We have to draw a reference axis (XYZ) placed at the bottom left corner of the view port. I am using OpenGL 4.3 Core profile.
I found some methods implementing it using Orthographic projection in another view port and positioning it in window coordinates.
But I need some help in placing the reference axis aligned with the (bottom left corner)view port using perspective projection.
That is the 3D object (XYZ axis) even though it has world space position it has to align itself with the view port and orient accordingly with
respect to the camera