Hi Tom,
although I'd hope that anyone writing a CameraManipulator would implement both
appropriately, otherwise an interface method is messed up! :)
Well yes obviously. But generally getMatrix() can just be written as
return osg::Matrix::inverse(getInverseMatrix()); and you're done. Since
it's not called by "the system" it's not that important if it isn't very
optimal...
And actually the base class CameraManipulator::getMatrix() could do this
by default, and then subclasses would only need to implement it if they
knew they had to do better. But we're talking details here.
Am I correct in thinking you are advocating an approach that blends these two
concepts?
Yes, well, advocating might be a strong word. I'm saying that
conceptually, it would make sense that a CameraManipulator would be able
to manipulate a camera in all ways necessary. But I'm not saying I want
to do anything about it! :-)
In our software, we do something like what you describe, blending camera
manipulators and an update callback on the camera. We have a data class
that contains all settings we would want to be able to change on a
camera. Our software can store multiple instances of this, which will
represent different cameras we can switch to, but only one will be
active for a given view at a time. Both the update callback and the
manipulator have a pointer to the active camera data object, and they
both apply the settings in this class when either we switch cameras or
change the data inside this object at runtime, and make sure the data is
up to date inside the object when the user alters the view using the
camera manipulator.
The whole thing involves more classes than I think should be necessary,
and it's a bit invasive, but it works well enough.
J-S
--
______________________________________________________
Jean-Sebastien Guay jean-sebastien.g...@cm-labs.com
http://www.cm-labs.com/
http://whitestar02.webhop.org/
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