virtualx-engine/core/templates/pooled_list.h
PouleyKetchoupp 3877ed73d0 Dynamic BVH broadphase in 2D & 3D Godot Physics
Port lawnjelly's dynamic BVH implementation from 3.x to be used in
both 2D and 3D broadphases.

Removed alternative broadphase implementations which are not meant to be
used anymore since they are much slower.

Includes changes in Rect2, Vector2, Vector3 that help with the template
implementation of the dynamic BVH by uniformizing the interface between
2D and 3D math.

Co-authored-by: lawnjelly <lawnjelly@gmail.com>
2021-05-10 16:28:55 -07:00

95 lines
4 KiB
C++

/*************************************************************************/
/* pooled_list.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
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/*************************************************************************/
#pragma once
// Simple template to provide a pool with O(1) allocate and free.
// The freelist could alternatively be a linked list placed within the unused elements
// to use less memory, however a separate freelist is probably more cache friendly.
// NOTE : Take great care when using this with non POD types. The construction and destruction
// is done in the LocalVector, NOT as part of the pool. So requesting a new item does not guarantee
// a constructor is run, and free does not guarantee a destructor.
// You should generally handle clearing
// an item explicitly after a request, as it may contain 'leftovers'.
// This is by design for fastest use in the BVH. If you want a more general pool
// that does call constructors / destructors on request / free, this should probably be
// a separate template.
#include "core/templates/local_vector.h"
template <class T, bool force_trivial = false>
class PooledList {
LocalVector<T, uint32_t, force_trivial> list;
LocalVector<uint32_t, uint32_t, true> freelist;
// not all list members are necessarily used
int _used_size;
public:
PooledList() {
_used_size = 0;
}
int estimate_memory_use() const {
return (list.size() * sizeof(T)) + (freelist.size() * sizeof(uint32_t));
}
const T &operator[](uint32_t p_index) const {
return list[p_index];
}
T &operator[](uint32_t p_index) {
return list[p_index];
}
int size() const { return _used_size; }
T *request(uint32_t &r_id) {
_used_size++;
if (freelist.size()) {
// pop from freelist
int new_size = freelist.size() - 1;
r_id = freelist[new_size];
freelist.resize(new_size);
return &list[r_id];
}
r_id = list.size();
list.resize(r_id + 1);
return &list[r_id];
}
void free(const uint32_t &p_id) {
// should not be on free list already
CRASH_COND(p_id >= list.size());
freelist.push_back(p_id);
_used_size--;
}
};