void PaintPathBack(TileObject currentTile) //starting from the exit tile change the color of the tiles along the path
{
if (currentTile.IsStart == true) // when you hit the start tile stop
{
return;
}
else if (currentTile.IsExit == true)// if the exit tile has no path to it stop
{
if (currentTile.PreviouseTile != null)
{
PaintPathBack(currentTile.PreviouseTile);
}
}
else
{
currentTile.SetColor(Color.cyan); //change the color of the tiles on the path
PaintPathBack(currentTile.PreviouseTile); // calls it self again
}
}
public List <Tile> FindPath(List <List <TileObject> > myList, TileObject startPoint, TileObject exitPoint, Vector2 gridLength)
{
//This seaction initalises the code used for the algorithm such as movement direction and heuristc
int searchDirections;//is used to determine if you are allowed to move diagonal while searching for a path
if (GameController.Diagonal == true)
{
searchDirections = 8;//search all squares touching yours
}
else
{
searchDirections = 4; //search up, down, left, right
}
int searchType = 4; // determines which directions the heuristic will check. same as above
bool isEcludian = false;
switch (GameController.SearchType)// 0 manhaton. 1 diagonal. 2 Ecludian
{
case 0:
searchType = 4;
isEcludian = false;
break;
case 1:
searchType = 8;
isEcludian = false;
break;
case 2:
searchType = 8;
isEcludian = true;
break;
}
for (int X = 0; X < myList.Count; X++)//sets all the values to a high number as we canot store infinity in a float
{
for (int Y = 0; Y < myList[X].Count; Y++)
{
myList[X][Y].EstimatedCost = 999999;
myList[X][Y].HasBeenChanged = false;
myList[X][Y].HasBeenChecked = false;
}
}
List <TileObject> searchList = new List <TileObject>(); //this is the open list which is used to store the current possible path options
myList[(int)exitPoint.Position.x][(int)exitPoint.Position.y].EstimatedCost = 0; // set the exit node estimated cost to 0 so we can use it as the start point for the heuristic
Vector2 cT = exitPoint.Position;
int stopper = 0;
int stop = 100000;//the maximuim limit the algorithm can cycle before it is stopped. This is put in to reduced the number of computer crashes due to bad logic
int searchRef = 0;
searchList.Add(myList[(int)exitPoint.Position.x][(int)exitPoint.Position.y]);
float bakeMod = 1f;//can be used to adjust the amount of influence the heuristic has on path finding. make it lower to have it closer to a Dijkstras or higher makes it closer to Best first search. I have left it at 1 as it shows it in its best comparison for this application
Vector2 tileToCheck = cT;
TileObject tileBeingChecked;
float moveCost = 1f;
while (stopper < stop) //while there are unchecked nodes or while the stoppper is below its allowed limit
{
for (int i = 0; i < searchType; i++) // if its 4 it only checks up down left right. if its 8 it goes diagonal as well
{
switch (i) //sets what tile to check next based on the position of the current tile. also sets the cost to move to that tile based to the searchtype settings
{
case 0:
tileToCheck = new Vector2(cT.x + 1, cT.y); //right
moveCost = 1;
break;
case 1:
tileToCheck = new Vector2(cT.x, cT.y + 1); //up
moveCost = 1;
break;
case 2:
tileToCheck = new Vector2(cT.x - 1, cT.y); //left
moveCost = 1;
break;
case 3:
tileToCheck = new Vector2(cT.x, cT.y - 1); //down
moveCost = 1;
break;
case 4:
tileToCheck = new Vector2(cT.x + 1, cT.y + 1); //up right
moveCost = 1.4f;
break;
case 5:
tileToCheck = new Vector2(cT.x + 1, cT.y - 1); //down Right
moveCost = 1.4f;
break;
case 6:
tileToCheck = new Vector2(cT.x - 1, cT.y - 1); //down left
moveCost = 1.4f;
break;
case 7:
tileToCheck = new Vector2(cT.x - 1, cT.y + 1); //up right
