VBJET Fighter - Visual Basic 游戏

• 下载 VBJET 1.1 源代码 - 54.34 KB

官方网站: http://vbjet-fighter.sourceforge.net/

引言

VBJet 是一个使用 Visual Basic 6 开发的非常小的游戏。我尽量使其尽可能简单，但它仍然具有不错的动画和控制效果。这个游戏的第一个版本是在 QuickBasic for DOS 中开发的，非常原始，我使用了 QuickBasic 的绘图函数来绘制图形，例如 Draw 和 PSet。迁移到 Visual Basic 非常有助于改进游戏，因为我可以使用位图图形来显示游戏对象，例如飞机和导弹。

代码

好吧，它的程序非常容易理解，但也可能有点令人困惑。所以这是我尝试解释代码工作原理的过程。

游戏对象/类

• JETPlane
• EnemyJETPlane
• Missile

以下是包含所有事件和主游戏循环的代码片段。

游戏循环和主代码文件

' Global variable declarations
Option Explicit
Dim u, d, l, r As Boolean ' Basic true/false variables
Dim VBJet As New JETPlane
Dim VBJetMissile As New Missile
Dim EnemyJet() As New EnemyJetPlane
Dim EnemyJetCount As Integer
Dim EnemyJetMVar As Integer
Dim score As Long
Dim stage As Long
Dim level_score As Integer

'___________________________________________________________________________
' Forma load routine that is used to initialize things
Private Sub Form_Load()
' Startup and basic settings

lblScore.Caption = "0"

VBJet.x = 0
VBJet.y = 0

EnemyJetCount = 2
EnemyJetMVar = 10

ReDim EnemyJet(EnemyJetCount)

Dim i As Integer
For i = 1 To EnemyJetCount
EnemyJet(i).speed = 5
Load en(i)
en(i).Visible = True
SetEn i
Next i

VBJet.Power = 1

stage = 1
End Sub
'__________________________________________________________________________
' Called each time main window is repainted
Private Sub Form_Paint()
shooter.SetFocus
End Sub
'___________________________________________________________________________

' This is the main inputs event that monitors the user input key down events
Private Sub shooter_KeyDown(KeyCode As Integer, Shift As Integer)
If KeyCode = 49 Then speed = speed - 1
If speed <= 0 Then speed = 0
If speed > 30 Then speed = 30

If KeyCode = 50 Then speed = speed + 1
If KeyCode = vbKeyLeft Then l = True
If KeyCode = vbKeyRight Then r = True
If KeyCode = vbKeyUp Then u = True
If KeyCode = vbKeyDown Then d = True

If KeyCode = vbKeySpace Then
If Not VBJetMissile.Visible Then
FireIt
End If
End If
If KeyCode = vbKeyEscape Then Unload Me: Form2.Show
End Sub
'___________________________________________________________________________
' This event is called when user releases the keyboard key
Private Sub shooter_KeyUp(KeyCode As Integer, Shift As Integer)
' Check keyup event
' If keyup call then disable movement check
If KeyCode = vbKeyLeft Then l = False
If KeyCode = vbKeyRight Then r = False
If KeyCode = vbKeyUp Then u = False
If KeyCode = vbKeyDown Then d = False
End Sub
'___________________________________________________________________________
This timer event is used to update the animation frames of Jet Fighter
Private Sub Timer1_Timer()
Static ch As Boolean
ch = Not ch
' Animation steps of Jet Fighter
If ch Then
shooter.Picture = Picture2.Picture
Else
shooter.Picture = Picture3.Picture
End If
End Sub
'___________________________________________________________________________
' This timer event is the main game loop that updates all things
Private Sub Timer2_Timer()
If l Then
VBJet.x = VBJet.x - speed
If VBJet.x < 0 Then VBJet.x = 0
End If

If r Then
VBJet.x = VBJet.x + speed
If VBJet.x >= Me.ScaleWidth - 100 Then VBJet.x = Me.ScaleWidth - 100
End If

If u Then
VBJet.y = VBJet.y - speed
If VBJet.y < 0 Then VBJet.y = 0
End If

If d Then
VBJet.y = VBJet.y + speed
If VBJet.y >= Me.ScaleHeight - 100 Then VBJet.y = Me.ScaleHeight - 100
End If

