[ REQ 5861]: Capturing rotations

[ug930176 at omega.scs.carleton.ca]

Hi, 

I'm a Carleton University student working on my honors project in computer science and I'm attempting to use 
geomview as a graphics engine for a visibility problem. In effect what I would like to do is load an initial 
set of polygons into geomview and have my program solve the visibility problem for it.

	My approach is to write and external modules (I already have all the examples working) load the 
initial set of polygons and then capture any say rotations performed on the geom. The only way I can think of 
doing this is to use the gcl commands to "freeze" the drawing of the camera and then use the "interest" to 
capture the rotation event i.e. "transform rotate". At this point my program would calculate the new set of 
visible polygons and then simply re-load the new polygons (I'm talking in the order of 10000 polygons here, 
only a fraction being visible at any one time). With the new geom loaded I would simply release the draw 
freeze.

Maybe you could let me know if there's a better way to do this.

My biggest problem is capturing the rotate command. The only example I can find of the "interest" command is 
the example3 which captures the "pick" command (which already has a pre-defined macro to assist). If some one 
could clarify how to use the interest and declare the handler function it would be greatly appreciated. (If 
you happen to have an example kicking around, I would for ever in your det if I could get a peek at it).

Again, any comments would be greatly appreciated,
thanks,

Gilles Beauparlant