使用 pgfmultipartnode 及其参数（在 pgflibraryshapes.callouts.code.tex 中）

Question

我想介绍一些我的发现，请原谅我对源代码的挖掘。通过 TikZ 界面轻松访问并进行改进，从头开始绘制/编程会容易得多，但尽可能地遵循要求是一项挑战，我想这有其原因。我把它当作提高 TeX 源代码阅读能力的练习。

所有调用的代码确实都在中\tex\generic\pgf\libraries\shapes\pgflibraryshapes.callouts.code.tex，它包含大量代码块，很难直接重新定义它们。无论如何，要分离各部分并不容易，因为它主要由计算组成。该文件部分被注释，命令的名称在某种程度上有所帮助。

我创建了一个备份文件并开始编辑（pgflibrarymalipivo.callouts.patch.v1.code.tex）。我主要关注绝对+相对矩形标注，其他包括圆+椭圆相关的计算。我需要：

一个新的维度/定义或一个新的 pgfkey。
存储 pgfkey。
正确使用 pgfkey。

至 1.我已\pgfkeys{/pgf/.cd在callout pointer move/.initial=0cm文件开头进行了扩展。

至 2。我已经输入\pgfmathsetlengthmacro\moveleftright{\pgfkeysvalueof{/pgf/callout pointer move}}%并\addtosavedmacro\moveleftright%进入\pgf@lib@rectanglecallout@pointer命令。

至 3。最后，我几乎在计算的最后阶段之前修改了pgf@xb维度，即x的坐标\borderpoint（然后测试该点是否位于矩形区域内，我没有修改那部分）。

编辑：我已经尝试完善代码，因此请按原样将其下载到本地目录（未剪切文件可供下载或下面的部分精炼版本）以及此答案中的两个 TeX 示例。我们需要复制\pgfdeclareshape精炼版本，否则 Linux 上会出现不需要的消息（我猜这是由于\savedmacro和\addtosavedmacro）。在 Windows XP 和 Linux Ubuntu 13.10 上使用 pdflatex、lualatex、xelatex 和 latex+dvips（TeXLive 2013）进行了测试。

请自行承担使用风险。这是pgflibrarymalipivo.callouts.patch.v1.code.tex：

% A patch to the c:\texlive\2013\texmf-dist\tex\generic\pgf\libraries\shapes\pgflibraryshapes.callouts.code.tex file.
%
% Copyright 2007 by Mark Wibrow
%
% This file may be distributed and/or modified
%
% 1. under the LaTeX Project Public License and/or
% 2. under the GNU Public License.
%
% See the file doc/generic/pgf/licenses/LICENSE for more details.

%\usepgflibrary{shapes.symbols}

% Keys for callouts
%
% Common to all callouts:
%   /pgf/callout absolute pointer
%   /pgf/callout relative pointer
%
% ellipse callout only:
%   /pgf/callout pointer arc    
%
% rectangle callout only:    
%   /pgf/callout pointer width      
%
% cloud callout only:
%   /pgf/callout pointer start size
%   /pgf/callout pointer end size
%   /pgf/callout pointer segments
%
%\newif\ifpgf@lib@callout@absolutepointer
\pgfkeys{/pgf/.cd,
    %callout pointer arc/.initial=15,
    %callout pointer width/.initial=.25cm,
    %callout pointer start size/.initial=.2 of callout,
    %callout pointer end size/.initial=.1 of callout,
    %callout pointer segments/.initial=2,
    %callout absolute pointer/.code={\pgf@lib@callout@makeabsolutepointer{#1}},
    %callout relative pointer/.code={\pgf@lib@callout@makerelativepointer{#1}},
    %callout pointer shorten/.initial=0cm,
     callout pointer move/.initial=0cm % malipivo
}

