void KMCentersTree::split_by_mid_point(
int start_ind, int end_ind, int &cut_dim, double &cut_val, int &n_lo) {
KMPoint *lo,*hi;
lo = bnd_box_->get_point(0);
hi = bnd_box_->get_point(1);
// find the long side with the largest spread (the cutting dimension)
double max_length = bnd_box_->max_length();
double max_spread = -1;
for (int d = 0; d < data_points_->get_dim(); d++) {
if (std::abs((*hi)[d] - (*lo)[d]-max_length) <1E-6){
double spr = spread(start_ind,end_ind,d);
if (spr > max_spread) {
max_spread = spr;
cut_dim = d;
}
}
}
// find the splitting value
double ideal_cut_val = ((*lo)[cut_dim] + (*hi)[cut_dim])/2;
//min_max represent the minimal and maximal
//values of points along the cutting dimension
std::pair<double,double> min_max =
limits_along_dimension(start_ind,end_ind, cut_dim);
//slide to min or max as needed
if (ideal_cut_val < min_max.first)
cut_val = min_max.first;
else if (ideal_cut_val > min_max.second)
cut_val = min_max.second;
else
cut_val = ideal_cut_val;
// permute points accordingly
std::pair<int,int>
break_ind = split_by_plane(start_ind,end_ind,cut_dim, cut_val);
IMP_LOG(VERBOSE, "split by mid point for indexes: "
<< start_ind << " to " << end_ind << "break index: "
<< break_ind.first << " to " << break_ind.second << std::endl);
//set n_lo such that each side of the split will contain at least one point
n_lo = (start_ind+end_ind)/2;
// if ideal_cut_val < min (y >= 1), we set n_lo = 1 (so there is one
// point on left)
if (ideal_cut_val < min_max.first) n_lo = start_ind+1;
// if ideal_cut_val > max (x <= n-1), we set n_lo = n-1 (so there is one
// point on right).
else if (ideal_cut_val > min_max.second) n_lo = end_ind;
// Otherwise, we select n_lo as close to the middle of [x..y] as possbile
else if (break_ind.first > n_lo) n_lo = break_ind.first;
else if (break_ind.second < n_lo) n_lo = break_ind.second;
}
/*
* receiver - points to the base room frustum, which portal leads to - it's taken from the portal!
* returns a pointer to newly generated frustum.
*/
std::shared_ptr<Frustum> Frustum::portalFrustumIntersect(Portal *portal, std::shared_ptr<Frustum> emitter, Render *render)
{
assert(emitter);
if(!portal->dest_room)
return nullptr;
if(portal->normal.distance(render->camera()->m_pos) < -SPLIT_EPSILON) // non face or degenerate to the line portal
{
return nullptr;
}
if(!portal->dest_room->frustum.empty() && emitter->hasParent(portal->dest_room->frustum.front()))
{
return nullptr; // Abort infinite loop!
}
bool in_dist = false, in_face = false;
for(const btVector3& v : portal->vertices)
{
if(!in_dist && render->camera()->frustum->norm.distance(v) < render->camera()->m_distFar)
in_dist = true;
if(!in_face && emitter->norm.distance(v) > 0.0)
in_face = true;
if(in_dist && in_face)
break;
}
if(!in_dist || !in_face)
return nullptr;
/*
* Search for the first free room's frustum
*/
portal->dest_room->frustum.emplace_back(std::make_shared<Frustum>());
auto current_gen = portal->dest_room->frustum.back();
current_gen->splitPrepare(portal); // prepare for clipping
if(current_gen->split_by_plane(emitter->norm)) // splitting by main frustum clip plane
{
for(size_t i = 0; i < emitter->vertices.size(); i++)
{
const auto& n = emitter->planes[i];
if(!current_gen->split_by_plane(n))
{
portal->dest_room->frustum.pop_back();
return nullptr;
}
}
current_gen->genClipPlanes(render->camera()); // all is OK, let's generate clip planes
current_gen->parent = emitter; // add parent pointer
current_gen->parents_count = emitter->parents_count + 1;
if(portal->dest_room->max_path < current_gen->parents_count)
{
portal->dest_room->max_path = current_gen->parents_count; // maximum path to the room
}
return current_gen;
}
portal->dest_room->frustum.pop_back();
return nullptr;
}