/** for a pair (p, q) of points, add the edge pq if their are visible to each other
*/
void handle(struct Point *p, struct Point *q, struct Map_info *out)
{
/* if it's a point without segments, just report the edge */
if (segment1(q) == NULL && segment2(q) == NULL && before(p, q, p->vis)) {
report(p, q, out);
}
else if (segment1(p) != NULL && q == other1(p)) {
/* we need to check if there is another segment at q so it can be set to the vis */
if (segment1(q) == segment1(p) && segment2(q) != NULL &&
left_turn(p, q, other2(q))) {
p->vis = segment2(q);
}
else if (segment2(q) == segment1(p) && segment1(q) != NULL &&
left_turn(p, q, other1(q))) {
p->vis = segment1(q);
}
else
p->vis = q->vis;
report(p, q, out);
}
else if (segment2(p) != NULL && q == other2(p)) {
/* we need to check if there is another segment at q so it can be set to the vis */
if (segment1(q) == segment2(p) && segment2(q) != NULL &&
left_turn(p, q, other2(q))) {
p->vis = segment2(q);
}
else if (segment2(q) == segment2(p) && segment1(q) != NULL &&
left_turn(p, q, other1(q))) {
p->vis = segment1(q);
}
else
p->vis = q->vis;
report(p, q, out);
}
else if (segment1(q) == p->vis && segment1(q) != NULL) {
/* we need to check if there is another segment at q so it can be set to the vis */
if (segment2(q) != NULL && left_turn(p, q, other2(q)))
p->vis = segment2(q);
else
p->vis = q->vis;
/* check that p and q are not on the same boundary and that the edge pq is inside the boundary */
if (p->cat == -1 || p->cat != q->cat ||
!point_inside(p, (p->x + q->x) * 0.5, (p->y + q->y) * 0.5))
report(p, q, out);
}
else if (segment2(q) == p->vis && segment2(q) != NULL) {
/* we need to check if there is another segment at q so it can be set to the vis */
if (segment1(q) != NULL && left_turn(p, q, other1(q)))
p->vis = segment1(q);
else
p->vis = q->vis;
/* check that p and q are not on the same boundary and that the edge pq is inside the boundary */
if (p->cat == -1 || p->cat != q->cat ||
!point_inside(p, (p->x + q->x) * 0.5, (p->y + q->y) * 0.5))
report(p, q, out);
}
else if (before(p, q, p->vis)) {
/* if q only has one segment, then this is the new vis */
if (segment2(q) == NULL)
p->vis = segment1(q);
else if (segment1(q) == NULL)
p->vis = segment2(q);
/* otherwise take the one with biggest slope */
else if (left_turn(p, q, other1(q)) && !left_turn(p, q, other2(q)))
p->vis = segment1(q);
else if (!left_turn(p, q, other1(q)) && left_turn(p, q, other2(q)))
p->vis = segment2(q);
else if (left_turn(q, other2(q), other1(q)))
p->vis = segment1(q);
else
p->vis = segment2(q);
/* check that p and q are not on the same boundary and that the edge pq is inside the boundary */
if (p->cat == -1 || p->cat != q->cat ||
!point_inside(p, (p->x + q->x) * 0.5, (p->y + q->y) * 0.5))
report(p, q, out);
}
}
/** for all points initiate their vis line to the one directly below
*/
void init_vis(struct Point *points, int num_points, struct Line *lines,
int num_lines)
{
int i;
double d;
struct avl_table *tree = avl_create(cmp_points, NULL, NULL);
struct avl_traverser it;
struct Point *p;
double y1, y2;
struct Point *s1, *s2;
for (i = 0; i < num_points; i++) {
points[i].vis = NULL;
d = PORT_DOUBLE_MAX;
avl_t_init(&it, tree);
/* loop through the tree */
while ((p = avl_t_next(&it)) != NULL) {
if (segment1(p) == NULL && segment2(p) == NULL)
continue;
/* test for intersection and get the intersecting point */
if (segment1(p) != NULL &&
segment_intersect(segment1(p), &points[i], &y1) > -1) {
