Tabularx alignment problem in the header with tikz figures and a diagonal line

Question

In a table created with tabularx of 6 columns and 7 rows (in the minimal example, I deleted some), I want to place figures created with tikz in the header.

These figures have already been defined and are used in another document. In order to be able to contain them in the header while being visible from the bottom of the class, I reduced them by a factor of 0.05.

By reducing this factor to 0.03, the problem disappears, but as a result the figures become too small to be visible from the back of the room.

In addition, I want to place the title of the header and the first column in the first cell at the top left separated by a diagonal.

I have tested the solutions to the following questions and none of them solve alignment problems.

• \def\tabularxcolumn#1{m{#1}} from Vertically center text in tabularx table
• \backslashbox from slashbox alternative
• makecell from slashbox alternative
• tikz from Diagonal lines in table cell But I didn't quite understand his code.

\documentclass[aspectratio=1610,10pt]{beamer} % Présentation générale et mise en page

\usepackage{tabularx}
\usepackage{tikz}           
\usepackage{slashbox,pict2e}

\usetheme{Warsaw}
\usefonttheme[onlymath]{serif}
\usecolortheme{dolphin}
\useoutertheme{infolines}       
\begin{document}

\def\tabularxcolumn#1{m{#1}}
\begin{frame}{Bilan}
\begin{tabularx}{7cm}{|c|*{2}{X|}}
\hline
\backslashbox{Unités}{Figures} %\rule[0pt]{0pt}{6mm} 
    & \centering\tikz[scale=.05]\draw[thick](0,0)--(6,6)--(0,12)--(0,18)--(6,12)--(12,12)--(18,18)--(18,12)--(12,6)--(18,0)--cycle;
    & \centering\tikz[scale=.05]\draw[thick](0,0)--(0,9)--(8,15)--(16,9)--(16,0)--cycle;
    \tabularnewline
\hline
$r_1$ \tikz[scale=.05]\draw(0,0)rectangle(6,3);&\rule[0mm]{0pt}{8mm} &  \tabularnewline
\hline
$t_1$ \tikz[scale=.05]\draw(0,0)--(3,3)--(6,0)--cycle;&\rule[0mm]{0pt}{8mm} &  \tabularnewline
\hline
\end{tabularx}

\end{frame}
\end{document}

How to make a correct diagonal line and center the figures correctly in the header without further reducing the size of the figures?

Translated with www.DeepL.com/Translator

Answer 1

The final problem was that the m{} column centers the contents offset by where it thinks the baseline should be, as does \backslashbox. When you scale \backslashbox, these compensations don't match.

This solution does not preserve the aspect ratio of \backslashbox, but is a lot simpler than adding \hspace{\tabcolsep} and @{} to both sides.

Removing the m{} column required adding this compensation to the \rule to center the next two rows.

\documentclass[aspectratio=1610,10pt]{beamer} % Présentation générale et mise en page

\usepackage{tabularx}
\usepackage{tikz}           
\usepackage{slashbox,pict2e}

\usetheme{Warsaw}
\usefonttheme[onlymath]{serif}
\usecolortheme{dolphin}
\useoutertheme{infolines}

\newlength{\offset}

\begin{document}

%\def\tabularxcolumn#1{m{#1}}
\begin{frame}{Bilan}
\sbox0{\raisebox{\dimexpr 0.5\depth-0.5\height}{\backslashbox{Unités}{Figures}}}% masuer width
\sbox1{\tikz[scale=.05,baseline=(current bounding box.center)]{\draw[thick](0,0)--(6,6)--(0,12)--(0,18)--(6,12)--(12,12)--(18,18)--(18,12)--(12,6)--(18,0)--cycle;}}% measure height (not quite .45cm)
\setlength{\offset}{\dimexpr 0.5\arraystretch\ht\strutbox-0.5\arraystretch\dp\strutbox}% offset from center to baseline
\begin{tabularx}{7cm}{|c|*{2}{X|}}
\hline
\resizebox{\wd0}{\ht1}{\usebox0}% scale to match height and not change width
    & \centering\usebox1
    & \centering\tikz[scale=.05,baseline=(current bounding box.center)]{\draw[thick](0,0)--(0,9)--(8,15)--(16,9)--(16,0)--cycle;}
    \tabularnewline
\hline
$r_1$  \tikz[scale=.05]{\draw(0,0)rectangle(6,3);} & \rule[\dimexpr \offset-4mm]{0pt}{8mm} & \\
\hline
$t_1$ \tikz[scale=.05]\draw(0,0)--(3,3)--(6,0)--cycle; & \rule[\dimexpr \offset-4mm]{0pt}{8mm} & \\
\hline
\end{tabularx}

\end{frame}
\end{document}

Answer 2

The package \diagbox solves your problem, because has height control; the slash is calculated to contain the pair of texts and the content of the next cells must be less height than these. In this case using \diagbox[height=4em]{Unités}{Figures} the height of the first cell is greater than the contents of the drawings in tikz...

