Small Basic Curriculum: Lesson 4.4: Advanced Games

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1/17/2024

Small Basic > Curriculum >** **Online > Lesson 4.4: Advanced Games

Estimated time to complete this lesson: 1 hour

Advanced Games

In this lesson, you will learn how to:

Create advanced games by using basic elements, objects, and other advanced concepts of Small Basic.

Advanced Games in Small Basic

Congratulations! You are now well acquainted with programming fundamentals and advanced concepts of Small Basic.

You have learned to use basic programming concepts in Small Basic. You have also been introduced to Small Basic objects and advanced concepts.

Let’s see how we can use all these concepts to create advanced games.

Tic-Tac-Toe – The Game

You are probably familiar with the popular Tic-Tac-Toe game. Let’s see how we can create our own version of this game.

The user and the computer try to win the game by placing Xs or Os in a horizontal, vertical, or diagonal row before the other player does.

Notice how you use the Shapes object to draw various game elements. You use mouse events to enable the user to place Xs in the graphics window.

Tic-Tac-Toe – How to Play

So how do you play this game?

Steps to play the game:

This game involves two players: the user and the computer. Each player takes a turn placing an X or an O in the 3x3 playing area. To start the game, the user places an X on the board.
The players alternate placing Xs or Os on the playing area.
The player who first places three Xs or three Os in a horizontal, vertical, or diagonal line wins the game.

Tic-Tac-Toe – The Code

Now let’s understand the code for the game in detail…

' Copyright (c) Microsoft Corporation.  All rights reserved.
GraphicsWindow.Hide()
gw = 350
gh = 350

gridX = 25
gridY = 25
cellSize = 100

GraphicsWindow.CanResize = "False"
GraphicsWindow.Width = gw
GraphicsWindow.Height = gh

GraphicsWindow.Top = (Desktop.Height - gh) / 2
GraphicsWindow.Left = (Desktop.Width - gw) / 2
GraphicsWindow.Title = "Tic-Tac-Toe"
GraphicsWindow.Show()

playerTurn = "True"
GraphicsWindow.MouseMove = OnMouseMove
GraphicsWindow.MouseDown = OnMouseDown

SetupBoard()

gameLoop:
CheckGameOver()
If gameOver = "True" Then
  Goto endGame
EndIf

If playerTurn = "True" Then
  Program.Delay(1000)
  Goto gameLoop
EndIf

TryWin()
If compRow <> -1 And compCol <> -1 Then
  PlayComputerTurn()
  Goto gameCheck
EndIf

TryBlock()
If compRow <> -1 And compCol <> -1 Then
  PlayComputerTurn()
  Goto gameCheck
EndIf

' Play Center
If cells[1][1] = "" Then
  compRow = 1
  compCol = 1
  PlayComputerTurn()
  Goto gameCheck
EndIf

' Pick a corner
PickCorner()
If compRow <> -1 And compCol <> -1 Then
  PlayComputerTurn()
  Goto gameCheck
EndIf

' Pick any empty cell
PickAny()
If compRow <> -1 And compCol <> -1 Then
  PlayComputerTurn()
  Goto gameCheck
EndIf

gameCheck:
CheckGameOver()
If gameOver <> "True" Then
  Goto gameLoop
EndIf

endGame:
If playerWins = "True" Then
  GraphicsWindow.ShowMessage("You win! Nice work.", "Game Over")
  Program.End()
ElseIf computerWins = "True" Then
  GraphicsWindow.ShowMessage("Computer wins! Better luck next time.", "Game Over")
  Program.End()
Else
  GraphicsWindow.ShowMessage("Tie game!", "Game Over")
  Program.End()
EndIf

