%!TEX TS-program = pdflatexmk
%!TEX root = sketch.tex

% Copyright 2018 Martin Scheidt (ISC license)
% Permission to use, copy, modify, and/or distribute this file for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

% dimensons for signal construction
\def\length{2.0}
\def\height{1.5}
\def\thick{0.4}
\def\gap{0.05}
\def\depth{2.0}

\tikzset{
  block_signal/.pic={
    % frame 
    \draw [thick] ( -1.5,-2.0) -- ( 1.5,-2.0) -- (1.5,-4.0) -- (-1.5,-4.0) --cycle;
  };
}
\tikzset{
  block_signal_cross_section/.pic={
    % lever
    \draw [thick] (0,0) -- ++( 0,\height) -- ++(\thick,0) -- ++(0,-\height)
      -- ++(\length,0) -- ++(0,-\thick)  -- ++(-\length,0) -- ++(-\thick,0) -- ++(-\length,0)
      -- ++(0,\thick,0) -- cycle;
    % frame
    \draw [thick] (-\gap,\gap) -- ++(-\length,0)
      -- ++(0,-\gap) -- ++(0,-\thick) -- ++(0,-\gap) % inner height
      -- ++(\gap,0) -- ++(\length,0) -- ++(\length,0)  -- ++(\length,0) -- ++(\gap,0) % inner bottom
      -- ++(0,\gap) -- ++(0,\thick) -- ++(0,\gap) % inner height
      -- ++(-\length,0)
      -- ++(0,\thick)
      -- ++(\length,0) -- ++(\thick,0)
      -- ++(0,-\thick) -- ++(0,-\gap) -- ++(0,-\thick) -- ++(0,-\gap) -- ++(0,-\thick) % outer height
      -- ++(-\thick,0) -- ++(-\gap,0) -- ++(-\length,0) -- ++(-\length,0)  -- ++(-\length,0) -- ++(-\gap,0) -- ++(-\thick,0) % outer bottom
      -- ++(0,\thick) -- ++(0,\gap) -- ++(0,\thick) -- ++(0,\gap) -- ++(0,\thick) % outer height
      -- ++(\length,0) -- ++(\thick,0)
      -- cycle;
  };
}
\tikzset{
  block_signal_top_view/.pic={
    % lever
    \draw [thick] (0,0) rectangle ++(\thick,\depth);
    % frame
    \draw [thick] (-\gap,0) -- ++(-\length,0) -- ++(-\thick,0)
    -- ++(0,\depth)
    -- ++(\length,0) -- ++(\thick,0)
    -- cycle;
    \draw [thick] (\length,0) -- ++(\length,0) -- ++(\thick,0)
    -- ++(0,\depth)
    -- ++(-\length,0) -- ++(-\thick,0)
    -- cycle;
  };
}
\tikzset{
  track_straight/.pic={
    % rails
    \filldraw [base1!60] (0, 1.0) rectangle ++ (14.5, 0.5);
    \filldraw [base1!60] (0,-1.0) rectangle ++ (14.5,-0.5);
    % frame
    \draw [thick] ( 0.0,-2.0) -- ( 0.0,-0.3) --
              ( 0.7,-0.3) arc[start angle=36.6, end angle=323.4, radius=-0.5] --
              ( 0.0,0.3) -- ( 0.0,2.0) --
              (14.5,2.0) -- (14.5,0.3) --
              (15.2,0.3) arc[start angle=323.4, end angle=36.6, radius=-0.5] --
              (14.5,-0.3) -- (14.5,-2.0) -- cycle;
  };
}
\tikzset{
  track_curved/.pic={
    % % rails
    % \filldraw [base1!60] (0,3.0) rectangle ++ (14.5,0.5);
    % \filldraw [base1!60] (0,0.5) rectangle ++ (14.5,0.5);
    % % frame: radius (center) 20,5 cm 
    % \draw [thick] ( 0.0,0.0) -- ( 0.0,1.7) --
    %           ( 0.7,1.7) arc[start angle=36.6, end angle=323.4, radius=-0.5] --
    %           ( 0.0,2.3) -- ( 0.0,4.0) --
    %           (14.5,4.0) -- (14.5,2.3) --
    %           (15.2,2.3) arc[start angle=323.4, end angle=36.6, radius=-0.5] --
    %           (14.5,1.7) -- (14.5,0.0) -- cycle;
  };
}

\begin{tikzpicture}
  % \pic at ( 0.0,0) {track_straight};
  % \pic at (14.5,0) {track_straight};
  % \pic at (14.5,0) {block_signal};
  \pic at (14.5,4) {block_signal_cross_section};
  \pic at (14.5,0) {block_signal_top_view};
\end{tikzpicture}