moveCost = 1.4f;
break;
}
if (isEcludian == true)// in an Ecludian Heuristic it is assumed that moving in any direction is the same cost and therefore the cost will allways be 1
{
moveCost = 1;
}
if (tileToCheck.x < gridLength.x && tileToCheck.x >= 0 && tileToCheck.y < gridLength.y && tileToCheck.y >= 0)// if the tile is not inside the grid skip it
{
tileBeingChecked = myList[(int)tileToCheck.x][(int)tileToCheck.y];
if (myList[(int)cT.x][(int)cT.y].EstimatedCost + (moveCost * bakeMod) < tileBeingChecked.EstimatedCost && tileBeingChecked.HasBeenChanged == false) //checks if the cost of the current tile is less than the current lowest cost to get to that tile
{
tileBeingChecked.EstimatedCost = myList[(int)cT.x][(int)cT.y].EstimatedCost + (moveCost * bakeMod); // sets the cost of the node by adding the movement cost to the tile from the current tile
tileBeingChecked.HasBeenChanged = true;
searchList.Add(tileBeingChecked); //adds the tileBeingChecked to the open list
}
}
}
searchRef = 0;
for (int i = 0; i < searchList.Count; i++)//finds the next lowest tile to the Heuristic to set is value
{
if (searchList[i].EstimatedCost < searchList[searchRef].EstimatedCost)
{
searchRef = i;
}
}
if (searchList.Count == 0)//once all tiles have been set break the while loop
{
Debug.Log("No more options");
break;
}
cT = searchList[searchRef].Position;
searchList.RemoveAt(searchRef);
}
Debug.Log("Set Path");
List <Tile> changeLog = new List <Tile>(); //Creates a new List to recorded the changes made by the algorithm
for (int X = 0; X < myList.Count; X++) //sets all the values to a high number as we canot store infinity in a int
{
for (int Y = 0; Y < myList[X].Count; Y++)
{
myList[X][Y].Cost = 999999;
myList[X][Y].HasBeenChanged = false;
myList[X][Y].HasBeenChecked = false;
}
}
myList[(int)startPoint.Position.x][(int)startPoint.Position.y].Cost = 0;
cT = startPoint.Position;
stopper = 0;
stop = 100000;
searchList.Clear();
searchList = new List <TileObject>();
searchRef = 0;
searchList.Add(myList[(int)startPoint.Position.x][(int)startPoint.Position.y]);
while (stopper < stop) //while there are unchecked nodes or while the stoppper is below its allowed limit
{
for (int i = 0; i < searchDirections; i++) // if its 4 it only checks up down left right. if its 8 it goes diagonal as well
{
switch (i) //sets what tile to check next based on the position of the current tile. also sets the cost to move to that tile based to the search direction setting
{
case 0:
tileToCheck = new Vector2(cT.x + 1, cT.y); //right
moveCost = 1;
break;
case 1:
tileToCheck = new Vector2(cT.x, cT.y + 1); //up
moveCost = 1;
break;
case 2:
tileToCheck = new Vector2(cT.x - 1, cT.y); //left
moveCost = 1;
break;
case 3:
tileToCheck = new Vector2(cT.x, cT.y - 1); //down
moveCost = 1;
break;
case 4:
tileToCheck = new Vector2(cT.x + 1, cT.y + 1); //up right
moveCost = 1.4f;
break;
case 5:
tileToCheck = new Vector2(cT.x + 1, cT.y - 1); //down Right
moveCost = 1.4f;
break;
case 6:
tileToCheck = new Vector2(cT.x - 1, cT.y - 1); //down left
moveCost = 1.4f;
break;
case 7:
tileToCheck = new Vector2(cT.x - 1, cT.y + 1); //up right
moveCost = 1.4f;
break;
}
if (tileToCheck.x < gridLength.x && tileToCheck.x >= 0 && tileToCheck.y < gridLength.y && tileToCheck.y >= 0)// if the tile is not inside the grid skip it
{
tileBeingChecked = myList[(int)tileToCheck.x][(int)tileToCheck.y];
if (tileBeingChecked.IsWall == false && tileBeingChecked.HasBeenChanged == false)
{
if (myList[(int)cT.x][(int)cT.y].Cost + moveCost < tileBeingChecked.Cost || tileBeingChecked.HasBeenChanged == false)//checks if the cost of the current tile is less than the current lowest cost to get to that tile
