int
triangle_intersects(const triangle_t *triangle, const ray_t *ray, intersection_t *result)
{
const v3_t* edge1;
const v3_t* edge2;
v3_t tvec;
v3_t pvec;
v3_t qvec;
float det;
float inv_det;
float t;
float u;
float v;
result->hit = 0;
//v3_sub(&edge1, &triangle->pt2, &triangle->pt1);
//v3_sub(&edge2, &triangle->pt3, &triangle->pt1);
edge1 = &triangle->edge1;
edge2 = &triangle->edge2;
v3_cross(&pvec, &ray->direction, edge2);
det = v3_dot(edge1, &pvec);
//No culling version
if(det > -EPSILON && det < EPSILON)
return 0;
inv_det = 1.0f / det;
v3_sub(&tvec, &ray->origin, &triangle->v0);
u = v3_dot(&tvec, &pvec) * inv_det;
if(u < 0.0f || u > 1.0f)
return 0;
v3_cross(&qvec, &tvec, edge1);
v = v3_dot(&ray->direction, &qvec) * inv_det;
if(v < 0.0f || u + v > 1.0f + EPSILON) //add EPSILON to offset small precision errors
return 0;
t = v3_dot(edge2, &qvec) * inv_det;
if(t > EPSILON) {
result->hit = 1;
result->distance = t;
return 1;
}
/*
v3_copy(&result->normal, &triangle->normal);
v3_copy(&result->hit_point, &r->direction);
v3_mul_scalar(&result->hit_point, t);
v3_add(&result->hit_point, &result->hit_point, &r->origin);
*/
return 0;
}
hit_test intersect(ray r, object obj) {
v3 ro = r.origin;
v3 rd = r.direction;
double t;
hit_test ht_out;
switch (obj.tag) {
case SPHERE: {
v3 sc = obj.o.s.center;
double sr = obj.o.s.radius;
v3 A = v3_sub(ro, sc);
double B = v3_dot(A, rd);
double C = v3_dot(A, A) - sr*sr;
double D = B*B - C;
t = -B - sqrt(D);
if (D > 0 && t > 0) {
v3 ray_pos = ray_position(r, t);
ht_out.miss = HIT;
ht_out.t = t;
ht_out.hit_point = ray_pos;
ht_out.surf = \
(*(obj.o.s.surface_color))(obj.o.s.center, ray_pos);
ht_out.shine = obj.o.s.shine;
ht_out.surf_norm = v3_norm(v3_sub(ray_pos, obj.o.s.center));
} else {
ht_out.miss = MISS;
}
break;
}
case POSTER: {
v3 n = v3_expr(0, 0, -1);
double d = obj.o.p.upper_left.z;
t = -(v3_dot(ro, n) + d) / v3_dot(rd, n);
v3 ray_pos = ray_position(r, t);
if (t > 0 && is_on_poster(ray_pos, obj.o.p)) {
ht_out.miss = HIT;
ht_out.t = t;
ht_out.hit_point = ray_pos;
ht_out.surf = \
(*(obj.o.p.surface_color))(obj.o.p.upper_left, ray_pos);
ht_out.shine = obj.o.p.shine;
ht_out.surf_norm = n;
} else {
ht_out.miss = MISS;
}
break;
}
default:
fprintf(stderr, "error in intersect: unrecognized tag\n");
exit(1);
}
return ht_out;
}
Inode *torus_intersect(Prim *p, Ray ro)
{
double a, b, c, disc, t0, t1;
Inode *i0, *i1;
Ray r = ray_transform(ro, p->ti);
a = v3_sqrnorm(r.d);
b = 2 * v3_dot(r.d, r.o);
c = v3_sqrnorm(r.o) - 1;
if ((disc = SQR(b) - 4 * a * c) <= 0)
return (Inode *)0;
t0 = (-b - sqrt(disc)) / (2 * a);
t1 = (-b + sqrt(disc)) / (2 * a);
if (t1 < RAY_EPS)
return (Inode *)0;
if (t0 < RAY_EPS) {
Vector3 n1 = v3_unit(torus_gradient(p, ray_point(r, t1)));
return inode_alloc(t1, n1, FALSE);
} else {
Vector3 n0 = v3_unit(torus_gradient(p, ray_point(ro, t0)));
Vector3 n1 = v3_unit(torus_gradient(p, ray_point(ro, t1)));
i0 = inode_alloc(t0, n0, TRUE);
i1 = inode_alloc(t1, n1, FALSE);
i0->next = i1;
return i0;
}
}
