/// <summary>
/// This function is for handling any checker piece actions.
/// Function take a checkers piece as parameter, and set it as the active game piece.
/// Function will also make the piece determine all its possible moves.
/// </summary>
/// <param name="activePiece">A piece to do an action on</param>
public void doGamePieceAction(CheckersPiece activePiece)
{
if (activePiece.getCaptureStatus() == false && activePiece.getColor() == turnColor)
{
activeGamePiece = activePiece;
activePiece.determineMoves(gameBoard, this);
}
}
/// <summary>
/// Function that is called whenever it is the turn of the AI to do its move
/// </summary>
public void doAiMove()
{
if (didAiMove == false)
{
bool onlyOneMove = false;
//Check if theres only 1 moveable piece
if (currentState.moveablePieces.Count == 1)
{
//If there only 1 moveable piece and only 1 available action, set best move to that move
if (currentState.moveablePieces.First().getPossibleMoves().Count == 1)
{
bestMove = currentState.moveablePieces.First().getPossibleMoves().First();
onlyOneMove = true;
Console.WriteLine("Only one move was available - Alpha-beta wasn't required"
+ "\n--------------------------------------------------------");
}
}
//If there is more than one move run algorithm
if (onlyOneMove == false)
{
int bestMoveValue = AlphaBetaSearch(new CheckersGameState(currentState));
//if the algorithm determines that the AI will win or lose regardless of which move,
//then make the ai do the first possible move it can
if (bestMoveValue == MIN_INT || bestMoveValue == MAX_INT)
{
bestMove = currentState.moveablePieces.First().getPossibleMoves()[0];
}
//if algorithm took 50 or more seconds to run, it has reach time cutoff
if ((endTime - startTime).TotalSeconds >= 55)
{
Console.Write("Tree reached time cutoff of 55 seconds"
+ "\n--Max Depth: " + maxDepth
+ "\n--Cut Off Depth: " + (cutoff + iterativeDepth));
//Reached time cutoff - reduce the cutoff by 1/4
float actualCutoff = 0.75f * (cutoff + iterativeDepth);
iterativeDepth = (((int)actualCutoff - cutoff) > 0) ? (int)actualCutoff - cutoff : 0;
}
//Else if maxDepth is equal to the cutoff depth, that means the tree reached cutoff level
else if (maxDepth == cutoff + iterativeDepth)
{
Console.Write("Tree reached cut off"
+ "\n--Cut Off Depth: " + (cutoff + iterativeDepth));
//Since alpha-beta was able to finish in reasonable time (< 50s)
// and the cutoff was reached, increased by 1 + (1/4)number of turns passed
iterativeDepth = 1 + (int)(currentState.numTurnsPassed * 0.25);
}
//else the tree completed before reaching cutoff
else
{
Console.Write("Tree completed before reaching cut off"
+ "\n--Max Depth: " + maxDepth
+ "\n--Cut Off Depth: " + (cutoff + iterativeDepth));
}
Console.WriteLine("\n--Nodes Generated: " + nodes
+ "\n--# times pruning occured in MAX-VALUE: " + maxPruned
+ "\n--# times pruning occured in MIN-VALUE: " + minPruned
+ "\nFound Move in: " + (endTime - startTime).TotalSeconds
+ "seconds\n--------------------------------------------------------");
//AI is completed sleep the thread
Thread.Sleep(1000);
}
//Do the actual move
CheckersPiece movePiece = bestMove.movePiece;
currentState.doGamePieceAction(currentState.getPiece(movePiece.getColor(), movePiece.position));
//Set now to when the delay for the AI to actually do the move to now
didAiMove = true;
aiMoveStart = DateTime.Now;
}
else
{
//If the delay for an AI to do the move has been reached do the move
if ((DateTime.Now - aiMoveStart).TotalSeconds > aiTimeDelay)
{
if (currentState.doTileAction(currentState.gameBoard.getTileAt(bestMove.destinationPosition)) == true)
{
currentState.activeGamePiece.Update(currentState);
didAiMove = false;
}
}
}
}
/// <summary>
/// Function that handles all drawings in the game
/// This function is called everytime after an update
/// </summary>
/// <param name="spriteBatch">Spritebatch initialized by main</param>
public void Draw(SpriteBatch spriteBatch)
{
spriteBatch.Begin();
//Draw the board
currentState.gameBoard.Draw(spriteBatch, checkerGameBoardTexture);
//Draw all white pieces
foreach (CheckersPiece piece in currentState.whiteGamePieces)
{
if (piece.getCaptureStatus() == false)
{
piece.Draw(spriteBatch, whitePieceTexture);
}
}
//Draw all black pieces
foreach (CheckersPiece piece in currentState.blackGamePieces)
{
if (piece.getCaptureStatus() == false)
{
piece.Draw(spriteBatch, blackPieceTexture);
}
}
//Draw the active game piece marking
CheckersPiece active = currentState.activeGamePiece;
if (active != null)
{
if (active.getColor() == PieceColor.White)
{
currentState.activeGamePiece.Draw(spriteBatch, activePieceTexture2, true);
}
else
{
currentState.activeGamePiece.Draw(spriteBatch, activePieceTexture, true);
}
}
//Draw any marked tiles
BoardTile[,] tiles = currentState.gameBoard.getTiles();
for (int x = 0; x < CheckersBoard.MAX_HORIZONTAL_TILES; x++)
{
for (int y = 0; y < CheckersBoard.MAX_VERTICAL_TILES; y++)
{
if (tiles[x, y].getStatus() == TileStatus.MOVE)
{
tiles[x, y].Draw(spriteBatch, moveTileTexture);
}
else if (tiles[x, y].getStatus() == TileStatus.JUMP)
{
tiles[x, y].Draw(spriteBatch, jumpTileTexture);
}
}
}
//Draw the text and buttons for the UI
spriteBatch.DrawString(textFont, "Select a color to start a new game", new Vector2(10, 610), Color.Bisque);
spriteBatch.Draw(blackButtonTexture, blackButton, Color.White);
spriteBatch.Draw(whiteButtonTexture, whiteButton, Color.White);
//Below displays the player's turn, or the winner if there exists
if (currentState.winner == PieceColor.None && currentState.turnColor != PieceColor.None)
{
String message = currentState.turnColor + " turn";
spriteBatch.DrawString(font, message, new Vector2(400, 630), Color.Bisque);
}
else
{
if (currentState.winner == PieceColor.Black)
{
String message = "Black Wins!";
spriteBatch.DrawString(font, message, new Vector2(385, 630), Color.Red);
}
if (currentState.winner == PieceColor.White)
{
String message = "White Wins!";
spriteBatch.DrawString(font, message, new Vector2(385, 630), Color.Blue);
}
}
spriteBatch.End();
}