int GetManhattanDistance(GridAreaLocation start, GridAreaLocation finish)
{
var x = Math.Abs(start.X - finish.X);
var y = Math.Abs(start.Y - finish.Y);
return(x + y);
}
Cell Search(GridAreaLocation start, GridAreaLocation finish, GridArea gridArea, List <GridAreaLocation> gPath)
{
int bestScore = int.MaxValue;
Cell bestCell = null;
foreach (var neighbor in GetNeighbors(start, gridArea))
{
if (neighbor == null || neighbor.State != CellState.None)
{
continue;
}
var loc = gridArea.GetCellLocation(neighbor);
if (gPath.Contains(loc))
{
continue;
}
var score = GetManhattanDistance(loc, finish);
if (score < bestScore)
{
bestScore = score;
bestCell = neighbor;
}
}
return(bestCell);
}
public GridAreaLocation GetCellLocation(Cell cell)
{
var index = Cells.IndexOf(cell);
int y = index / (Width * 3);
int x = index % (Width * 3);
var gl = new GridAreaLocation(x, y);
return(gl);
}
List <Cell> GetNeighbors(GridAreaLocation location, GridArea gridArea)
{
var top = gridArea.GetCell(location.Add(0, 1));
var bottom = gridArea.GetCell(location.Add(0, -1));
var right = gridArea.GetCell(location.Add(1, 0));
var left = gridArea.GetCell(location.Add(-1, 0));
return(new List <Cell>
{
top, bottom, right, left
});
}
public static List <GridAreaLocation> SemiGeneticGetNextLocation(GridArea gridArea, GridAreaLocation current, GridAreaLocation finishEntrance, GridAreaLocation previousLocation)
{
float entranceDirectionWeight = 700f; //tend to go towards entrance
float straightLineWeight = .7f; //tendency to choose
float randomWeight = .1f;
GridAreaLocation currentLocation = current;
GridAreaLocation previousVector = previousLocation;
if (previousLocation == null)
{
previousVector = new GridAreaLocation(0, 0);
straightLineWeight = 0;
}
//int yDirection = Random.Range (0, 2); //1 up
//int xDirection = Random.Range (0, 2); //1 right
//var nextLocation = new GridAreaLocation (currentLocation.X + xDirection, currentLocation.Y + yDirection);
var direction = currentLocation.GetRelativeDirection(finishEntrance);
Dictionary <GridAreaLocation, float> nextWeightDict = new Dictionary <GridAreaLocation, float> ();
for (int i = 0; i < 4; i++)
{
float weight = randomWeight;
var v = NeighborToLocation(i);
if (v.X == direction.x)
{
weight += entranceDirectionWeight;
if (v.X == previousVector.X)
{
weight += straightLineWeight;
}
}
if (v.Y == direction.y)
{
weight += entranceDirectionWeight;
if (v.Y == previousVector.Y)
{
weight += straightLineWeight;
}
}
nextWeightDict.Add(v, weight);
}
var wints = GetNextCell(nextWeightDict);
return(wints);
}
public Cell GetCell(GridAreaLocation location)
{
if (location.X < 0 || location.Y < 0)
{
return(null);
}
if (location.X / 3 >= Width || location.Y / 3 >= Height)
{
return(null);
}
var index = location.Y * Width * 3 + location.X;
if (index >= Cells.Count || index < 0)
{
return(null);
}
return(Cells[index]);
}
public List <GridAreaLocation> FindPath(GridAreaLocation start, GridAreaLocation finish, GridArea gridArea)
{
var gPath = new List <GridAreaLocation>();
gPath.Add(start);
var currentLocation = start;
while (currentLocation != finish)
{
var nextCell = Search(currentLocation, finish, gridArea, gPath);
if (nextCell == null)
{
return(gPath);
}
var loc = gridArea.GetCellLocation(nextCell);
if (loc.X < 0 || loc.Y < 0)
{
Debug.Log("A* invalid x, y");
return(gPath);
}
if (Math.Abs(loc.X - currentLocation.X) + Math.Abs(loc.Y - currentLocation.Y) > 1)
{
Debug.Log("A* invalid path");
return(gPath);
}
if (gPath.Contains(loc))
{
Debug.Log("A* duplicate path");
return(gPath);
}
gPath.Add(loc);
nextCell.State = CellState.Path;
currentLocation = loc;
}
return(gPath);
}