/// <summary>
/// Generates a board to play with
/// </summary>
public void CreateBoard()
{
matrix = new Cell[this.numTiles, this.numTiles];
heroList = new List<Hero>();
charInstances = new Dictionary<Guid, GameObject>();
cellInstances = new Dictionary<Guid, GameObject>();
boardHolder = this.transform;
bool foundSolution = false;
List<Assignment> assignments = new List<Assignment>();
while (!foundSolution)
{
matrix = InitializeBoard(matrix);
matrix = GenerateRandomTiles(matrix);
//Create a CSP to fill the remaining data
List<Variable> vars = ConvertMatrixToVars(matrix);
List<OverFloorType> values = Enum.GetValues(typeof(OverFloorType)).OfType<OverFloorType>().Where(o => Convert.ToInt32(o) >= 0).ToList();
CSP problem = new CSP(vars, values, toleranceFW, toleranceFM);
//Use recursive backtracking to get a solution
assignments = Search.RecursiveBacktrackingSearch(problem);
if (assignments != null)
foundSolution = true;
}
//Loop assignments
foreach (var ass in assignments)
{
int x = (int)ass.variable.pos.x;
int y = (int)ass.variable.pos.y;
matrix[x,y].overFloor = ass.value;
CreateTile(new Vector3(ass.variable.pos.x, ass.variable.pos.y), ass.value);
}
//Initialize heroes
matrix = GenerateRandomHeroes(matrix);
//Loop heroes to render
foreach (var hero in heroList)
{
CreateHero(hero.Position, hero);
}
}
/// <summary>
/// Loop all variables and values searching for a solution for the CSP
/// </summary>
/// <param name="problem"></param>
/// <returns></returns>
public static List <Assignment> RecursiveBacktrackingSearch(CSP problem)
{
if (problem.Goal())
{
Debug.Log("Goal completed!");
return(problem.GetAssignments());
}
//Loop unassigned
var orderedVars = problem.OrderVariablesByMinimumRemainingValues();
foreach (var variable in orderedVars)
{
Debug.Log("Variable evaluated:" + variable.pos.ToString());
var orderedAssignments = problem.OrderAssignmentsByLeastRestrictingValues(variable);
foreach (var assign in orderedAssignments)
{
Debug.Log("Value evaluated:" + assign.value.ToString());
//Assign value
bool validResult = problem.AssignValue(assign.variable, assign.value);
if (!validResult)
{
throw new Exception("Error getting available values");
}
List <Assignment> validAssignments = null;
validAssignments = RecursiveBacktrackingSearch(new CSP(problem));
if (validAssignments != null)
{
return(validAssignments);
}
else
{
Debug.Log("Backtracking value:" + assign.value.ToString());
problem.RemoveValue(assign.variable);
}
}
}
Debug.Log("Backtracking");
return(null);
}
public CSP(CSP cspToBeCopied)
{
this.vars = new List <Variable>();
cspToBeCopied.vars.ForEach(v => this.vars.Add(new Variable(v.pos, v.val, v.remDomain)));
this.domain = cspToBeCopied.domain.ToList();
this.neighbours = new Dictionary <Vector2, List <Variable> >();
foreach (var key in cspToBeCopied.neighbours.Keys)
{
var listNeigh = new List <Variable>();
foreach (var neighSour in cspToBeCopied.neighbours[key])
{
var variableDest = this.vars.First(v => v.pos == neighSour.pos);
listNeigh.Add(variableDest);
}
this.neighbours[key] = listNeigh;
}
this.assignments = new List <Assignment>();
foreach (var ass in cspToBeCopied.assignments)
{
var variableDest = this.vars.First(v => v.pos == ass.variable.pos);
var assignDest = new Assignment(variableDest, ass.value);
assignDest.domainPrune = new Dictionary <Vector2, List <OverFloorType> >();
foreach (var domPruneKey in ass.domainPrune.Keys)
{
var listOfdomainprune = new List <OverFloorType>();
foreach (var valuePruned in ass.domainPrune[domPruneKey])
{
listOfdomainprune.Add(valuePruned);
}
assignDest.domainPrune[domPruneKey] = listOfdomainprune;
}
this.assignments.Add(assignDest);
}
this.toleranceFM = cspToBeCopied.toleranceFM;
this.toleranceFW = cspToBeCopied.toleranceFW;
this.MAC3 = cspToBeCopied.MAC3;
}
public CSP(CSP cspToBeCopied)
{
this.vars = new List<Variable>();
