Slow Rendering in SFML

[starfruitinc]

Hello everyone,

I have been playing around with SFML for a game I am designing, but I came across a problem, of which I am unable to determine if it is the result of just my poor coding or if SFML is designed to be called a different way.

Currently, I have a class called Module and it is a container for some variables and a Sprite.

Code: [Select]


class Module {
    public:
        sf::Sprite s_module;
        std::vector<Module> children;
        void addModule();
        void moveFromSpeed(float, float);
        void drawAll(sf::RenderWindow &);
        void setImage(sf::Image & i_module);
};


Here are the methods

Code: [Select]

void Module::drawAll(sf::RenderWindow & App) {
    cout << "Drawing Self\t" << children.size() << " Children" << endl;
    App.Draw(s_module);
    cout << "Drawing Children" << endl;
    for (int i = 0; i < (int)children.size(); i++) {
        children[i].drawAll(App);
    }
}

void Module::addModule() {
    children.push_back(Module());
}

void Module::setImage(sf::Image & i_module) {

    //Set Sprite
    s_module.SetImage(i_module);
    s_module.SetBlendMode(sf::Blend::Alpha);
    s_module.SetPosition(x, y);
}

void Module::moveFromSpeed(float tvelx, float tvely) {
    //Uses the speed variables to move the ship
    x += tvelx;
    y += tvely;
    s_module.SetPosition(x,y);
    for (int i = 0; i < (int)children.size(); i++) {
        children[i].moveFromSpeed(tvelx, tvely);
    }
}

When I add Module classes to children, it slows down considerably. Around 30 children, it slows to maybe 5-10 fps.

Input is appreciated.

Thanks

[Laurent]

Using std::cout is very slow, have you tried without it?

[starfruitinc]

Wow. std::cout is VERY slow. I removed all lines with std::cout and there is a definite boost to the performance. Thank you very much

Is there a better way to output to the console without cout?

[Laurent]

Usually we do this for debugging, so we don't care about performances.

Why do you want to print to the console so many times per second and keep good performances??

[Serapth]

cout is not buffered on Windows.


Add:

char buf[1024];
setvbuf(stdout, buf, _IOLBF, 1024);


in your main() and you will see an order of magnitude increase in speed.  In my test, it went from 200FPS to 7-800FPS.

[starfruitinc]

It works very well, thank you very much for your help!

I'm using the output mainly for debugging right now, and I'm keeping a lot of verbose info on. I want it to run at full speed because it is a real time application. I will be removing the couts later.