[comp.sys.mac.programmer] Transfer Modes and DrawPicture

Eric.J.Baumgartner@dartmouth.edu (Eric J. Baumgartner) (05/07/91)

Is there a way to associate transfer modes with DrawPicture the way you
can with CopyBits?  Specifically, I want to be able to draw a PICT of,
say, a doughnut, where the doughnut is colored and the doughnut hole is
white, on top of a blue rectangle, and have the doughnut hole be blue
when I'm done.  (The equivalent, I think, of calling CopyBits with the
mode transparent + patCopy.)

DrawPicture seems to ignore the current PenMode (as well it should) but
when I tried to substitute my own QDProc for StdBits (on the theory
that the PICT consisted of one giant CopyBits call) my QDProc never got
called!

I guess I could draw the PICT in its own offscreen port and then
CopyBits that to the screen with the right transfer mode, but I'm
dealing with 24-bit PICTs and really can't afford to take the space the
extra port would need.  Any suggestions??  Thanks.

Eric Baumgartner                   *  ebaum@dartmouth.edu
Interactive Media Lab              *  - When in danger or in doubt,
Dartmouth Medical School           *      run in circles, scream and
shout.