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使用自定义形状作为“构建块”

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使用自定义形状作为“构建块”

我想创建一个自定义形状（不是很大）并在自定义位置使用它。该形状是一台相机，非常简单：

    \draw [fill=black](0,0) -- (2,2.5) -- (-2,2.5) -- cycle;
    \draw [fill=white,ultra thick](0,0) circle (1);

我想要的是能够将自定义形状放置在任意位置并能够旋转它。放置和旋转的原点应该是 (0,0) 点。

有没有简单的方法可以做到这一点，还是我必须重新绘制它以进行旋转和定位？ 在此处输入图片描述

答案1

首先要说的是：JLDiaz 的回答没有错。

但你想要一个形状。

定义\pgfdeclareshape是从 复制而来forbidden sign（即只有一个带全直径斜线的圆圈），并进行了调整以添加实际的相机。两个实现的相机都继承了形状circle，因此适用于 的所有内容也circle适用于fix- 和rotcamera。

还有很大的改进空间（例如，不要使用没有 的相机形状），我实际上不喜欢相机“看”的默认方向是北方，因为人们会认为东方是标准方向（即角度 = 0）。这可以通过替换线draw轻松修复rotcamera

\pgftransformrotate{\pgf@camera@rotate}%

和

\pgftransformrotate{\pgf@camera@rotate-90}%

也可以替换\pgfmathsetmacro线条或重新定义\pgfmath…线条。

对于fixcamera一个必须只添加行

\pgftransformrotate{-90}%

在该\pgfmath…部分之前。

我更喜欢rotcamera默认的东方向（即-90添加）。

圆形部分（很像原始circle形状）是透明的，因此背景可见并且不会过度绘制（fill=white如果需要可以使用）；这可以在最后一个例子和图片中看到。

内容

fixcamera形状

形状fixcamera只能用/tikz/rotate键旋转（类似于 JLDiaz' \camera）。请注意，这也会旋转.参考（如.90或.north）。

rotcamera形状和/tikz/camera rotate

该形状rotcamera与 几乎相同，只是它通过键的值（用 初始化）fixcamera旋转相机对象（而不是圆圈本身）。/tikz/camera rotate0

camera及其可选参数。

另外，我引入了一个camera带有一个可选参数（旋转）的键。

该键还包含键draw、设置minimum size = 2cm和ultra thick模仿原始设计。参数#1将提供给camera rotate，默认设置0为

 camera/.default=0

在其自身定义之后camera/.style。

代码

\documentclass[tikz,border=2pt]{standalone}

\makeatletter

% this declares a camera that rotates
\pgfdeclareshape{rotcamera}
{
  \inheritsavedanchors[from=circle] % this is nearly a circle
  \inheritanchorborder[from=circle]
  \inheritanchor[from=circle]{north}
  \inheritanchor[from=circle]{north west}
  \inheritanchor[from=circle]{north east}
  \inheritanchor[from=circle]{center}
  \inheritanchor[from=circle]{west}
  \inheritanchor[from=circle]{east}
  \inheritanchor[from=circle]{mid}
  \inheritanchor[from=circle]{mid west}
  \inheritanchor[from=circle]{mid east}
  \inheritanchor[from=circle]{base}
  \inheritanchor[from=circle]{base west}
  \inheritanchor[from=circle]{base east}
  \inheritanchor[from=circle]{south}
  \inheritanchor[from=circle]{south west}
  \inheritanchor[from=circle]{south east}
  \inheritbackgroundpath[from=circle]
  \foregroundpath{
    \centerpoint%
    \pgf@xc=\pgf@x%                                                                                                                   \pgf@xc = x value of centerpoint
    \pgf@yc=\pgf@y%                                                                                                                   \pgf@yc = y value of centerpoint
    \pgfutil@tempdima=\radius%                                                                                              \pgfutil@tempdima = radius
    \pgfmathsetlength{\pgf@xb}{\pgfkeysvalueof{/pgf/outer xsep}}%                                                                     \pgf@xb = outer xsep
    \pgfmathsetlength{\pgf@yb}{\pgfkeysvalueof{/pgf/outer ysep}}%                                                                     \pgf@yb = outer ysep
    \pgfmathsetmacro{\pgf@camera@rotate}{\pgfkeysvalueof{/tikz/camera rotate}}%                                            \pgf@camera@rotate = camera rotate
    \ifdim\pgf@xb<\pgf@yb%
      \advance\pgfutil@tempdima by-\pgf@yb%
    \else%
      \advance\pgfutil@tempdima by-\pgf@xb%
    \fi%
