I am a learner of OpenGL,and use it to write a full-screen programme with big scene,in which user can walk around.Now I want to add a compass(A box and Needle)at the right-top conner of the screen to indicate the direction.I known how to draw the appearance
of the compass but do not known how to make some setting before drawing the compass.
Can you give me some code or advice?Any help are appreciated!