It's kind of ironic that with the Squeak pixel format completely
optimised for Mac, Apple still manage to make a change that ruins
performance. Almost every machine other than Macs need to mess with the
pixel order and colour mapping in the process of moving the Display to
the display.

For now the Acorn machines keep a complete window bitmap cache and do
the munging every time ioShowDisplay is called so that the OS display
events only do the pixel transfer. The cost is extra memory usage, the
saving is in the time to 'unreverse' all the pixels after each OS
display event.  I still don't have any real firm opinion on which is the
better way. Clearly I would much prefer that Squeak's bitmap handling
could work cleanly with little endian and well as big endian but we had
that debate several years ago after I implemented a working little
endian bitblt.

 tim
--
Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
Oxymorons: Clearly misunderstood