object.h

#ifndef OBJECT_H
#define OBJECT_H

#include "particle.h"
#include <QtGui/qpainter.h>
#include <QColor>

class Object
{
public:
    Object() = default;

    template <typename... Particles>
    Object(QColor color, Particles&&... particles)
        : color(color)
    {
        (addParticle(std::make_unique<Particle>(particles)), ...);
        computeMass();
    }

    float mass;
    QColor color;
    std::vector<std::unique_ptr<Particle>> particles;
    inline void addParticle(std::unique_ptr<Particle> particle) { particles.push_back(std::move(particle)); }

    void render(QPainter *painter, const std::function<Vec2(const Vec2&)>& worldToView);

private:
    void computeMass() {
        mass = 0;
        for (const auto& particle : particles) {
            if (particle) {
                mass += particle->mass;
            }
        }
    }
};

#endif // OBJECT_H