Minimize Processing in Input Point Callbacks

The input point API is powerful and complex, and it deserves special attention if your ObjectARX application wants to use it.

The callback members AcEdInputPointMonitor::monitorInputPoint() and AcEdInputPointFilter::processInputPoint() are invoked on every digitizer event that AutoCAD processes. Be careful about the amount of processing you perform during these callbacks. Other monitors or filters may also be present. Consider doing the following in your applications that use these powerful features:

• Minimize the contexts in which your input point monitors and filters are registered with AcEdInputPointFilter. Make use of AcEditorReactor and AcEdInputContextReactor to determine when to add and remove them from the manager's callback chains.
• If you have processing that should occur only when the digitizer has moved, then use AcEdInputPointManager::mouseHasMoved() to determine when this has been done.