http://theory.stanford.edu/~amitp/GameProgramming/ImplementationNotes.html
https://en.wikipedia.org/wiki/A*_search_algorithm
http://theory.stanford.edu/~amitp/GameProgramming/AStarComparison.html
https://www.redblobgames.com/pathfinding/a-star/introduction.html
https://rosettacode.org/wiki/Ramer-Douglas-Peucker_line_simplification
https://en.wikipedia.org/wiki/Ramer%E2%80%93Douglas%E2%80%93Peucker_algorithm
http://www.theholymath.com/2016/07/02/turning-gps-route-network/
http://www.theholymath.com/2016/07/06/calculus-iii-can-help-us-identify-ambiturners/