To enable dragging a Camera2D, you can attach the draggable-camera script to any Camera2D Node.
Create a Camera2D node, and look for the draggable-camera script to it from the Inspector.
Now, if you add a TextureRect as a sibling of the Camera2D, you'll be able to drag it to move the camera.
(Experimental) Adding a sibling ReferenceRect called boundaries allows boundaries to be set for the camera.
