A shader for h.jit.homography using jit.gl.slab

Hello Forum.
I am trying to create a shader, and using a jit.gl.slab in order to apply cornerpin and keystone correction to a texture using the h.jit.homography object by hons.

I have just started to read OpenGL shading book, and how to do this, but unfortunately, it is a bit complicating.
I have made a mockup of how I want the patch to look like in the end. Is there some one that would like to explane how I would go about doing this? or better, contribute with such a shader? I do not know how much work that actually would be, since I cannot grasp the full scope of writing a shader yet.

Let me know what you think.

Ricardo