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Help => General => Topic started by: Mortal on January 19, 2016, 01:10:58 am

Title: How to swap the transform of two objects[Solved]
Post by: Mortal on January 19, 2016, 01:10:58 am

i'm facing problem with swapping transform(position, scale, rotate) of two object of same type that has transformable member data. i can do it by swapping each of them manually but i think this is noneffective. if i understood it correctly, i think this can be done by std::swap or by "=operator" which is used copy constructor of each given objects and their transform to the new object.

 here example that supposed to work but it didn't.

#include <SFML/Graphics.hpp>

class Tile : public sf::Drawable
{
public:
        Tile(const sf::Texture& texture)
                : mSprite(texture)
                , mTransform()
        {
        }
        ~Tile() = default;

        Tile(const Tile& othher)
                : mSprite(othher.mSprite)
                , mTransform(othher.mTransform)
        {
        }

        Tile& operator=(Tile other) noexcept
        {
                other.swap(*this);
                return *this;
        }

        //Tile(Tile&& other)
        //{
        //      swap(*this, other);
        //}
        //Tile& operator=(Tile&&) = default;

        void swap(Tile& other) noexcept
        {
                using std::swap;

                swap(mTransform, other.mTransform);
                swap(mSprite, other.mSprite);

        }

        friend void swap(Tile& lhs, Tile& rhs) noexcept
        {
                using std::swap;
                swap(lhs.mTransform, rhs.mTransform);
                swap(lhs.mSprite, rhs.mSprite);
        }

        void setPosition(float x, float y)
        {
                mTransform.setPosition(x, y);
        }

        void setPosition(sf::Vector2f pos)
        {
                mTransform.setPosition(pos);
        }

        sf::Vector2f getPosition() const
        {
                return mTransform.getPosition();
        }

        void draw(sf::RenderTarget& target, sf::RenderStates states) const
        {
                states.transform = mTransform.getTransform();
                target.draw(mSprite, states);
        }


private:
        sf::Sprite mSprite;
        sf::Transformable mTransform;
};

int main()
{
        sf::RenderWindow window(sf::VideoMode(480u, 480u), "Tile tut");
        window.setVerticalSyncEnabled(true);

        sf::Texture texture1, texture2;
        if (!texture1.loadFromFile("0.png"))
                return 1;

        if (!texture2.loadFromFile("1.png"))
                return 1;

        Tile tile1(texture1), tile2(texture2);

        tile1.setPosition(100.f, 120.f);
        tile2.setPosition(100.f + texture1.getSize().x, 120.f);

        bool toggle = false;

        while (window.isOpen())
        {
                sf::Event event;
                while (window.pollEvent(event))
                {
                        if (event.type == sf::Event::Closed)
                                window.close();

                        else if (event.type == sf::Event::KeyPressed)
                        {
                                if (event.key.code == sf::Keyboard::Space)
                                {
                                        toggle = !toggle;
                                }
                        }
                }

                if (toggle)
                {
                        toggle = false;

                        // normal position swap works fine:~ do same thing for rotate and scale
                        //auto pos = tile1.getPosition();
                        //tile1.setPosition(tile2.getPosition());
                        //tile2.setPosition(pos);


                        // doesn't works
                        //auto tile = tile1;
                        //tile1 = tile2;
                        //tile2 = tile;
                       
                        //tile1.swap(tile2); // doesn't works
                        //std::swap(tile1, tile2); // doesn't works
                }

                window.clear();
                window.draw(tile1);
                window.draw(tile2);
                window.display();
        }
}

how to fixed this it, did i miss something that i should take care of?

Edit
sorry it seems the problem with sf::sprite's texture not with tansform, i fixed it