I’ve come across another problem in my SDL project. My approach is to set window as borderless and fully transparent and draw my own window in OpenGL. Unfortunately, using SDL_SetWindowOpacity I set opacity for window and everything that’s inside it. I tried retrieving hwnd info and set transparency by “SetLayeredWindowAttributes” but it does the same. Everything I want to achieve are rounded window edges. Tried to google my problem and find anything related to my problem in SDL 2.0 documentation but didn’t manage to solve it.