Screen pixel to its location in global coordinate.

OpenGL OpenGL: Basic Coding
1

How can I translate a position (x, y) on screen to its global match (x, y, 0)? (suppose z = 0).

Thank you

2

I found the answer my self.
Using gluUnproject(…)

Originally posted by jxruan:
[b]How can I translate a position (x, y) on screen to its global match (x, y, 0)? (suppose z = 0).

Thank you[/b]