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TrinityCore/src/common/Collision/BoundingIntervalHierarchyWrapper.h

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/*
* This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef TRINITYCORE_BOUNDING_INTERVAL_HIERARCHY_WRAPPER_H
#define TRINITYCORE_BOUNDING_INTERVAL_HIERARCHY_WRAPPER_H
#include "BoundingIntervalHierarchy.h"
#include <span>
#include <unordered_map>
template<class T, class BoundsFunc = BoundsTrait<T> >
class BIHWrap
{
template<class RayCallback>
struct MDLCallback
{
std::size_t objects_size;
T const* const* objects;
RayCallback& _callback;
MDLCallback(RayCallback& callback, T const* const* objects_array, std::size_t objects_size ) : objects_size(objects_size), objects(objects_array), _callback(callback) { }
/// Intersect ray
bool operator() (G3D::Ray const& ray, std::size_t idx, float& maxDist, bool /*stopAtFirst*/)
{
if (idx >= objects_size)
return false;
if (T const* obj = objects[idx])
return _callback(ray, *obj, maxDist/*, stopAtFirst*/);
return false;
}
/// Intersect point
void operator() (G3D::Vector3 const& p, std::size_t idx)
{
if (idx >= objects_size)
return;
if (T const* obj = objects[idx])
_callback(p, *obj);
}
};
BIH m_tree;
std::vector<T const*> m_objects;
std::unordered_map<T const*, std::size_t> m_obj2Idx;
int unbalanced_times;
public:
BIHWrap() : unbalanced_times(0) { }
void insert(T const& obj)
{
auto [itr, isNew] = m_obj2Idx.try_emplace(&obj, m_objects.size());
if (!isNew)
return;
m_objects.push_back(itr->first);
++unbalanced_times;
}
void remove(T const& obj)
{
auto node = m_obj2Idx.extract(&obj);
if (!node)
return;
if (node.key() != m_objects.back())
{
// update index of last element (will be swapped with removed one)
m_obj2Idx.find(m_objects.back())->second = node.mapped();
// move last into removed element slot
m_objects[node.mapped()] = m_objects.back();
}
m_objects.pop_back();
++unbalanced_times;
}
void balance()
{
if (unbalanced_times == 0)
return;
m_tree.build(m_objects, BoundsFunc());
unbalanced_times = 0;
}
template<typename RayCallback>
void intersectRay(G3D::Ray const& ray, RayCallback& intersectCallback, float& maxDist)
{
balance();
MDLCallback<RayCallback> temp_cb(intersectCallback, m_objects.data(), m_objects.size());
m_tree.intersectRay(ray, temp_cb, maxDist, true);
}
template<typename IsectCallback>
void intersectPoint(G3D::Vector3 const& point, IsectCallback& intersectCallback)
{
balance();
MDLCallback<IsectCallback> callback(intersectCallback, m_objects.data(), m_objects.size());
m_tree.intersectPoint(point, callback);
}
std::span<T const* const> getObjects() const { return m_objects; }
};
#endif // TRINITYCORE_BOUNDING_INTERVAL_HIERARCHY_WRAPPER_H