L-Tromino by using Tables with zero padding

Question

I want to display a L-Tromino. L-tromino is a shape consisting of three equal squares joined at the edges to form a shape resembling the capital letter L. I have tried

\begin{array}{cc} \square& \\ \square&\square\end{array}

but this contains paddings. How can I use zero padding for a 2x2 table?

Answer 1

\documentclass{article}
\usepackage{array,amssymb,tikz,graphicx}%  
\begin{document}

Using \verb|tabular|:
  \scalebox{.6}{%
  \begin{tabular}{|c|c}\cline{1-1}
     & \\\hline
     & \multicolumn{1}{c|}{} \\\hline
  \end{tabular}} 
  Compare the size with that of \verb|\square| : $\square$

  Using \verb|TikZ| %% (just for fun as many of us are obsessed with tikz):
  \begin{tikzpicture}[scale=.5]
    \draw[thick] (0,0) -- (1,0) -- (1,.5) -- (0,.5) -- cycle;
    \draw[thick] (0,.5) -- (0,1) -- (.5,1) -- (.5,0);
  \end{tikzpicture}
\end{document}

PS: The size has been reduced using \scalebox from graphicx. In tikz, the option scale is used.

If you are using them frequently, you can define a macro as in

\documentclass{article}
\usepackage{array,amssymb,tikz,graphicx}% 
%
\newcommand{\Ltromino}{%
  \scalebox{.6}{%
  \begin{tabular}{|c|c}\cline{1-1}
     & \\\hline
     & \multicolumn{1}{c|}{} \\\hline
  \end{tabular}}
  }
%
\newcommand{\LTromino}{%
  \begin{tikzpicture}[scale=.5]
    \draw[thick] (0,0) -- (1,0) -- (1,.5) -- (0,.5) -- cycle;
    \draw[thick] (0,.5) -- (0,1) -- (.5,1) -- (.5,0);
  \end{tikzpicture}
  }

\begin{document}
Using \verb|tabular|:

  \Ltromino

Compare the size with that of \verb|\square| : $\square$

Using \verb|TikZ|:

  \LTromino
\end{document}

Answer 2

\begin{array}{@{} c @{} c @{}} 
  \square & \\ 
  \square & \square
\end{array}

Answer 3

Of course, the additional spaces of the array/tabular can be minimized to zero:

\documentclass[12pt]{article}
\usepackage{amssymb}
\usepackage{color}

\setlength{\parskip}{1ex}

\begin{document}

$
\renewcommand*{\arraystretch}{0}
\begin{array}{@{}c@{}c@{}}
  \square & \\
  \square & \square
\end{array}
$

\begingroup
  \renewcommand*{\arraystretch}{0}%
  \setlength{\tabcolsep}{0pt}%
  \setlength{\mathsurround}{0pt}%
  \begin{tabular}{cc}
    $\square$ &\\
    $\square$ & $\square$
  \end{tabular}%
\endgroup

\setlength{\fboxsep}{0pt}
\fbox{\textcolor{red}{$\square$}}

\end{document}

But that does not solve your problems:

• The character box is larger than the character itself. The black \fbox frame is wider than the red \sqare. These white spaces are called left and right side bearings. The values of these are unkown in TeX.

• The upper line of the left lower box and the lower line of the upper box make a horizontal line with double line width. Also the line width of the glyph is not known in TeX.

Therefore I would do the drawing by graphics. An example for tikz that also allows rounded corners:

\documentclass[12pt]{article}
\usepackage{amssymb}

\usepackage{tikz}

\newdimen\squareunit
\newdimen\squarelinewidth 
\newcommand*{\BaseSquare}[1]{%
  \begingroup
    \settoheight{\squareunit}{$\square$}%
    \setlength{\squarelinewidth}{.055\squareunit}%
    \addtolength{\squareunit}{-\squarelinewidth}%
    \begin{tikzpicture}[
      x=\squareunit,   
      y=\squareunit,
      line width=\squarelinewidth,
      line join=round,
    ]
      \draw[line join=round]#1;%
    \end{tikzpicture}%
  \endgroup
}   
\newcommand*{\Square}{%
  \BaseSquare{(0,0) rectangle (1,1)}%
}

\newcommand*{\Ltromino}{%
  \BaseSquare{%   
    (0,0) -- (2,0) -- (2,1) -- (1,1) -- (1,2) -- (0,2) -- cycle
    (0,1) -- (1,1) -- (1,0)
  }%
}   

\newcommand*{\ltromino}{%
  \BaseSquare{%
    (0,0) -- (1,0) -- (1,3) -- (0,3) -- cycle
    (0,1) -- (1,1)
    (0,2) -- (1,2)
  }%
}

\begin{document}

$\square$\,\Square\,\Ltromino\,\ltromino

\end{document}