Discussion on how to fix centering of jaggy maps

[roblabs]

Issue — ScrollyTelling for this repo is based on a line with >1300 coordinates. When the scroll event fires, then the center of the map is updated, potentially too many times. Source of the problem —  It's possible that when the scroll event is fired, that the map center could be updated every coordinate in the line.

• This particular repo is copy (not fork) of an original project, https://github.com/willymaps/scrollydrive
  • The original blog post, by FormerSpatial.com, also shows the center jumping around.  See this link to section 6 of the blog post. FormerSpatial did an excellent job making lines work in ScrollyTelling.
  • The original source, https://github.com/willymaps/scrollydrive, is where any fixes should be done
• The source code in this repo that does the centering is something called jumpTo
  • Mapbox API Reference for jumpTo
  • Which relies on CameraOptions

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Here are some detailed thoughts on how to solve (all need implementation and testing).

• Keep in mind that the solution needs to work for this Scrolly, plus the original repo and other future users.
• Your data set has >1300 data points.  jumpTo should use a fraction of those to center.  
  • Idea: Add logic to jumpTo every 10th or 25th coordinate
• around — Exploit the around parameter in conjunction with a zoom setting.
• padding — Exploit the padding parameter

[roblabs]

Some testing results on this logic

• change center every time scroll event fires
  • Most jaggy center moves, move center, every index = 1
• change center every 10th scroll event
  • Medium jaggy center moves, move center, every index = 10
• change center every 25th scroll event
  • Least jaggy center moves, move center, every index = 25

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