\pgfdeclareshape{rectangle callout}{%
\savedmacro\rectanglecalloutpoints{%
    %
    \pgfmathsetlength\pgf@x{\pgfkeysvalueof{/pgf/inner xsep}}%
    \advance\[email protected]\wd\pgfnodeparttextbox%
    \pgfmathsetlength\pgf@xa{\pgfkeysvalueof{/pgf/minimum width}}%
    \ifdim\pgf@x<.5\pgf@xa%
        \[email protected]\pgf@xa%
    \fi%
    \edef\xtemp{\the\pgf@x}%
    \pgfmathaddtolength\pgf@x{\pgfkeysvalueof{/pgf/outer xsep}}%
    %
    \pgfmathsetlength\pgf@y{\pgfkeysvalueof{/pgf/inner ysep}}%
    \advance\[email protected]\ht\pgfnodeparttextbox%
    \advance\[email protected]\dp\pgfnodeparttextbox%
    \pgfmathsetlength\pgf@ya{\pgfkeysvalueof{/pgf/minimum height}}%
    \ifdim\pgf@y<.5\pgf@ya%
        \[email protected]\pgf@ya%
    \fi%
    \edef\ytemp{\the\pgf@y}%
    \pgfmathaddtolength\pgf@y{\pgfkeysvalueof{/pgf/outer ysep}}%
    %
    \edef\xlength{\the\pgf@x}%
    \edef\ylength{\the\pgf@y}%
    \addtosavedmacro\xlength%
    \addtosavedmacro\ylength%
    %
    \pgfmathsetlengthmacro\pointerwidth{\pgfkeysvalueof{/pgf/callout pointer width}}%
    \addtosavedmacro\pointerwidth%
    %
    \pgfextract@process\centerpoint{%
        \[email protected]\wd\pgfnodeparttextbox%
        \[email protected]\ht\pgfnodeparttextbox%
        \advance\[email protected]\dp\pgfnodeparttextbox%
    }%
    %
    % Process the relative callout pointer.
    %
    \ifpgf@lib@callout@absolutepointer%
    \else%
        \pgfextract@process\calloutpointer{%
            \pgfextract@process\borderpoint{%
                \expandafter\pgfpointborderrectangle\expandafter{\pgf@lib@callout@relativepointer}%
                    {\pgfqpoint{\xtemp}{\ytemp}}%
            }%
            \pgfmathanglebetweenpoints{\pgfpointorigin}{\borderpoint}%
            \let\pointerangle\pgfmathresult%
            \expandafter\pgf@process\expandafter{\pgf@lib@callout@relativepointer}%
            \pgfmathveclen@{\pgfmath@tonumber{\pgf@x}}{\pgfmath@tonumber{\pgf@y}}%
            \edef\pointerradius{\pgfmathresult pt}%
            \pgfpointadd{\borderpoint}{\pgfqpointpolar{\pointerangle}{\pointerradius}}%
            \pgf@xa\pgf@x%
            \pgf@ya\pgf@y%
            \centerpoint%
            \advance\pgf@x\pgf@xa%
            \advance\pgf@y\pgf@ya%
        }%
        \pgf@lib@callouts@shortenpointer%
        \addtosavedmacro\calloutpointer%
        \pgf@lib@rectanglecallout@pointer%
        \addtosavedmacro\calloutpointeranchor%
        \addtosavedmacro\beforecalloutpointer%
        \addtosavedmacro\aftercalloutpointer%
        \addtosavedmacro\firstpoint%
        \addtosavedmacro\secondpoint%
        \addtosavedmacro\thirdpoint%
        \addtosavedmacro\fourthpoint%
    \fi%
}
\savedanchor\centerpoint{%
    \[email protected]\wd\pgfnodeparttextbox%
    \[email protected]\ht\pgfnodeparttextbox%
    \advance\[email protected]\dp\pgfnodeparttextbox%
}
\savedanchor\basepoint{%
    \[email protected]\wd\pgfnodeparttextbox%
    \pgf@y0pt\relax%
}
\savedanchor\midpoint{%
    \[email protected]\wd\pgfnodeparttextbox%
    \pgfmathsetlength\pgf@y{+.5em}%
}
\anchor{center}{\centerpoint}
\anchor{mid}{\midpoint}
\anchor{mid east}{%
    \rectanglecalloutpoints%
    \midpoint%
    \advance\pgf@x\xlength\relax%       
}
\anchor{mid west}{%
    \rectanglecalloutpoints%
    \midpoint%
    \advance\pgf@x-\xlength\relax%      
}
\anchor{base}{\basepoint}
\anchor{base east}{%
    \rectanglecalloutpoints%
    \basepoint%
    \advance\pgf@x\xlength\relax%       
}
\anchor{base west}{%
    \rectanglecalloutpoints%
    \basepoint%
