在非线性变换下，圆角在 Tikz 中不能很好地变换

Question 1

在这种情况下，该rounded corners命令似乎不起作用（请参阅此处使用自定义图片对路径上的装饰应用非线性变换）我建议用这种方法来解决这个问题。

\documentclass[tikz,border=3mm]{standalone}

\usepgfmodule{nonlineartransformations}

\makeatletter
\def\mytransformation{%
\pgfmathsetmacro{\myX}{\pgf@x + 4*sin(4*\pgf@y) }
\pgfmathsetmacro{\myY}{\pgf@y}
\setlength{\pgf@x}{\myX pt}
\setlength{\pgf@y}{\myY pt}
}
\makeatother

\begin{document}
\begin{tikzpicture}
\newcommand\xx{1}
\pgftransformnonlinear{\mytransformation}
\draw (-5,-5) grid [step=1] (5,5);
\draw[fill=green!30, draw=blue, very thick,opacity=.5, dashed]
(-2,-1+\xx) -- (-2,1-\xx).. controls (-2,1) ..
(-2+\xx,1) -- (2-\xx,1).. controls (2,1) ..
(2,1-\xx) -- (2,-1+\xx).. controls (2,-1) ..
(2-\xx,-1) -- (-2+\xx,-1).. controls (-2,-1) ..
(-2,-1+\xx);
\end{tikzpicture}
\end{document}

当然，您可以\xx在一定范围内使用该参数。

Answer

在这种情况下，该rounded corners命令似乎不起作用（请参阅此处使用自定义图片对路径上的装饰应用非线性变换）我建议用这种方法来解决这个问题。

\documentclass[tikz,border=3mm]{standalone}

\usepgfmodule{nonlineartransformations}

\makeatletter
\def\mytransformation{%
\pgfmathsetmacro{\myX}{\pgf@x + 4*sin(4*\pgf@y) }
\pgfmathsetmacro{\myY}{\pgf@y}
\setlength{\pgf@x}{\myX pt}
\setlength{\pgf@y}{\myY pt}
}
\makeatother

\begin{document}
\begin{tikzpicture}
\newcommand\xx{1}
\pgftransformnonlinear{\mytransformation}
\draw (-5,-5) grid [step=1] (5,5);
\draw[fill=green!30, draw=blue, very thick,opacity=.5, dashed]
(-2,-1+\xx) -- (-2,1-\xx).. controls (-2,1) ..
(-2+\xx,1) -- (2-\xx,1).. controls (2,1) ..
(2,1-\xx) -- (2,-1+\xx).. controls (2,-1) ..
(2-\xx,-1) -- (-2+\xx,-1).. controls (-2,-1) ..
(-2,-1+\xx);
\end{tikzpicture}
\end{document}

当然，您可以\xx在一定范围内使用该参数。

Question 2

这个选项rounded corners有时相当顽固：它有几个缺陷。例如，它不能很好地与配合使用scale，请参阅手册.pdf，14.5 圆角。

为了避免使用此选项，一种简单的方法是定义自己的圆角矩形路径

\def\myround{.4}        % radius of the rounding corners    
\def\myrectangle{(0,2)
    --(3-\myround,2)   arc(90:0:\myround)
    --(3,-2+\myround)  arc(0:-90:\myround)
    --(-3+\myround,-2) arc(-90:-180:\myround)
    --(-3,2-\myround)  arc(180:90:\myround)--cycle;
}

因此，\pgftransformnonlinear{\mytransformation}

并且没有\pgftransformnonlinear{\mytransformation}

完整代码：

\documentclass[tikz,border=3mm]{standalone}
\usepgfmodule{nonlineartransformations}
\makeatletter
\def\mytransformation{%
    \pgfmathsetmacro{\myX}{\pgf@x + 4*sin(4*\pgf@y) }
    \pgfmathsetmacro{\myY}{\pgf@y}
    \setlength{\pgf@x}{\myX pt}
    \setlength{\pgf@y}{\myY pt}
}
\makeatother
\begin{document}
\begin{tikzpicture}
\def\myround{.4}        % radius of the rounding corners    
\def\myrectangle{(0,2)
    --(3-\myround,2)   arc(90:0:\myround)
    --(3,-2+\myround)  arc(0:-90:\myround)
    --(-3+\myround,-2) arc(-90:-180:\myround)
    --(-3,2-\myround)  arc(180:90:\myround)--cycle;
}   
\begin{scope} % Inside the scope, the transformation is active
\pgftransformnonlinear{\mytransformation}
\draw[gray!30] (-5,-3) grid (5,3);
\draw[blue,fill=green!30,very thick,fill opacity=.5,dashed] \myrectangle;
\end{scope}
\end{tikzpicture}
\end{document}

Answer