Posted by Art on Apr 20, 2016; 2:56pm
URL: https://forum.jogamp.org/Get-pixel-Coordinates-tp4036625p4036635.html

The link I posted has code that does unproject. Which is converting from screen to world coordinates. All you have to do is create methods, like the unproject ones, using glProject instead. They take a few different parameters, but are essentially the same.