int dir_coupling(Cone a, Vector3 v)
{
if (v3_dot(a.d, v3_scale(-1, v)) > a.cosa)
return TRUE;
else
return FALSE;
}
Color ray_shade(int level, Real w, Ray v, RContext *rc, Object *ol)
{
Inode *i = ray_intersect(ol, v);
if (i != NULL) { Light *l; Real wf;
Material *m = i->m;
Vector3 p = ray_point(v, i->t);
Cone recv = cone_make(p, i->n, PIOVER2);
Color c = c_mult(m->c, c_scale(m->ka, ambient(rc)));
rc->p = p;
for (l = rc->l; l != NULL; l = l->next)
if ((*l->transport)(l, recv, rc) && (wf = shadow(l, p, ol)) > RAY_WF_MIN)
c = c_add(c, c_mult(m->c,
c_scale(wf * m->kd * v3_dot(l->outdir,i->n), l->outcol)));
if (level++ < MAX_RAY_LEVEL) {
if ((wf = w * m->ks) > RAY_WF_MIN) {
Ray r = ray_make(p, reflect_dir(v.d, i->n));
c = c_add(c, c_mult(m->s,
c_scale(m->ks, ray_shade(level, wf, r, rc, ol))));
}
if ((wf = w * m->kt) > RAY_WF_MIN) {
Ray t = ray_make(p, refract_dir(v.d, i->n, (i->enter)? 1/m->ir: m->ir));
if (v3_sqrnorm(t.d) > 0) {
c = c_add(c, c_mult(m->s,
c_scale(m->kt, ray_shade(level, wf, t, rc, ol))));
}
}
}
inode_free(i);
return c;
} else {
return BG_COLOR;
}
}
t_mat4 m4_look_at(t_vec3 from, t_vec3 to, t_vec3 up)
{
t_vec3 x;
t_vec3 y;
t_vec3 z;
z = v3_muls(v3_norm(v3_sub(to, from)), -1);
x = v3_norm(v3_cross(up, z));
y = v3_cross(z, x);
return (mat4(
x.x, x.y, x.z, -v3_dot(from, x),
y.x, y.y, y.z, -v3_dot(from, y),
z.x, z.y, z.z, -v3_dot(from, z),
0, 0, 0, 1
));
}
scalar_t noise3(scalar_t x, scalar_t y, scalar_t z)
{
int i, j;
int bx0, bx1, by0, by1, bz0, bz1;
int b00, b10, b01, b11;
scalar_t rx0, rx1, ry0, ry1, rz0, rz1;
scalar_t sx, sy, sz;
scalar_t u, v, a, b, c, d;
if(!tables_valid) {
init_noise();
tables_valid = 1;
}
setup(x, bx0, bx1, rx0, rx1);
setup(y, by0, by1, ry0, ry1);
setup(z, bz0, bz1, rz0, rz1);
i = perm[bx0];
j = perm[bx1];
b00 = perm[i + by0];
b10 = perm[j + by0];
b01 = perm[i + by1];
b11 = perm[j + by1];
/* calculate hermite interpolating factors */
sx = s_curve(rx0);
sy = s_curve(ry0);
sz = s_curve(rz0);
/* interpolate along the top slice of the cell */
u = v3_dot(grad3[b00 + bz0], v3_cons(rx0, ry0, rz0));
v = v3_dot(grad3[b10 + bz0], v3_cons(rx1, ry0, rz0));
a = lerp(u, v, sx);
u = v3_dot(grad3[b01 + bz0], v3_cons(rx0, ry1, rz0));
v = v3_dot(grad3[b11 + bz0], v3_cons(rx1, ry1, rz0));
b = lerp(u, v, sx);
c = lerp(a, b, sy);
/* interpolate along the bottom slice of the cell */
u = v3_dot(grad3[b00 + bz0], v3_cons(rx0, ry0, rz1));
v = v3_dot(grad3[b10 + bz0], v3_cons(rx1, ry0, rz1));
a = lerp(u, v, sx);
u = v3_dot(grad3[b01 + bz0], v3_cons(rx0, ry1, rz1));
v = v3_dot(grad3[b11 + bz0], v3_cons(rx1, ry1, rz1));
b = lerp(u, v, sx);
d = lerp(a, b, sy);
/* interpolate between slices */
return lerp(c, d, sz);
}
static Real formfactor(int i, int j, int n, Poly **p, Real *a)
{
Vector3 vi, vj, vji, d;
Real r2, ci, cj;
vi = poly_centr(p[i]);
vj = poly_centr(p[j]);
vji = v3_sub(vi, vj);
if ((r2 = v3_sqrnorm(vji)) < REL_EPS)
return 0;
d = v3_scale(1.0/sqrt(r2), vji);
if ((cj = v3_dot(poly_normal(p[j]), d)) < REL_EPS)
return 0;
if ((ci = -v3_dot(poly_normal(p[i]), d)) < REL_EPS)
