Messages

1

Window / Event handling in multiple threads.

« on: March 15, 2015, 08:44:55 pm »

I've seen that when handling events normally in one thread my game goes to several problems: for example, if mouse is moving, the continuous key pressing is not detected. This is because all the handling is in one window class, with one sf::Event object. But how to make it happen in multiple threads, with multiple event objects, for example one thread handles keyboard, another thread mouse?

2

General / Re: error: class sf::Window has no member named...

« on: March 02, 2015, 08:19:42 pm »

Thanks! so small difference that i have not even noticed 

3

General / error: class sf::Window has no member named...

« on: March 01, 2015, 10:55:40 am »

Hello.
I was trying to run this code from Laurent Gomilla's Github. However, for every method of every sfml class this error shows up (class sf::... has no member named...). I have all libraries linked statically, and everything was working before trying this code. The code:

////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Window.hpp>
#include <SFML/OpenGL.hpp>


////////////////////////////////////////////////////////////
// Put here the exported GIMP image array!
////////////////////////////////////////////////////////////

int main()
{
    // Create the main window
    sf::Window window(sf::VideoMode(640, 480, 32), "SFML Window", sf::Style::Default, sf::ContextSettings(32));
    window.SetFramerateLimit(60);

    ////////////////////////////////////////////////////////////
    /// This line is added! Make sure the name of your image is the same
    ///
    //window.SetIcon( sfml_icon.width,  sfml_icon.height,  sfml_icon.pixel_data );
    ///
    ////////////////////////////////////////////////////////////

    // Create a clock for measuring the time elapsed
    sf::Clock clock;

    // Set the color and depth clear values
    glClearDepth(1.f);
    glClearColor(0.f, 0.f, 0.f, 0.f);

    // Enable Z-buffer read and write
    glEnable(GL_DEPTH_TEST);
    glDepthMask(GL_TRUE);

    // Setup a perspective projection
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(90.f, 1.f, 1.f, 500.f);

    // Start the game loop
    while (window.IsOpened())
    {
        // Process events
        sf::Event event;
        while (window.PollEvent(event))
        {
            // Close window : exit
            if (event.Type == sf::Event::Closed)
                window.Close();

            // Escape key : exit
            if ((event.Type == sf::Event::KeyPressed) && (event.Key.Code == sf::Key::Escape))
                window.Close();

            // Resize event : adjust viewport
            if (event.Type == sf::Event::Resized)
                glViewport(0, 0, event.Size.Width, event.Size.Height);
       }

        // Activate the window before using OpenGL commands.
        // This is useless here because we have only one window which is
        // always the active one, but don't forget it if you use multiple windows
        window.SetActive();

        // Clear color and depth buffer
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        // Apply some transformations
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        glTranslatef(0.f, 0.f, -200.f);
        glRotatef(clock.GetElapsedTime() * 0.05f, 1.f, 0.f, 0.f);
        glRotatef(clock.GetElapsedTime() * 0.03f, 0.f, 1.f, 0.f);
        glRotatef(clock.GetElapsedTime() * 0.09f, 0.f, 0.f, 1.f);

        // Draw a cube
        glBegin(GL_QUADS);

            glColor3f(1.f, 0.f, 0.f);
            glVertex3f(-50.f, -50.f, -50.f);
            glVertex3f(-50.f,  50.f, -50.f);
            glVertex3f( 50.f,  50.f, -50.f);
            glVertex3f( 50.f, -50.f, -50.f);

            glColor3f(1.f, 0.f, 0.f);
            glVertex3f(-50.f, -50.f, 50.f);
            glVertex3f(-50.f,  50.f, 50.f);
            glVertex3f( 50.f,  50.f, 50.f);
            glVertex3f( 50.f, -50.f, 50.f);

            glColor3f(0.f, 1.f, 0.f);
            glVertex3f(-50.f, -50.f, -50.f);
            glVertex3f(-50.f,  50.f, -50.f);
            glVertex3f(-50.f,  50.f,  50.f);
            glVertex3f(-50.f, -50.f,  50.f);

            glColor3f(0.f, 1.f, 0.f);
            glVertex3f(50.f, -50.f, -50.f);
            glVertex3f(50.f,  50.f, -50.f);
            glVertex3f(50.f,  50.f,  50.f);
            glVertex3f(50.f, -50.f,  50.f);

            glColor3f(0.f, 0.f, 1.f);
            glVertex3f(-50.f, -50.f,  50.f);
            glVertex3f(-50.f, -50.f, -50.f);
            glVertex3f( 50.f, -50.f, -50.f);
            glVertex3f( 50.f, -50.f,  50.f);

            glColor3f(0.f, 0.f, 1.f);
            glVertex3f(-50.f, 50.f,  50.f);
            glVertex3f(-50.f, 50.f, -50.f);
            glVertex3f( 50.f, 50.f, -50.f);
            glVertex3f( 50.f, 50.f,  50.f);

        glEnd();

        // Finally, display the rendered frame on screen
        window.Display();
    }

    return EXIT_SUCCESS;
}

4

System / Re: High CPU usage when using Threads!

