Possible to automatically compensate for irreguarities on the XY plane?

Hey, does LinuxCNC have the functionality to correct for irregularities on an axis surface plane like the XY on a gantry/router CNC? If I make a surface map file of offsets in the Z direction of the XY plane is it possible to have LinuxCNC automatically compensate for them? I’ve been doing a project involving a laser line projection onto a webcam sensor that is attached to a W axis and spring loaded so it can touch a surface It acts kinda like a CMM but only gives me about 2.5mm of range in Z to work with but does allow me to get down to a couple microns of measurement. I’ve still got some problems with it to work out but here a recent video on it’s progress

 And here is how it operates www.youtube.com/shorts/vuXR8RIW44o  What I’d like to do is generate an offset map of the XY plane by taking a grid of measurements with the sensor in the air (not touching anything) and then feed that data back into LinuxCNC to automatically compensate when running gcode. 

Have a look at this:
forum.linuxcnc.org/10-advanced-configura...nting?start=0#167181

I think this is still python 2 which runs on linuxcnc version 2.8.x while version 2.9 and higher would require updating the code to python 3.

I would argue (strongly) that the compensation should be a realtime HAL component.
This does make things more difficult as there is no file access from a realtime HAL component.
However, it would not be too unmanageable to pass a set of XYZ probe points in as a parameter array (max 4096 characters)
The main INI file could #INCLUDE a fixed filename for the height map
This file would be of the format Then the HAL file could use
loadrt height_compensation map=[HEIGHTMAP]
Which would (I think) pass the ile contents in at load time.

This is all a bit clunky, but it saves coding and setting up a shared memory area.

A better way would be to have a pair of components, userspace (probably C for data representation reasons, but Python could probably work too) and realtime which used a private shared memory area for the height data.
I think that the latter approach is what Probekins used. (but Probekins didn't really work, for other reasons)

Hmmm..... Now we have 64 bit HAL pins, I wonder if the userspace component would be able to rtapi_kmalloc a C struct of height date, then populate it, and just pass a pointer to that struct to the realtime code?
Though this is really just a rather bad way of spoofing a shared mamery region.

linuxcnc.org/docs/stable/html/man/man3/rtapi_shmem.3rtapi.html

I wonder if somehow a hal_port could be used to pass a point array, much like a survey grid format
The component could extrapolate the height at a given point as you would plot a contour line and adjust the height using external offsets in real time.