OpenGL particle system

I’m really new with OpenGL, so bear with me.

I’m trying to simulate a particle system using OpenGl but I can’t get it to work, this is what I have so far:

    #include <GL/glut.h>
    int main (int argc, char **argv){
    
      // data allocation, various non opengl stuff
      ............
      glutInit(&argc, argv);
      glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE );
      glutInitWindowPosition(100,100);
      glutInitWindowSize(size, size);
      glPointSize (4);
      glutCreateWindow("test gl");
      ............
      // initial state, not opengl
      ............
      glViewport(0,0,size,size);
      glutDisplayFunc(display);
      glutIdleFunc(compute);
      glutMainLoop();
     
    
    }
    
    void compute (void) {
    
     // change state not opengl
    
      glutPostRedisplay();
    
    }
    
    void display (void) {
    
      glClear(GL_COLOR_BUFFER_BIT);
      glBegin(GL_POINTS);
      
      for(i = 0; i<nparticles; i++) {
        
        // two types of particles
        if (TYPE(particle[i]) == 1) glColor3f(1,0,0);
    	  else glColor3f(0,0,1);
    	
        glVertex2f(X(particle[i]),Y(particle[i]));
    
      }
      
      glEnd();
      glFlush();
      glutSwapBuffers();
    
    }

I get a black window after a couple of seconds (the window has just the title bar before that). Where do I go wrong? Any help would be very much appreciated. Thanks.

The x and y coordinates of each particle are within the interval (0,size)

There are a number of things wrong here

1. You should always call gl functions after calling glutCreateWindow. Here u r calling glPointSize before this call.
2. You have not setup ur projection matrix, modelview matrix .

Most particle systems use GL_POINT_SPRITES instead of GL_POINTS. Also, use the alpha channel to simulate fading out of particles.