Proposed Interaction Feature — Add node to existing polygon

[gcmillar]

Proposed Interaction Feature — Add node to existing polygon - then be able to move / edit its placement

[shannonkjones]

This functionality is not supported in mapbox-gl-draw. We could write our own custom functionality (for example, I created the circle tool), but you'd have to think very carefully about how to implement it.

1. How to differentiate drawing a new point on the existing polygon VS drawing a first point on a new polygon.
2. Differentiating drawing a new point on the polygon VS selecting the polygon VS moving the polygon.
3. Would probably need a new 'add point' tool, that could only create a single point. Then there is the additional complication of knowing HOW to integrate the point. Adding of the 4th point in your example could easily end up looking like a 'bow tie' rather than a rectangle. You could rely on the user to then fix it to be the shape they wanted (but if they have to do that, then they might as well delete the original shape and draw what they want). Otherwise, there would have to be some math (perhaps not too terribly complicated) to figure out the most probable way the user intended for the point to be added.