Re: Rapid gfx display Qs

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Schmidt wrote:
"Jim Mack" schrieb...

It's my understanding that using a flipping chain with 2
backbuffers can eliminate the need to delay updates
while waiting for the VBlank to flip.

If you fiddled that out, then I would be interested in your
results (the "flipping-code") - haven't played around with
that DX-stuff yet.

To use flipping -- I haven't tried triple-buffering yet -- is actually
a bit easier but less flexible. Speed seems about the same here.

Since all I care about is full-screen, I simplified your DxInit as
follows, and pass in the Form hwnd...

'======================
'
Public Function DxInit(hWnd as Long) As String

Dim PD As DDSURFACEDESC2
Dim BCaps As DDSCAPS2

On Error Resume Next

Set objDX = New DirectX7

Set objDD = objDX.DirectDrawCreate("")

' ** moved from below
'
BlthWnd = hWnd

' ** must have exclusive / fullscreen to flip screen?
'
objDD.SetCooperativeLevel BlthWnd, _
DDSCL_FULLSCREEN Or DDSCL_EXCLUSIVE

'define the primary surface

' ** add BACKBUFFERCOUNT flag
'
PD.lFlags = DDSD_CAPS Or DDSD_BACKBUFFERCOUNT

' ** add FLIP and COMPLEX caps
'
PD.ddsCaps.lCaps = _
DDSCAPS_PRIMARYSURFACE _
Or DDSCAPS_FLIP _
Or DDSCAPS_COMPLEX

' ** ask for a backbuffer surface
'
PD.lBackBufferCount = 1

' ** Because BACKBUFFERCOUNT = 1, this also attaches
' a second matching surface which we'll get later
'
' In theory, setting it =2 gives triple-buffering
'
Set PSrf = objDD.CreateSurface(PD)

' ** this replaces all other OSrf setup
'
BCaps.lCaps = DDSCAPS_BACKBUFFER
Set OSrf = PSrf.GetAttachedSurface(BCaps)

If Err Then DxInit = GetErrString(): Err.Clear

End Function

'======================
'
' Also, the Blt() function now reduces to:
'
'
Public Function Blt(Optional ByVal WaitForSync As Boolean) As String

PSrf.Flip OSrf, DDFLIP_WAIT ' I always wait.
'
' It isn't clear that this actually waits here,
' or threads and continues...?

End Function

.