Q:
How do I get my QuickDraw graphics onscreen once I've captured
the display using CGDirectDisplay?
A:
CGDirectDisplay is great for capturing displays, changing
resolutions and bit depths, and doing gamma fades. In order
to combine that with QuickDraw, you need to use a function
from QuickDraw.h, CreateNewPortForCGDisplayID.
Take the display ID you've used in CGDirectDisplay and pass it to
CreateNewPortForCGDisplayID to create a brand new QuickDraw
CGrafPort. Once you've used SetPort to switch to this new
port, you can draw using any QuickDraw graphics function but
the most likely use will be to call CopyBits to
move graphics from an offscreen GWorld to the screen. Don't
forget to use GetPortBitMapForCopyBits and definitely don't
forget to call DisposePort on the new port once you are finished
with it.
[Apr 11 2001]
|