VB Reversi Game

Reversi Game Implementation in Visual Basic

This Reversi game demonstrates core programming concepts using Visual Basic 6 and VB.NET

VB Reversi Implementation

The implementation uses two-dimensional arrays to track game state and includes logic for validating moves and flipping pieces.

Core Game Logic

The game uses two 4×4 Boolean arrays:

white(4,4) tracks positions of white pieces
black(4,4) tracks positions of black pieces

When a piece is placed on the board, the corresponding array element is set to True. The game logic then checks adjacent positions to determine which pieces should be flipped.

Game Implementation Details

Board Representation

The game board is implemented using an array of 16 image controls arranged in a 4×4 grid. Each square is represented by an indexed image control (Image1(0) to Image1(15)).

Drag-and-Drop Mechanics

Players drag either the white or black piece image onto the board. The game validates each move to ensure it follows Reversi rules before updating the game state.

Game Logic

Using If...Then and Select Case statements, the program checks valid moves and flips trapped pieces between the newly placed piece and existing pieces of the same color.

Score Tracking

The game continuously counts and displays the number of white and black pieces. At game end, it declares the winner based on piece count.

Designing the Interface

To create the game interface:

Insert an image control and duplicate it to create a 4×4 grid
Create solid white and black circle images (saved as JPEG files)
Implement drag-and-drop functionality using the DragDrop method

Board Layout Positions

Image1(12)	Image1(13)	Image1(14)	Image1(15)
Image1(8)	Image1(9)	Image1(10)	Image1(11)
Image1(4)	Image1(5)	Image1(6)	Image1(7)
Image1(0)	Image1(1)	Image1(2)	Image1(3)

Figure 1: Image control positions on the game board

Game Interface at Runtime

Figure 2: Reversi game in action with white and black pieces

Code Implementation

The following subroutine checks the status of each position on the board:

Option Base 1
Dim white(4, 4) As Boolean
Dim black(4, 4) As Boolean
Dim i, j, k, w, b As Integer
Dim imgtag As String

' Check board status and update piece positions
Sub checkstatus()
    k = 0
    For j = 1 To 4
        For i = 1 To 4
            ' Check for white pieces
            If Image1(k).Picture = Image17.Picture Then
                white(i, j) = True
            Else
                white(i, j) = False
            End If
            
            ' Check for black pieces
            If Image1(k).Picture = Image18.Picture Then
                black(i, j) = True
            Else
                black(i, j) = False
            End If
            
            k = k + 1
        Next i
    Next j
End Sub

How the CheckStatus Subroutine Works

This procedure:

Iterates through each position on the 4×4 board
Checks if the image at each position matches the white piece image (Image17)
Updates the white array accordingly
Checks if the image matches the black piece image (Image18)
Updates the black array accordingly

Game Logic Implementation

The core game mechanics involve:

Move validation: Ensuring moves follow Reversi rules
Piece flipping: Identifying and flipping trapped pieces
Turn management: Alternating between players
Win detection: Determining when the game ends and who won

' Example of move validation logic
If ValidMove(row, col, currentPlayer) Then
    PlacePiece(row, col, currentPlayer)
    FlipPieces(row, col, currentPlayer)
    currentPlayer = IIf(currentPlayer = WHITE, BLACK, WHITE)
Else
    MsgBox "Invalid move! Please try again."
End If

Equivalent VB.NET Code

The following example shows how a simple Reversi game can be implemented in VB.NET using Windows Forms. This version uses an 8×8 grid of buttons, tracks the current player, validates moves, flips captured pieces, and updates the board after each turn.

VB.NET Reversi Code

Public Class Form1
    Private board(7, 7) As Integer
    Private buttons(7, 7) As Button
    Private currentPlayer As Integer = 1   ' 1 = Black, 2 = White

    Private directions As Integer(,) = {
        {-1, -1}, {-1, 0}, {-1, 1},
        {0, -1},           {0, 1},
        {1, -1},  {1, 0},  {1, 1}
    }

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        CreateBoard()
        InitializeGame()
    End Sub

    Private Sub CreateBoard()
        Dim size As Integer = 45

        For r As Integer = 0 To 7
            For c As Integer = 0 To 7
                Dim btn As New Button()
                btn.Width = size
                btn.Height = size
                btn.Left = 20 + c * size
                btn.Top = 20 + r * size
                btn.Tag = r & "," & c
                btn.BackColor = Color.ForestGreen
                btn.FlatStyle = FlatStyle.Flat
                AddHandler btn.Click, AddressOf Cell_Click
                Me.Controls.Add(btn)
                buttons(r, c) = btn
            Next
        Next
    End Sub

    Private Sub InitializeGame()
        For r As Integer = 0 To 7
            For c As Integer = 0 To 7
                board(r, c) = 0
            Next
        Next

        board(3, 3) = 2
        board(3, 4) = 1
        board(4, 3) = 1
        board(4, 4) = 2

        currentPlayer = 1
        DrawBoard()
        UpdateStatus()
    End Sub

    Private Sub DrawBoard()
        For r As Integer = 0 To 7
            For c As Integer = 0 To 7
                Select Case board(r, c)
                    Case 0
                        buttons(r, c).Text = ""
                    Case 1
                        buttons(r, c).Text = "●"
                        buttons(r, c).ForeColor = Color.Black
                    Case 2
                        buttons(r, c).Text = "●"
                        buttons(r, c).ForeColor = Color.White
                End Select
            Next
        Next
    End Sub

