void stl_fix_normal_values(stl_file *stl) {
int i;
if (stl->error) return;
for(i = 0; i < stl->stats.number_of_facets; i++) {
stl_check_normal_vector(stl, i, 1);
}
}
void
stl_fix_normal_directions(stl_file *stl)
{
char *norm_sw;
/* int edge_num;*/
/* int vnot;*/
int checked = 0;
int facet_num;
/* int next_facet;*/
int i;
int j;
struct stl_normal
{
int facet_num;
struct stl_normal *next;
};
struct stl_normal *head;
struct stl_normal *tail;
struct stl_normal *newn;
struct stl_normal *temp;
/* Initialize linked list. */
head = (struct stl_normal*)malloc(sizeof(struct stl_normal));
if(head == NULL) perror("stl_fix_normal_directions");
tail = (struct stl_normal*)malloc(sizeof(struct stl_normal));
if(tail == NULL) perror("stl_fix_normal_directions");
head->next = tail;
tail->next = tail;
/* Initialize list that keeps track of already fixed facets. */
norm_sw = (char*)calloc(stl->stats.number_of_facets, sizeof(char));
if(norm_sw == NULL) perror("stl_fix_normal_directions");
facet_num = 0;
/* If normal vector is not within tolerance and backwards:
Arbitrarily starts at face 0. If this one is wrong, we're screwed. Thankfully, the chances
of it being wrong randomly are low if most of the triangles are right: */
if(stl_check_normal_vector(stl, 0, 0) == 2)
stl_reverse_facet(stl, 0);
/* Say that we've fixed this facet: */
norm_sw[facet_num] = 1;
checked++;
for(;;)
{
/* Add neighbors_to_list.
Add unconnected neighbors to the list:a */
for(j = 0; j < 3; j++)
{
/* Reverse the neighboring facets if necessary. */
if(stl->neighbors_start[facet_num].which_vertex_not[j] > 2)
{
/* If the facet has a neighbor that is -1, it means that edge isn't shared by another facet */
if(stl->neighbors_start[facet_num].neighbor[j] != -1)
{
stl_reverse_facet
(stl, stl->neighbors_start[facet_num].neighbor[j]);
}
}
/* If this edge of the facet is connected: */
if(stl->neighbors_start[facet_num].neighbor[j] != -1)
{
/* If we haven't fixed this facet yet, add it to the list: */
if(norm_sw[stl->neighbors_start[facet_num].neighbor[j]] != 1)
{
/* Add node to beginning of list. */
newn = (struct stl_normal*)malloc(sizeof(struct stl_normal));
if(newn == NULL) perror("stl_fix_normal_directions");
newn->facet_num = stl->neighbors_start[facet_num].neighbor[j];
newn->next = head->next;
head->next = newn;
}
}
}
/* Get next facet to fix from top of list. */
if(head->next != tail)
{
facet_num = head->next->facet_num;
if(norm_sw[facet_num] != 1) /* If facet is in list mutiple times */
{
norm_sw[facet_num] = 1; /* Record this one as being fixed. */
checked++;
}
temp = head->next; /* Delete this facet from the list. */
head->next = head->next->next;
free(temp);
}
else /* if we ran out of facets to fix: */
{
/* All of the facets in this part have been fixed. */
stl->stats.number_of_parts += 1;
if(checked >= stl->stats.number_of_facets)
{
/* All of the facets have been checked. Bail out. */
break;
}
else
{
/* There is another part here. Find it and continue. */
for(i = 0; i < stl->stats.number_of_facets; i++)
{
if(norm_sw[i] == 0)
{ /* This is the first facet of the next part. */
facet_num = i;
if(stl_check_normal_vector(stl, i, 0) == 2)
{
stl_reverse_facet(stl, i);
}
norm_sw[facet_num] = 1;
checked++;
break;
}
}
}
}
}
free(head);
free(tail);
free(norm_sw);
}