« on: February 25, 2015, 05:59:27 pm »

Now i added sf::sleep to the event checking thread.

But there is weird thing: when using  sf::sleep(sf::microseconds(1000)), or 1 millisecond, CPU usage goes down to zero, perfectly good.

But when sleeping for less than 1 millisecond, for example sf::sleep(sf::microseconds(900)), then CPU usage jumps as high as 25% !!!

How so small change in sleep time can make CPU usage so high? This might be a SFML bug.

5

System / High CPU usage when using Threads!

« on: February 25, 2015, 03:07:05 pm »

Hello.

I'm using SFML threads, and this makes very high CPU usage.  Windows task manager is used to measure the CPU usage.

When only main thread is running, CPU usage is only 1 %, but when 2 threads run, CPU gets as high as 25 %, 3 threads - 50% and so on!!

My CPU has 4 cores, so it seems that each additional thread consumes the whole core!

Why this happens, with 1 thread adding 25% CPU?

It's nothing related to the framerate or sf::sleep(), they make no effect to CPU.

There's a little experimental program which shows everything. When running this code CPU is 25%.
When using addidional threads (commented) then goes as high as 75 %.

    #include <iostream>
    #include <string>
    #include <fstream>
    #include <SFML/Graphics.hpp>
    #include <SFML/System.hpp>

    using namespace std;

    sf::RenderWindow window;
    sf::Event ev;

    bool areEvents=false;
    bool Window_Closed=false;


    void drawZumthin()
    {
    for(int i=0; i<4; i++)
    {
        sf::CircleShape shape(50);
        shape.setFillColor(sf::Color::Green);
        shape.setPosition(i*100,0);

        window.draw(shape);
    }
    }

    void threadOne(int num)
    {
    long i=0;
    while(1)
    {
        if(i==0) cout<<"Thread no. "<<num<<endl;
        //sf::sleep(sf::milliseconds(20));
        i++;
    }
    }

    struct Chunk
    {
    int type;
    int tiles[64];
    };

    void loadNewChunks()
    {
    cout<<"Loading Chunks\n";

    Chunk chunks[25];

    for(int i=0; i<25; i++)
    {
        chunks[i].type=i;

        for(int j=0; j<64; j++)
        {
            chunks[i].tiles[j]=j-i;
        }
    }
    }

    void startWind()
    {
    window.create(sf::VideoMode(400,300),"test");
    window.setFramerateLimit(60);

    while(window.isOpen())
    {
        while(window.pollEvent(ev))
        {
            areEvents=true;

            if(ev.type==sf::Event::Closed)
            {
                window.close();
                Window_Closed=true;
            }
        }

        window.clear();

        drawZumthin();

        window.display();
    }
    }

    void getEvents()
    {
    cout<<"getEvents started\n";
    while(!Window_Closed)
    {
        if(areEvents)
        {
            bool newChunk=false;

            if(ev.type==sf::Event::TextEntered)
            {
                if(char(ev.text.unicode)=='w') cout<<"\nUp!\n\n";
                if(char(ev.text.unicode)=='s') cout<<"\nDown!\n\n";
                if(char(ev.text.unicode)=='a') cout<<"\nLeft!\n\n";
                if(char(ev.text.unicode)=='d') cout<<"\nRight!\n\n";

                newChunk=true;
            }

            if(newChunk) loadNewChunks();

            areEvents=false;
        }
    }
    cout<<"GetEvents Stopped.\n";
    }

    int main()
    {
    /*cout<<"Launching experimental threads\n";

    sf::Thread thr2(threadOne, 1);
    sf::Thread thr3(threadOne, 2);
    thr2.launch();
    thr3.launch();*/

    cout<<"Launching startWind()\n";

    sf::Thread thr1(startWind);

    thr1.launch();

    sf::sleep(sf::seconds(2));

    getEvents();

    return 0;
    }

   

Please help me with this issue. Thanks!

6

Window / How to make window fixed size (cant be resized)?

« on: October 22, 2014, 07:38:01 pm »

I cant find how to do it. My program window needs to be always 800x600, and i dont want it to allow resizing, because resizing causes bugs in my program.

7

Graphics / Set size of the sprtite

« on: September 08, 2014, 04:48:10 pm »

Hello! I need to set the the specific size of the sprite. SetScale() is not a solution there, because sprite may come in unknown dimensions, and program must resize it to lets say 160x100. What to do???