/* These template methods are called if ApplyMoves() is called.
*
* The default implementations here are to update the Direction, X and Y properties of the Unit and Bullet objecdts.
* When a tank or bullet is destroyed, the corresponding slot in the Tanks and Bullets arrays is set to null.
*
* Override these template methods in derived classes to implement the appropriate update logic.
*/
protected virtual void MoveUnit(MoveRequest request)
{
request.Tank.X = request.NewPosition.X;
request.Tank.Y = request.NewPosition.Y;
request.Tank.Direction = request.NewDirection;
// NOTE: If on the server, override to do whatever is required to generate unit events to move the tank
}
private void CancelMove(int moveRequestIndex)
{
MoveRequest request = Requests[moveRequestIndex];
request.Status = MoveStatus.Cancelled;
// Update dependencies on this tank, based on its move being cancelled:
for (int i = 0; i < Requests.Length; i++)
{
if (i != moveRequestIndex && Requests[i].Status == MoveStatus.Unresolved)
{
// Determine how tank i depends on this tank:
DependencyType depType = DependencyMatrix[i, moveRequestIndex];
switch (depType)
{
case DependencyType.OnNewLeadingEdge:
// Since the move is cancelled, the new leading edge will never occur, so is no longer a dependency:
DependencyMatrix[i, moveRequestIndex] = DependencyType.None;
break;
case DependencyType.OnUnchangedBody:
case DependencyType.OnOldTrailingEdge:
// Since the tank move has been cancelled, its old trailing edge is now blocking tank i's move:
CancelMove(i);
break;
}
}
}
}
/// <summary>
/// This method can be called for applying all the resolved moves.
/// To make this truly useful, the protected virtual template methods
/// lower down will probably need to be overridden in a derived class.
/// </summary>
public void ApplyMoves()
{
for (int i = 0; i < Requests.Length; i++)
{
MoveRequest request = Requests[i];
switch (request.Status)
{
case MoveStatus.Approved:
MoveUnit(request);
break;
case MoveStatus.Destroyed:
DestroyUnit(i);
break;
case MoveStatus.Cancelled:
if (request.NewDirection != request.Tank.Direction)
{
// The tank is still changing direction
ChangeDirectionOfUnit(request);
}
else
{
UnitWillNotMove(request);
}
break;
case MoveStatus.NotMoving:
UnitWillNotMove(request);
break;
}
}
}
/// <summary>
/// Resolve the next move
/// </summary>
/// <param name="wasAMoveResolved">
/// Returns true once all moves are resolved, or a set of circular dependencies is found which prevents further resolution
/// </param>
/// <param name="nextMoveOnly">
/// Set to true to only run the next move (useful for stepping through).
/// Set to false (the default) to complete a single pass through all the tanks, resolving all that can be resolved in that pass. This is more efficient.
/// </param>
public void ResolveNextMoves(out bool wasAMoveResolved, bool nextMoveOnly = false)
{
wasAMoveResolved = false;
for (int i = 0; i < Requests.Length; i++)
{
MoveRequest request = Requests[i];
if (request.Status == MoveStatus.Unresolved)
{
// A move can be resolved if there are no dependencies on another tank:
bool canResolve = true;
for (int j = 0; j < Constants.TANK_COUNT; j++)
{
if (i != j && DependencyMatrix[i, j] != DependencyType.None)
{
canResolve = false;
break;
}
}
if (canResolve)
{
ApproveMove(i); // Note: This might still lead to a destroyed tank if it moves into a bullet
wasAMoveResolved = true;
if (nextMoveOnly)
{
break;
}
}
}
}
}
/// <summary>
/// Derived classes can override DestroyUnit to update their status to indicate that the tank was destroyed.
/// They should also remove any bullets which were in the cells of request.NewLeadingEdge.
/// They could do this by calling RemoveBulletThatATankMovedInto(MoveRequest).
