A navigation grid is a graph consisting of connected grid cells
nodes(): number[]
getNeighbors(tile: number ): number[]
getCost(a: number , b: number ): number
getHeuristic(a: number , b: number ): number
getPath(start: number , goal: number ): number[]
getWaypointPath(start: Vec2 , goal: Vec2 ): Vec2[]