return 0;
if (vis_flag && visible(n, p, vj, vji) < REL_EPS)
return 0;
return a[i] * ((cj * ci) / (PI * r2 + a[i]));
}
//get the angle from vector v1 to vector v2 around the axis
double GetAngle(double* v1, double* v2, double* axis)
{
double dot_prod = v3_dot(v1, v2);
double r_axis_len = v3_mag(axis);
double theta = atan2(r_axis_len, dot_prod);
return theta;
}
hit_test intersect_poster (ray r, poster p)
{
hit_test result = {0};
v3 ro = r.origin;
v3 rd = r.direction;
v3 n = v3_expr(0, 0, -1);
double d = p.upper_left.z;
double t = -(v3_dot(ro, n) + d) / v3_dot(rd, n);
result.miss = MISS;
v3 intersection = ray_position(r, t);
if (t>0 && within_poster(intersection, p)) {
result.miss = HIT;
result.t = t;
result.hit_point = intersection;
result.surf = p.surface_color(p.upper_left, intersection);
result.shine = p.shine;
result.surf_norm = n;
}
return result;
}
hit_test intersect_sphere (ray r, sphere s)
{
hit_test result = {0};
v3 sc = s.center;
double sr = s.radius;
v3 a = v3_sub(r.origin, sc);
double b = v3_dot(a, r.direction);
double c = v3_dot(a, a) - (sr * sr);
double d = (b * b) - c;
double t = -b - sqrt(d);
result.miss = MISS;
if (d > 0 && t > 0) {
v3 intersection = ray_position(r, t);
result.miss = HIT;
result.t = t;
result.hit_point = intersection;
result.surf = s.surface_color(sc, intersection);
result.shine = s.shine;
result.surf_norm = v3_norm(v3_sub(intersection, sc));
}
return result;
}
void makeviewV(void)
{
Vector3 n,u,v,t;
n = view->normal;
v = v3_sub(view->up, v3_scale(v3_dot(view->up, n), n));
if (v3_norm(v) < ROUNDOFF)
error("view up parallel to view normal");
v = v3_unit(v);
u = v3_cross(n, v);
t.x = v3_dot(view->center, u);
t.y = v3_dot(view->center, v);
t.z = v3_dot(view->center, n);
view->V = m4_ident();
view->V.r1.x = u.x; view->V.r2.x = v.x; view->V.r3.x = n.x;
view->V.r1.y = u.y; view->V.r2.y = v.y; view->V.r3.y = n.y;
view->V.r1.z = u.z; view->V.r2.z = v.z; view->V.r3.z = n.z;
view->V.r1.w = -t.x; view->V.r2.w = -t.y; view->V.r3.w = -t.z;
makeviewVi();
}
Vector3 refract_dir(Vector3 d, Vector3 n, Real eta)
{
Real c1, c2;
if ((c1 = v3_dot(d, n)) < 0)
c1 = -c1;
else
n = v3_scale(-1.0, n);
if ((c2 = 1 - SQR(eta) * (1 - SQR(c1))) < 0)
return v3_make(0,0,0);
else
return v3_add(v3_scale(eta, d), v3_scale(eta*c1 - sqrt(c2), n));
}
void
camera_setup(
camera_t * const c,
v3_t eye,
v3_t lookat,
v3_t up,
float fov
)
{
// compute the basis for the camera
// negative look direction from eye to destination
v3_t w = v3_norm(v3_sub(eye, lookat));
// compute the side axis
v3_t u = v3_norm(v3_cross(up, w));
// and the "up" normal
v3_t v = v3_norm(v3_cross(w, u));
m44_t cam = {{
{ u.p[0], u.p[1], u.p[2], -v3_dot(u,eye) },
{ v.p[0], v.p[1], v.p[2], -v3_dot(v,eye) },
{ w.p[0], w.p[1], w.p[2], -v3_dot(w,eye) },
{ 0, 0, 0, 1 },
}};
fprintf(stderr, "Camera:\n");
for(int i = 0 ; i < 4 ; i++)
{
for(int j = 0 ; j < 4 ; j++)
fprintf(stderr, " %+5.3f", cam.m[i][j]);
fprintf(stderr, "\n");
}
// now compute the perspective projection matrix
