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首页 - 经验之谈 - 用VB编写DirectX7.0游戏(二)
发表评论(0)作者:不详, 平台:VB6.0+Win98, 阅读:9585, 日期:2002-04-27
建立一个新的工程文件,点击菜单中的 Project | Reference 选项,打开Object Library 列表窗口,将DirectX 7.0 For Visual Basic Type Library 加入工程文件。将Form1的Name属性改变为MainForm,在MainForm中加入一个PictureBox控件,将其的Visible属性设置为False。然后在MainForm的代码窗口中加入以下代码:



  Private Sub Form_KeyPress(KeyAscii As Integer)
   Dim sRect As RECT
   Dim hdcSrc As Long
   If KeyAscii = 27 Then
   ExitLoop = True
   注释:End
   ElseIf KeyAscii = vbKeyReturn Then
  DDSFront.BltToDC Picture1.hDC, sRect, sRect
   With Picture1
   注释:获得与主显示平面兼容的图形设备句柄
   hdcSrc = DDSFront.GetDC
   注释:保存图像
   Set .Picture = SaveTohBmp(hdcSrc, 0, 0, 640, 480)
   注释:释放图形句柄
   DDSFront.ReleaseDC hdcSrc
   SavePicture Picture1, “c:\a.bmp”
   End With
   End If
  End Sub
  
  Public Sub Form_Paint()
   BlitRect.Right = DDSBackDesc.lWidth
   BlitRect.Bottom = DDSBackDesc.lHeight
   DDSFront.Blt BlitRect, DDSBack, BlitRect, DDBLT_WAIT
  End Sub
  在工程文件中加入一个Module文件,这个文件中DirectDraw操作做出了定义,在这个Module中加入以下代码:
  Option Explicit
  Public DX As New DirectX7
  Public DDraw As DirectDraw7
  Public DDSFront As DirectDrawSurface7
  Public DDSFrontDesc As DDSURFACEDESC2
  Public DDSBack As DirectDrawSurface7
  Public DDSBackDesc As DDSURFACEDESC2
  Public Clipper As DirectDrawClipper
  Dim Pict() As Byte
  Dim AlphaRect As RECT
  Dim X As Long, Y As Long
  Dim Temp As Long
  Dim Index As Long
  Dim Index2 As Long
  Dim Pos As Long
  Dim PosPlus1 As Long
  Dim PosPlus2 As Long
  Dim PosPlus3 As Long
  Public Pal(255) As PALETTEENTRY
  Public Palette As DirectDrawPalette
  Public BlitRect As RECT
  Public FullSize As Boolean
  Public ExitLoop As Boolean
  Dim Accum As Long
  Dim Msg(9) As String
  Dim Counter As Long
  Dim MsgIndex As Long
  Dim bDrawText As Boolean
  Dim lastTime As Long
  Dim XPos As Long, YPos As Long
  Dim wait As Long
  Dim Angle As Single
  Dim Flag As Boolean
  Dim Count As Long
  Dim CurModeActiveStatus As Boolean
  Dim bRestore As Boolean
  Dim Mode As Boolean
  Private Sub Main()
   InitializeDX
  注释:初始化Picture1以获得DirectDraw界面图像
   With MainForm.Picture1 .Width = 640 * Screen.TwipsPerPixelX .Height = 480 * Screen.TwipsPerPixelY
   End With
  DDSBack.SetForeColor RGB(255, 255, 255)
   MainForm.Font.Name = “宋体”
   DDSBack.SetFont MainForm.Font
  Msg(0) =“一个显示火焰字的演示”
  Msg(1) =“演示”
  Msg(2) =“利用VB阵列”
  Msg(3) =“对显示内存”
  Msg(4) =“进行直接存取”
  Msg(5) =“{Esc}键退出”
   注释:设置8位的调色板
   For Index = 0 To 84
   Pal(Index + 1).red = Index * 3 + 3
   Pal(Index + 1).green = 0
   Pal(Index + 1).blue = 0
   Pal(Index + 86).red = 255
   Pal(Index + 86).green = Index * 3 + 3
   Pal(Index + 86).blue = 0
   Pal(Index + 171).red = 255
   Pal(Index + 171).green = 255
   Pal(Index + 171).blue = Index * 3 + 3
   Next
  Set Palette = DDraw.CreatePalette(DDPCAPS_8BIT _ Or DDPCAPS_ALLOW256, Pal())
   DDSFront.SetPalette Palette
  AlphaRect.Right = DDSBackDesc.lWidth - 1
  AlphaRect.Bottom=DDSBackDesc.lHeight- 1
   DDSBack.Lock AlphaRect, DDSBackDesc, DDLOCK_WAIT, 0
  
