Trouble with glReadPixels

[Schlogenburg]

Can someone tell me the useage of glReadPixels? Here's my simple
requirements:

read from RED(0-255 colors)
read one single pixel
return it to an integer called 'select'

[DFrey]

Well, it is very simple:

glReadPixels(x,y,1,1,GL_RED,GL_INT,&select);

But also be sure you use glReadBuffer to read from the correct buffer. Also watch out for dithering artifacts if you are using this method to select polys. I think it would be better to use either the selection buffer or your own collision detection for selection code.