if(1) {
float s = 1000.0 / tan(fov * M_PI / 180 / 2);
c->near = 1;
c->far = 200;
float f1 = - c->far / (c->far - c->near);
float f2 = - c->far * c->near / (c->far - c->near);
m44_t pers = {{
{ s, 0, 0, 0 },
{ 0, s, 0, 0 },
{ 0, 0, f2, -1 },
{ 0, 0, f1, 0 },
}};
fprintf(stderr, "Perspective:\n");
for(int i = 0 ; i < 4 ; i++)
{
for(int j = 0 ; j < 4 ; j++)
fprintf(stderr, " %+5.3f", pers.m[i][j]);
fprintf(stderr, "\n");
}
m44_mult(&c->r, &pers, &cam);
} else {
// no perspective
m44_t pers = {{
{ 1, 0, 0, 0 },
{ 0, 1, 0, 0 },
{ 0, 0, 1, 0 },
{ 0, 0, 0, 1 },
}};
// and apply it to the camera matrix to generate transform
m44_mult(&c->r, &pers, &cam);
}
fprintf(stderr, "Cam*Pers\n");
for(int i = 0 ; i < 4 ; i++)
{
for(int j = 0 ; j < 4 ; j++)
fprintf(stderr, " %+5.3f", c->r.m[i][j]);
fprintf(stderr, "\n");
}
}
Vector3 reflect_dir(Vector3 d, Vector3 n)
{
return v3_add(d, v3_scale(-2 * v3_dot(n, d), n));
}
GLvoid sample_world() {
// int timing;
u_int i,j,d;
// float t0,t1,t2;
v3* temp;
v3* disp;
// v3* disp2;
float dot;
float dm;
char* temp_s1;
char* temp_s2;
for (i = 0; i < PARTICLES; i++) {
// printf("adding g %d,%f\n", i,ps[i].v[1]);
v3_add(ps[i].v, gr);
// ps[i].v->v[1] -= g;
v3_mult(ps[i].v, LOSS_V);
for (d = 0; d < D; d++) {
v3_mult_add(ps[i].c, ps[i].v, 1 / (float) SPS); // ps[i].c[d] += ps[i].v[d] / (float) SPS;
if (ps[i].c->v[d] < -B + RADIUS) {
disp = v3_new(0,0,0);
disp->v[d] = ps[i].c->v[d] + B;
dm = 1 / (1 - (RADIUS - v3_mag(disp)) / RADIUS);
v3_unit(disp);
v3_mult_add(ps[i].v, disp, dm * LOSS_WALL * dt);
// ps[i].c->v[d] = -B + RADIUS;
// ps[i].v->v[d] *= -1 * LOSS_WALL;
}
if (ps[i].c->v[d] > B - RADIUS) {
disp = v3_new(0,0,0);
disp->v[d] = ps[i].c->v[d] - B;
// dm = (RADIUS - v3_mag(disp)) / RADIUS;
dm = 1 / (1 - (RADIUS - v3_mag(disp)) / RADIUS);
v3_unit(disp);
v3_mult_add(ps[i].v, disp, dm * LOSS_WALL * dt);
// ps[i].c->v[d] = B - RADIUS;
// ps[i].v->v[d] *= -1 * LOSS_WALL;
}
}
}
for (i = 0; i < PARTICLES; i++) {
for (j = 0; j < PARTICLES; j++) {
if (i == j) continue;
if (v3_dist(ps[i].c, ps[j].c) >= RADIUS * 2) continue;
/* temp_s1 = v3_str(ps[i].c);
temp_s2 = v3_str(ps[j].c);
printf("collision pos: %s %s\n", temp_s1, temp_s2);
free(temp_s1);
free(temp_s2);*/
/*
temp_s1 = v3_str(ps[i].v);
temp_s2 = v3_str(ps[j].v);
printf("collision vel: %s %s\n", temp_s1, temp_s2);
free(temp_s1);
free(temp_s2);
*/
temp = v3_copy(ps[i].v);
v3_sub(temp, ps[j].v);
/*
temp_s1 = v3_str(temp);
printf("temp = %s\n", temp_s1);
free(temp_s1);
*/
disp = v3_copy(ps[i].c);
v3_sub(disp, ps[j].c);
// disp2 = v3_copy(disp);
dm = RADIUS - v3_mag(disp) / 2;
/*
temp_s1 = v3_str(disp);
printf("disp = %s\n", temp_s1);
free(temp_s1);
*/
v3_unit(disp);
/*
temp_s1 = v3_str(disp);
printf("disp unit = %s\n", temp_s1);
free(temp_s1);
*/
dot = v3_dot(temp, disp);
/*
printf("dot = %f\n", dot);
*/
v3_mult_add(ps[i].v, disp, dm*LOSS_COL*dt);
v3_mult_sub(ps[j].v, disp, dm*LOSS_COL*dt);
// v3_mult_add(ps[i].c, disp, dm);
// v3_mult_sub(ps[j].c, disp, dm);
v3_del(disp);
v3_del(temp);
}
}
}
