使用什么数据结构来存储基于游戏对象的二维单元地图?

我知道你可能在想2D数组或2D向量，但请听我说。

我实际上已经在为瓦片地图使用 2D 数组，效果很好。但是，我正在尝试开发一种数据结构，该结构可以存储位于此类图块地图顶部的游戏对象。

我的要求如下：

• 映射必须允许将多个对象定位在同一单元格中

• 对象映射必须可按行和列迭代，以便我可以将迭代空间剔除到某些坐标(这样我就可以只渲染实际在屏幕上的对象等)

优选地，对象映射

• 还应提供快速查找，以确定1：给定单元格中有哪些对象，2：给定对象当前是否在对象映射的某个位置，以及 3：给定对象在对象映射上的位置

我起草了一个使用两个 STL 容器的基本数据结构：

• 3Dstd::map<int, std::map<int, std::vector<Object*>>>用于提供可迭代、易于剔除的容器。使用 std：：vector 以便可以在同一单元格中包含许多对象。也可以通过_map[x][y]访问单元格。

• 此外，我正在使用 1Dstd::map<Object*, Vec2<int>*>，它包含与 3D std：：map 完全相同的对象，只是我认为它可以允许更快的搜索，因为它是 1D。Vec2<int>*指针的原因是，游戏对象可以向 ObjectMap 询问其在地图上的位置，可能保存它，然后在将来无需搜索即可立即访问它。

根据我的要求，是否有比我使用的容器更合适的容器？

如果有帮助，我已经粘贴了下面的 ObjectMap 代码：

#pragma once
#include <vector>
#include <map>
template<typename T>
struct Vec2 {
Vec2() { x = 0; y = 0; }
Vec2(T xVal, T yVal) : x(xVal), y(yVal) {}
void Set(T xVal, T yVal) { x = xVal; y = yVal; }
T x, y;
Vec2& operator+=(const Vec2& rhs) { x += rhs.x; y += rhs.y; return *this; }
Vec2 operator+(const Vec2& rhs) { return Vec2<T>(x + rhs.x, y + rhs.y); }
};
/// <summary>
/// Represents a map of objects that can be layered on top of a cell-based map
/// Allows for multiple objects per map cell
/// </summary>
template <typename Object>
class ObjectMap {
public:
/// <summary>
/// Gets the objects located at the given map cell
/// </summary>
/// <param name="row">The row of the cell to inspect</param>
/// <param name="column">The column of the cell to inspect</param>
/// <returns>
/// A pointer to a vector of objects residing at the given cell.
/// Returns a nullptr if there are no objects at the cell.
/// </returns>
std::vector<Object*>* At(int row, int column);
/// <summary>
/// Checks whether the ObjectMap contains the given object
/// </summary>
/// <param name="object">A pointer to the object to check for</param>
/// <returns>True if the ObjectMap contains the object</returns>
bool Contains(Object* object);
/// <summary>
/// Adds the given object to the ObjectMap at the given cell
/// </summary>
/// <param name="object">The object to add to the map</param>
/// <param name="row">The row of the cell to add the object to</param>
/// <param name="column">The column of the cell to add the object to</param>
/// <returns>True if successful, false if the object is already in the ObjectMap</returns>
bool Add(Object* object, int row, int column);
/// <summary>
/// Moves the given object by some number of rows and columns
/// </summary>
/// <param name="object">The object to move</param>
/// <param name="rows">The number of rows to move the object by</param>
/// <param name="columns">The number of columns to move the object by</param>
/// <returns>True if successful, false if the object does not exist in the ObjectMap</returns>
bool MoveBy(Object* object, int rows, int columns);
/// <summary>
/// Moves the given object to the given cell
/// </summary>
/// <param name="object">The object to move</param>
/// <param name="row">The row of the cell to move the object to</param>
/// <param name="column">The column of the cell to move the object to</param>
/// <returns>True if successful, false if the object does not exist in the ObjectMap</returns>
bool MoveTo(Object* object, int row, int column);
/// <summary>
/// Gets the position of the given object
/// </summary>
/// <param name="object">A pointer to the object to check the position of</param>
/// <returns>
/// A pointer to the position of the object.
/// Returns a nullptr if the object does not exist in the ObjectMap.
/// </returns>
Vec2<int>* GetPosition(Object* object);
private:
/// <summary>
/// A 3D container allowing object access via cell positions
/// Provides the ability to iterate across sections of the map
/// Useful for object culling and rendering
/// Useful for object lookup when the position is known
/// Example: _map[a][b] is a vector objects positioned at the map cell (x=a,y=b)
/// </summary>
std::map<int, std::map<int, std::vector<Object*>>> _map;
/// <summary>
/// A 1D container of all objects and pointers to their positions
/// Useful for quickly checking whether an object exists
/// Useful for quickly getting the location of an object
/// </summary>
std::map<Object*, Vec2<int>*> _objects;
};
/// 
/// ObjectMap.tpp
/// The implementation has not been separated into a .cpp file because templated 
/// functions must be implemented in header files.
/// 
/// See http://stackoverflow.com/questions/495021/why-can-templates-only-be-implemented-in-the-header-file
/// 
#include <algorithm>
template <typename Object>
std::vector<Object*>* ObjectMap<Object>::At(int column, int row) {
// Checks whether a key exists for the given column
if (_map.find(column) != _map.end()) {
// Checks whether a key exists for the given row
if (_map.at(column).find(row) != _map.at(column).end()) {
// Return the objects residing in the cell
return &_map.at(column).at(row);
}
}
return nullptr;
}
template <typename Object>
bool ObjectMap<Object>::Contains(Object* object) {
return _objects.find(object) != _objects.end();
}
template <typename Object>
bool ObjectMap<Object>::Add(Object* object, int column, int row) {
if (!Contains(object)) {
_objects[object] = new Vec2<int>(column, row);
_map[column][row].push_back(object);
return true;
}
return false;
}
template <typename Object>
bool ObjectMap<Object>::MoveBy(Object* object, int columns, int rows) {
Vec2<int> newPosition = *_objects[object] + Vec2<int>(columns, rows);
return MoveTo(object, newPosition.x, newPosition.y);
}
template <typename Object>
bool ObjectMap<Object>::MoveTo(Object* object, int column, int row) {
if (Contains(object)) {
// Get the position reference of the object
Vec2<int>* position = _objects[object];
// Erase the object from its current position in the map
auto *oldTile = &_map[position->x][position->y];
oldTile->erase(std::remove(oldTile->begin(), oldTile->end(), object), oldTile->end());
// Erase any newly-empty keys from the map
if (oldTile->size() == 0) {
_map[position->x].erase(_map[position->x].find(position->y));
if (_map[position->x].size() == 0) {
_map.erase(_map.find(position->x));
}
}
// Add the object to its new position on the map
_map[column][row].push_back(object);
// Set the position of the object
position->Set(column, row);
return true;
}
return false;
}
template <typename Object>
Vec2<int>* ObjectMap<Object>::GetPosition(Object * object) {
if (Contains(object)) {
return _objects[object];
}
return nullptr;
}