    \pgftransformrotate{\pgf@camera@rotate}% add -90 for standard east direction
    \pgfpathmoveto{\pgfpointadd{\pgfqpoint{\pgf@xc}{\pgf@yc}}{\pgfqpoint{0.624695047\pgfutil@tempdima}{0.780868809\pgfutil@tempdima}}}
    \pgfpathlineto{\pgfpointadd{\pgfqpoint{\pgf@xc}{\pgf@yc}}{\pgfqpoint{2\pgfutil@tempdima}{2.5\pgfutil@tempdima}}}
    \pgfpathlineto{\pgfpointadd{\pgfqpoint{\pgf@xc}{\pgf@yc}}{\pgfqpoint{-2\pgfutil@tempdima}{2.5\pgfutil@tempdima}}}
    \pgfpathlineto{\pgfpointadd{\pgfqpoint{\pgf@xc}{\pgf@yc}}{\pgfqpoint{-0.624695047\pgfutil@tempdima}{0.780868809\pgfutil@tempdima}}}
    \pgfpatharc{128.6598083}{51.34019175}{\pgfutil@tempdima}
    \pgfpathclose
    \pgfsetfillcolor{black}
    \pgfusepath{fill}
  }
}

% this declares a fixed camera, it has to be rotated by the /tikz/rotate key
\pgfdeclareshape{fixcamera}
{
  \inheritsavedanchors[from=circle] % this is nearly a circle
  \inheritanchorborder[from=circle]
  \inheritanchor[from=circle]{north}
  \inheritanchor[from=circle]{north west}
  \inheritanchor[from=circle]{north east}
  \inheritanchor[from=circle]{center}
  \inheritanchor[from=circle]{west}
  \inheritanchor[from=circle]{east}
  \inheritanchor[from=circle]{mid}
  \inheritanchor[from=circle]{mid west}
  \inheritanchor[from=circle]{mid east}
  \inheritanchor[from=circle]{base}
  \inheritanchor[from=circle]{base west}
  \inheritanchor[from=circle]{base east}
  \inheritanchor[from=circle]{south}
  \inheritanchor[from=circle]{south west}
  \inheritanchor[from=circle]{south east}
  \inheritbackgroundpath[from=circle]
  \foregroundpath{
    \centerpoint%
    \pgf@xc=\pgf@x%                                                                                                                   \pgf@xc = x value of centerpoint
    \pgf@yc=\pgf@y%                                                                                                                   \pgf@yc = y value of centerpoint
    \pgfutil@tempdima=\radius%                                                                                              \pgfutil@tempdima = radius
    \pgfmathsetlength{\pgf@xb}{\pgfkeysvalueof{/pgf/outer xsep}}%                                                                     \pgf@xb = outer xsep
    \pgfmathsetlength{\pgf@yb}{\pgfkeysvalueof{/pgf/outer ysep}}%                                                                     \pgf@yb = outer ysep
    \ifdim\pgf@xb<\pgf@yb%                                                                                                           correction of radius variable
      \advance\pgfutil@tempdima by-\pgf@yb%
    \else%
      \advance\pgfutil@tempdima by-\pgf@xb%
    \fi%
    %\pgftransformrotate{-90}%
    \pgfpathmoveto{\pgfpointadd{\pgfqpoint{\pgf@xc}{\pgf@yc}}{\pgfqpoint{0.624695047\pgfutil@tempdima}{0.780868809\pgfutil@tempdima}}}
    \pgfpathlineto{\pgfpointadd{\pgfqpoint{\pgf@xc}{\pgf@yc}}{\pgfqpoint{2\pgfutil@tempdima}{2.5\pgfutil@tempdima}}}
    \pgfpathlineto{\pgfpointadd{\pgfqpoint{\pgf@xc}{\pgf@yc}}{\pgfqpoint{-2\pgfutil@tempdima}{2.5\pgfutil@tempdima}}}
    \pgfpathlineto{\pgfpointadd{\pgfqpoint{\pgf@xc}{\pgf@yc}}{\pgfqpoint{-0.624695047\pgfutil@tempdima}{0.780868809\pgfutil@tempdima}}}
    \pgfpatharc{128.6598083}{51.34019175}{\pgfutil@tempdima}
    \pgfpathclose
    \pgfsetfillcolor{black}
    \pgfusepath{fill}
  }
}

