I'm using the code provided by Mark Wibrow (Text spirals with TikZ) to generate a spiral text that I could include as a front cover to a report.
The below code works perfectly fine when using latin characters. However, I need to be able to write greek text. How can I adapt/fix this code to allow greek writing?
\documentclass[tikz,border=5]{standalone}
\usepackage{ucs}
\usepackage[utf8x]{inputenc}
\usepackage[english, greek]{babel}
\newcommand{\en}{\selectlanguage{english}}
\newcommand{\gr}{\selectlanguage{greek}}
\usetikzlibrary{decorations.text}
\begin{document}
\begin{tikzpicture}[
decoration={
reverse path,
text effects along path,
text={Κείμενο στα ελληνικά.}, %text in greek
text effects/.cd,
text along path,
character count=\i, character total=\n,
characters={scale=1-\i/\n}
}
]
\draw [decorate] (0,0)
\foreach \i [evaluate={\r=(\i/2000)^2;}] in {0,5,...,2880}{ -- (\i:\r)};
\end{tikzpicture}
\end{document}
I should mention that I included two new commands for switching language more easily plus the usual Babel package to enable greek writing.

tikzis processing the Unicode text. I tried putting the Greek text in a macro and then putting the macro in the text field; that just printed the Greek text one time, not in a spiral. – musarithmia Feb 16 '16 at 18:54