texture question

I have mapped texture on a 2D polygon. Is it possible to get the RGB values of a particular point in the polygon.

Only by reading from the frame buffer. There are several ways of doing this one is to use glReadPixels

I find difficulty in using glReadPixels. Could you give some sample code?

try
http://ogldev.atspace.co.uk/www/tuto...utorial29.html

This site has a lot of good tutorials