Function set_seenv

src/display.c:3368–3377

Set the seen vector of lev as if seen from (x0,y0) to (x,y). */

/* Set the seen vector of lev as if seen from (x0,y0) to (x,y). */
staticfn void
set_seenv(
    struct rm *lev,
    coordxy x0, coordxy y0, /* from */
    coordxy x, coordxy y)   /*  to  */
{
    coordxy dx = x - x0, dy = y0 - y;

    lev->seenv |= seenv_matrix[sign(dy) + 1][sign(dx) + 1];
}

#undef sign