   DDSBack.GetLockedArray Pict()
   For X = 0 To 639
   For Y = 0 To 479
   Pict(X, Y) = 0
   Next
   Next
   注释:Corresponding unlock
   DDSBack.Unlock AlphaRect
   While Not ExitLoop
   Mode = ExModeActive
   bRestore = False
   Do Until ExModeActive
   DoEvents
   bRestore = True
   Loop
   DoEvents
   If bRestore Then
   bRestore = False
   DDraw.RestoreAllSurfaces
   End If
   DDSBack.Lock AlphaRect, DDSBackDesc, DDLOCK_WAIT, 0
   DDSBack.GetLockedArray Pict()
   For Y = 0 To 479
   Pict(0, Y) = 0
   Pict(639, Y) = 0
   Next
   For X = 0 To 639
   Pict(X, 477) = Rnd * 220 + 35
   Pict(X, 478) = Rnd * 220 + 35
   Pict(X, 479) = Rnd * 220 + 35
   Next
   Accum = 0
   For X = 1 To 638
   For Y = 0 To 477
   Accum = (Accum + Pict(X, Y + 1) _
   + Pict(X, Y + 2) _
   + Pict(X + 1, Y + 1) _
   + Pict(X - 1, Y + 1)) \ 5
   If Accum < 0 Then
   Accum = 0
   ElseIf Accum > 255 Then
   Accum = 255
   End If
   Pict(X, Y) = Accum
   Next
   Next
   For X = 0 To 639
   Pict(X, 0) = 0
   Pict(X, 1) = 0
   Next
   X = Rnd * 639
   For Y = 50 To 439
   Next
   DDSBack.Unlock AlphaRect
  If DX.TickCount() - lastTime > wait Then
   If Counter = 0 Then
   bDrawText = True
   Counter = 1
   XPos = Rnd * 200
   YPos = 300 + Rnd * 140
   wait = 400
   ElseIf Counter = 1 Then
   MsgIndex = MsgIndex + 1
   If MsgIndex > 5 Then MsgIndex = 0
   bDrawText = False
   Counter = 0
   wait = 2000
   End If
   lastTime = DX.TickCount
   End If
   If bDrawText Then
   On Error Resume Next
   DDSBack.DrawText XPos, YPos, Msg(MsgIndex), False
   On Error GoTo 0
   End If
   MainForm.Form_Paint
   Wend
   TerminateDX
   End
  End Sub
  Function ExModeActive() As Boolean
   Dim TestCoopRes As Long
  TestCoopRes = DDraw.TestCooperativeLevel
   Select Case TestCoopRes
   Case DDERR_NOEXCLUSIVEMODE
   ExModeActive = False
   Case DD_OK
   ExModeActive = True
   End Select
  End Function
  Public Sub InitializeDX()
  MainForm.Left = 0
  MainForm.Top = 0
  MainForm.Height =640 * Screen.TwipsPerPixelY
  MainForm.Width = 480 * Screen.TwipsPerPixelX
  MainForm.Show
   注释:建立DirectDraw对象
   Set DDraw = DX.DirectDrawCreate(“”)
   注释:设定DirectDraw对象的协作层
   DDraw.SetCooperativeLevel MainForm.hWnd, DDSCL_EXCLUSIVE Or DDSCL_FULLSCREEN 注释: DDSCL_NORMAL
   注释:设定显示模式位640×480×8位颜色
   DDraw.SetDisplayMode 640, 480, 8, 0, DDSDM_DEFAULT
   注释:设定DDSFrontDesc为主平面
   With DDSFrontDesc
  .lFlags = DDSD_CAPS
  .ddsCaps.lCaps = DDSCAPS_PRIMARYSURFACE 注释:Or DDSCAPS_SYSTEMMEMORY
   End With
   注释:设定DDSBackDesc为后台缓冲平面
   With DDSBackDesc
  .ddsCaps.lCaps = DDSCAPS_SYSTEMMEMORY
  .lFlags = DDSD_CAPS Or DDSD_WIDTH Or DDSD_HEIGHT
  .lWidth = 640
  .lHeight = 480
   End With
   注释:建立平面
   Set DDSFront = DDraw.CreateSurface(DDSFrontDesc)
   Set DDSBack = DDraw.CreateSurface(DDSBackDesc)
   Set Clipper = DDraw.CreateClipper(0)
   Clipper.SetHWnd MainForm.hWnd
   DDSFront.SetClipper Clipper
   DDSBack.SetClipper Clipper
   DoEvents
   Exit Sub
  ERRoUT:
   If Not (DDraw Is Nothing) Then
   DDraw.RestoreDisplayMode
   DDraw.SetCooperativeLevel MainForm.hWnd, DDSCL_NORMAL
   DoEvents
   End If
   MsgBox “无法对DirectDraw进行初始化 ”+Chr(13)+“也许你的显示卡不支持 640×480×8 显示模式 ”
   End
  End Sub
  Public Sub TerminateDX()
   注释:子程序TerminateDX回复原来的显示模式并且释放所有的DirectDraw有关对象
   DDraw.RestoreDisplayMode
   DDraw.SetCooperativeLevel MainForm.hWnd, DDSCL_NORMAL
   DoEvents
   Set Clipper = Nothing
   Set DDSBack = Nothing
   Set DDSFront = Nothing
   Set DDraw = Nothing
   Set DX = Nothing
  End Sub
  在工程文件中再加入一个Module,这个Module主要定义与图像保存相关的操作,在建立的Module中加入以下代码:
   Option Explicit
  Option Base 0
  Private Type PALETTEENTRY
   peRed As Byte
   peGreen As Byte
   peBlue As Byte
   peFlags As Byte
  End Type
  
