Function find_output_overlap 

pub(crate) fn find_output_overlap(
    nodes: &[OutputNode],
    skip_id: Option<u32>,
    logical: (i32, i32, i32, i32),
    physical: (i32, i32, i32, i32),
) -> Option<(u32, &'static str, (i32, i32, i32, i32))>

The first live screen (excluding skip_id; views stand behind their owner’s rectangle) whose rectangle overlaps a candidate placement. Both rectangle flavors are checked — logical (Space layout, scale-divided) and physical (mode pixels at the same origin) — because input injection and cursor compositing key off the physical rects while window layout keys off the logical ones, and neither may overlap.