double tore_equation(t_ray *ray, t_obj *obj)
{
double result[4];
double n[11];
int nbroots;
t_tor tor;
nbroots = 0;
init_tab(result, 0, 4);
n[5]= ray->v[0] * ray->v[0] + ray->v[1] * ray->v[1] + ray->v[2] * ray->v[2];
n[6] = 2.0 * (ray->v[0] * ray->eye[0] + ray->v[1]
* ray->eye[1] + ray->v[2] * ray->eye[2]);
n[7] = ray->eye[0] * ray->eye[0] + ray->eye[1] * ray->eye[1] + ray->eye[2] *
ray->eye[2] + obj->rayon * obj->rayon - pow((obj->angle / PI * 180), 2);
n[8] = 4.0 * obj->rayon * obj->rayon;
n[9] = n[8] * (ray->v[0] * ray->v[0] + ray->v[2] * ray->v[2]);
n[10] = n[8] * 2 * (ray->v[0] * ray->eye[0] + ray->v[2] * ray->eye[2]);
n[11] = n[8] * (ray->eye[0] * ray->eye[0] + ray->eye[2] * ray->eye[2]);
n[0] = n[5] * n[5];
n[1] = 2.0 * n[5] * n[6];
n[2] = 2.0 * n[5] * n[7] + n[6] * n[6] - n[9];
n[3] = 2.0 * n[6] * n[7] - n[10];
n[4] = n[7] * n[7] - n[11];
fill_tor_struct_normal(&tor, n);
nbroots = solve_quartic(result, &tor);
return (mini_k(result, nbroots));
}
int Solve_Polynomial(int n, DBL *c0, DBL *r, int sturm, DBL epsilon)
{
int roots, i;
DBL *c;
Increase_Counter(stats[Polynomials_Tested]);
roots = 0;
/*
* Determine the "real" order of the polynomial, i.e.
* eliminate small leading coefficients.
*/
i = 0;
while ((fabs(c0[i]) < SMALL_ENOUGH) && (i < n))
{
i++;
}
n -= i;
c = &c0[i];
switch (n)
{
case 0:
break;
case 1:
/* Solve linear polynomial. */
if (c[0] != 0.0)
{
r[roots++] = -c[1] / c[0];
}
break;
case 2:
/* Solve quadratic polynomial. */
roots = solve_quadratic(c, r);
break;
case 3:
/* Root elimination? */
if (epsilon > 0.0)
{
if ((c[2] != 0.0) && (fabs(c[3]/c[2]) < epsilon))
{
Increase_Counter(stats[Roots_Eliminated]);
roots = solve_quadratic(c, r);
break;
}
}
/* Solve cubic polynomial. */
if (sturm)
{
roots = polysolve(3, c, r);
}
else
{
roots = solve_cubic(c, r);
}
break;
case 4:
/* Root elimination? */
if (epsilon > 0.0)
{
if ((c[3] != 0.0) && (fabs(c[4]/c[3]) < epsilon))
{
Increase_Counter(stats[Roots_Eliminated]);
if (sturm)
{
roots = polysolve(3, c, r);
}
else
{
roots = solve_cubic(c, r);
}
break;
}
}
/* Test for difficult coeffs. */
if (difficult_coeffs(4, c))
{
sturm = true;
}
/* Solve quartic polynomial. */
if (sturm)
{
roots = polysolve(4, c, r);
}
else
{
roots = solve_quartic(c, r);
}
break;
default:
if (epsilon > 0.0)
{
if ((c[n-1] != 0.0) && (fabs(c[n]/c[n-1]) < epsilon))
{
Increase_Counter(stats[Roots_Eliminated]);
roots = polysolve(n-1, c, r);
}
}
/* Solve n-th order polynomial. */
roots = polysolve(n, c, r);
break;
}
return(roots);
}
