static float8 calc_tanimoto_distance(float8* array1, float8* array2, int32 dimension)
{
if( array1 == NULL || array2 == NULL )
{
elog(ERROR, "In %s, arrays should not be NULL", __FUNCTION__);
}
float8 dot_product = calc_dot_product(array1, array2, dimension);
float8 array1_l2norm = calc_l2norm_val(array1, dimension);
float8 array2_l2norm = calc_l2norm_val(array2, dimension);
float8 denominator = array1_l2norm*array1_l2norm+
array2_l2norm*array2_l2norm-dot_product;
float8 distance = dot_product/denominator;
if (distance > 1.0)
{
distance = 1.0;
}
else if (distance < 0)
{
distance = 0;
}
return 1. - distance;
}
static float8 calc_cosine_distance(float8* array1, float8* array2, int32 dimension)
{
if( array1 == NULL || array2 == NULL )
{
elog(ERROR, "In %s, arrays should not be NULL", __FUNCTION__);
}
float8 dot_product = calc_dot_product(array1, array2, dimension);
float8 array1_l2norm = calc_l2norm_val(array1, dimension);
float8 array2_l2norm = calc_l2norm_val(array2, dimension);
float8 distance = dot_product/(array1_l2norm*array2_l2norm);
if (distance > 1.0)
{
distance = 1.0;
}
else if (distance < -1.0)
{
distance = -1.0;
}
return acos(distance);
}
void MeshObject::recursive_orient(int face_index,
float * faces_normals,
int * faces_indices,
int ** vertex_in_faces,
bool * visited) {
if(visited[face_index])
return;
//mark this face as visited
visited[face_index] = true;
//current_face normal
float current_face_normal[3] = {
faces_normals[(face_index * 3)],
faces_normals[(face_index * 3) + 1],
faces_normals[(face_index * 3) + 2]
};
//vertex indices that is connected to the current_face
int vi1 = faces_indices[(face_index * 3)];
int vi2 = faces_indices[(face_index * 3) + 1];
int vi3 = faces_indices[(face_index * 3) + 2];
int i;
for(i = 0; i < 9; i++) {
//the face indexes that is connected to the current_face
int fi1 = vertex_in_faces[vi1][i];
int fi2 = vertex_in_faces[vi2][i];
int fi3 = vertex_in_faces[vi3][i];
if(fi1 != -1 && fi1 != face_index && !visited[fi1]) {
float nface_normal[3] = {
faces_normals[(fi1 * 3)],
faces_normals[(fi1 * 3) + 1],
faces_normals[(fi1 * 3) + 2]
};
if(calc_dot_product(nface_normal, current_face_normal) < -0.1) {
faces_normals[(fi1 * 3)] = -1 * faces_normals[(fi1 * 3)];
faces_normals[(fi1 * 3) + 1] = -1 * faces_normals[(fi1 * 3) + 1];
faces_normals[(fi1 * 3) + 2] = -1 * faces_normals[(fi1 * 3) + 2];
}
}
if(fi2 != -1 && fi2 != face_index && !visited[fi1]) {
float nface_normal[3] = {
faces_normals[(fi2 * 3)],
faces_normals[(fi2 * 3) + 1],
faces_normals[(fi2 * 3) + 2]
};
if(calc_dot_product(nface_normal, current_face_normal) < -0.1) {
faces_normals[(fi2 * 3)] = -1 * faces_normals[(fi2 * 3)];
faces_normals[(fi2 * 3) + 1] = -1 * faces_normals[(fi2 * 3) + 1];
faces_normals[(fi2 * 3) + 2] = -1 * faces_normals[(fi2 * 3) + 2];
}
}
if(fi3 != -1 && fi3 != face_index && !visited[fi1]) {
float nface_normal[3] = {
faces_normals[(fi3 * 3)],
faces_normals[(fi3 * 3) + 1],
faces_normals[(fi3 * 3) + 2]
};
if(calc_dot_product(nface_normal, current_face_normal) < -0.1) {
faces_normals[(fi3 * 3)] = -faces_normals[(fi3 * 3)];
faces_normals[(fi3 * 3) + 1] = -faces_normals[(fi3 * 3) + 1];
faces_normals[(fi3 * 3) + 2] = -faces_normals[(fi3 * 3) + 2];
}
}
if(fi1 != -1) {
recursive_orient(fi1,
faces_normals,
faces_indices,
vertex_in_faces,
visited);
}
if(fi2 != -1) {
recursive_orient(fi2,
faces_normals,
faces_indices,
vertex_in_faces,
visited);
}
if(fi3 != -1) {
recursive_orient(fi3,
faces_normals,
faces_indices,
vertex_in_faces,
visited);
}
}
}
/*******************************************************************************
* For each pixel we must generate a primary ray and test for intersection with
* all of the objects in the scene. If there is more than one ray-object
* intersection then we must choose the closest intersection (the smallest
* positive value of t).To ensure that there are no objects intersected in
* front of the image plane (this is called near plane clipping), we keep the
* distance of the primary ray to the screen and test all intersections against
* this distance. If the t value is less than this distance, then we ignore the
* object.
