Seeking comments on double-buffered 2D graphics in Squeak

Noel J. Bergman noel at
Fri Jun 8 04:24:05 UTC 2001

>>> I haven't worked directly with Windows APIs before, and haven't run
>>> across the ones that let me get at the vertical blanking
>> I am not aware of the existance of such an API in Win32.
> It is [supported] in DirectX. Look at the IDirectDraw interface;
> it supports both, retrieving and waiting for vertical blank status ...

Weird!  When I searched MSDN for "wait vertical blank", it gave me
references to just the version of DirectDraw released on WinCE for a game
console (Dreamcube), not in the general DirectDraw docs.  After your
reference, I went so far as to download the DirectX 8 SDK documentation, and
even there there is no documentation for IDirectDraw (for further reading,
it says to look in the SDK docs ... rather self-referential); I had to find
the CAggDirectDraw C++ class to locate the supported API.

FWIW, the DDVIDEOPORTCAPS structure seems to provide for hardware supported
automatic double buffering (the hardware has multple buffers, and will flip
for you on the VBI).

FWIW, it is not in GAPI.  Not a surprise, given the hardware.  :-)

	--- Noel

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