public IEnumerator <YieldInstruction> CalculatePath()
{
if (Running)
{
yield break;
}
Running = true;
MasterPath = new Dictionary <int, Dictionary <int, Path> >();
//for each entrance find path to every exit
foreach (int i in Entrances)
{
Square startSquare = Grid.squares[i];
Vector2Int dirFromEntrance = new Vector2Int(0, 1);
if (GridUtilities.IsLeft(i))
{
dirFromEntrance = new Vector2Int(1, 0);
}
else if (GridUtilities.IsRight(i))
{
dirFromEntrance = new Vector2Int(-1, 0);
}
else if (GridUtilities.IsTop(i))
{
dirFromEntrance = new Vector2Int(0, -1);
}
else if (!GridUtilities.IsBottom(i))
{
Debug.Log("Enterance must be on edge of board");
}
startSquare = GridUtilities.GetNextSquare(startSquare, dirFromEntrance);
if (startSquare.hasBox)
{
Debug.LogWarning("Enterance not valid");
continue;
}
Dictionary <int, Path> currentPath = new Dictionary <int, Path>();
foreach (int j in Exits)
{
Branches = 0;
MaxPath = (Grid.width - 2) * (Grid.height - 2) + 2;
LowestTotalPath = MaxPath;
PathIds = new List <int>();
Path head = new Path();
Square current = startSquare;
endSquare = Grid.squares[j];
head.Current = startSquare;
head.FutureSquares = new List <Path>();
Path newPath = new Path(current, head);
head.FutureSquares.Add(newPath);
forward = dirFromEntrance;
if (GridUtilities.IsLeft(j))
{
forward = new Vector2Int(-1, 0);
}
else if (GridUtilities.IsRight(j))
{
forward = new Vector2Int(1, 0);
}
else if (GridUtilities.IsTop(j))
{
forward = new Vector2Int(0, 1);
}
else if (GridUtilities.IsBottom(j))
{
forward = new Vector2Int(0, -1);
}
else
{
Debug.LogError("Exit must be on edge of board");
}
Square squareNextToExit = GridUtilities.GetNextSquare(endSquare, -forward);
if (squareNextToExit.hasBox)
{
Debug.LogWarning("Exit not valid");
continue;
}
left = new Vector2Int(-forward.y, forward.x);
diagLeft = left + forward;
right = -left;
diagRight = right + forward;
back = -forward;
DownPath(newPath, 1, dirFromEntrance);
if (newPath.FutureSquares.Count == 0)
{
Debug.LogWarning($"No routes where found to exit {endSquare.gridCoord}");
}
else
{
currentPath.Add(j, head);
}
yield return(null);
}
if (currentPath.Count != 0)
{
//add all paths from current entrance to all exits
MasterPath.Add(i, currentPath);
}
}
Running = false;
}
Path DownPath(Path currentPath, int pathInt, Vector2Int lastTime)
{
pathInt++;
if (pathInt > MaxPath)
{
return(null);
}
if (Branches >= MaxBranch)
{
return(null);
}
Vector2Int coord = currentPath.Current.gridCoord;
Square current = currentPath.Current;
if (coord == endSquare.gridCoord)
{
if (pathInt < LowestTotalPath)
{
MaxPath = (int)(pathInt * 1.2f);
LowestTotalPath = pathInt;
}
Branches++;
return(currentPath);
}
Vector2Int difCoord = coord - endSquare.gridCoord;
int diff = Mathf.Abs(difCoord.x) + Mathf.Abs(difCoord.y);
if (pathInt + diff > MaxPath)
{
return(null);
}
PathIds.Add(GridUtilities.TwoToOne(coord));
//squares on the edge of the map should either be boxes or
//enterances/exits so there's no point in us checking them
//if the straight distance to the exit will make out path too
//long we shouldn't bother checking it either
if (GridUtilities.IsOnEdge(current))
{
return(null);
}
if (RightIsBetter(current.gridCoord, endSquare.gridCoord, right))
{
Vector2Int temp = right;
right = left;
left = temp;
temp = diagRight;
diagRight = diagLeft;
diagLeft = temp;
}
Square forwardSquare = GridUtilities.GetNextSquare(current, forward);
Square leftSquare = GridUtilities.GetNextSquare(current, left);
Square diagLeftSquare = GridUtilities.GetNextSquare(current, diagLeft);
Square diagBackLeftSquare = GridUtilities.GetNextSquare(current, -diagRight);
Square rightSquare = GridUtilities.GetNextSquare(current, right);
Square diagRightSquare = GridUtilities.GetNextSquare(current, diagRight);
Square diagBackRightSquare = GridUtilities.GetNextSquare(current, -diagLeft);
Square backSquare = GridUtilities.GetNextSquare(current, back);
currentPath.FutureSquares = new List <Path>();
//FORWARD
if (back != lastTime)
{
CheckNextPath(ref currentPath, forwardSquare, pathInt, forward);
}
//LEFT
if (CheckDirection(left, forwardSquare, diagLeftSquare, lastTime, coord))
{
CheckNextPath(ref currentPath, leftSquare, pathInt, left);
}
//RIGHT
if (CheckDirection(right, forwardSquare, diagRightSquare, lastTime, coord))
{
CheckNextPath(ref currentPath, rightSquare, pathInt, right);
}
//BACK
if (forward != lastTime &&
((leftSquare != null && leftSquare.hasBox) ||
(rightSquare != null && rightSquare.hasBox) ||
(diagBackLeftSquare != null && diagBackLeftSquare.hasBox) ||
(diagBackRightSquare != null && diagBackRightSquare.hasBox)))
{
CheckNextPath(ref currentPath, backSquare, pathInt, back);
}
PathIds.Remove(GridUtilities.TwoToOne(coord));
if (currentPath.FutureSquares.Count > 0)
{
return(currentPath);
}
return(null);
}