*
* If there is an intersection then we must compute the shadow rays and the
* reflection rays. */
color_t trace_ray(ray3_t* test_ray, int depth) {
int occluded = 0;
ray3_t shadow_ray;
ray3_t reflected_ray;
color_t ray_color = { 0.0, 0.0, 0.0, 0.0 };
color_t nul_color = {0.0, 0.0, 0.0, 1.0};
light_t* light_ptr = 0;
double intersect_ray_length_curr = 0.0;
double intersect_ray_length_close = 0.0;
int intersection_exists = 0;
colored_sphere_t* sphere_close_ptr = 0;
vector3_t intersection;
vector3_t intersection_vector;
int sphere_index = 0;
int light_index = 0;
int shadow_index;
color_t add_color;
/* test ray against all objects in scene, search until closest intersection
* is found. */
for (sphere_index = 0; sphere_index < sphere_list_count; ++sphere_index) {
colored_sphere_t* sphere_ptr = &sphere_list[sphere_index];
/* test for intersection between ray and scene object */
if (1 == find_ray_sphere_intersect(test_ray, &sphere_ptr->sphere, &intersect_ray_length_curr)) {
if (intersect_ray_length_curr < 0.0)
continue;
if (0 == intersection_exists) {
intersection_exists = 1;
intersect_ray_length_close = intersect_ray_length_curr;
sphere_close_ptr = sphere_ptr;
}
else if (intersect_ray_length_curr < intersect_ray_length_close) {
intersect_ray_length_curr = intersect_ray_length_close;
sphere_close_ptr = sphere_ptr;
}
}
}
if (1 == intersection_exists) {
intersection.x = test_ray->origin.x + test_ray->vector.x * intersect_ray_length_close;
intersection.y = test_ray->origin.y + test_ray->vector.y * intersect_ray_length_close;
intersection.z = test_ray->origin.z + test_ray->vector.z * intersect_ray_length_close;
shadow_ray.origin = intersection;
/* Shadow rays are sent towards all light sources to determine if any objects occlude the intersection spot. */
for (light_index = 0; light_index < light_list_count; ++light_index) {
occluded = 0;
light_ptr = &light_list[light_index];
shadow_ray.vector.x = (light_ptr->origin.x - shadow_ray.origin.x);
shadow_ray.vector.y = (light_ptr->origin.y - shadow_ray.origin.y);
shadow_ray.vector.z = (light_ptr->origin.z - shadow_ray.origin.z);
normalize_vector(&shadow_ray.vector);
/* Test intersection to determine if ray is in occlusion. */
for (shadow_index = 0; shadow_index < sphere_list_count; ++shadow_index) {
if (1 == find_ray_sphere_intersect(&shadow_ray, &sphere_list[shadow_index].sphere, &intersect_ray_length_curr)) {
occluded = 1;
break;
}
}
if (occluded == 0) {
/* Calculate the total light intensity. */
double light_intensity = calc_dot_product(&shadow_ray.vector, &test_ray->vector);
if (light_intensity < 0.0) light_intensity = -light_intensity;
ray_color = mix_colors(&nul_color, &sphere_close_ptr->color, light_intensity);
if (depth < 4) {
reflected_ray.origin.x = intersection.x;
reflected_ray.origin.y = intersection.y;
reflected_ray.origin.z = intersection.z;
intersection_vector.x = (intersection.x - sphere_close_ptr->sphere.center.x);
intersection_vector.y = (intersection.y - sphere_close_ptr->sphere.center.y);
intersection_vector.z = (intersection.z - sphere_close_ptr->sphere.center.z);
normalize_vector(&intersection_vector);
calc_reflected_vector(&reflected_ray.vector, &test_ray->vector, &intersection_vector);
add_color = trace_ray(&reflected_ray, ++depth);
if ((add_color.r != 0x00) ||
(add_color.g != 0x00) ||
(add_color.b != 0x00)) {
double mix_ratio = calc_dot_product(&reflected_ray.vector, &intersection_vector);
if (mix_ratio < 0.0) mix_ratio = -mix_ratio;
ray_color = mix_colors(&ray_color, &add_color, mix_ratio);
}
}
}
}
}
return ray_color;
}