Thanks for the input, but for other reasons this project is best done in WPF. I'm a WinForms guy at heart, but one of the few things I prefer about WPF is the ease with which you can build custom controls and stick them in things like listboxes. It's dead-easy in WPF, and other areas of this app will benefit from that.

I'm figuring out how it works piece by piece, though... lines and circles are overlays, stored as ellipse or line objects, that can be redrawn whenever needed. There's also a PolyLine object that can be used to draw curves. I just need to capture the points and plug them into the correct shape, and it should work fine. Right now it's all canned, but I should be working on the UI sometime this weekend.

But thanks for weighing in, it IS good to know that the post isn't being ignored.

I've done searches to find some kind of tutorial online, and I found nothing directly on point... I found it irritating that what articles I found were either too simple or far too complex for what I needed. Most of the former tutorials I found were for something that was nothing more than a doodle tool using InkCanvas... and since the ability to doodle with the mouse is built-in to the InkCanvas, not even requiring any special coding to make happen, it wasn't very much help. And the complex ones were obviously aimed at games... which this isn't.

Once I get this done, I may just write a CodeProject article about it. That way, the next shmuck like me who wants to do something like this may actually be able to find some help.