Label5.Caption = "X = " & VBJet.x
Label6.Caption = "Y = " & VBJet.y

shooter.Left = VBJet.x
shooter.Top = VBJet.y

Label3.Caption = CStr(speed)

Dim i As Integer
For i = 1 To EnemyJetCount

If VBJetMissile.Visible Then

VBJetMissile.x = VBJetMissile.x + 20
If VBJetMissile.x > Me.ScaleWidth Then
VBJetMissile.Visible = False
fire.Visible = False

End If

fire.Left = VBJetMissile.x
fire.Top = VBJetMissile.y

If level_score = 9 Then
stage = stage + 1
level_score = 0
EnemyJet(i).speed = EnemyJet(i).speed + 5 ' Increase enemy speed
en(i).Picture = LoadPicture((App.Path & "\data\op2.gif"))
End If

If (VBJetMissile.y > EnemyJet(i).y And VBJetMissile.y < EnemyJet(i).y + 60) _
	And (VBJetMissile.x > EnemyJet(i).x) Then
score = score + 10
level_score = level_score + 1
VBJetMissile.Visible = False
SetEn i
End If
Else
fire.Visible = False
End If

EnemyJet(i).x = EnemyJet(i).x - EnemyJet(i).speed
If EnemyJet(i).y > VBJet.y Then
EnemyJet(i).y = EnemyJet(i).y - (Rnd(EnemyJetMVar))
Else
EnemyJet(i).y = EnemyJet(i).y + (Rnd(EnemyJetMVar))
End If

en(i).Left = EnemyJet(i).x
en(i).Top = EnemyJet(i).y

If EnemyJet(i).x < -200 Then
SetEn i
en(i).Top = EnemyJet(i).y
End If
lblScore = CStr(score)
lblStage = CStr(stage)

Label8.Caption = "EX = " & EnemyJet(i).x
Label7.Caption = "EY = " & EnemyJet(i).y

If (VBJet.y > EnemyJet(i).y - 40 And VBJet.y < EnemyJet(i).y + 30) _
	And (VBJet.x > EnemyJet(i).x And VBJet.x < EnemyJet(i).x + 100) Then

VBJet.Power = VBJet.Power + 1
Picture1.BackColor = RGB(Rnd * 255, Rnd * 255, Rnd * 255)

SetEn i

Select Case VBJet.Power

Case 2
Image1.Picture = LoadPicture(App.Path & "\data\fuel50.gif")

Case 3
Image1.Picture = LoadPicture(App.Path & "\data\fuel20.gif")

Case 4
Image1.Picture = LoadPicture(App.Path & "\data\game-over.gif")

End Select

If VBJet.Power = 4 Then

MsgBox "Game Over", vbCritical, "Shooter"
Unload Me
Form2.Show

End If

End If

Next i
End Sub
'___________________________________________________________________________
' Fires missile
Private Sub FireIt()
VBJetMissile.Visible = True

VBJetMissile.x = shooter.Left + 100
VBJetMissile.y = shooter.Top + 50
fire.Visible = True
End Sub
'___________________________________________________________________________
' Set enemy position
Public Sub SetEn(index As Integer)

EnemyJet(index).y = Int(Rnd * Me.ScaleHeight) - 100
EnemyJet(index).x = Int(Rnd * Me.ScaleHeight) + Me.ScaleWidth
en(index).Left = EnemyJet(index).x
en(index).Top = EnemyJet(index).y

End Sub
'___________________________________________________________________________
'This is timer event is used to move the enemy fighters.
Private Sub Timer3_Timer()
Dim i As Integer
For i = 1 To EnemyJetCount
EnemyJet(i).speed = EnemyJet(i).speed + 5
EnemyJetMVar = EnemyJetMVar + 5
Next i
End Sub

结论

虽然这是一个非常简单的 VB6 应用程序，但它传达了一些游戏编程的基础知识。这个游戏也证明了游戏编程是有趣的，可以从像这样简单但有趣的小努力开始。