    \advance\pgf@x-\xlength\relax%      
}
\anchor{north}{%
    \rectanglecalloutpoints%
    \centerpoint%
    \advance\pgf@y\ylength\relax%
}%
\anchor{south}{%
    \rectanglecalloutpoints%
    \centerpoint%
    \advance\pgf@y-\ylength\relax%
}%
\anchor{east}{%
    \rectanglecalloutpoints%
    \centerpoint%
    \advance\pgf@x\xlength\relax%
}%
\anchor{west}{%
    \rectanglecalloutpoints%
    \centerpoint%
    \advance\pgf@x-\xlength\relax%
}%
\anchor{north east}{%
    \rectanglecalloutpoints%
    \centerpoint%
    \advance\pgf@x\xlength\relax%
    \advance\pgf@y\ylength\relax%
}%
\anchor{south west}{%
    \rectanglecalloutpoints%
    \centerpoint%
    \advance\pgf@x-\xlength\relax%
    \advance\pgf@y-\ylength\relax%
}%
\anchor{south east}{%
    \rectanglecalloutpoints%
    \centerpoint%
    \advance\pgf@x\xlength\relax%
    \advance\pgf@y-\ylength\relax%
}%
\anchor{north west}{%
    \rectanglecalloutpoints%
    \centerpoint%
    \advance\pgf@x-\xlength\relax%
    \advance\pgf@y\ylength\relax%
}%
\anchor{pointer}{%
    \rectanglecalloutpoints%
    \calloutpointeranchor%
}%
\backgroundpath{%
    \rectanglecalloutpoints%
    \pgf@x\xlength\relax%
    \pgf@y\ylength\relax%
    \pgfmathaddtolength\pgf@x{-\pgfkeysvalueof{/pgf/outer xsep}}%
    \pgfmathaddtolength\pgf@y{-\pgfkeysvalueof{/pgf/outer ysep}}%
    \edef\xtemp{\the\pgf@x}%
    \edef\ytemp{\the\pgf@y}%
    %
    % The absolute pointer must be calculated here because the
    % anchor of the shape (which is calculated after the saved
    % macros and points) affects how the pointer joins the 
    % main rectangle. 
    %
    \ifpgf@lib@callout@absolutepointer%
        \pgfextract@process\calloutpointer{%
            \pgfpointanchor{pgf@lib@callout@pointer}{center}%
        }%
        \pgf@lib@callouts@shortenpointer%
        \pgfmathsetlengthmacro\pointerwidth{\pgfkeysvalueof{/pgf/callout pointer width}}%
        \pgf@lib@rectanglecallout@pointer%
        %
        % \pgf@node@name = the shape name (from \pgfmultipartnode)
        %
        \ifx\pgf@node@name\pgfutil@empty%
        \else%
            %
            % Now hack an extra saved anchor \calloutpointeranchor,
            % with the new anchor for the callout pointer.
            %
            \edef\pgf@sh@@temp{\noexpand\expandafter\noexpand\pgfutil@g@addto@macro\noexpand\csname pgf@sh@np@\pgf@node@name\noexpand\endcsname}%
            \edef\pgf@sh@@@temp{%
                \noexpand\def\noexpand\calloutpointeranchor{%
                    \noexpand\pgf@x\the\pgf@x%
                    \noexpand\pgf@y\the\pgf@y%
                }%
            }%
            \expandafter\pgf@sh@@temp\expandafter{\pgf@sh@@@temp}%
        \fi%
    \fi%
    {%
        \pgfsetcornersarced{\pgfqpoint{0pt}{0pt}}%
        \pgfpathmoveto{\beforecalloutpointer}%
    }%
    \pgfpathlineto{\calloutpointer}%
    {%
        \pgfsetcornersarced{\pgfqpoint{0pt}{0pt}}%
        \pgfpathlineto{\aftercalloutpointer}%
    }%
    {%
        \pgftransformshift{\centerpoint}%
        \pgfpathlineto{\firstpoint}%
        \pgfpathlineto{\secondpoint}%
        \pgfpathlineto{\thirdpoint}%
        \pgfpathlineto{\fourthpoint}%
        {%
            \pgfsetcornersarced{\pgfqpoint{0pt}{0pt}}%
            \pgfpathclose%
        }%
    }           
}
\anchorborder{%
    \pgfextract@process\externalpoint{}%
    \rectanglecalloutpoints%
    \pgfpointadd{\centerpoint}%
    {%
        \pgfpointborderrectangle{\pgfpointadd{\centerpoint}{\externalpoint}}%
        {\pgfqpoint{\xlength}{\ylength}}%
    }%
}%
}


