void render()
{
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  const glm::mat4 mvp = camera.transformation();

  suzanne1->draw(mvp);
  teapot1->draw(mvp);
  bunny1->draw(mvp);

  glEnable(GL_STENCIL_TEST);
  glStencilFunc(GL_ALWAYS, 1, 0xFF);
  glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
  glStencilMask(0xFF);
  glDepthMask(GL_FALSE);
  glClear(GL_STENCIL_BUFFER_BIT);

  mirror1->draw(mvp);

  glStencilFunc(GL_EQUAL, 1, 0xFF);
  glStencilMask(0x00);
  glDepthMask(GL_TRUE);

  const glm::mat4 mirror_mvp = glm::scale(camera.transformation(), glm::vec3(1.0f, 1.0f, -1.0f))
    * glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, 0.0f, 10.0f));

  suzanne1->draw(mirror_mvp);
  teapot1->draw(mirror_mvp);
  bunny1->draw(mirror_mvp);

  glDisable(GL_STENCIL_TEST);
}