How to draw line between 2 waypoints in gazebo map

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Ros Kinetic Gazebo 7 Ubuntu 16.04

So I would like to create a tool that allows a user to manually select waypoints in a simulation I envision the software working the following way

1. loads a pre-made gazebo world
2. In gazebo lets the user select a point in the map via a double click
3. draws a line connecting the last 2 points that were clicked on in the world
4. The user saves the way point by clicking on a button. This is the origin of the next line that is drawn

I have figured out who to generate X, Y coordinates from the gazebo world via a double click. I can use drawLine but it will only draw a line connecting the last waypoints. I would like the software to remember all the waypoints selected and draw the lines connecting them

Should I be using the DyanmicLines class for this?