% \pgf@lib@rectanglecallout@pointer
%
% Internal macro for calculations relating to the rectangle callout.
%
% Requires the following to be set up:
%
% \calloutpointer - the location of the callout point.
% \xtemp          - the half width of the rectangle
% \ytemp          - the half height of the rectangle
% \pointerwidth   - the width of the pointer.
%
\def\pgf@lib@rectanglecallout@pointer{%
    %
    % Ensure that the pointer never connects to the main shape
    % too near to a corner. This is done for two reasons:
    % 1. It can look ugly.
    % 2. If the corners are rounded, a mess can result.
    %
% By malipivo, 2014-03-17, two lines
\pgfmathsetlengthmacro\moveleftright{\pgfkeysvalueof{/pgf/callout pointer move}}%
\addtosavedmacro\moveleftright%
    \pgfextract@process\borderpoint{%
            \pgfpointborderrectangle{%
                \centerpoint%
                \pgf@xa\pgf@x%
                \pgf@ya\pgf@y%
                \calloutpointer%
                \advance\pgf@x-\pgf@xa%
            }{\pgfqpoint{\xtemp}{\ytemp}}%
        }%
    \pgfmathanglebetweenpoints{\pgfpointorigin}{\borderpoint}%
    \let\borderangle\pgfmathresult%
    %
    \pgfutil@tempdima\pointerwidth\relax%
    \pgf@xa\xtemp\relax%
    \advance\pgf@xa-\pgfutil@tempdima%
    \pgf@ya\ytemp\relax%
    \advance\pgf@ya-\pgfutil@tempdima%
    %
    \pgf@process{%
        \pgfutil@ifundefined{pgf@corner@arc}{\pgfpointorigin}{%
            \expandafter\pgfqpoint\pgf@corner@arc}%
    }%
    \advance\pgf@xa-\pgf@x%
    \advance\pgf@ya-\pgf@y%
    %
    \borderpoint%
    \pgf@xb\pgf@x%
\advance\pgf@xb by \moveleftright% malipivo
    \pgf@yb\pgf@y%
    %
    \pgf@xc0pt\relax%
    \pgf@yc0pt\relax%
    %
    \pgfmathanglebetweenpoints{\pgfpointorigin}{\pgfqpoint{\xtemp}{\ytemp}}%
    \ifdim\borderangle pt<\pgfmathresult pt\relax%
        \[email protected]\pgfutil@tempdima%
        \ifdim\pgf@yb>\pgf@ya%
            \pgf@yb\pgf@ya%
        \fi%
        %
        % Establish the order for drawing the rectangle corners.
        %
        \edef\firstpoint{\noexpand\pgfqpoint{\xtemp}{\ytemp}}%
        \edef\secondpoint{\noexpand\pgfqpoint{-\xtemp}{\ytemp}}%
        \edef\thirdpoint{\noexpand\pgfqpoint{-\xtemp}{-\ytemp}}%
        \edef\fourthpoint{\noexpand\pgfqpoint{\xtemp}{-\ytemp}}%
    \else%
        \pgfmathanglebetweenpoints{\pgfpointorigin}{\pgfqpoint{-\xtemp}{\ytemp}}%
        \ifdim\borderangle pt<\pgfmathresult pt\relax%
            \[email protected]\pgfutil@tempdima%
            \ifdim\pgf@xb>\pgf@xa%
                \pgf@xb\pgf@xa%
            \else%
                \ifdim\pgf@xb<-\pgf@xa%
                    \pgf@xb-\pgf@xa%
                \fi%
            \fi%
            \edef\firstpoint{\noexpand\pgfqpoint{-\xtemp}{\ytemp}}%
            \edef\secondpoint{\noexpand\pgfqpoint{-\xtemp}{-\ytemp}}%
            \edef\thirdpoint{\noexpand\pgfqpoint{\xtemp}{-\ytemp}}%
