[Vb6] Windowed DirectX8[Resolved]

[Nove]

I have windowed DirectX8 set up with a picturebox on my form. This works fine, except that the picture box changes shape as the form resizes. Perhaps I'm doing this wrong, or perhaps it's by default, but when the pixturebox changes size the blitting from directx warps to fit inside the picturebox. Here's my initialization code.

Public Function Initialize() As Boolean
  'On Error GoTo ErrHandler:
  
  Dim DispMode As D3DDISPLAYMODE 
  Dim D3DWindow As D3DPRESENT_PARAMETERS 
  Dim ColorKeyVal As Long 
  
  Set dx = New DirectX8  
  Set D3D = dx.Direct3DCreate() 
  Set D3DX = New D3DX8 
  
  
 
  DispMode.Format = D3DFMT_X8R8G8B8    
  D3DWindow.Windowed = 1
  D3DWindow.SwapEffect = D3DSWAPEFFECT_COPY_VSYNC
  'D3DWindow.BackBufferCount = 1 
  D3DWindow.BackBufferFormat = DispMode.Format 
  'D3DWindow.BackBufferHeight = 480
  'D3DWindow.BackBufferWidth = 640
  D3DWindow.hDeviceWindow = frmEditor.picMain.hWnd
 
 
  Set D3DDevice = D3D.CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, frmEditor.picMain.hWnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, D3DWindow)
  
  D3DDevice.SetVertexShader FVF
  
  D3DDevice.SetRenderState D3DRS_LIGHTING, False
  
  D3DDevice.SetRenderState D3DRS_SRCBLEND, D3DBLEND_SRCALPHA
  D3DDevice.SetRenderState D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA
  D3DDevice.SetRenderState D3DRS_ALPHABLENDENABLE, True
  
  Set DI = dx.DirectInputCreate()
  Set DIDEV = DI.CreateDevice("GUID_SysKeyboard")
  
  DIDEV.SetCommonDataFormat DIFORMAT_KEYBOARD
  DIDEV.SetCooperativeLevel frmEditor.hWnd, DISCL_BACKGROUND Or DISCL_NONEXCLUSIVE
  DIDEV.Acquire
  
  Initialize = True
  Exit Function
ErrHandler:
Debug.Print "Error Number Returned: " & Err.Number
Debug.Print "Error Description: " & Err.description
Initialize = False
End Function

Where frmEditor is a standard VB form and frmEditor.picMain is a regular picturebox. Do I need to reinitialize directX each time the picturebox changes shape or is there an easier way around this? Thanks.

[Fox]

> Do I need to reinitialize directX each time the picturebox changes shape

Kinda; you need to re-initialize the D3D device whenever you enlarge the box (when making it smaller you can just change the present rect).

[Nove]

Present Rect?

[Nove]

Also, when I call the intialize sub again, it totally screws directx up, I get that scrambled stuff when I blit. Why is this?

[Fox]

I guess you want to go the easy way.. well, just remember that DirectX internally renders to a backbuffer that can be any size. Just when you call the Device.Present() function the contents of the backbuffer are copied to your window. By default DirectX copies the whole buffer to the whole target, stretching or shrinking it if necessary. However you can tell the Present function the width/height of your target so there's no need for stretching.

So what you basically do is to create a backbuffer that matches the screen size (because we assume that the window won't ever get larger than the screen). Then you setup the Present rect just the size of your picturebox/window/whatever.

This way you don't have to care about size changes (except you have to store the new size)

[Nove]

So basically, when I call the Present function I supply a RECT the size of my picturebox for the first two parameters?

[Fox]

Yep, but only for the first (source rect). The destination rect will match the size but not the position - let DirectX determine that for you

[Nove]

Ok, thank you very much.

[Fox]

May I ask what you're developing? "Editor" sounds like "game"

[Nove]

Well, I'm working on it. I'd like to see if I can get a a stable server-client game going in vb6, so far it's going allright, I'm mostly doing editor work right now.
Would you happen to know if there are any problems in DirectX 8 just filling the screen completely black? I tried using the same method I've been using with tiles, a 4 element array of TLVERTEX, but I couldn't get anything to blit. Can you foresee any problem I would have or is it just poor coding?

[Fox]

There should not be any problems with that. However, to clear the screen all you do is:

Device.Clear 0, ByVal 0, D3DCLEAR_TARGET Or D3DCLEAR_ZBUFFER, D3DColorRGBA(0, 0, 0, 0), 1, 0

For black you wouldn't even have to use D3DColorRGBA (black is simply 0 you know).

By "blit" do you mean BitBlt? Well, after the rendering is done (Device.EndScene) you can safely blit to the DC - as long as you're in windowed mode, fullscreen would cause problems here.

[Nove]

Nah, not bitblt, I just kinda refer to everything as blitting. I should probably say draw.

[Fox]

But you could BitBlt Ah well, go on then and have fun. If filling the screen doesn't work you probably setup the vertices wrong.. or the FVF.. or something else ^^;

[Nove]

Clear worked fine, thanks. I guess this thing is totally resolved now, thanks a bunch.