  Private Type LOGPALETTE
   palVersion As Integer
   palNumEntries As Integer
   palPalEntry(255) As PALETTEENTRY
  End Type
  
  Private Type GUID
   Data1 As Long
   Data2 As Integer
   Data3 As Integer
   Data4(7) As Byte
  End Type
  Private Const RASTERCAPS As Long = 38
  Private Const RC_PALETTE As Long = &H100
  Private Const SIZEPALETTE As Long = 104
  Private Declare Function CreateCompatibleDC Lib “GDI32” (ByVal hDC As Long) As Long
  Private Declare Function CreateCompatibleBitmap Lib “GDI32” (ByVal hDC As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
  Private Declare Function GetDeviceCaps Lib “GDI32” (ByVal hDC As Long, ByVal iCapabilitiy As Long) As Long
  Private Declare Function GetSystemPaletteEntries Lib “GDI32” (ByVal hDC As Long, ByVal wStartIndex As Long, ByVal wNumEntries As Long, lpPaletteEntries As PALETTEENTRY) As Long
  Private Declare Function CreatePalette Lib “GDI32”(lpLogPalette As LOGPALETTE) As Long
  Private Declare Function SelectObject Lib “GDI32”(ByVal hDC As Long, ByVal hObject As Long) As Long
  Private Declare Function BitBlt Lib “GDI32”(ByVal hDCDest As Long, ByVal XDest As Long, ByVal YDest As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hdcSrc As Long, ByVal XSrc As Long, ByVal YSrc As Long, ByVal dwRop As Long) As Long
  Private Declare Function DeleteDC Lib “GDI32”(ByVal hDC As Long) As Long
  Private Declare Function GetForegroundWindow Lib “USER32” () As Long
  Private Declare Function SelectPalette Lib “GDI32”(ByVal hDC As Long, ByVal hPalette As Long, ByVal bForceBackground As Long) As Long
  Private Declare Function RealizePalette Lib “GDI32” (ByVal hDC As Long) As Long
  Private Declare Function GetWindowDC Lib “USER32” (ByVal hWnd As Long) As Long
  Private Declare Function GetDC Lib “USER32"(ByVal hWnd As Long) As Long
  Private Declare Function GetWindowRect Lib “USER32”(ByVal hWnd As Long, lpRect As RECT) As Long
  Private Declare Function ReleaseDC Lib “USER32”(ByVal hWnd As Long, ByVal hDC As Long) As Long
  Private Declare Function GetDesktopWindow Lib “{USER32"() As Long
  
  Private Type PicBmp
   Size As Long
   Type As Long
   hBmp As Long
   hPal As Long
   Reserved As Long
  End Type
  Private Declare Function OleCreatePictureIndirect Lib “olepro32.dll” (PicDesc As PicBmp, RefIID As GUID, ByVal fPictureOwnsHandle As Long, IPic As IPicture) As Long
  
