OpenGL crosshair

crosshair.c

void draw_crosshair() {
  /* Draws a crosshair in the center of the screen */
  glDisable(GL_DEPTH_TEST);
  glDisable(GL_LIGHTING);

  glMatrixMode(GL_PROJECTION);
  glPushMatrix();
    glLoadIdentity();
    gluOrtho2D(0, width, height, 0);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    // Draw a (colour) inverted cross (not satanic)
    glEnable(GL_COLOR_LOGIC_OP);
    glLogicOp(GL_INVERT);
    glTranslatef(width/2-10,height/2-10, 0);
    glLineWidth(2);
    glBegin(GL_LINES);
      glVertex3f(10.0f, 20.0f, 0.0f);
      glVertex3f(10.0f, 0.0f, 0.0f);
      glVertex3f(0, 10, 0.0f);
      glVertex3f(20, 10, 0.0f);
    glEnd();
    glDisable(GL_COLOR_LOGIC_OP);

    glMatrixMode(GL_PROJECTION);
  glPopMatrix();

  glEnable(GL_DEPTH_TEST);
  glEnable(GL_LIGHTING);
  glMatrixMode(GL_MODELVIEW);
}