Function cell_admits 

pub fn cell_admits(
    cells: &Cells,
    terrain: &HeightGrid<'_>,
    x: i32,
    y: i32,
    mask: u32,
    min_normal: f32,
    tolerance: f32,
    reference: f32,
    override_occupant: bool,
    override_flag: bool,
    owner_ok: impl Fn(usize) -> bool,
) -> bool

Whether a cell admits a building: its type is in mask, the ground is flat enough and level enough, and its occupant (if any) may be replaced.

Original: FUN_1400a4aa0(map, x, y, mask, min_normal, tolerance, reference, override_occupant, override_flag, owner).