// 设置摄像机
void matrix_set_lookat(matrix_t *m, const vector_t *eye, const vector_t *at, const vector_t *up) {
vector_t xaxis, yaxis, zaxis;
vector_sub(&zaxis, at, eye);
vector_normalize(&zaxis);
vector_crossproduct(&xaxis, up, &zaxis);
vector_normalize(&xaxis);
vector_crossproduct(&yaxis, &zaxis, &xaxis);
m->m[0][0] = xaxis.x;
m->m[1][0] = xaxis.y;
m->m[2][0] = xaxis.z;
m->m[3][0] = -vector_dotproduct(&xaxis, eye);
m->m[0][1] = yaxis.x;
m->m[1][1] = yaxis.y;
m->m[2][1] = yaxis.z;
m->m[3][1] = -vector_dotproduct(&yaxis, eye);
m->m[0][2] = zaxis.x;
m->m[1][2] = zaxis.y;
m->m[2][2] = zaxis.z;
m->m[3][2] = -vector_dotproduct(&zaxis, eye);
m->m[0][3] = m->m[1][3] = m->m[2][3] = 0.0f;
m->m[3][3] = 1.0f;
}
t_bool intersect_cone(t_ray ray, t_cone *obj, float *t)
{
float a;
float b;
float c;
float tmp;
t_vector3 ec;
ec = vector_substract(ray.pos, obj->pos);
tmp = (1 + obj->radius * obj->radius);
a = vector_dotproduct(ray.dir, ray.dir);
a = a - (tmp * SQUARE(vector_dotproduct(ray.dir, obj->dir)));
b = vector_dotproduct(ray.dir, obj->dir) * vector_dotproduct(ec, obj->dir);
b = 2 * (vector_dotproduct(ray.dir, ec) - b * tmp);
c = vector_dotproduct(ec, ec);
c -= tmp * SQUARE(vector_dotproduct(ec, obj->dir));
if ((*t = compute_len(a, b, c)) > 0.)
{
ec = vector_substract(create_intersect(ray, *t), obj->pos);
if (obj->height == 0 || obj->dir.x > 0)
return (TRUE);
else if (obj->height > 0. && vector_dotproduct(obj->dir, ec) > 0.)
if ((obj->height / cos(atan(obj->radius)) > vector_magnitude(ec)))
return (TRUE);
}
return (FALSE);
}
t_bool intersect_sphere(t_ray ray, t_sphere* obj, float *t)
{
t_vector3 etoc;
float radius;
float vector_radius;
etoc = vector_substract(obj->pos, ray.pos);
if ((vector_radius = vector_dotproduct(etoc, ray.dir)) < 0.)
return (FALSE);
*t = vector_dotproduct(etoc, etoc) - SQUARE(vector_radius);
if (*t > (radius = SQUARE(obj->radius)))
return (FALSE);
*t = sqrt(radius - *t);
*t = FT_MIN((vector_radius - *t), (vector_radius + *t));
return (TRUE);
}
t_ray create_reflection(t_ray ray, t_intersect inter)
{
t_ray newray;
t_vector3 norm;
norm = inter.v_normal;
newray.dir = vector_substract(ray.dir,
vector_mul(norm, 2.0f * vector_dotproduct(ray.dir, norm)));
newray.pos = inter.pos;
return (newray);
}
t_bool intersect_triangle(t_ray ray, t_triangle *obj, float *out)
{
t_tri tri;
tri.e1 = vector_substract(obj->pos2, obj->pos);
tri.e2 = vector_substract(obj->pos3, obj->pos);
tri.p = vector_product(ray.dir, tri.e2);
tri.det = vector_dotproduct(tri.e1, tri.p);
if (tri.det > -1e-4f && tri.det < 1e-4f)
return (FALSE);
tri.det = 1.f / tri.det;
tri.t = vector_substract(ray.pos, obj->pos);
tri.u = vector_dotproduct(tri.t, tri.p) * tri.det;
if (tri.u < 0. || tri.u > 1.)
return (FALSE);
tri.q = vector_product(tri.t, tri.e1);
tri.v = vector_dotproduct(ray.dir, tri.q) * tri.det;
if (tri.v < 0. || (tri.u + tri.v) > 1.)
return (FALSE);
*out = vector_dotproduct(tri.e2, tri.q) * tri.det;
if (*out > 1e-4f)
return (TRUE);
return (FALSE);
}
void matrix_from_vectors (VECTOR direction, VECTOR upvect, MATRIX *m) {
VECTOR w;
VECTOR v,u;
float lambda;
v = direction;
u = upvect;
vector_normalize( &v );
lambda = vector_dotproduct( u,v );
u.x -= lambda*v.x;
u.y -= lambda*v.y;
u.z -= lambda*v.z;
vector_normalize( &u );
w = vector_crossproduct( v,u );
m->el[0][0] = w.x;
m->el[0][1] = w.y;
m->el[0][2] = w.z;
m->el[1][0] = u.x;
m->el[1][1] = u.y;
m->el[1][2] = u.z;
m->el[2][0] = v.x;
m->el[2][1] = v.y;
m->el[2][2] = v.z;
};
t_bool intersect_cylinder(t_ray ray, t_cylinder* obj, float *t)
{
float a;
float b;
float c;
float d;
t_vector3 x;
a = vector_dotproduct(ray.dir, ray.dir) - SQUARE(vector_dotproduct(ray.dir, obj->dir));
x = vector_substract(ray.pos, obj->pos);
b = (vector_dotproduct(ray.dir, x) - vector_dotproduct(ray.dir, obj->dir) * vector_dotproduct(x, obj->dir))* 2;
c = vector_dotproduct(x, x) - SQUARE(vector_dotproduct(x, obj->dir)) - (obj->radius * obj->radius);
d = b * b - 4 * a * c;
if (d > 0.)
{
if (((-b - sqrt(d)) / (2 * a)) > 0)
*t = (-b - sqrt(d)) / (2 * a);
else
*t = (-b + sqrt(d)) / (2 * a);
return (TRUE);
}
return (FALSE);
}
