Ytukyg

I am interested in the line-to operation |- (or -| ) with rounded corner. Now, I would like to add a node on the rounded corner. But the node then appears not on the rounded corner -- it is rather on the `original corner'. How to force this node to be on the line?

Here is an MWE

documentclass{article}

usepackage{tikz}



begin{document}

begin{tikzpicture}

draw (0,0)|-node{mid}(2,3);

end{tikzpicture}

begin{tikzpicture}

draw [rounded corners=1cm] (0,0)|-node{mid}(2,3);

end{tikzpicture}

end{document}

This gives the output

I know it can be done with to and also with controls (though I couldn't get the desired result without a bit of tweaking)

I feel tweaking is not the right thing to do. It is like doing paint in tikz; if we are doing tweaking, why not draw on a WYSIWYG drawing software or geometry software and export?

So, my question is
Is there any way to put a node exactly on a rounded corner?

(preferably without using to or controls; but if you can do them in a rather neat way, you are more than welcome)

Oh, I almost forgot. Just being curious, is there a name for this |- or -| operation?

Thank you

This depends a bit on what do you intend for "middle"; I would use intersections generally. In this example, I am using as "middle point" the intersection of the curved path and the rectangle formed by the two parts for the red dot, and with a 45 degree angle in the case of the blue one.

documentclass{article}

usepackage{tikz}

usetikzlibrary{calc, intersections}

begin{document}

begin{tikzpicture}

    draw (0,0)|-node{mid}(2,3);

end{tikzpicture}quad

begin{tikzpicture}

    draw [rounded corners=1cm] (0,0)|-node{mid}(2,3);

end{tikzpicture}quad

begin{tikzpicture}

    coordinate (one) at (0,0);

    coordinate (two) at (2,3);

    draw [rounded corners=1cm, name path=A] (one)|-(two);

    % remove draw=red

    path [draw=red, name path=B] (one -| two) -- (two -| one);

    coordinate[name intersections={of=A and B, by=DOT}];

    node [circle, red, fill] at (DOT){};

end{tikzpicture}quad

begin{tikzpicture}

    coordinate (one) at (0,0);

    coordinate (two) at (2,3);

    draw [rounded corners=1cm, name path=A] (one)|-(two);

    coordinate (mid) at  (one |- two);

    % remove draw=blue

    path [draw=blue, name path=B] (mid) -- ($(mid)+(1,-1)$);

    coordinate[name intersections={of=A and B, by=DOT}];

    node [circle, blue, fill] at (DOT){};

end{tikzpicture}

end{document}

You cal also use a decoration, but in this case you have to guessestimate the pos parameter:

documentclass{article}

usepackage{tikz}

usetikzlibrary{decorations.markings}

begin{document}

tikzset{markpos/.style args={#1 at #2}{decoration={

  markings,

  mark=at position #2 with {coordinate(#1);}},postaction={decorate}}}

begin{tikzpicture}

    draw (0,0)|-node{mid}(2,3);

end{tikzpicture}quad

begin{tikzpicture}

    draw [rounded corners=1cm] (0,0)|-node{mid}(2,3);

end{tikzpicture}quad

begin{tikzpicture}

    draw [rounded corners=1cm, markpos=mymark at 0.6] (0,0)|-node{mid}(2,3);

    node [circle, red, fill] at (mymark){};

end{tikzpicture}

end{document}

Here is a broad approach using node anchor that can certainly be improved:

documentclass{article}

usepackage{tikz}



    begin{document}

    begin{tikzpicture}

    draw (0,0)|-node{mid}(2,3);

    end{tikzpicture}

    begin{tikzpicture}

    draw [rounded corners=1cm] (0,0)|-node[below right]{mid}(2,3);

    end{tikzpicture}

 end{document}

You can use xshift and yshift to place the node properly. The value of these shifts can be obtained with simple geometry calculation.

  draw [rounded corners=rndc] (0,0)|-node[xshift=0.293*rndc),yshift=-0.293*rndc)]{mid}(2,3);

The number 0.293 is 1-1/sqrt(2).

The complete code

documentclass{article}

usepackage{tikz}

begin{document}

begin{tikzpicture}

  draw (0,0)|-node{mid}(2,3);

end{tikzpicture}

begin{tikzpicture}

  defrndc{1cm}

  draw [rounded corners=rndc] (0,0)|-node[xshift=0.293*rndc),yshift=-0.293*rndc)]{mid}(2,3);

end{tikzpicture}

end{document}