Messages

1

Graphics / [SOLVED]Is it possible to batch lines?

« on: November 18, 2021, 11:58:31 am »

Is it possible to draw the lines that I created with the Vertex Array in a one draw call, instead of drawing them individually?

Edit: Yes it is possible. It was not nice of me to open a topic like this without being sure. I apologize in advance. 

2

General / How to implement sprite group?

« on: January 10, 2020, 12:04:44 pm »

I wanna try implement sprite group as in pygame. I acted according to this article, but I confused. Firstly, I don't understand how to pass Drawable object to group. I typed the code as following:

struct Group : public sf::Drawable {
    std::vector<std::reference_wrapper<const sf::Drawable>> sprites;

    Group() : sprites{} {}
   
    virtual ~Group() = default;

    virtual void draw(sf::RenderTarget& target, sf::RenderStates states) const {
        for(const auto& sprite : sprites){
            target.draw(sprite, states);
        }
    }

    const sf::Drawable& operator[](std::size_t index){
        return sprites[index];
    }

    std::size_t add(const sf::Drawable& sprite){
        sprites.push_back(sprite);
        return sprites.size() - 1;
    }

    const sf::Drawable& remove(){
        const auto& sprite = sprites.back();
        sprites.pop_back();
        return sprite;
    }
};


struct Box : public sf::Drawable, public sf::Transformable{
    sf::Texture texture;
    std::vector<sf::Vertex> vertices;
    sf::PrimitiveType m_type;

    virtual void draw(sf::RenderTarget &target, sf::RenderStates states) const{
        states.transform *= getTransform();
        states.texture = &texture;
        target.draw(&vertices[0], vertices.size(), m_type, states);
    }

    Box(const std::string path, sf::PrimitiveType type, int length, float *coords){
        for(int i = 0; i < length * 2; i++){
            vertices.push_back(sf::Vertex(sf::Vector2f(coords[i], coords[i+1]),sf::Vector2f(coords[i], coords[i+1])));
            i++;
        }

        if(!texture.loadFromFile(path)){
            std::cerr << "Failed to loading file!" << std::endl;
        }

        m_type = type;
    }
};



float coords[] = {
    0.0f,   0.0f,
    32.0f,  0.0f,
    32.0f,  32.0f,
    0.0f,   32.0f,
};

int main()
{
    Group spriteGroup;

    sf::RenderWindow window(sf::VideoMode(640, 480), "SFML works!");
   
    std::vector<Box> boxes;

    for(int i=0; i < 10; i++){
        boxes.push_back(Box("../resources/box.png", sf::Quads, 4, coords));
        spriteGroup.add(boxes[i]);
    }

    while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
        }
        window.clear(sf::Color::White);
        window.draw(spriteGroup[1]);
        window.display();
    }


    return 0;
}

In addition, I got these runtime errors:

pure virtual method called
terminate called without an active exception
Aborted (core dumped)