    Private Sub Cell_Click(sender As Object, e As EventArgs)
        Dim btn As Button = CType(sender, Button)
        Dim parts() As String = btn.Tag.ToString().Split(","c)
        Dim row As Integer = Convert.ToInt32(parts(0))
        Dim col As Integer = Convert.ToInt32(parts(1))

        If MakeMove(row, col, currentPlayer) Then
            currentPlayer = If(currentPlayer = 1, 2, 1)
            DrawBoard()
            UpdateStatus()

            If Not HasValidMove(currentPlayer) Then
                currentPlayer = If(currentPlayer = 1, 2, 1)
                If Not HasValidMove(currentPlayer) Then
                    ShowWinner()
                Else
                    MessageBox.Show("No valid moves. Turn passes back.", "Reversi")
                End If
            End If
        Else
            MessageBox.Show("Invalid move.", "Reversi")
        End If
    End Sub

    Private Function MakeMove(row As Integer, col As Integer, player As Integer) As Boolean
        If board(row, col) <> 0 Then Return False

        Dim opponent As Integer = If(player = 1, 2, 1)
        Dim flipped As Boolean = False

        For i As Integer = 0 To directions.GetLength(0) - 1
            Dim dr As Integer = directions(i, 0)
            Dim dc As Integer = directions(i, 1)

            Dim r As Integer = row + dr
            Dim c As Integer = col + dc
            Dim path As New List(Of Point)

            While r >= 0 AndAlso r <= 7 AndAlso c >= 0 AndAlso c <= 7 AndAlso board(r, c) = opponent
                path.Add(New Point(r, c))
                r += dr
                c += dc
            End While

            If r >= 0 AndAlso r <= 7 AndAlso c >= 0 AndAlso c <= 7 AndAlso board(r, c) = player AndAlso path.Count > 0 Then
                For Each p As Point In path
                    board(p.X, p.Y) = player
                Next
                flipped = True
            End If
        Next

        If flipped Then
            board(row, col) = player
        End If

        Return flipped
    End Function

    Private Function HasValidMove(player As Integer) As Boolean
        For r As Integer = 0 To 7
            For c As Integer = 0 To 7
                Dim testBoard(7, 7) As Integer
                Array.Copy(board, testBoard, board.Length)
                If MakeMovePreview(r, c, player, testBoard) Then
                    Return True
                End If
            Next
        Next
        Return False
    End Function

    Private Function MakeMovePreview(row As Integer, col As Integer, player As Integer, tempBoard(,) As Integer) As Boolean
        If tempBoard(row, col) <> 0 Then Return False

        Dim opponent As Integer = If(player = 1, 2, 1)
        Dim flipped As Boolean = False

        For i As Integer = 0 To directions.GetLength(0) - 1
            Dim dr As Integer = directions(i, 0)
            Dim dc As Integer = directions(i, 1)

            Dim r As Integer = row + dr
            Dim c As Integer = col + dc
            Dim count As Integer = 0

            While r >= 0 AndAlso r <= 7 AndAlso c >= 0 AndAlso c <= 7 AndAlso tempBoard(r, c) = opponent
                count += 1
                r += dr
                c += dc
            End While

            If r >= 0 AndAlso r <= 7 AndAlso c >= 0 AndAlso c <= 7 AndAlso tempBoard(r, c) = player AndAlso count > 0 Then
                flipped = True
            End If
        Next

        Return flipped
    End Function

    Private Sub UpdateStatus()
        Dim blackCount As Integer = 0
        Dim whiteCount As Integer = 0

        For r As Integer = 0 To 7
            For c As Integer = 0 To 7
                If board(r, c) = 1 Then blackCount += 1
                If board(r, c) = 2 Then whiteCount += 1
            Next
        Next

        lblStatus.Text = "Current Player: " &
                         If(currentPlayer = 1, "Black", "White") &
                         " | Black: " & blackCount &
                         " | White: " & whiteCount
    End Sub

    Private Sub ShowWinner()
        Dim blackCount As Integer = 0
        Dim whiteCount As Integer = 0

        For r As Integer = 0 To 7
            For c As Integer = 0 To 7
                If board(r, c) = 1 Then blackCount += 1
                If board(r, c) = 2 Then whiteCount += 1
            Next
        Next

        If blackCount > whiteCount Then
            MessageBox.Show("Black wins!", "Game Over")
        ElseIf whiteCount > blackCount Then
            MessageBox.Show("White wins!", "Game Over")
        Else
            MessageBox.Show("It's a draw!", "Game Over")
        End If
    End Sub
End Class

In this VB.NET version, the board is stored in a two-dimensional array. Each cell is represented by a button, and the game checks all eight directions to determine whether opponent pieces should be flipped after a valid move.

Suggested VB.NET controls:
64 Buttons created dynamically for the board
1 Label for status: lblStatus
Optional buttons: btnNewGame, btnReset

VB.NET Reversi Simulation

This interactive demo shows how a simplified Reversi board works in a VB.NET-style application. Click a valid square to place a piece and flip the opponent’s pieces.

Current Player: Black

Black

White

Tip: The actual implementation would include more complex logic to check all eight directions around the placed piece to determine which opponent pieces are trapped between two pieces of the current player's color.