Highlight a part of a bounding box in Tikz. Use with \negativebox{x1,y1}{x2,y2} inside tikzpicture

negativebox.tex

\newcommand\negativebox[2]{%
	\def\opc{0.75}
	\def\opcol{white}
	% Left
	\fill[opacity=\opc, color=\opcol]
		let
			\p{sw} = (current bounding box.south west),
			\p{nw} = (current bounding box.north west),
			\p1 = (#1)
		in (\p{sw}) rectangle (\x1, \y{nw});%
	% Above
	\fill[opacity=\opc, color=\opcol]
		let
			\p{sw} = (current bounding box.south west),
			\p{ne} = (current bounding box.north east),
			\p1 = (#1),
			\p2 = (#2)
		in (\x1, \y2) rectangle (\x2, \y{ne});
	% Right
	\fill[opacity=\opc, color=\opcol]
		let
			\p{se} = (current bounding box.south east),
			\p{ne} = (current bounding box.north east),
			\p2 = (#2)
		in (\x2, \y{se}) rectangle (\p{ne});
	% Below
	\fill[opacity=\opc, color=\opcol]
		let
			\p{sw} = (current bounding box.south west),
			\p{nw} = (current bounding box.north west),
			\p1 = (#1),
			\p2 = (#2)
		in (\x1, \y{sw}) rectangle (\x2, \y1);
}