Sub TryWin
  compRow = -1
  compCol = -1
  For i = 0 to 2
    If cells[i][0] = "O" And cells[i][1] = "O" And cells[i][2] = "" Then
      compRow = i
      compCol = 2
    ElseIf cells[i][0] = "O" And cells[i][1] = "" And cells[i][2] = "O" Then
      compRow = i
      compCol = 1
    ElseIf cells[i][0] = "" And cells[i][1] = "O" And cells[i][2] = "O" Then
      compRow = i
      compCol = 0
    ElseIf cells[0][i] = "O" And cells[1][i] = "O" And cells[2][i] = "" Then
      compCol = i
      compRow = 2
    ElseIf cells[0][i] = "O" And cells[1][i] = "" And cells[2][i] = "O" Then
      compCol = i
      compRow = 1
    ElseIf cells[0][i] = "" And cells[1][i] = "O" And cells[2][i] = "O" Then  
      compCol = i
      compRow = 0
    EndIf    
  EndFor
  If cells[0][0] = "O" And cells[1][1] = "O" And cells[2][2] = "" Then
    compCol = 2
    compRow = 2
  ElseIf cells[0][0] = "O" And cells[1][1] = "" And cells[2][2] = "O" Then
    compCol = 1
    compRow = 1
  ElseIf cells[0][0] = "" And cells[1][1] = "O" And cells[2][2] = "O" Then
    compCol = 0
    compRow = 0
  EndIf
EndSub

Sub TryBlock
  compRow = -1
  compCol = -1
  For i = 0 to 2
    If cells[i][0] = "X" And cells[i][1] = "X" And cells[i][2] = "" Then
      compRow = i
      compCol = 2
    ElseIf cells[i][0] = "X" And cells[i][1] = "" And cells[i][2] = "X" Then
      compRow = i
      compCol = 1
    ElseIf cells[i][0] = "" And cells[i][1] = "X" And cells[i][2] = "X" Then
      compRow = i
      compCol = 0
    ElseIf cells[0][i] = "X" And cells[1][i] = "X" And cells[2][i] = "" Then
      compCol = i
      compRow = 2
    ElseIf cells[0][i] = "X" And cells[1][i] = "" And cells[2][i] = "X" Then
      compCol = i
      compRow = 1
    ElseIf cells[0][i] = "" And cells[1][i] = "X" And cells[2][i] = "X" Then  
      compCol = i
      compRow = 0
    EndIf    
  EndFor
  If cells[0][0] = "X" And cells[1][1] = "X" And cells[2][2] = "" Then
    compCol = 2
    compRow = 2
  ElseIf cells[0][0] = "X" And cells[1][1] = "" And cells[2][2] = "X" Then
    compCol = 1
    compRow = 1
  ElseIf cells[0][0] = "" And cells[1][1] = "X" And cells[2][2] = "X" Then
    compCol = 0
    compRow = 0
  EndIf
EndSub

Sub CheckGameOver
  For i = 0 to 2 
    If cells[i][0] = "X" And cells[i][1] = "X" And cells[i][2] = "X" Then
      playerWins = "True"
      gameOver = "True"
    ElseIf cells[i][0] = "O" And cells[i][1] = "O" And cells[i][2] = "O" Then
      computerWins = "True"
      gameOver = "True"
    ElseIf cells[0][i] = "X" And cells[1][i] = "X" And cells[2][i] = "X" Then
      playerWins = "True"
      gameOver = "True"
    ElseIf cells[0][i] = "O" And cells[1][i] = "O" And cells[2][i] = "O" Then
      computerWins = "True"
      gameOver = "True"
    EndIf
  EndFor
  If cells[0][0] = "X" And cells[1][1] = "X" And cells[2][2] = "X" Then
    playerWins = "True"
    gameOver = "True"
  ElseIf cells[0][0] = "O" And cells[1][1] = "O" And cells[2][2] = "O" Then
    computerWins = "True"
    gameOver = "True"
 ElseIf cells[0][2] = "O" And cells[1][1] = "O" And cells[2][0] = "O" Then
     computerWins = "True"
     gameOver = "True"   
  ElseIf cells[0][2] = "X" And cells[1][1] = "X" And cells[2][0] = "X" Then
     playerWins = "True"
     gameOver = "True"  
  EndIf
  
  If gameOver <> "True" Then
    gameOver = "True"
    For i = 0 to 2
      For j = 0 To 2
        If cells[i][j] = "" Then
          gameOver = "False"
        EndIf
      EndFor
    EndFor
  EndIf
EndSub