/* find the closest one below */
if (y1 < points[i].y && (points[i].y - y1) < d) {
d = points[i].y - y1;
points[i].vis = segment1(p);
}
}
if (segment2(p) != NULL &&
segment_intersect(segment2(p), &points[i], &y2) > -1) {
if (y2 < points[i].y && (points[i].y - y2) < d) {
d = points[i].y - y2;
points[i].vis = segment2(p);
}
}
} /* end loop */
s1 = s2 = NULL;
/* now if the other point is on the right, we can delete it */
if (segment1(&points[i]) != NULL &&
cmp_points(&points[i], other1(&points[i]), NULL) > 0) {
p = other1(&points[i]);
/* unless the other point of it is on the left */
if (segment1(p) != NULL && other1(p) != &points[i] &&
cmp_points(&points[i], other1(p), NULL) > 0)
s1 = avl_delete(tree, p);
else if (segment2(p) != NULL && other2(p) != &points[i] &&
cmp_points(&points[i], other2(p), NULL) > 0)
s1 = avl_delete(tree, p);
}
/* now if the other point is on the right, we can delete it */
if (segment2(&points[i]) != NULL &&
cmp_points(&points[i], other2(&points[i]), NULL) > 0) {
p = other2(&points[i]);
/* unless the other point of it is on the left */
if (segment1(p) != NULL && other1(p) != &points[i] &&
cmp_points(&points[i], other1(p), NULL) > 0)
s2 = avl_delete(tree, p);
else if (segment2(p) != NULL && other2(p) != &points[i] &&
cmp_points(&points[i], other2(p), NULL) > 0)
s2 = avl_delete(tree, p);
}
/* if both weren't deleted, it means there is at least one other
point on the left, so add the current */
/* also there is no point adding the point if there is no segment attached to it */
if ((s1 == NULL || s2 == NULL)) {
avl_insert(tree, &points[i]);
}
}
avl_destroy(tree, NULL);
}
size_t BVH4MB::rotate(Base* nodeID, size_t depth)
{
/*! nothing to rotate if we reached a leaf node. */
if (nodeID->isLeaf()) return 0;
Node* parent = nodeID->node();
/*! rotate all children first */
ssei cdepth;
for (size_t c=0; c<4; c++)
cdepth[c] = (int)rotate(parent->child[c],depth+1);
/* compute current area of all children */
ssef sizeX = parent->upper_x-parent->lower_x;
ssef sizeY = parent->upper_y-parent->lower_y;
ssef sizeZ = parent->upper_z-parent->lower_z;
ssef childArea = sizeX*(sizeY + sizeZ) + sizeY*sizeZ;
/*! transpose node bounds */
ssef plower0,plower1,plower2,plower3; transpose(parent->lower_x,parent->lower_y,parent->lower_z,ssef(zero),plower0,plower1,plower2,plower3);
ssef pupper0,pupper1,pupper2,pupper3; transpose(parent->upper_x,parent->upper_y,parent->upper_z,ssef(zero),pupper0,pupper1,pupper2,pupper3);
BBox<ssef> other0(plower0,pupper0), other1(plower1,pupper1), other2(plower2,pupper2), other3(plower3,pupper3);
/*! Find best rotation. We pick a target child of a first child,
and swap this with an other child. We perform the best such
swap. */
float bestCost = pos_inf;
int bestChild = -1, bestTarget = -1, bestOther = -1;
for (size_t c=0; c<4; c++)
{
/*! ignore leaf nodes as we cannot descent into */
if (parent->child[c]->isLeaf()) continue;
Node* child = parent->child[c]->node();
/*! transpose child bounds */
ssef clower0,clower1,clower2,clower3; transpose(child->lower_x,child->lower_y,child->lower_z,ssef(zero),clower0,clower1,clower2,clower3);
ssef cupper0,cupper1,cupper2,cupper3; transpose(child->upper_x,child->upper_y,child->upper_z,ssef(zero),cupper0,cupper1,cupper2,cupper3);
BBox<ssef> target0(clower0,cupper0), target1(clower1,cupper1), target2(clower2,cupper2), target3(clower3,cupper3);
/*! put other0 at each target position */
float cost00 = halfArea3f(merge(other0 ,target1,target2,target3));
