure(2) should be g.measure()(2) type of 2 isn't function
  - gaugeface window should take a ... of windows, see flight altitude
  - metric update could diff w.r.t. prior metrics to avoid no-op updates
  - metric update could warn to console when expected metric(s) are missing in the initial update [done?]

- features:
  - cylindrical projection axis style for a magnetic compass, where we're looking at a disc edge on.
    an [orthographic globe projection](https://github.com/d3/d3-geo#geoOrthographic)
    would also work better 360 loop/roll attitude indicator
  - custom tick mark shape option for VSI arrows
  - indicateOdometer - maybe indicateText option? - https://github.hubspot.com/odometer/
    or a collection of cylindrical self-indicators with a form of snapscale
  - indicateBall - two axis metrics, using g3 projection
  - add more standard pointer shapes, e.g. https://upload.wikimedia.org/wikipedia/commons/b/bc/Watch_hands_styles_fr.svg

- ideas:
  - how can we reuse common patterns, e.g. subdial formatting in speedmaster
  - similar, what if I want several copies of same gauge driven by different metrics, like left & right engine
  - re-usability is not great, e.g. draw & modify different versions of a gauge, or reuse tick labeling components