Function gmsh_sys::gmshModelGetNormal

pub unsafe extern "C" fn gmshModelGetNormal(
    tag: c_int, 
    parametricCoord: *mut f64, 
    parametricCoord_n: usize, 
    normals: *mut *mut f64, 
    normals_n: *mut usize, 
    ierr: *mut c_int
)

Get the normal to the surface with tag tag at the parametric coordinates parametricCoord. parametricCoord are given by pairs of u and v coordinates, concatenated: [p1u, p1v, p2u, ...]. normals are returned as triplets of x, y, z components, concatenated: [n1x, n1y, n1z, n2x, ...].