bendera berkibar

\documentclass[border=3.14mm]{standalone}
%https://tex.stackexchange.com/questions/483459/how-to-draw-a-waving-flag-in-tikz?noredirect=1&lq=1
\usepackage{xcolor,warna}
\usepackage{tikz}
\usepgfmodule{nonlineartransformations}
\makeatletter
\def\flagtransformation{%
\pgf@xa=\pgf@x%
\pgf@ya=\pgf@y%
\pgfmathsetmacro{\myy}{\pgf@ya+7*sin(\pgf@xa*3.6)-0.1*\pgf@xa}%
\pgf@y=\myy pt}
\makeatother
\definecolor{merah}{rgb}{0.86274511,0.11764706,0.20784314}
\newcommand\benderaku{
\fill[white] (0,0) rectangle (25,9);
\fill[merah] (0,9) rectangle (25,18);}
\begin{document}
\begin{tikzpicture}[font=\sffamily,scale=0.2]
\begin{scope}
 \pgftransformnonlinear{\flagtransformation}
 \benderaku
 \shade[left color=black,right color=black,middle color=white,opacity=0.15]
 (0,0) rectangle (12.5,18);
\shade[left color=black,right color=black,middle color=white,opacity=0.15]
 (12.5,0) rectangle (25,18);
\end{scope}
% tiang bendera --------------------------------------------------------------------
\shade[left color=black,right color=black,middle color=white,opacity=0.5]
 (-1,-25) rectangle (0,19);
\shade[left color=black,right color=black,middle color=white,opacity=0.5]
 (-.5,19) ellipse (.7 and .3);
\end{tikzpicture}
\end{document}