screen extrems of the geometry projected on the screen

Dear opengl Programmers,

Is it possible to find a bounding rectangle(minimum and maximum extreams) of an object projected on the screen. The minimum and maximum extreams have to be in pixels(screen coordinates).
Thanks in advance

It is possible!

One way is to iterate over the projected vertices and min/max them (see gluProject). But it really depends on how accurate a bound you need. Sometimes projecting a bounding box or a sphere is enough.