PreQiew object is a Pure Data abstraction let you have a preview window of the main Gem Window content. You can regulate the dimension of the preview. It works on GNU/linux systems and should (with a little effort) works on Mac. This abstraction uses pix_share_read/pix_share_write that are not supported on window.
The 0.2 version uses pd~ object.
For more infos and download go to planetQ