如何用 tikz 绘制斯涅尔定律的图？

Question

我尝试绘制图形，但有没有一种方法可以不逐点进行绘制，而是以有效的方式进行绘制？

Answer 1

一些剪辑、旋转的边缘和交叉点可以让你走得更远。

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{intersections}
\begin{document}
\begin{tikzpicture}[pics/v/.style={code={\draw (0,-#1) -- (0,#1);}}]
 \begin{scope}
  \clip[overlay] (-5,0) rectangle (5,5);
  \path[rotate=30,overlay=false,very thick] 
      foreach \x in {0,...,9}
    {(-2,-2+0.6*\x) coordinate (L\x) edge[blue,name path global=p\x] ++ (4,0) coordinate (R\x)} 
   (-2,-2) edge[gray!30] ++(0,6)
   (2,-2) edge[gray!30] ++(0,6)
   (0,-2) edge[gray!30] ++(0,7)
   (0,4.5) edge[blue,thick,dashed,-latex] ++ (0,-3);
 \end{scope}
 \begin{scope}
  \clip[overlay] (-5,0) rectangle (5,-5);
  \pgfmathsetmacro{\myx}{2*cos(20)/cos(30)}
  \path[rotate=200,overlay=false,very thick] 
      foreach \x in {0,...,5}
    {(-\myx,0.8+0.4*\x) coordinate (L-\x) edge[green!70!black] ++ (2*\myx,0) coordinate (R-\x)} 
   (-\myx,-2) edge[gray!30] ++(0,6)
   (\myx,-2) edge[gray!30] ++(0,6)
   (0,-2) edge[gray!30] ++(0,7)
   (0,3.6) edge[green!70!black,thick,dashed,latex-] ++ (0,-2);
 \end{scope}
 \path[name path=h] (-5,0) coordinate (L) -- (5,0) coordinate (R);
 \foreach \x in {2,3,4,5}
 {\path[name intersections={of=h and p\x,by=i\x}] (i\x);
 \foreach \y in {1,...,\the\numexpr\x-1}
 {\pgfmathtruncatemacro{\myf}{50/(\x-\y)}
 \draw[thick,gray!\myf] (i\x) ++ (-0.18+\y*0.41,0) 
    arc[start angle=0,end angle=-180,radius=-0.18+0.41*\y];}}
 \draw (L) -- (R);
 \path foreach \x in {2,3,4,5} {(i\x) node[circle,fill,yellow,inner sep=2pt]{}};
\end{tikzpicture}
\end{document}