Sub PickCorner
  If cells[0][0] = "X" And cells[2][2] = "" Then
    compRow = 2 
    compCol = 2
  ElseIf cells[0][2] = "X" And cells[2][0] = "" Then
    compRow = 2
    compCol = 0
  ElseIf cells[2][0] = "X" And cells[0][2] = "" Then
    compRow = 0
    compCol = 2
  ElseIf cells[2][2] = "X" And cells[0][0] = "" Then
    compRow = 2
    compCol = 2
  ElseIf cells[0][0] = "" Then
    compRow = 0
    compCol = 0
  ElseIf cells[0][2] = "" Then
    compRow = 0
    compCol = 2
  ElseIf cells[2][0] = "" Then
    compRow = 2
    compCol = 0
  ElseIf cells[2][2] = "" Then
    compRow = 2
    compCol = 2
  EndIf
EndSub

Sub PickAny
  For i = 0 to 2
    For j = 0 To 2
      If cells[i][j] = "" Then
        compRow = i
        compCol = j
        Goto endPickAny
      EndIf
    EndFor
  EndFor
endPickAny:
EndSub

Sub PlayComputerTurn
  r = compRow
  c = compCol
  
  cells[r][c] = "O"
        
  GraphicsWindow.BrushColor = "Black"
  GraphicsWindow.FontSize = 40
  GraphicsWindow.FontBold = "False"
  cellText = Shapes.AddText("O")
  Shapes.Move(cellText, c * cellSize + gridX + 40, r * cellSize + gridY + 26)
  playerTurn = "True"
EndSub

Sub OnMouseDown
  If playerTurn = "True" Then

    mx = GraphicsWindow.MouseX
    my = GraphicsWindow.MouseY
    If mx > gridX And my > gridY And mx < (gridX + 3 * cellSize) And my < (gridY + 3 * cellSize) Then
      c = Math.Floor((mx - gridX) / cellSize)
      r = Math.Floor((my - gridY) / cellSize)
      
      If cells[r][c] = "" Then
        cells[r][c] = "X"
        
        GraphicsWindow.BrushColor = "Black"
        GraphicsWindow.FontSize = 40
        GraphicsWindow.FontBold = "False"
        cellText = Shapes.AddText("X")
        Shapes.Move(cellText, c * cellSize + gridX + 40, r * cellSize + gridY + 26)
        playerTurn = "False"
      EndIf
    EndIf
  EndIf
EndSub

Sub OnMouseMove
  If playerTurn = "True" Then
    hover = "False"
    DrawCell()
    
    mx = GraphicsWindow.MouseX
    my = GraphicsWindow.MouseY
    If mx > gridX And my > gridY And mx < (gridX + 3 * cellSize) And my < (gridY + 3 * cellSize) Then
      col = Math.Floor((mx - gridX) / cellSize)
      row = Math.Floor((my - gridY) / cellSize)

      hover = "True"
      DrawCell()
    EndIf
  EndIf
EndSub

Sub SetupBoard
  hover = "False"
  For col = 0 to 2
    For row = 0 To 2
      DrawCell()
    EndFor
  EndFor
  
  row = -1
  col = -1
EndSub

Sub DrawCell
  If row >= 0 And col >= 0 And row <= 2 And col <=2 Then
    x = col * cellSize + gridX
    y = row * cellSize + gridY
      
    If hover = "True" Then
      GraphicsWindow.BrushColor = "Azure"
    Else
      GraphicsWindow.BrushColor = "White"
    EndIf
    GraphicsWindow.FillRectangle(x, y, cellSize, cellSize)
    
    GraphicsWindow.PenColor = "Black"
    GraphicsWindow.DrawRectangle(x, y, cellSize, cellSize)
  EndIf
EndSub

This is the output you will see:

Create the game interface by using the GraphicsWindow object.
Use the Shapes object to create the playing area for the Xs and Os in the graphics window.
Use mouse events and conditions such as If-Else to describe various actions that the user and the computer perform during the game.

Let’s Summarize…

Congratulations!

Now you know how to:

Create advanced games by using basic elements, objects, and advanced concepts of Small Basic.

Show What You Know

Create a game that involves the following objects: a wall of colored and grey blocks, a ball, and a paddle. The wall slowly moves down toward the paddle. Using the paddle, you must hit all the colored blocks with the ball before the wall hits the paddle.

You use the mouse to move the paddle; the paddle controls the movement of the ball. The ball will bounce off grey blocks. After you hit all the colored blocks, you win the game. You lose the game if the paddle misses the ball or if the blocks hit the paddle before you can remove all the colored blocks.

To see the answers to these questions, go to the Answer Key page.

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