{
tileBeingChecked.PreviouseTile = myList[(int)cT.x][(int)cT.y];
tileBeingChecked.Cost = myList[(int)cT.x][(int)cT.y].Cost + moveCost; // sets the cost of the tile by adding the movement cost to the node from the current tile
tileBeingChecked.HasBeenChanged = true;
tileBeingChecked.TileColor = Color.blue; //changes the color that will be stored to blue as blue is the color used to represent tiles in the open set
searchList.Add(tileBeingChecked); //adds the tileBeingChecked to the open list
changeLog.Add(new Tile(tileBeingChecked)); //adds the action to the change log
}
}
}
}
myList[(int)cT.x][(int)cT.y].TileColor = Color.grey; //changes the color of the tile to grey as that is the colour used to show that it has been checked
changeLog.Add(new Tile(myList[(int)cT.x][(int)cT.y])); //adds the action to the change log
searchRef = 0; //sets the referance to 0 so it starts at the first item in the open list
for (int i = 0; i < searchList.Count; i++)
{
if (searchList[i].ActualCost() < searchList[searchRef].ActualCost())//if searchlist[i] has a lower actual cost then the current searchRef tile that tile is now the searchRef tile
{
searchRef = i;
}
else if (searchList[i].ActualCost() == searchList[searchRef].ActualCost()) //if searchlist[i] has the same actual cost as current searchRef tile......
{
if (searchList[i].EstimatedCost < searchList[searchRef].EstimatedCost) //if that tile has a lower Heurstic cost then the current SearchRef tile that tile is now the searchRef tile
{
searchRef = i;
}
}
}
if (searchList.Count == 0)//if the search list is empty break the while loop
{
Debug.Log("No more options");
break;
}
if (searchList[searchRef].Position == exitPoint.Position)// if you found the exit break the while loop
{
Debug.Log("Found Exit");
break;
}
cT = searchList[searchRef].Position; //set the lowest found seachRef to the current tile
searchList.RemoveAt(searchRef); //Remove the current tile from the open set
stopper += 1; //increment stopper
}
Debug.Log("FoundPath");
GameController.NumberOfTilesSearched = (changeLog.Count / 2); // the number of tiles checked is half the number of actions taken to find the tiles as each tile that is checked is first added to teh open set and then checked after
return(changeLog); //send the recorded chang log back to the pathfinder interface
}
public List <Tile> FindPath(List <List <TileObject> > myList, TileObject startPoint, TileObject exitPoint, Vector2 gridLength)
{
//This seaction initalises the code used for the algorithm such as movement direction
int searchDirections;//is used to determine if you are allowed to move diagonal while searching for a path
if (GameController.Diagonal == true)
{
searchDirections = 8;//search all squares touching yours
}
else
{
searchDirections = 4; //search up, down, left, right
}
List <Tile> changeLog = new List <Tile>(); //Creates a new List to recorded the changes made by the algorithm
for (int X = 0; X < myList.Count; X++)
{
for (int Y = 0; Y < myList[X].Count; Y++)//sets all the values to a high number as we canot store infinity in a int
{
myList[X][Y].Cost = 999999;
myList[X][Y].HasBeenChanged = false;
myList[X][Y].HasBeenChecked = false;
}
}
List <TileObject> searchList = new List <TileObject>(); //this is the open list which is used to store the current possible path options
myList[(int)startPoint.Position.x][(int)startPoint.Position.y].Cost = 0; // set the start tile cost to 0 so we can use it as the start point
Vector2 cT = startPoint.Position;
int stopper = 0;
int stop = 100000;//the maximuim limit the algorithm can cycle before it is stopped. This is put in to reduced the number of computer crashes due to bad logic
