texture manual deformation

hi there,
a texture applied to a plane
a grid evenly placed

I send x,y coordinates, it takes the point of the grid which is the closest of x,y and I can drag that point, deforming the texture rendering (in a plane only)

I tried to inspire me from this https://cycling74.com/forums/topic.php?id=18017 but not sure it is the right path.
I also tried to use the Day 11's patch ( https://cycling74.com/tutorials/gen-patch-a-day/2/ ) and instead of using the jit.noise which generates random deformation, I tried to feed a matrix with current grid position ... not really nice.

anyone would point me to a lead to the patch architecture I'd need to design ?

basicaly, it would be : I need to alter the mesh related to the plane on which I apply the texture