cspToBeCopied.vars.ForEach(v=>this.vars.Add(new Variable(v.pos,v.val,v.remDomain)));
this.domain = cspToBeCopied.domain.ToList();
this.neighbours = new Dictionary<Vector2, List<Variable>>();
foreach (var key in cspToBeCopied.neighbours.Keys)
{
var listNeigh = new List<Variable>();
foreach (var neighSour in cspToBeCopied.neighbours[key])
{
var variableDest = this.vars.First(v => v.pos == neighSour.pos);
listNeigh.Add(variableDest);
}
this.neighbours[key] = listNeigh;
}
this.assignments = new List<Assignment>();
foreach (var ass in cspToBeCopied.assignments)
{
var variableDest = this.vars.First(v => v.pos == ass.variable.pos);
var assignDest = new Assignment(variableDest, ass.value);
assignDest.domainPrune = new Dictionary<Vector2, List<OverFloorType>>();
foreach (var domPruneKey in ass.domainPrune.Keys)
{
var listOfdomainprune = new List<OverFloorType>();
foreach (var valuePruned in ass.domainPrune[domPruneKey])
{
listOfdomainprune.Add(valuePruned);
}
assignDest.domainPrune[domPruneKey] = listOfdomainprune;
}
this.assignments.Add(assignDest);
}
this.toleranceFM = cspToBeCopied.toleranceFM;
this.toleranceFW = cspToBeCopied.toleranceFW;
this.MAC3 = cspToBeCopied.MAC3;
}
private static List<OverFloorType> MAC3HeadTailChecker(Variable headVar, Variable tailVar, CSP problem)
{
var ret = new List<OverFloorType>();
//Loop remaining domain values
var remainingDomains = tailVar.remDomain.ToList();
foreach (var remDomTail in remainingDomains)
{
int validTailValue = 0;
problem.AssignValue(tailVar, remDomTail, false);
var remDomainHead = headVar.remDomain.ToList();
foreach (var remDomHead in remDomainHead)
{
var alreadyAssigned = problem.IsVariableAssigned(headVar);
if(!alreadyAssigned)problem.AssignValue(headVar, remDomHead, false);
bool valid = problem.ValidateConstraints();
if (!valid)
{
validTailValue++;
break;
}
if (!alreadyAssigned) problem.RemoveValue(headVar);
}
if (validTailValue == remDomainHead.Count())
ret.Add(remDomTail);
problem.RemoveValue(tailVar);
}
return ret;
}
/// <summary>
/// Loop all variables and values searching for a solution for the CSP
/// </summary>
/// <param name="problem"></param>
/// <returns></returns>
public static List<Assignment> RecursiveBacktrackingSearch(CSP problem)
{
if (problem.Goal())
{
Debug.Log("Goal completed!");
return problem.GetAssignments();
}
//Loop unassigned
var orderedVars = problem.OrderVariablesByMinimumRemainingValues();
foreach (var variable in orderedVars)
{
Debug.Log("Variable evaluated:" + variable.pos.ToString());
var orderedAssignments = problem.OrderAssignmentsByLeastRestrictingValues(variable);
foreach (var assign in orderedAssignments)
{
Debug.Log("Value evaluated:" + assign.value.ToString());
//Assign value
bool validResult = problem.AssignValue(assign.variable, assign.value);
if (!validResult)
throw new Exception("Error getting available values");
List<Assignment> validAssignments = null;
validAssignments = RecursiveBacktrackingSearch(new CSP(problem));
if (validAssignments != null)
{
return validAssignments;
}
else
{
Debug.Log("Backtracking value:" + assign.value.ToString());
problem.RemoveValue(assign.variable);
}
}
}
Debug.Log("Backtracking");
return null;
}
/// <summary>
/// Maintenance Arc Consistency, this algorithm will check how many domain prunes are done when a assignemnt is executed
/// </summary>
/// <param name="assign">Assignment to be evaluated and updated</param>
/// <param name="neighbours">List of neighbours to start with (difference between AC3 and MAC3)</param>
/// <returns></returns>
public static bool MAC3(ref Assignment assign,CSP problem)
{
var position = assign.variable.pos;
var variableInLocalProblem = problem.vars.First(v => v.pos == position);
//Add the assignment to the problem
problem.AssignValue(variableInLocalProblem, assign.value,false);
