Missing example: mouse cursor position to render position

[ethereumdegen]

I cant figure out how to get the current mouse position and create a window/widget at the mouse position (like a windows right-click menu).

pub fn get_ui_cursor_position(window: &Window) -> Option {

   let size = Vec2::new(window.width(), window.height());

    let mut pos = window.cursor_position()? ;
   
    
    Some(Vec2::new(  pos.x,  - pos.y   ))

}

I use this and then render to the result and it KIND of works but it is offset by a weird ratio related to the window height. The X is good but the Y is totally off. Also i dont understand why I have too inverse the Y. It seems like getting the cursor position is inverted to the rendering of a window but then also skewed by the window height i am just so confused.