Partially click-through transparent window ontop of desktop using OpenGL

Question

I want to render graphics seemingly on top of the Windows desktop. There are a lot of solutions for rendering transparent and click-through windows. However, I want some of the rendered sprites to be clickable. How would I got about doing this?

I'm using C# on Windows and was planning to use OpenTK. If this is unfeasible please explain.

Answer 1

No "clean" solution for this if you want it to work in semitransparent areas. The usual solution would be to determine which window lies directly beneath the clicked position and send it a synthetic click event message.

If all you're interested in is giving your window a solid shape, you can use the XShape (on X11) extension or use SetWindowRgn to cut out from the "sensitive" area of your window, which clicks will practically "fall through" to what's beneath.