RESULT:

MWE:

% arara: pdflatex: {synctex: yes, action: nonstopmode}
\documentclass[aspectratio=1610,10pt]{beamer} % Présentation générale et mise en page
\usepackage{tabularx}
\usepackage{tikz}           
\usepackage{diagbox,pict2e} %Change to diagbox that controls the height of te first cell
\usetheme{Warsaw}
\usefonttheme[onlymath]{serif}
\usecolortheme{dolphin}
\useoutertheme{infolines}       
\begin{document}
    \def\tabularxcolumn#1{m{#1}}
    \begin{frame}{Bilan}
    \begin{table}[!h]
        \centering
        \begin{tabularx}{7cm}{|c|*{2}{X|}}\hline
            %Row1
            \diagbox[height=4em]{Unités}{Figures} %\rule[0pt]{0pt}{6mm} 
            &\centering\tikz[scale=.05]\draw[thick](0,0)--(6,6)--(0,12)--(0,18)--(6,12)--(12,12)--(18,18)--(18,12)--(12,6)--(18,0)--cycle;
            &\centering\tikz[scale=.05]\draw[thick](0,0)--(0,9)--(8,15)--(16,9)--(16,0)--cycle;
            \tabularnewline
            \hline
            %Row2
            $r_1$ \tikz[scale=.05]\draw(0,0)rectangle(6,3);&\rule[0mm]{0pt}{8mm} &  \tabularnewline
            \hline
            $t_1$ \tikz[scale=.05]\draw(0,0)--(3,3)--(6,0)--cycle;&\rule[0mm]{0pt}{8mm} &  \tabularnewline
            \hline
        \end{tabularx}
    \end{table}

    \end{frame}
\end{document}

---

ADDENDUM:

From the package documentation diagbox there are more controls for vertical position tuning, and as I see there is nothing for the vertical position adjustment, so I try with \vspace{} but it does not work, however the classic line break adjustment as suggested by @marmot, is a good option.

RESULT:

MWE + marmot:

% arara: pdflatex: {synctex: yes, action: nonstopmode}
\documentclass[aspectratio=1610,10pt]{beamer} % Présentation générale et mise en page
\usepackage{tabularx}
\usepackage{tikz}           
\usepackage{diagbox,pict2e} %Change to diagbox that control the height of te first cell
\usetheme{Warsaw}
\usefonttheme[onlymath]{serif}
\usecolortheme{dolphin}
\useoutertheme{infolines}  
\usepackage{tikzmarmots}     
\begin{document}
    \def\tabularxcolumn#1{m{#1}}
    \begin{frame}{Bilan}
    \begin{table}[!h]
        \centering
        \begin{tabularx}{7cm}{|c|*{2}{X|}}\hline
            %Row1
            \diagbox[
                height=4em,
                innerwidth=6em,
                innerleftsep=0.5em,
                innerrightsep=0.5em
            ]{Unités\\[0.5em]}{\\[-0.5em]Figures} %\rule[0pt]{0pt}{6mm} 
            &\centering\tikz[scale=0.5]\marmot[teeth,whiskers];
            &\centering\tikz[scale=.05]\draw[thick](0,0)--(0,9)--(8,15)--(16,9)--(16,0)--cycle;
            \tabularnewline
            \hline
            %Row2
            $r_1$ \tikz[scale=.05]\draw(0,0)rectangle(6,3);&\rule[0mm]{0pt}{8mm} &  \tabularnewline
            \hline
            $t_1$ \tikz[scale=.05]\draw(0,0)--(3,3)--(6,0)--cycle;&\rule[0mm]{0pt}{8mm} &  \tabularnewline
            \hline
        \end{tabularx}
    \end{table}

    \end{frame}
\end{document}

RESULT: