I am using the V3d_View class and I've met some problems with it, related with zoom in/out.
When the zoom in factor is too big(calling Zoom (x1, y1, x2, y2)) the application crashes. The same problem occurs when the zoom out factor is exceeded a certain threshold.
The solution is to limit the zoom in/out factors. But I can't find how to limit the zoom factor, where is the query function do to this?