ray_def();

    ray_def(double accx = 0.0, double accy = 0.0, double slope = 0.0,
            int quadrant = 0, int fullray_idx = -1);

    int footprint(int radius2, int xpos[], int ypos[]);

}
// Shoot a ray from the given start point (accx, accy) with the given
// slope, bounded by LOS radius. Store the visited cells in
// xpos[] and ypos[], and return the number of cells visited.
int shoot_ray(double accx, double accy, const double slope,
              int maxrange, int xpos[], int ypos[])
{
    int curx, cury;
    int cellnum;
    for (cellnum = 0; true; ++cellnum)
    {
        _find_next_intercept(&accx, &accy, slope);
        curx = static_cast<int>(accx);
        cury = static_cast<int>(accy);
        if (curx*curx + cury*cury > get_los_radius_squared())
            break;
        xpos[cellnum] = curx;
        ypos[cellnum] = cury;
    }
    return cellnum;

ray_def::ray_def()
    : accx(0.0), accy(0.0), slope(0.0), quadrant(0), fullray_idx(-1)

ray_def::ray_def(double ax, double ay, double s, int q, int idx)
    : accx(ax), accy(ay), slope(s), quadrant(q), fullray_idx(idx)

    }
}
// Shoot a ray from the given start point (accx, accy) with the given
// slope, bounded by the given pre-squared LOS radius.
// Store the visited cells in xpos[] and ypos[], and
// return the number of cells visited.
int ray_def::footprint(int radius2, int xpos[], int ypos[])
{
    int curx, cury;
    int cellnum;
    for (cellnum = 0; true; ++cellnum)
    {
        _find_next_intercept(&accx, &accy, slope);
        curx = static_cast<int>(accx);
        cury = static_cast<int>(accy);
        if (curx*curx + cury*cury > radius2)
            break;
        xpos[cellnum] = curx;
        ypos[cellnum] = cury;

    return cellnum;

// pre-squared LOS radius
#define LOS_RADIUS2 (LOS_RADIUS * LOS_RADIUS + 1)

int _los_radius_squared = LOS_RADIUS * LOS_RADIUS + 1;

int _los_radius_squared = LOS_RADIUS2;

    int raylen = shoot_ray(accx, accy, slope, LOS_MAX_RANGE, xpos, ypos);

    ray_def ray = ray_def(accx, accy, slope, 0);
    // find out which cells the ray passes through
    int raylen = ray.footprint(LOS_RADIUS2, xpos, ypos);

    ray_def ray;
    ray.accx = accx;
    ray.accy = accy;
    ray.slope = slope;
    ray.quadrant = 0;