TikZ - How to automate the creation of patterns having irregularities

Question

This is a continuation of How to automatically calculate parameters of a TikZ repeating pattern?

I am trying to find the best way to draw a series of industrial patterns. Thanks to the help received, I was able to draw regular patterns. However I now need to draw patterns that have a distribution and size of cavities that vary. I was also forced to move the origin to the center of the envelope, a configuration less convenient than before. I have tried a different approach than before, making the exact shape I am looking for, however it is very much hard-coded, since the cavity numbering pattern does not follow the natural order. I have tried the \foreach \x / \n [count=\xi] option, that looked promising, but I have not found a way to use it for every row. Is there a way to optimize the code, and particularly the counter of cavities, missing here?

\documentclass{standalone}
\usepackage{tikz}   
\renewcommand{\familydefault}{\sfdefault} 
\begin{document} 

\begin{tikzpicture}[scale=2.54, thick,  
twenty/.style={circle, draw, very thin, fill,text=white, minimum size=.097in , text centered,font=\tiny, inner sep=0.1pt}, 
sixteen/.style={circle, draw, very thin, fill,text=white, minimum size=.150in, text centered,font=\tiny, inner sep=0.1pt}, 
] 
\newlength{\hspacing} %Vertical spacing
\newlength{\vspacing} %Horiz spacing
\setlength{\hspacing}{.108cm}

%Begin envelope
\coordinate (O) at (0,0) ; 
\coordinate (A) at ( - 0.7475,-0.435) ; 
\coordinate (B) at ( 0.7475,-0.435) ; 
\coordinate (C) at (0.7475, 0.249) ; 
\coordinate (D) at (0.516 ,0.435) ; 
\coordinate (E) at (-0.516 ,0.435) ; 
\coordinate (F) at (-0.7475, 0.249) ; 
\draw (A) --(B)--(C)--(D)-- (E)--(F)-- cycle ;
%End envelope

\node[red, very thin] at (O)  {+}; %origin

%--------------------------------
% Begin top row -mixed cavities- uneven spacing
\setlength{\vspacing}{.28cm}
%small cavity right side
\foreach \x / \n [count=\xi] in {4.5 / \xi,  3.5 / \xi} {
\node [twenty] at (\hspacing*\x, \vspacing){\xi};
}
%Begin large cavity
\foreach \x / \n  in {2 / 3,  0 / 4} {
\node [sixteen] at (\hspacing*\x, \vspacing){\n};
}
\foreach \x / \n  in {2 / 5} {
\node [sixteen] at (-\hspacing*\x, \vspacing){\n};
}
%small cavity left side
\foreach \x /  \n  in  {4.5/ 6,  3.5/ 7} {
\node [twenty] at (-\hspacing*\x, \vspacing){\n};
}
% end top row
%---------------------------
% Begin row 2 small cavity uneven spacing
\setlength{\vspacing}{.168cm}
%---------------------------
\foreach \x /  \n  in {6/ 8,  5 / 9,  4 / 10, 3/ 11, 1/12 } {
\node [twenty] at (\hspacing*\x, \vspacing){\n};
}
\foreach \x /  \n  in  {6/ 17,  5/ 16,  4 / 15, 3/ 14, 1/ 13 } {
\node [twenty] at (-\hspacing*\x, \vspacing){\n};
}
%End small cavity
% end row 2
%---------------------------
% Begin row 3 - small cavity
\setlength{\vspacing}{.056cm}
%Begin small cavity
\foreach \x / \n  in {5.5/18, 4.5/19, 3.5/20, 2.5/21, 1.5/22, 0.5/23} {
\node [twenty] at (\hspacing*\x, \vspacing){\n};
}
\foreach \x / \n  in   {5.5/29, 4.5/28, 3.5/27, 2.5/26, 1.5/25, 0.5/24} {
\node [twenty] at (-\hspacing*\x, \vspacing){\n};
}
%End small cavity
% end row 3
%---------------------------
% Begin row 4 - small cavity
\setlength{\vspacing}{-.056cm}
\foreach \x / \n  in {6/30, 5/31, 4/32, 3/33, 2/34, 1/35, 0/36} {
\node [twenty] at (\hspacing*\x,\vspacing){\n};
}
\foreach \x / \n  in   {6 /42, 5/41, 4/40, 3/39, 2/38, 1/37} {
\node [twenty] at (-\hspacing*\x, \vspacing){\n};
}
%End small cavity
% end row 5
%---------------------------
% Begin row 5  - small cavity
\setlength{\vspacing}{-0.162cm}
%Begin small cavity
\foreach \x / \n  in {5.5/43, 4.5/44, 3.5/45, 2.5/46, 1.5/47, 0.5/48} {
\node [twenty] at (\hspacing*\x, \vspacing){\n};
}
\foreach \x / \n  in {5.5/54, 4.5/53, 3.5/52, 2.5/51, 1.5/50, 0.5/49} {
\node [twenty] at (-\hspacing*\x, \vspacing){\n};
}
%---------------------------
% end row 5
% Begin row 6 -small cavity
\setlength{\vspacing}{-0.27cm}

\foreach \x /  \n  in {6 /55, 5/56, 4/57, 3/58, 2/59, 1/60, 0/61} {
\node [twenty] at (\hspacing*\x,\vspacing){\n};
}
\foreach \x / \n  in  {6 /67, 5/65, 4/65, 3/64, 2/63, 1/62} {
\node [twenty] at (-\hspacing*\x, \vspacing){\n};
}
% end row 6
\end{tikzpicture}
\end{document} 

Answer 1

HTH! Comments throughout the source.

