Why are pointers slower in this case

Question

I am implementing a quadtree. I re-implemented my first draft (full version can be seen here) that used smart pointers and references with a version using raw pointers.

But filling the new tree is apparently up to two times slower, why is this the case?

The old versions code:

// returns if coordinates fit in the tree
const bool contains(const double &x, const double &y, const double &w, const double &h) const {
    return (this->x < x &&
            this->y < y &&
            this->x + this->w > x + w &&
            this->y + this->h > x + h);
}
// returns if an element fits in the tree
const bool contains(const std::shared_ptr<Rectangle> &rect) const {
    return contains(rect->getX(), rect->getY(), rect->getW(), rect->getH());
}

// inserts an element in the tree
const bool insert(const std::shared_ptr<Rectangle> &rect) {
    // if rect is too big for this quadtree
    if(!contains(rect)) {
        auto sp = getParent();
        if(sp == nullptr) {
            return false;
        }
        return sp->insert(rect);
    }
    // if element theoretically fits in subtree
    else if(rect->getW() < getW() / 2 && rect->getH() < getH() / 2) {
        if(!subtrees[0]) {
            generateSubtrees();
        }
        for(const auto &subtree: subtrees) {
            if(subtree->contains(rect)) {
                return subtree->insert(rect);
            }
        }
    }
    children.insert(children.end(), rect);
    return true;
}

void generateSubtrees() {
    subtrees[0] = std::make_shared<QuadTree>(getW() / 2.0f, getH() / 2.0f, getX(),                 getY(),                 this);
    subtrees[1] = std::make_shared<QuadTree>(getW() / 2.0f, getH() / 2.0f, getX() + getW() / 2.0f, getY(),                 this);
    subtrees[2] = std::make_shared<QuadTree>(getW() / 2.0f, getH() / 2.0f, getX(),                 getY() + getH() / 2.0f, this);
    subtrees[3] = std::make_shared<QuadTree>(getW() / 2.0f, getH() / 2.0f, getX() + getW() / 2.0f, getY() + getH() / 2.0f, this);

}

The time filling the tree with this version is ca. 0.001367 seconds for 1000 elements.

Then I re-implemented this function:

// Returns if a Rectangle fits in the tree
const bool contains(const Rectangle *rect) const {
    return (this->x < rect->x &&
            this->y < rect->y &&
            this->x + this->w > rect->x + rect->w &&
            this->y + this->h > rect->y + rect->h);
}

// Inserts an element in the tree
const bool insert(Rectangle *rect) {
    if(!contains(rect) && parent == nullptr) {
        return false;
    }
    if(rect->w < this->w / 2.0f && rect->w < this->w / 2.0f) {
        if(children[0]==nullptr){
            generateSubtrees();
        }
        for(const auto child: children) {
            if(child->contains(rect)) {
                return child->insert(rect);
            }
        }
    }
    elements.push_back(rect);
    return true;
}

// Generate the subtrees
void generateSubtrees() {
    children[0] = new Quadtree(w/2.0f, h/2.0f, x,        y,        this);
    children[1] = new Quadtree(w/2.0f, h/2.0f, x+w/2.0f, y,        this);
    children[2] = new Quadtree(w/2.0f, h/2.0f, x,        y+w/2.0f, this);
    children[3] = new Quadtree(w/2.0f, h/2.0f, x+w/2.0f, y+w/2.0f, this);
}

The time for filling this version with 1000 elements takes ca. 0.00312 seconds.

As you see, the second version using pointers is a much slower.

PS: I fill the old tree (version 1) in a loop with

insert(std::make_shared<Rectangle>(std::rand()%999, std::rand()%999, 1, 1))

and the new one (version 2) with

insert(new Quadtree::Rectangle(std::rand()%999, std::rand()%999, 1, 1)).

Can you tell me where the reason for the performance loss lies?

(Look up the comments for additional information)

Answer 1

This code

const bool contains(const double &x, const double &y, const double &w, const double &h) const {
    return (this->x < x &&
            this->y < y &&
            this->x + this->w > x + w &&
            this->y + this->h > x + h);  <---- error here
}

is not the same as this code

const bool contains(const Rectangle *rect) const {
    return (this->x < rect->x &&
            this->y < rect->y &&
            this->x + this->w > rect->x + rect->w &&
            this->y + this->h > rect->y + rect->h);
}

the first wrongly says x + h, it should say y + h.