[comp.sys.mac.programmer] SwapMMUMode? or GetPixBaseAddr? and 8*24GC problems

tim@hoptoad.uucp (Tim Maroney) (12/01/90)

In article <77758@ipl.jpl.nasa.gov> mkt059@ipl.jpl.nasa.gov (Mike Tschudi
(Cartographic Applic.)) writes:
>Has anyone had experience with SwapMMUMode or 32-bit QuickDraw's
>GetPixBaseAddr?

I tried.  It didn't seem to work on the 8*24 GC.  I did a
GetPixBaseAddr, did a StripAddress on the address of a (non-gWorld)
buffer filled with pixel data, switched MMU mode to 32-bit, did a
BlockMove(strippedSourcePtr, gWorldPix, pixelSize), and switched back
to the old MMU mode.  This had no effect on the data in the offscreen
gWorld.  Because of this, I wound up removing nearly all uses of
offscreen gWorlds from our program.  If we can't BlockMove to them,
then we might as well just use offscreen pixmaps we allocate
ourselves.

We've been having several problems with the GC, by the way.  How about
other developers?  Has anyone else noticed, for instance, that
SetDirectEntries stops working for the rest of the boot session if you
bring up the Color Picker (for instance, from the Color CDEV or
ViewEdit), but only in applications launched after the Color Picker is
put away?  How about problems with scaling pixmaps through CopyBits for
zooming leaving blank lines at the bottom of the destination rectangle
on the screen?  These problems only occur on the 8*24 GC, not on any of
the many other video boards and graphic accelerators that we have.
-- 
Tim Maroney, Mac Software Consultant, sun!hoptoad!tim, tim@toad.com

"Philosophy is the talk on a cereal box
 Religion is the smile on a dog" -- Edie Brickell, "What I Am"