astar

type AStar interface {
	// Fill a given tile with a given weight this is used for making certain areas more complicated
	// to cross than others. For example you may have a higher weight for a wall or mountain.
	// This weight will be given back to you in the SetWeight function
	// Inbuilt A*'s use -1 to determine that it can not be passed at all.
	FillTile(p Point, weight int)

	// Resets the weight back to 0 for a given tile
	ClearTile(p Point)

	// Calculate the easiest path from ANY element in source to ANY element in target.
	// There is no hard rules about which element will become the start and end (unless your config
	// enforces it).
	// The start of the path is returned to you. If no path exists then the function will
	// return nil as the path.
	FindPath(config AStarConfig, source, target []Point) *PathPoint
}

type AStarConfig interface {
	// Determine if a valid end point has been reached. The end parameter
	// is the value passed in as source because the algorithm works backwards.
	IsEnd(p Point, end []Point, end_map map[Point]bool) bool

	// Calculate and set the weight for p.
	// fill_weight is the weight assigned to the tile when FillTile was called
	// or 0 if it was never called for that tile.
	// end is also provided so you can perform calculations such as distance remaining.
	SetWeight(p *PathPoint, fill_weight int, end []Point, end_map map[Point]bool) (allowed bool)

	// PostProcess the path after it has been calculated this might be useful if you want do do things
	// like reverse it or add constant moves at the start or end etc.
	PostProcess(p *PathPoint, rows, cols int, filledTiles map[Point]int) *PathPoint
}

type PathPoint struct {
	Point
	Parent *PathPoint

	Weight       int
	FillWeight   int
	DistTraveled int

	WeightData interface{}
}

type Point struct {
	Row int
	Col int
}

type ReversePostProcess struct {
}

type VoidPostProcess struct {
}