            \edef\fourthpoint{\noexpand\pgfqpoint{\xtemp}{\ytemp}}%
        \else%
            \pgfmathanglebetweenpoints{\pgfpointorigin}{\pgfqpoint{-\xtemp}{-\ytemp}}%
            \ifdim\borderangle pt<\pgfmathresult pt\relax%
                \[email protected]\pgfutil@tempdima%
                \ifdim\pgf@yb>\pgf@ya%
                    \pgf@yb\pgf@ya%
                \else%
                    \ifdim\pgf@yb<-\pgf@ya%
                        \pgf@yb-\pgf@ya%
                    \fi%
                \fi%
                \edef\firstpoint{\noexpand\pgfqpoint{-\xtemp}{-\ytemp}}%
                \edef\secondpoint{\noexpand\pgfqpoint{\xtemp}{-\ytemp}}%
                \edef\thirdpoint{\noexpand\pgfqpoint{\xtemp}{\ytemp}}%
                \edef\fourthpoint{\noexpand\pgfqpoint{-\xtemp}{\ytemp}}%
            \else%
                \pgfmathanglebetweenpoints{\pgfpointorigin}{\pgfqpoint{\xtemp}{-\ytemp}}%
                \ifdim\borderangle pt<\pgfmathresult pt\relax%
                    \[email protected]\pgfutil@tempdima%
                    \ifdim\pgf@xb>\pgf@xa%
                        \pgf@xb\pgf@xa%
                    \else%
                        \ifdim\pgf@xb<-\pgf@xa%
                            \pgf@xb-\pgf@xa%
                        \fi%
                    \fi%
                    \edef\firstpoint{\noexpand\pgfqpoint{\xtemp}{-\ytemp}}%
                    \edef\secondpoint{\noexpand\pgfqpoint{\xtemp}{\ytemp}}%
                    \edef\thirdpoint{\noexpand\pgfqpoint{-\xtemp}{\ytemp}}%
                    \edef\fourthpoint{\noexpand\pgfqpoint{-\xtemp}{-\ytemp}}%
                \else%
                    \[email protected]\pgfutil@tempdima%
                    \ifdim\pgf@yb<-\pgf@ya%
                        \pgf@yb-\pgf@ya%
                    \fi%
                    \edef\firstpoint{\noexpand\pgfqpoint{\xtemp}{\ytemp}}%
                    \edef\secondpoint{\noexpand\pgfqpoint{-\xtemp}{\ytemp}}%
                    \edef\thirdpoint{\noexpand\pgfqpoint{-\xtemp}{-\ytemp}}%
                    \edef\fourthpoint{\noexpand\pgfqpoint{\xtemp}{-\ytemp}}%
                \fi%
            \fi%
        \fi%
    \fi%
    \pgfextract@process\beforecalloutpointer{%
        \centerpoint%
        \advance\pgf@x\pgf@xb%
        \advance\pgf@y\pgf@yb%
        \advance\pgf@x-\pgf@xc%     
        \advance\pgf@y-\pgf@yc%
    }%  
    \pgfextract@process\aftercalloutpointer{%
        \centerpoint%
        \advance\pgf@x\pgf@xb%
        \advance\pgf@y\pgf@yb%
        \advance\pgf@x\pgf@xc%      
        \advance\pgf@y\pgf@yc%
    }%  
    %
    % Now calculate the pointer anchor.
    %
    \pgfmathsetlength\pgf@x{\pgfkeysvalueof{/pgf/outer xsep}}%
    \pgfmathsetlength\pgf@y{\pgfkeysvalueof{/pgf/outer ysep}}%
    \ifdim\pgf@x>\pgf@y%
        \edef\outersep{\the\pgf@x}%
    \else%
        \edef\outersep{\the\pgf@y}%
    \fi%
    \pgf@lib@callouts@pointeranchor%
}

