Mac Forum / Programming / Mac Programming / November 2005

I've set up a simple direct display routine using

 CGDisplayCapture()
 CGDisplayBaseAddress()
 CGDisplayBeamPosition()
which are available from OSX Core Graphics.

I've increased the speed by double buffering,
i.e. interpreting contrast values as RGB triplets
into a back buffer, then copying to the video
memory from CGDisplayBaseAddress(). The copy
is done with "memcpy()", which is ~2x faster
than copying 4-byte integers.

Although similar to double-buffering,
hardware-based page flipping (i.e. moving
the hardware display page pointer instead
of copying bytes) is potentially faster.
However I have not found any obvious way
to accomplish page flipping using Mac OSX
Core Graphics.

I imagine that many Mac video cards have the
hardware capacity for this -- which might
depend on the driver for the video card.
However I haven't found an obvious way
to do the pointer swap using Core Graphics
routines.

Does anyone know whether page flipping is
possible in Mac OSX with Core Graphics?

What would be the most likely way to
accomplish this?

Rob Smith