Your explanation “looking for a way to get a GL drawable” summarizes my matter much better than all my explanations above. Thanks.
So, yes, what I am actually searching for is a way to get a GL drawable using the ROOT infrastructure for OpenGL (initialization, context creation) and not my own infrastructure (e.g. glfw3). Additionally I also need the possibility to capture keyboard/mouse input for the drawable to be able to react to user input.
However I don’t need ROOT graphics in my canvas.
Do you see a way to achieve this?