float cost01 = halfArea3f(merge(target0,other0 ,target2,target3));
float cost02 = halfArea3f(merge(target0,target1,other0 ,target3));
float cost03 = halfArea3f(merge(target0,target1,target2,other0 ));
ssef cost0 = ssef(cost00,cost01,cost02,cost03);
ssef min0 = vreduce_min(cost0);
int pos0 = (int)__bsf(movemask(min0 == cost0));
/*! put other1 at each target position */
float cost10 = halfArea3f(merge(other1 ,target1,target2,target3));
float cost11 = halfArea3f(merge(target0,other1 ,target2,target3));
float cost12 = halfArea3f(merge(target0,target1,other1 ,target3));
float cost13 = halfArea3f(merge(target0,target1,target2,other1 ));
ssef cost1 = ssef(cost10,cost11,cost12,cost13);
ssef min1 = vreduce_min(cost1);
int pos1 = (int)__bsf(movemask(min1 == cost1));
/*! put other2 at each target position */
float cost20 = halfArea3f(merge(other2 ,target1,target2,target3));
float cost21 = halfArea3f(merge(target0,other2 ,target2,target3));
float cost22 = halfArea3f(merge(target0,target1,other2 ,target3));
float cost23 = halfArea3f(merge(target0,target1,target2,other2 ));
ssef cost2 = ssef(cost20,cost21,cost22,cost23);
ssef min2 = vreduce_min(cost2);
int pos2 = (int)__bsf(movemask(min2 == cost2));
/*! put other3 at each target position */
float cost30 = halfArea3f(merge(other3 ,target1,target2,target3));
float cost31 = halfArea3f(merge(target0,other3 ,target2,target3));
float cost32 = halfArea3f(merge(target0,target1,other3 ,target3));
float cost33 = halfArea3f(merge(target0,target1,target2,other3 ));
ssef cost3 = ssef(cost30,cost31,cost32,cost33);
ssef min3 = vreduce_min(cost3);
int pos3 = (int)__bsf(movemask(min3 == cost3));
/*! find best other child */
ssef otherCost = ssef(extract<0>(min0),extract<0>(min1),extract<0>(min2),extract<0>(min3));
int pos[4] = { pos0,pos1,pos2,pos3 };
sseb valid = ssei(int(depth+1))+cdepth <= ssei(maxDepth); // only select swaps that fulfill depth constraints
if (none(valid)) continue;
size_t n = select_min(valid,otherCost);
float cost = otherCost[n]-childArea[c]; //< increasing the original child bound is bad, decreasing good
/*! accept a swap when it reduces cost and is not swapping a node with itself */
if (cost < bestCost && n != c) {
bestCost = cost;
bestChild = (int)c;
bestOther = (int)n;
bestTarget = pos[n];
}
}
/*! if we did not find a swap that improves the SAH then do nothing */
if (bestCost >= 0) return 1+reduce_max(cdepth);
/*! perform the best found tree rotation */
Node* child = parent->child[bestChild]->node();
swap(parent,bestOther,child,bestTarget);
parent->lower_x[bestChild] = reduce_min(child->lower_x);
parent->lower_y[bestChild] = reduce_min(child->lower_y);
parent->lower_z[bestChild] = reduce_min(child->lower_z);
parent->upper_x[bestChild] = reduce_max(child->upper_x);
parent->upper_y[bestChild] = reduce_max(child->upper_y);
parent->upper_z[bestChild] = reduce_max(child->upper_z);
parent->lower_dx[bestChild] = reduce_min(child->lower_dx);
parent->lower_dy[bestChild] = reduce_min(child->lower_dy);
parent->lower_dz[bestChild] = reduce_min(child->lower_dz);
parent->upper_dx[bestChild] = reduce_max(child->upper_dx);
parent->upper_dy[bestChild] = reduce_max(child->upper_dy);
parent->upper_dz[bestChild] = reduce_max(child->upper_dz);
/*! This returned depth is conservative as the child that was
* pulled up in the tree could have been on the critical path. */
cdepth[bestOther]++; // bestOther was pushed down one level
return 1+reduce_max(cdepth);
}