Jim Wilson wrote:
 > David Megginson wrote:
 > > I think what Andy's suggesting is that the panel be part of the
 > > model's scene graph.

Yeah.  What he said. :)

 > So am I, but panel isn't moved to a scene graph yet.  Now that I think
 > about it though, he is still going to need the offsets that the model
 > doesn't know about to implement the mouse action.

Nope; just the matrices.  The panel knows that if it runs an airframe
coordinate through teh modelview and projection matrices, it'll get
screen coordinates in the range [-1:1].  Just invert that matrix and
we can go from screen coordinates to airframe, thence to panel
coordinates.  It's a little more complicated in practice, but that's
the essence of the problem.  The panel certainly doesn't need to know
anything specific about the model or the viewer.  It can do it all on
its own, without reference to anything but the OpenGL render state.
Again, that's the point behind scene graph architectures.

Andy

-- 
Andrew J. Ross                NextBus Information Systems
Senior Software Engineer      Emeryville, CA
[EMAIL PROTECTED]              http://www.nextbus.com
"Men go crazy in conflagrations.  They only get better one by one."
  - Sting (misquoted)


_______________________________________________
Flightgear-devel mailing list
[EMAIL PROTECTED]
http://mail.flightgear.org/mailman/listinfo/flightgear-devel

Reply via email to