int searchRef = 0;
searchList.Add(myList[(int)startPoint.Position.x][(int)startPoint.Position.y]);
Vector2 tileToCheck = cT;
TileObject tileBeingChecked;
float moveCost = 1;
while (stopper < stop) //while there are unchecked nodes or while the stoppper is below its allowed limit
{
for (int i = 0; i < searchDirections; i++) // if its 4 it only checks up down left right. if its 8 it goes diagonal as well
{
switch (i) //sets what tile to check next based on the position of the current tile. also sets the cost to move to that tile based to the search direction setting
{
case 0:
tileToCheck = new Vector2(cT.x + 1, cT.y); //right
moveCost = 1;
break;
case 1:
tileToCheck = new Vector2(cT.x, cT.y + 1); //up
moveCost = 1;
break;
case 2:
tileToCheck = new Vector2(cT.x - 1, cT.y); //left
moveCost = 1;
break;
case 3:
tileToCheck = new Vector2(cT.x, cT.y - 1); //down
moveCost = 1;
break;
case 4:
tileToCheck = new Vector2(cT.x + 1, cT.y + 1); //up right
moveCost = 1.4f;
break;
case 5:
tileToCheck = new Vector2(cT.x + 1, cT.y - 1); //down Right
moveCost = 1.4f;
break;
case 6:
tileToCheck = new Vector2(cT.x - 1, cT.y - 1); //down left
moveCost = 1.4f;
break;
case 7:
tileToCheck = new Vector2(cT.x - 1, cT.y + 1); //up right
moveCost = 1.4f;
break;
}
if (tileToCheck.x < gridLength.x && tileToCheck.x >= 0 && tileToCheck.y < gridLength.y && tileToCheck.y >= 0)// if the tile is not inside the grid skip it
{
tileBeingChecked = myList[(int)tileToCheck.x][(int)tileToCheck.y];
if (tileBeingChecked.IsWall == false)
{
if (myList[(int)cT.x][(int)cT.y].Cost + moveCost < tileBeingChecked.Cost || tileBeingChecked.HasBeenChanged == false)//checks if the cost of the current tile is less than the current lowest cost to get to that tile
{
tileBeingChecked.PreviouseTile = myList[(int)cT.x][(int)cT.y];
tileBeingChecked.Cost = myList[(int)cT.x][(int)cT.y].Cost + moveCost; // sets the cost of the tile by adding the movement cost to the tile from the current tile
tileBeingChecked.HasBeenChanged = true;
tileBeingChecked.TileColor = Color.blue; //changes the color that will be stored to blue as blue is the color used to represent tiles in the open set
searchList.Add(tileBeingChecked); //adds the tileBeingChecked to the open list
changeLog.Add(new Tile(tileBeingChecked)); //adds the action to the change log
}
}
}
}
myList[(int)cT.x][(int)cT.y].HasBeenChecked = true; //removes the node from the list so it doesnt check it again
myList[(int)cT.x][(int)cT.y].TileColor = Color.grey; //changes the color of the tile to grey as that is the colour used to show that it has been checked
changeLog.Add(new Tile(myList[(int)cT.x][(int)cT.y])); //adds the action to the change log
searchRef = 0; //sets the referance to 0 so it starts at the first item in the open list
if (searchList.Count == 0) //if the search list is empty break the while loop
{
Debug.Log("No more options");
break;
}
if (searchList[searchRef].Position == exitPoint.Position)// if you found the exit break the while loop
{
Debug.Log("Found Exit");
break;
}
cT = searchList[searchRef].Position; //set the lowest found seachRef to the current tile
searchList.RemoveAt(searchRef); //Remove the current tile from the open set
stopper += 1; //increment stopper
}
Debug.Log("FoundPath");
GameController.NumberOfTilesSearched = (changeLog.Count / 2); // the number of tiles checked is half the number of actions taken to find the tiles as each tile that is checked is first added to teh open set and then checked after
return(changeLog); //send the recorded chang log back to the pathfinder interface
}