Yesterday I tried to layout a bunch of program windows via xdotools moveto and resize. In theory they should have been all the same size, but they came out all different, and none had the targeted size. They all had space around them. What is involved in this process? Are there invisible borders, or stuff like that?
Most windows in X are actually two windows: one inset inside the other. That’s how you get a border & title bar. Does that account for the error you’re seeing?