The world is represented by a WorldGrid that is essentially a matrix of the C# short data type. A value of 0 indicates the cell is closed / blocked. Any other number indicates the cell is open and traversable. It is recommended to use 1 for open cells as numbers greater and less than 0 may be used to apply penalty or priority to movement through those nodes in the future.

The WorldGrid can be indexed via either:

1. The provided Position struct where a row represents the vertical axis and column the horizontal axis (Similar to indexing into a matrix P_rc).

2. The C# Point struct that operates like a cartesian co-ordinate system where X represents the horizontal axis and Y represents the vertical axis (P_xy).

Paths can be found using either Positions (matrix indexing) or Points (cartesian indexing).

A Go version is also in to works

varpathfinderOptions=newPathFinderOptions{PunishChangeDirection=true,UseDiagonals=false,};vartiles=newshort[,]{{1,0,1},{1,0,1},{1,1,1},};varworldGrid=newWorldGrid(tiles);varpathfinder=newPathFinder(worldGrid,pathfinderOptions);// The following are equivalent:// matrix indexingPosition[]path=pathfinder.FindPath(newPosition(0,0),newPosition(0,2));// point indexingPoint[]path=pathfinder.FindPath(newPoint(0,0),newPoint(2,0));

• Allowing / restricting diagonal movement
• A choice of heuristic (Manhattan, MaxDxDy, Euclidean, Diagonal shortcut)
• The option to punish direction changes.
• A search limit to short circuit the search

q. why doesn't this algorithm always find the shortest path?

a. A* optimises speed over accuracy. Because the algorithm relies on a heuristic to determine the distances from start and finish, it won't necessarily produce the shortest path to the target.

• Introduced path weighting to favour or penalize cells. This is off by default and can be opted into using the new options. See this blog post for more info

varlevel=@"1111115 1511151 1155511 1111111";varworld=Helper.ConvertStringToPathfinderGrid(level);varopts=newPathFinderOptions{Weighting=Weighting.Positive};varpathfinder=newPathFinder(world,opts);

• Introduced IgnoreClosedEndCell option to allow pathing to a closed cell

• Reimplemented the punish change direction to perform more consistently

• The world is now represented by a WorldGrid that uses shorts internally instead of bytes
• If no path is found, the algorithm now reports an empty array instead of null
• Moved out of the AStar.Core namespace into simply AStar
• Replaced former Point class with the new Position class that uses Row / Column instead of X / Y to avoid confusion with cartesian co-ordinates
• Implemented support for Point class indexing and pathing which represent a traditional cartesian co-ordinate system
• Changed path from List to Array and changed type from PathFinderNode to Position or Point
• Reversed the order of the returned path to start at the start node
• Rationalised and dropped buggy options (heavy diagonals)