  Public Function SaveTohBmp(ByVal hdcSrc As Long, ByVal LeftSrc As Long, _
   ByVal TopSrc As Long, ByVal WidthSrc As Long, ByVal HeightSrc As Long) As Picture
   Dim hDCMemory As Long
   Dim hBmp As Long
   Dim hBmpPrev As Long
   Dim r As Long
   Dim hPal As Long
   Dim hPalPrev As Long
   Dim RasterCapsScrn As Long
   Dim HasPaletteScrn As Long
   Dim PaletteSizeScrn As Long
   Dim LogPal As LOOGPALETTE
   注释:建立一个内存图形设备句柄
  hDCMemory=CreateCompatibleDC(hdcSrc)
  注释:建立一个bitmap并保存到hDCMemory中
  hBmp = CreateCompatibleBitmap(hdcSrc, WidthSrc, HeightSrc)
   hBmpPrev = SelectObject(hDCMemory, hBmp)
   RasterCapsScrn = GetDeviceCaps(hdcSrc, RASTE图CAPS) 注释:rRaste
   HasPaletteScrn = RasterCapsScrn And RC_PALtTTEic1 注释: Palette
   PaletteSizeScrn = GetDeviceCaps(hdcSrc, SIZEPALETTE) 注释: Size of
   If HasPaletteScrn And (PaletteSizeScrn = 256) Then
   注释:建立系统调色板的拷贝
   LogPal.palVersion = &H300
   LogPal.palNumEntries = 256
   r = GetSystemPaletteEntries(hdcSrc, 0, 256, LogPal.palPalEntry(0))
   hPal = CreatePalette(LogPal)
   hPalPrev = SelectPalette(hDCMemory, hPal, 0)
   r = RealizePalette(hDCMemory)
   End If
   注释:将屏幕图形拷贝到内存图形设备句柄中
   r = BitBlt(hDCMemory, 0, 0, WidthSrc, HeightSrc, hdcSrc, LeftSrc, TopSrc, vbSrcCopy)
   hBmp = SelectObject(hDCMemory, hBmpPrev)
   If HasPaletteScrn And (PaletteSizeScrn = 256) Then
   hPal = SelectPalette(hDCMemory, hPalPrev, 0)
   End If
  注释:释放图形设备句柄
   r = DeleteDC(hDCMemory)
   Debug.Print r
   注释:调用CreateBitmapPicture函数从指定的bitmap对象和调色板中建立一个picture对象
   Set SaveTohBmp = CreateBitmapPicture(hBmp, hPal)
  End Function
  Public Function CreateBitmapPicture(ByVal hBmp As Long, ByVal hPal As Long) As Picture
   Dim r As Long
   Dim Pic As PicBmp
   Dim IPic As IPicture
   Dim IID_IDispatch As GUID
   注释:填充IDispatch界面
   With IID_IDispatch
   .Data1 = &H20400
   .Data4(0) = &HC0
   .Data4(7) = &H46
   End With
   注释:填充Pic结构
   With Pic
   .Size = Len(Pic) 注释: Length of structure.
   .Type = vbPicTypeBitmap 注释: Type of Picture (bitmap).
   .hBmp = hBmp 注释: Handle to bitmap.
   .hPal = hPal 注释: Handle to palette (may be null).
   End With
   注释:建立Picture对象
   r = OleCreatePictureIndirect(Pic, IID_IDispatch, 1, IPic)
   注释:返回Picture对象
   Set CreateBitmapPicture = IPic
  End Function

  运行程序,在屏幕上会出现一些火焰字的特效,按Enter键可以将屏幕保存到“c:\a.bmp”中,按Esc键退出程序回到Windows。

  在上面的程序中,程序首先建立一个DirectDraw对象,然后设置该对象的协作层为全屏协作模式,接下来设置显示模式为640×480×8位颜色,建立一个前台DirectDrawSurface对象和一个后台缓冲DirectDrawSurface对象,建立和设置DirectDrawClipper对象。

  在主程序段中,程序首先对前台绘图平面的调色板(DirectDrawPalette)对象进行操作以改变显示的文字的颜色,然后对后台缓冲绘图平面进行字节操作,以产生文字弥散的效果,然后再将后台缓冲绘图平面翻转到前台。当用户按下Enter键之后,程序获得与前台绘图平面相兼容的图形设备句柄,然后再调用Windows API函数将绘图平面内存中的内容保存到Windows位图文件中。

  上面粗略地介绍了DirectX7 SDK的新特性以及初步的DirectDraw编程,希望对大家能有所帮助。以上的程序在Windows98、VB6.0下运行通过。