Creating a Circle and Cross Game in B4X

Requirement Summary

In this task, we will be creating a simple game of Circle and Cross using the B4X programming language. The game will be played on a grid, and the players will take turns placing their respective symbols (circle or cross) on the grid. The objective of the game is to get three of your symbols in a row, either horizontally, vertically, or diagonally.

Code Generated

language-b4x
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Sub Process_Globals
    'Declare the variables and objects here
    Dim grid(2, 2) As Int 'The game grid
    Dim currentPlayer As Int 'The current player (1 for circle, 2 for cross)
End Sub

Sub AppStart (Form1 As Form, Args() As String)
    'Initialize the game grid and set the current player
    For i = 0 To 2
        For j = 0 To 2
            grid(i, j) = 0 '0 represents an empty cell
        Next
    Next
    currentPlayer = 1 'Circle starts first
    
    'Add the game grid to the form
    For i = 0 To 2
        For j = 0 To 2
            Dim btn As Button
            btn.Initialize("btn")
            btn.Tag = i & "," & j 'Store the cell coordinates in the button's tag
            btn.Text = ""
            btn.SetLayout(i * 100dip, j * 100dip, 100dip, 100dip)
            Form1.AddView(btn, i * 100dip, j * 100dip, 100dip, 100dip)
        Next
    Next
End Sub

Sub btn_Click
    Dim btn As Button = Sender
    Dim coordinates() As String = btn.Tag.Split(",")
    Dim row As Int = coordinates(0)
    Dim col As Int = coordinates(1)
    
    'Check if the clicked cell is empty
    If grid(row, col) = 0 Then
        'Place the current player's symbol on the grid
        grid(row, col) = currentPlayer
        
        'Update the button's text with the current player's symbol
        If currentPlayer = 1 Then
            btn.Text = "O"
        Else
            btn.Text = "X"
        End If
        
        'Check if the current player has won
        If CheckWin(currentPlayer) Then
            ToastMessageShow("Player " & currentPlayer & " wins!", True)
            'Reset the game
            ResetGame()
        Else
            'Switch to the next player
            currentPlayer = 3 - currentPlayer
        End If
    Else
        ToastMessageShow("Invalid move!", True)
    End If
End Sub

Sub CheckWin(player As Int) As Boolean
    'Check for a winning combination in rows, columns, and diagonals
    For i = 0 To 2
        If grid(i, 0) = player And grid(i, 1) = player And grid(i, 2) = player Then Return True 'Check rows
        If grid(0, i) = player And grid(1, i) = player And grid(2, i) = player Then Return True 'Check columns
    Next
    If grid(0, 0) = player And grid(1, 1) = player And grid(2, 2) = player Then Return True 'Check diagonal
    If grid(0, 2) = player And grid(1, 1) = player And grid(2, 0) = player Then Return True 'Check anti-diagonal
    Return False
End Sub

Sub ResetGame
    'Reset the game grid and the current player
    For i = 0 To 2
        For j = 0 To 2
            grid(i, j) = 0
            Dim btn As Button = Form1.GetView(i * 3 + j)
            btn.Text = ""
        Next
    Next
    currentPlayer = 1
End Sub

Code Explanation

The code provided above creates a Circle and Cross game using the B4X programming language. Here's a breakdown of how the code works:

1. The Process_Globals section declares the necessary variables and objects for the game. The grid variable represents the game grid, and the currentPlayer variable keeps track of the current player.

2. The AppStart sub initializes the game grid and sets the current player. It also adds buttons to the form to represent the cells of the grid. Each button is assigned a tag that stores its coordinates on the grid.

3. The btn_Click sub is triggered when a button is clicked. It checks if the clicked cell is empty and places the current player's symbol on the grid. The button's text is updated accordingly. It then checks if the current player has won by calling the CheckWin function. If a player wins, a toast message is displayed, and the game is reset.

4. The CheckWin function checks for winning combinations in rows, columns, and diagonals. If a winning combination is found, it returns True; otherwise, it returns False.

5. The ResetGame sub resets the game grid and the current player. It clears the text of all buttons and sets the current player back to 1.

By following the steps above, you can create a simple Circle and Cross game using the B4X programming language. Feel free to modify the code to add additional features or customize the game to your liking. Happy coding!