Heads up display (HUD) dynamic text input

Hi I am new to OpelGL, but have been using Opencascade with Qt. I am developing an open source CAD tool kit on Linux using C++. I want to show sketch dimensions etc using HUD for example like so:

I have looked up links on google to show a HUD, but didn’t help much. I want the HUD to be dynamic and the user should be able to interact with the text displayed more like a text box shown in the above link. I have no idea how to proceed. Any suggestions to implement this is is greatly appreciated. Do I have to use SDL? please help.



You already posted this question in the begginers forum.
Please don’t cross-post.

Understood. I won’t again.