Sum Gai

distort this was a bit too imprecise, and the window it brings up first does not display the rest of the visible image, with no way to display it to more easily line things up, and the image in the opened window does not update along with the adjustments displayed on the main image. And I've tried Perspective transform, but again, it's not precise enough for what I need. Honestly, a control scheme with actual feedback like from Grip Warp would be perfect if it also could show the full image, and if it had a way to keep the edges straight instead of curving things at the edges.

See title. I'm looking for something that will let me grab the corners to skew the image, preferably while still showing the background/full image so I can more readily transform the selection to match up with the layer beneath. I've already tried quadrilateral correction, TR's distort this, Perspective, and I think a couple others, but they all rely on either using sliders, are too imprecise, do not show the background, or simply do not do what I am looking for. If I had to describe what I want to do with this, I'd like to take a square image and be able to perspective transform one corner at a time to match it up with a rhombus shaped window pane or TV screen so that the transformed image is now fitting perfectly inside, with the image contents skewed to match the new angle. So far, everything I's tried hasn't worked, so I figured I'd try asking directly instead of trying to find someone looking for something similar in the archives. Would anyone know of an addon that can let me do this with a high degree of precision, and let me see the full image outside the selection so I can actually line things up? Otherwise, I'll just have to deal with constantly importing/exporting between paint and gimp whenever I want a perspective transform.