title: OpenGL glRectf() not displaying
body: <p>glRectf() is not being displayed inside my window:</p>
  
  <pre><code>#include &lt;GL/gl.h&gt;
  #include &lt;GL/glut.h&gt;
  
  void renderScene(){
      glClearColor(0.0f,1.0f,1.0f,1.0f);
      glClear(GL_COLOR_BUFFER_BIT);
      glColor3f(1.0f,0.0f,0.0f);
      glRectf(225.0f,150.0f,150.0f,100.0f);
      glFlush();
  }
  
  int main(int argc, char*argv[]){
      glutInitDisplayMode(GLUT_SINGLE|GLUT_RGBA);
      glutInitWindowSize(450, 350);
      glutCreateWindow("My first OpenGL Program...took forever");
      glutDisplayFunc(renderScene);
      glutMainLoop();
      return 0;
  }
  </code></pre>