Posted by Wade Walker on Jul 15, 2015; 12:41am
URL: https://forum.jogamp.org/Showing-overview-of-image-viewer-tp4034879p4034902.html

Well, you could just render the overview in a second viewport with the camera much farther away and stationary, and put a square of 3D lines over that. If you have good mipmapping for all your textures this might get good performance. But I'm assuming your original image must be very large or you wouldn't have it tiled, so mipmapping all of these is probably not a good solution, since it'll just use up more texture memory :)