I use the KOMA scrreprt document class and I specify a BCOR. Now I want to draw with a TikZ overlay, which respects the BCOR.
My command to get the BCOR setting is the following. Maybe that can be improved?
Anyways, now I want to draw 1cm from the page border plus BCOR. I tried:
\draw[semithick,rounded corners=0.5cm] ($(current page.north west) + ( 1cm,-1cm) + (\myBCOR,0)$) -- ($(current page.north east) + (-1cm,-1cm)$) -- ($(current page.south east) + (-1cm, 1.5cm)$);
However, this gives the error
Missing number, treated as zero.
I found nothing on how to integrate commands into coordinate calculations.