I am working on a 3D/physics engine using C++ and OpenGL.

Currently I’m in the process of implementing the “Sweep and Prune”-method for collisions checks using AABB (axis aligned bounding boxes). I’m roughly following the method outlined here (part 1 & 2): https://leanrada.com/notes/sweep-and-prune/

The algorithm works by sorting the min & max coordinates of each axis for each AABB box:

1. vectors (sorted by coordinate) for the X-, Y- and Z-axises
2. The algorithm also requires to know if each edge is the minimum coordinate or the maximum.
3. Also the ID of the entity it belongs to.

For this data I’m using this struct called Edge:

struct Edge {
    int id;
    bool isLeft;
    float coord;

    Edge(int id, bool isLeft, float coord)
        : id(id), isLeft(isLeft), coord(coord) {}
    }
};

Example of Entity class with relevant functions for Edge:

class Entity
{
public:
    int id;
    std::vector<Edge> edgesList;

    std::vector<glm::vec3> vertices;
    std::vector<unsigned int> indices;
    glm::vec3 position;

    // create Edges
    void setupEdges(const std::vector<float>& minMax)
    {
        // Create Edge objects and add them to edgesList
        edgesList.emplace_back(id, true,  minMax[0]); // min_X
        edgesList.emplace_back(id, false, minMax[1]); // max_X
        edgesList.emplace_back(id, true,  minMax[2]); // min_Y
        edgesList.emplace_back(id, false, minMax[3]); // max_Y
        edgesList.emplace_back(id, true,  minMax[4]); // min_Z
        edgesList.emplace_back(id, false, minMax[5]); // max_Z
    }

    // update Edges. The new coordinates are calculated separately in another function
    void updateEdges(const std::vector<float>& minMax)
    {
        edgesList[0].coord = minMax[0];   // new min_X
        edgesList[1].coord = minMax[1];   // new max_X
        edgesList[2].coord = minMax[2];   // new min_Y
        edgesList[3].coord = minMax[3];   // new max_Y
        edgesList[4].coord = minMax[4];   // new min_Z
        edgesList[5].coord = minMax[5];   // new max_Z
    }

To save on performance I want to use insertion sort for the axis-vectors (since generally Entities will not switch places every frame).

Also I would like to update the Edge-structs from inside the Entity-objects and have it automatically update the axis-vectors.

Question: How do I put all Edge-structs from all Entities inside a single vector, while still being able to update the values from inside each Entity (which the structs belong to)? Especially after sorting said vector