\endinput

这是一个最小的工作示例{lua|pdf|xe|}latex，其他格式的用户可能知道如何处理这样的代码，因为 TikZ 在 Plain TeX 和 ConTeXt 中工作（PDF 版本)：

\documentclass[10pt,a4paper]{article}
\pagestyle{empty}
\usepackage{tikz}
\usetikzlibrary{shapes}
\usepgflibrary{malipivo.callouts.patch.v1}
\begin{document}
\begin{tikzpicture}
\node[draw, rounded corners=2pt, rectangle] 
   at (2.6,-1.7) (c22) {Further Rectangle};
\node[rectangle callout, draw, red, inner sep=2pt, 
   callout absolute pointer={(c22.west)},
   callout pointer move=-23mm,
   callout pointer width=9mm,
   ] at (1.48,-.95) {no workarounds; no exceptions to optimizations}; 
\end{tikzpicture}
\end{document}

平均能量损失

指针宽度为 9 毫米（这是 TikZ 中的常规选项），并向左侧移动 23 毫米。我对这两个参数进行了一些实验，以便您可以更好地了解正在发生的事情。我附上了一个非最小示例及其预览。第一页带有洋红色矩形是绝对定位的示例，接下来的两页说明了相对定位（PDF 版本）。

\documentclass[10pt,a4paper]{article}
\pagestyle{empty} % No page numbers please...
\usepackage{tikz}  % The core of graphics engine...
\usetikzlibrary{shapes}  % The core for callouts...
\usepgflibrary{malipivo.callouts.patch.v1} % An experiment...
\usepackage{multicol} \columnsep=10mm
\voffset=-1.5in \hoffset=-1.5in
\addtolength{\textwidth}{8cm}
\addtolength{\textheight}{7cm}
\begin{document}
\begin{multicols}{3}
\foreach\mytype/\mycolor in {absolute/magenta, relative/blue} {\newpage
\foreach\mymove in {-10,-8,...,10} {% Different moves and
\foreach\mywidth in {2,4,...,10} {% different widths of pointers.
\begin{tikzpicture}
\node[draw, rounded corners=2pt, rectangle] at (2.6,-1.7) (c22) {Further Rectangle};
\node[rectangle callout,
   % ellipse callout, % Unsolved case...
   % cloud callout, % Unsolved case...
   draw, inner sep=2pt, \mycolor, align=center, text width=5cm,
   callout \mytype\space pointer={(c22.west)}, % Type of pointer
   callout pointer width=\mywidth mm, % Variable width (TikZ)
   callout pointer move=\mymove mm, % Variable move (experiment)
   ] at (1.48,-.95) {width=\mywidth mm; move=$\mymove$ mm}; 
\end{tikzpicture}\par}\vspace{1cm}}}% The end of \foreach cycles
\end{multicols}
\end{document}

纳米MWE1 纳米分子纳米MWE3

Answer 1