Hi Eduardo,
I think the function the original poster is looking for is, e.g.: bool
DriveManipulator::calcMovement().
Well, that method and the equivalents in other manipulators do calculate
some parts of the final camera view matrix, but the final calculations
are done directly inside the get{Inverse}Matrix() methods. And I think
the OP was specifically asking how the manipulator affected the camera,
since no part of the camera manipulator code actually ever touches any
part of the view or camera...
So the answer is that the view calls getInverseMatrix() at each frame to
get an updated view matrix which it will then give to the camera.
That also has another implication. If you're making a camera manipulator
that needs to modify the projection matrix, then you need to put in some
other mechanism in your own code to get the projection matrix that the
manipulator would calculate to the camera. Because the only thing that
will happen automatically when using a camera manipulator is that
getInverseMatrix() will be called to get an updated view matrix each
frame, nothing will be done about the projection matrix at all. I've
always found that weird... A more general camera manipulator should have
a mechanism to alter any relevant property of the camera, not just the
view matrix... It could even have a pointer to the camera, which IMHO
would have been a more straightforward and clear design, at the cost of
higher coupling.
One example of this would be implementing a camera manipulator for
otho2D views which would implement zooming by altering the
left,right,top,bottom values of the frustum (or even the same principle
for perspective views which would zoom by altering the FOV). This alters
the projection matrix, and you'll have to get that projection matrix
from your manipulator to the camera each frame yourself.
Hope this helps,
J-S
--
______________________________________________________
Jean-Sebastien Guay jean-sebastien.g...@cm-labs.com
http://www.cm-labs.com/
http://whitestar02.webhop.org/
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