mjhjmtu

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

documentclassarticle
usepackagetikz

begindocument
begintikzpicture
draw (0,0)|-nodemid(2,3);
endtikzpicture
begintikzpicture
draw [rounded corners=1cm] (0,0)|-nodemid(2,3);
endtikzpicture
enddocument

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.

documentclassarticle
usepackagetikz
usetikzlibrarycalc, intersections
begindocument
begintikzpicture
 draw (0,0)|-nodemid(2,3);
endtikzpicturequad
begintikzpicture
 draw [rounded corners=1cm] (0,0)|-nodemid(2,3);
endtikzpicturequad
begintikzpicture
 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);
endtikzpicturequad
begintikzpicture
 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);
endtikzpicture
enddocument

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

documentclassarticle
usepackagetikz
usetikzlibrarydecorations.markings
begindocument
tikzsetmarkpos/.style args=#1 at #2decoration=
 markings,
 mark=at position #2 with coordinate(#1);,postaction=decorate
begintikzpicture
 draw (0,0)|-nodemid(2,3);
endtikzpicturequad
begintikzpicture
 draw [rounded corners=1cm] (0,0)|-nodemid(2,3);
endtikzpicturequad
begintikzpicture
 draw [rounded corners=1cm, markpos=mymark at 0.6] (0,0)|-nodemid(2,3);
 node [circle, red, fill] at (mymark);
endtikzpicture
enddocument

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

documentclassarticle
usepackagetikz

 begindocument
 begintikzpicture
 draw (0,0)|-nodemid(2,3);
 endtikzpicture
 begintikzpicture
 draw [rounded corners=1cm] (0,0)|-node[below right]mid(2,3);
 endtikzpicture
 enddocument

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

documentclassarticle
usepackagetikz
begindocument
begintikzpicture
 draw (0,0)|-nodemid(2,3);
endtikzpicture
begintikzpicture
 defrndc1cm
 draw [rounded corners=rndc] (0,0)|-node[xshift=0.293*rndc),yshift=-0.293*rndc)]mid(2,3);
endtikzpicture
enddocument