/// </summary>
/// <param name="request">The movement request for a particular tank</param>
protected virtual void DestroyUnit(int moveRequestIndex)
{
// Remove bullets:
MoveRequest request = Requests[moveRequestIndex];
RemoveBulletsThatATankMovedInto(request);
Tanks[moveRequestIndex] = null;
// NOTE: If on the server, override to do whatever is required to destroy the tank
}
protected virtual void RemoveBulletsThatATankMovedInto(MoveRequest request)
{
for (int b = 0; b < Bullets.Length; b++)
{
Bullet bullet = Bullets[b];
if (bullet != null && request.NewLeadingEdge.ContainsPoint(new Point(bullet.X, bullet.Y)))
{
Bullets[b] = null;
}
}
// NOTE: If on the server, override to do whatever is required to destroy any bullets which the tank moved into
}
public bool IsTankMovingIntoABullet(MoveRequest request)
{
for (int b = 0; b < Bullets.Length; b++)
{
Bullet bullet = Bullets[b];
if (bullet != null && request.NewLeadingEdge.ContainsPoint(new Point(bullet.X, bullet.Y)))
{
return(true);
}
}
return(false);
}
private void CancelAllUnresolvedMoveRequests()
{
for (int i = 0; i < Requests.Length; i++)
{
MoveRequest request = Requests[i];
if (request.Status == MoveStatus.Unresolved)
{
request.Status = MoveStatus.Cancelled;
// This is safer than calling CancelMove() which might have unexpected side-effects
}
}
}
public void GenerateMoveRequests()
{
for (int i = 0; i < Tanks.Length; i++)
{
Unit tank = Tanks[i];
MoveRequest request = new MoveRequest(tank);
/* Note: The constructor automatically calculates properties such as:
* Status, NewLeadingEdge, OldTrailingEdge, UnchangedBody, OldPosition, NewPosition
*/
Requests[i] = request;
}
}
private void ApproveMove(int moveRequestIndex)
{
MoveRequest request = Requests[moveRequestIndex];
if (IsTankMovingIntoABullet(request))
{
request.Status = MoveStatus.Destroyed;
}
else
{
request.Status = MoveStatus.Approved;
}
// Update dependencies on this tank, based on its move being approved:
for (int i = 0; i < Requests.Length; i++)
{
if (i != moveRequestIndex && Requests[i].Status == MoveStatus.Unresolved)
{
// Determine how tank i depends on this tank:
DependencyType depType = DependencyMatrix[i, moveRequestIndex];
switch (depType)
{
case DependencyType.OnNewLeadingEdge:
// Since the move is approved, the new leading edge becomes a barrier (in theory this should never happen):
CancelMove(i);
break;
case DependencyType.OnUnchangedBody:
if (request.Status == MoveStatus.Destroyed && RuleConfiguration.CanATankMoveIntoTheSpaceLeftByATankThatJustMovedIntoABullet)
{
// Since the tank was destroyed, and the rules allow moving into its space, remove the dependency that was blocking tank i:
DependencyMatrix[i, moveRequestIndex] = DependencyType.None;
}
else
{
// Otherwise the tank is blocked by the other tank (which was there first,
// since there is a dependency on the unchanged cells in its body), so cancel its move:
CancelMove(i);
}
break;
case DependencyType.OnOldTrailingEdge:
// Since the tank move has been approved, its old trailing edge is no longer blocking tank i's move:
DependencyMatrix[i, moveRequestIndex] = DependencyType.None;
break;
}
}
}
}
public void CancelTankMovesBlockedByWallsOrOutOfBoundsAreas()
{
for (int i = 0; i < Requests.Length; i++)
{
MoveRequest request = Requests[i];
if (request.Status == MoveStatus.Unresolved)
{
Rectangle nle = request.NewLeadingEdge;
// Check if out-of-bounds:
if (nle.TopLeft.X < 0 || nle.TopLeft.Y < 0 || nle.BottomRight.X >= BoardWidth || nle.BottomRight.Y >= BoardHeight)
{
CancelMove(i);
continue;
}
// Check if any of the cells in the new leading edge is a wall:
if (nle.GetPoints().Any(pt => IsAWall[pt.X, pt.Y]))
{
CancelMove(i);
}
}
}
}
protected TankMovementResolver()
{
Bullets = new Bullet[Constants.TANK_COUNT];
DependencyMatrix = new DependencyType[Constants.TANK_COUNT, Constants.TANK_COUNT];
Requests = new MoveRequest[Constants.TANK_COUNT];
}
protected virtual void UnitWillNotMove(MoveRequest request)
{
// NOTE: If on the server, override to do whatever is required for a tank that is not moving
}
protected virtual void ChangeDirectionOfUnit(MoveRequest request)
{
request.Tank.Direction = request.NewDirection;
// NOTE: If on the server, override to do whatever is required to generate unit events to move the tank
}
public void GenerateDependencyMatrix()
{
for (int i = 0; i < Requests.Length; i++)
{
MoveRequest request = Requests[i];
if (request.Status == MoveStatus.Unresolved)
{
for (int j = 0; j < Requests.Length; j++)
{
if (j != i)
{
MoveRequest otherRequest = Requests[j];
switch (otherRequest.Status)
{
case MoveStatus.TankDoesNotExist:
break;
case MoveStatus.NotMoving:
case MoveStatus.Cancelled:
if (request.NewLeadingEdge.IntersectsWith(otherRequest.UnchangedBody))
{
DependencyMatrix[i, j] = DependencyType.OnUnchangedBody;
}
break;
case MoveStatus.Approved:
case MoveStatus.Unresolved:
if (request.NewLeadingEdge.IntersectsWith(otherRequest.UnchangedBody))
{
DependencyMatrix[i, j] = DependencyType.OnUnchangedBody;
}
else
if (request.NewLeadingEdge.IntersectsWith(otherRequest.OldTrailingEdge))
{
DependencyMatrix[i, j] = DependencyType.OnOldTrailingEdge;
}
else
if (request.NewLeadingEdge.IntersectsWith(otherRequest.NewLeadingEdge))
{
if (otherRequest.NewLeadingEdge.IntersectsWith(request.UnchangedBody))
{
/* The other tank is trying to move into space already occupied by this tank.
* So there is no dependency on the other tank.
*/
DependencyMatrix[i, j] = DependencyType.None;
}
else
{
// Neither tank is already in the space the other is trying to move to, so neither has preference:
DependencyMatrix[i, j] = DependencyType.OnNewLeadingEdge;
}
}
else
{
DependencyMatrix[i, j] = DependencyType.None;
}
break;
}
}
}
}
}
}