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Small BasicOnline > Lesson 4.4: Advanced Games

Estimated time to complete this lesson: 1 hour

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"
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"
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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