[comp.sys.mac.programmer] CopyBits Query

rampil@cca.ucsf.edu (Ira Rampil) (08/08/89)

Greetings,

I have recently been having a jolly time with CopyBits,
but it is now time to get back to productive work and
seek enlightenment.
I have an application with a lot of 8bit bitmapped PICT
windows, and I just added a window into which I draw
some graphs with QD.  To be clever, I use OpenPict and
picWindow to  do autoUpdates on this one window with
the window mgr.  All well and good so far, the auto-
updates work.  Unfortunately, after I close this
graph window, and Close and Kill the update PIC, the
nextmost (and only the nextmost) Bitmapped Window
does not Update correctly, the update region stays
blank (white).  All the lower windows do update
correctly.  My update proc uses a CopyBits from an
offscreen bitmap to blit from.  Using Jasik's
debugger through CopyBits I see all the windows call
CopyBits with appropriate parameters, but strangely
that topmost window, gets a premature RTS in the ROM.
That is to say, it returns before going through the
DevLoop or the BitBlt!  This divergence from good
behaviour takes place at (SE/30 ROM):
82458C : rCO393 where there is a TST  66(A3)

Can somebody PLEASE tell me what this is testing (and
how to fix it!)?

Many Thanks,
Ira Rampil
Dept of Anesthesia
UCSF
rampil@cca.ucsf.edu