[valine]

I'd look at other programs for inspiration. Blender for example allows you to place the anchor point and then gives you the option for how many segments you want connecting the anchors. Turning the resolution up and down gives you a feel for how many subdivisions you'll need for a smooth curve.

At the very least you'll need a UI for placing the anchors and handles, but how the UI works is really subjective. Your next step is to take those anchors and desired resolution and generate a list of vertices. After that it's just an exercise in rasterization.