The result:

And the code:

\documentclass{standalone}

\usepackage{tikz}

% e-TeX power  =)
\usepackage{etoolbox}

\newcounter{cavities}

% associates each cavity with its style
% #1: row number
% #2: column number
% #3: small or big (styles)
\newcommand\setcavitystyle[3]{\csgdef{cavitystyler#1c#2}{#3}}
\newcommand\getcavitystyle[2]{\csuse{cavitystyler#1c#2}}

% determines whether or not the cavity is drawn
% #1: row number
% #2: column number
% #3: 0 (disabled) or 1 (enabled)
\newcommand\setpointenabled[3]{\csnumgdef{styler#1c#2}{#3}}
\newcommand\getpointenabled[2]{\csuse{styler#1c#2}}

% builds the possible locations of the cavities
% #1: max absolute x
% #2: max absolute y
\newcommand{\makebase}[2]{
    \pgfmathtruncatemacro{\x}{#1}
    \pgfmathtruncatemacro{\y}{#2}
    \foreach \i in { -\x, ..., \x} {
        \foreach \j in { -\y, ..., \y} {
            \coordinate (base-\i-\j) at (\i, \j);
        }
    }
    \drawenvelope
}

% draw envelope and defines useful area 
% from (-\xuseful, -\yuseful) to (\xuseful, \yuseful)
\newcommand{\drawenvelope} {
    \pgfmathtruncatemacro{\xuseful}{\x - 1}
    \pgfmathtruncatemacro{\yuseful}{\y - 1}
    \draw [
        line width = 1mm
    ] (-\x, -\y) -- (-\x, \yuseful) -- (-\xuseful, \y) -- (\xuseful, \y) -- (\x, \yuseful) -- (\x, -\y) -- cycle;
}

% defines all possible cavities to be used with a basic style.
% uses only useful area
\newcommand{\makebasicpoints}{
    \foreach \j in {\yuseful, ..., -\yuseful} {
        \foreach \i in {\xuseful, ..., -\xuseful} {
            \ifboolexpr{
                (test{\ifnumequal{\j}{\yuseful}} and test{\ifnumequal{\i}{\xuseful}})
                or
                (test{\ifnumequal{\j}{\yuseful}} and test{\ifnumequal{\i}{-\xuseful}})
            }{
                \setpointenabled{\i}{\j}{0}
            }{
                \ifboolexpr{
                    (test{\ifnumodd{\i}} and test{\ifnumodd{\j}})
                    or
                    (not(test{\ifnumodd{\i}}) and not(test{\ifnumodd{\j}}))
                }{
                    \setpointenabled{\i}{\j}{0}
                }{
                    \setpointenabled{\i}{\j}{1}
                    \setcavitystyle{\i}{\j}{small}
                }
            }
        }
    }
}


% defines a specific cavities with "big" style.
% disables drawing near cavities (above, below, right and left)
% #1: x
% #2: y
\newcommand{\makebiggerpoint}[2]{
    \setpointenabled{#1}{#2}{1}
    \setcavitystyle{#1}{#2}{big}

    \pgfmathtruncatemacro{\ytemp}{#2}
    \pgfmathtruncatemacro{\xtemp}{#1 - 1}
    \setpointenabled{\xtemp}{\ytemp}{0}

    \pgfmathtruncatemacro{\ytemp}{#2}
    \pgfmathtruncatemacro{\xtemp}{#1 + 1}
    \setpointenabled{\xtemp}{\ytemp}{0}

    \pgfmathtruncatemacro{\ytemp}{#2 + 1}
    \pgfmathtruncatemacro{\xtemp}{#1}
    \setpointenabled{\xtemp}{\ytemp}{0}

    \pgfmathtruncatemacro{\ytemp}{#2 - 1}
    \pgfmathtruncatemacro{\xtemp}{#1}
    \setpointenabled{\xtemp}{\ytemp}{0}
}

% draw each cavity if it is enabled. 
\newcommand{\makecavities}{
    \foreach \j in {\yuseful, ..., -\yuseful} {
        \foreach \i in {\xuseful, ..., -\xuseful} {
            \ifnumequal{\getpointenabled{\i}{\j}}{1}{
                \stepcounter{cavities}
                \coordinate (cavity-\thecavities) at (\i, \j);
                \node [\getcavitystyle{\i}{\j}] at (cavity-\thecavities) {\thecavities};
            }{
            }
        } 
    }
}

% styles
\tikzset{
    small/.style = {
        circle
        , fill
        , minimum size = 10mm
        , inner sep = 0mm
        , font = \small\bf
        , text = white
        , inner sep = 0pt
    }
    , big/.style = {
        circle
        , fill
        , minimum size = 15mm
        , inner sep = 0mm
        , text = white
        , font = \bf
        , inner sep = 0pt
    }
}

\begin{document}
    \begin{tikzpicture}

        \makebase{10}{5}
        \draw [red, ultra thick] (0,0) +(0, 4mm) -- +(0, -4mm) +(4mm, 0) -- +(-4mm, 0);

        \makebasicpoints

        \foreach \k in {-6, -3, ..., 6} {\makebiggerpoint{\k}{3}}
        \foreach \k in {-7, -4, ..., 8} {\makebiggerpoint{\k}{-2}}

        \makecavities

    \end{tikzpicture}
\end{document}