title: change the axis Y. From "bottom left" to "top left"? (opengl)
body: <p>change the axis Y. From "bottom left" to "top left"?
  Tried glScalef (1.f,-1.f, 1.f);
  But it turns everything upside down.
  How to make a
  glRectf (0,0,200,200);
  draw in the upper left corner instead of the bottom left?</p>