GLFW frame rate

[bigadel]

Hi All,

I am actually working on a simulation to draw little cube.

I would like to fix the frame rate of the display.

I've got the idea of creating a timer which will call glswapbuffer every xx time but it seems not to work.

Here is the code :

#include "main.h"



//----------------------------------------------------------------------
// openWindow() - Open a window to render.
//----------------------------------------------------------------------

int openWindow(void)
{
int ok = 0;

    ok = glfwOpenWindow(
        640, 480,          // Width and height of window
        8, 8, 8,           // Number of red, green, and blue bits for color buffer
        8,                 // Number of bits for alpha buffer
        24,                // Number of bits for depth buffer (Z-buffer)
        0,                 // Number of bits for stencil buffer
        GLFW_WINDOW        // We want a desktop window (could be GLFW_FULLSCREEN)
    );
    
return ok;
}




//----------------------------------------------------------------------
// initCamera() - Initialisation of view and camera system.
//----------------------------------------------------------------------
void initCamera(void)
{
    int    width, height;  // Window dimensions

 // Get window size
    glfwGetWindowSize( &width, &height );

    // Make sure that height is non-zero to avoid division by zero
    height = height < 1 ? 1 : height;

    // Set viewport
    glViewport( 0, 0, width, height );

    // Clear color and depht buffers
    glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

    // Set up projection matrix
    glMatrixMode( GL_PROJECTION );    // Select projection matrix
    glLoadIdentity();                 // Start with an identity matrix
    gluPerspective(                   // Set perspective view
        85.0,                         // Field of view = 65 degrees
        (double)width/(double)height, // Window aspect (assumes square pixels)
        1.0,                          // Near Z clipping plane
        100.0                         // Far Z clippling plane
    );

    // Set up modelview matrix
    glMatrixMode( GL_MODELVIEW );     // Select modelview matrix
    glLoadIdentity();                 // Start with an identity matrix
    gluLookAt(                        // Set camera position and orientation
        0.0, 0.0, 20.0,               // Camera position (x,y,z)
        0.0, 0.0, 0.0,                // View point (x,y,z)
        0.0, 1.0, 0.0                 // Up-vector (x,y,z)
    );

}    






//----------------------------------------------------------------------
// draw() - Main OpenGL drawing function that is called each frame
//----------------------------------------------------------------------
 

void drawSim( void )
{

    // ****Draw a Grille which is fading***

    
    // Now draw the quad
    
    if(colorR>=1.00)
    {
        down = 1;
        up = 0 ;
    }
    else if (colorR <= 0)
    {
        down = 0;
        up = 1 ;
    }
    
    if(up == 1)
        colorR += 0.001;  
    else if (down == 1)
        colorR -= 0.001;
    
    
    Burn.setGlobalLightness(colorR);
    Burn.draw();     
    
}



//----------------------------------------------------------------------
// main() - Program entry point
//----------------------------------------------------------------------
int main( int argc, char **argv )
{
    int    ok;             // Flag telling if the window was opened
    int    running;        // Flag telling if the program is running

    int    frames;
	double fps, time, t0;
	char   title[150];

	frames = 0;
	t0 = glfwGetTime();


    // Initialize GLFW
    glfwInit();
 
    // Open window
    ok = openWindow();
    
    // If we could not open a window, exit now
    if( !ok )
    {
        glfwTerminate();
        return 0;
    }

    // Set window title
    glfwSetWindowTitle( "cube 1.0" );

    // Enable sticky keys
    glfwEnable( GLFW_STICKY_KEYS );
    
    //Initialize camera
    initCamera();


    // Main rendering loop
    do
    {
                //get the current time
        time = glfwGetTime();

		// Calcul and display the FPS
        if((time-t0) > 1.0 || frames == 0)
        {
            fps = (double)frames / (time-t0);
            sprintf(title, "cube 1.0 (%.1f FPS)", fps);
            glfwSetWindowTitle(title);
            t0 = time;
            frames = 0;
        }
        frames ++;
        
    

    
        // Call our rendering function
        drawSim();
                
        //Limit the frameRate to 60fps.
       glfwSwapInterval(1);
        
        
        // Swap front and back buffers (we use a double buffered display)
 
         glfwSwapBuffers();

        // Check if the escape key was pressed, or if the window was closed
        running = !glfwGetKey( GLFW_KEY_ESC ) &&
                  glfwGetWindowParam( GLFW_OPENED );
    }
    while( running );

    // Terminate GLFW
    glfwTerminate();

    // Exit program
    return 0;
}

I actually use glfwSwapInterval(1); so that it allows to get a fixed frame rate about 60fps. But i can not manage to do something else. Oh by the way, I would like to fixe the frame rate and in the same time do not stop the programm because I need to do other stuff before drawing my cube.

Thank you all !

I hope you will help

(sorry for the bad english)