double calc_root(double *coeff, int deg, double l, double r)
{
t_dicho d;
double tmp;
d.l = l;
d.r = r;
tmp = calc_poly(coeff, deg, l);
d.sl = SIGNOF(tmp);
tmp = calc_poly(coeff, deg, r);
d.sr = SIGNOF(tmp);
if (d.sl * d.sr > 0)
return (MAX_ROOT + 1);
return (loop_dicho(coeff, deg, &d));
}
static double loop_dicho(double *coeff, int deg, t_dicho *d)
{
int i;
double tmp;
i = -1;
while (++i < 1000000)
{
if (d->sl == 0 || d->sr == 0)
return ((d->sl == 0) ? d->l : d->r);
d->mid = d->l / 2.0 + d->r / 2.0;
tmp = calc_poly(coeff, deg, d->mid);
d->smid = SIGNOF(tmp);
if (fabs(d->l - d->r) < 0.0001 || !d->smid)
return (d->mid);
else if (d->sl * d->smid > 0)
{
d->l = d->mid;
d->sl = d->smid;
}
else
{
d->r = d->mid;
d->sr = d->smid;
}
}
return ((d->l + d->r) / 2.0);
}
float inter_cylindre(t_obj *object, t_ray *ray, t_inter *inter)
{
t_cylindre *cylindre;
float tmp;
t_vect pos;
cylindre = (t_cylindre*)object->obj;
tmp = calc_poly(cylindre, ray);
if (tmp != -1)
{
pos = add_vect(ray->o, mult_float(ray->dir, tmp));
tmp = magnitude(sub_vect(pos, ray->o));
if (inter->dist == -1 || tmp < inter->dist)
{
inter->pos = pos;
inter->normal = calc_normal(cylindre, pos);
inter->dist = tmp;
inter->obj = object;
}
}
return (tmp);
}
