I'm so glad that you responded.
But, what I was asking was not that.
The width:height ratio of the screen is 4:3, of course (resolution 800x600).
But what I do not know is this:
If I see a plane as a dot on the right end of the screen (right beside the plastic monitor case),
what is the plane's position with respect to the direction of my plane's heading.
(I'm sorry, it is so hard for me to write in English.)
In other word, how far is the plane located from the guncross-line, in degrees.
What is the angle. (Can I say it as forward--aspect-angle?)
And what if the plane is on the top of the screen.
Please...
[This message has been edited by Newbie1 (edited 12-29-1999).]