[cairo] image memory alternatives

[Jonathan Morton]

On Thu, 2010-08-19 at 01:52 +0800, M.R. wrote:
> I assume that method (1) will be preferred if there is a lot of
> drawing to be done, since back-end driver can use graphics device
> memory and hardware-accelerated primitives.

The image backend does not use hardware acceleration.  It operates
entirely on an ordinary block of memory, which you may provide yourself.

If you were to use a potentially accelerated backend, eg. X11, then such
a tradeoff would exist.  At the end of rendering, you would need to
retrieve the finished image into your shared memory block.  This
retrieval may sometimes be slow, depending on the hardware in use.

-- 
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From: Jonathan Morton
      jonathan.morton at movial.com