List<Variable> queueToPrune = new List<Variable>();
queueToPrune.Add(variableInLocalProblem);
while (queueToPrune.Any())
{
//Get the first variable
var headVariable = queueToPrune.First();
queueToPrune.Remove(headVariable);
//Get the neighbours of the variable
List<Variable> neighbours = problem.GetNeighbours(headVariable).Where(n => !problem.IsVariableAssigned(n)).ToList();
//Loop over neighbours
foreach (var neigh in neighbours)
{
//Get the list of values to delete for conflict
List<OverFloorType> valuesToPrune = new List<OverFloorType>();
//Check if value is compatible with remaining values in head
foreach (var valPruned in MAC3HeadTailChecker(headVariable, neigh, problem))
{
if (!valuesToPrune.Any(v => v == valPruned))
valuesToPrune.Add(valPruned);
}
//Remove the value from the variable domain in temporal CSP and add to the domain prune
foreach (var prunedVal in valuesToPrune)
{
//Remove domain from variable in problem
problem.RemoveDomainElementFromVariable(neigh, prunedVal);
//remove domain from variable in current variable
neigh.removeDomainElement(prunedVal);
if (!neigh.remDomain.Any())
return false;
//Add prune action to assignment
assign.AddDomainPrune(neigh.pos, prunedVal);
}
if (valuesToPrune.Any())
{
queueToPrune.Add(neigh);
}
}
}
return true;
}
/// <summary>
/// Generates a random number of tiles using CSP constraint validaton
/// </summary>
/// <param name="matrix">Cell matrix to be filled</param>
/// <returns>Cell matrix with random values generated</returns>
private Cell[,] GenerateRandomTiles(Cell[,] matrix)
{
//Initialize a new random generator
System.Random random = new System.Random();
//Get number of tiles
var totalNumberOfTiles = this.numTiles * this.numTiles;
var numberOfRandomTiles = totalNumberOfTiles * randomGeneratedTilesRate / 100;
//List with all possible values
List<OverFloorType> values = Enum.GetValues(typeof(OverFloorType)).OfType<OverFloorType>().Where(o => Convert.ToInt32(o) >= 0).ToList();
for (int i = 0; i < numberOfRandomTiles; i++)
{
bool generatedValue = false;
//Loop until a valid random generated value has been created for this turn
while (!generatedValue)
{
//Generate a random number for x and y
var x = random.Next(numTiles);
var y = random.Next(numTiles);
//Only assign value to unassigned
if (matrix[x, y].overFloor == OverFloorType.NONE)
{
//Generate a random value
Array overfloortypes = Enum.GetValues(typeof(OverFloorType));
OverFloorType randomType = OverFloorType.NONE;
while (randomType == OverFloorType.NONE)
randomType = (OverFloorType)overfloortypes.GetValue(random.Next(0, overfloortypes.Length));
//Assign the value
matrix[x, y].overFloor = randomType;
List<Variable> vars = ConvertMatrixToVars(matrix);
CSP problem = new CSP(vars, values, toleranceFW, toleranceFM);
if (problem.ValidateConstraints())
{
generatedValue = true;
Debug.Log(string.Format("Position assigned:[{0},{1}] Value: {2}",x.ToString(),y.ToString(),randomType.ToString()));
}
else
matrix[x, y].overFloor = OverFloorType.NONE;
}
}
}
return matrix;
}
private static List <OverFloorType> MAC3HeadTailChecker(Variable headVar, Variable tailVar, CSP problem)
{
var ret = new List <OverFloorType>();
//Loop remaining domain values
var remainingDomains = tailVar.remDomain.ToList();
foreach (var remDomTail in remainingDomains)
{
int validTailValue = 0;
problem.AssignValue(tailVar, remDomTail, false);
var remDomainHead = headVar.remDomain.ToList();
foreach (var remDomHead in remDomainHead)
{
var alreadyAssigned = problem.IsVariableAssigned(headVar);
if (!alreadyAssigned)
{
problem.AssignValue(headVar, remDomHead, false);
}
bool valid = problem.ValidateConstraints();
if (!valid)
{
validTailValue++;
break;
}
if (!alreadyAssigned)
{
problem.RemoveValue(headVar);
}
}
if (validTailValue == remDomainHead.Count())
{
ret.Add(remDomTail);
}
problem.RemoveValue(tailVar);
}
return(ret);
}