\makeatother

% this sets the default value of /tikz/camera rotate to 0 (no rotation, camera is oriented north)
% if we don't set it, it's automatically zero
\pgfkeyssetvalue{/tikz/camera rotate}{0}

% this defines a /tikz/camera style that takes one optional argument,
%  i.e. the rotation of the camera (which, again, is zero, if the argument is omitted
\tikzset{
    camera/.style={
        draw,
        ultra thick,
        minimum size=2cm,
        rotcamera,
        camera rotate=#1
    },
    camera/.default=0
}

\begin{document}
\begin{tikzpicture}[every node/.style={draw, ultra thick, minimum size=2cm}]
\node[fixcamera, rotate =    0] (c1) at (0,0)    {};
\node[fixcamera, rotate =   30] (c2) at (3,3)    {};
\node[fixcamera, rotate = -100] (c3) at (2.8,-1) {};

\draw[ultra thick, blue] (c1.south) to[out=270, in=210] (c3.210)
                         (c3.80)    to[out=80,  in=320] (c2.320)
                         (c2.255)   to[out=255, in=15]  (c1.15);
\end{tikzpicture}

\begin{tikzpicture}[every node/.style={draw, ultra thick, minimum size=2cm}]
\node[rotcamera, camera rotate =    0] (c1) at (0,0)    {};
\node[rotcamera, camera rotate =   30] (c2) at (3,3)    {};
\node[rotcamera, camera rotate = -100] (c3) at (2.8,-1) {};

\draw[ultra thick, blue] (c1.south) to[out=270, in=210] (c3.210)
                         (c3.80)    to[out=80,  in=320] (c2.320)
                         (c2.255)   to[out=255, in=15]  (c1.15);
\end{tikzpicture}

\begin{tikzpicture}
\node[camera      ] (c1) at (0,0)    {};
\node[camera=   30] (c2) at (3,3)    {};
\node[camera= -100] (c3) at (2.8,-1) {};

\draw[ultra thick, blue] (c1.south) to[out=270, in=210] (c3.210)
                         (c3.80)    to[out=80,  in=320] (c2.320)
                         (c2.255)   to[out=255, in=15]  (c1.15);
\end{tikzpicture}

\begin{tikzpicture}[every node/.style={draw}]
\draw (0,0) -- node[midway,rotcamera]                   {} (3,0)
            -- node[pos=.7,rotcamera, camera rotate=90] {} (3,3) to[out=180,in=90] (0,0) -- cycle;
\end{tikzpicture}
\end{document}

输出

输出rotcamera（和可选camera rotate）或camera

旋转相机

输出fixcamera（及附加rotate）

固定相机

使用相机输出绘制路径

路径上的摄像机

答案2

以下代码实现了一个宏，该宏可在给定的位置和角度绘制相机符号。其中包含一个使用示例。

\documentclass{article}
\usepackage{tikz}
\begin{document}
\def\camera#1#2{
\begin{scope}[shift={#1}, rotate=#2]
    \draw [fill=black](0,0) -- (2,2.5) -- (-2,2.5) -- cycle;
    \draw [fill=white,ultra thick](0,0) circle (1);
\end{scope}
}

\begin{tikzpicture}
\camera{(0,0)}{0}
\camera{(3,3)}{30}
\camera{(2.8,-1)}{-100}
\end{tikzpicture}
\end{document}

结果

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