How to define a global constant or a global RPN function without \pstheader?

Question

I want to put

\pstVerb
{
    true setglobal
    globaldict begin
    /side 4 def
    /potocar {2 copy cos mul 3 1 roll sin mul} bind def
    end
    false setglobal
}

in the preamble instead of in pspicture to make it global.

\documentclass[12pt]{beamer}

\usepackage{pst-eucl}

\usepackage[active,tightpage]{preview}
\PreviewBorder=12pt
\PreviewEnvironment{pspicture}

\pstVerb
{
    true setglobal
    globaldict begin
    /side 4 def
    /potocar {2 copy cos mul 3 1 roll sin mul} bind def
    end
    false setglobal
}

\begin{document}

\begin{frame}
\begin{pspicture}(-0.2,-0.2)(8,5)
\pstGeonode[PosAngle={180,225,-45,0},CurveType=polygon]
    (!0 side){A}
    (!0 0){B}
    (!80 sin 2 exp side mul 40 sin div 70 sin div 0){C}
    (!80 sin side mul 30 sin div 20 potocar){D}\pause

\psset{linecolor=red}
\pstLineAB{A}{D}\pause
\pstLineAB{B}{D}\pause

\psset
{
    linecolor=magenta,
    linewidth=0.5\pslinewidth,
    arcsep=\pslinewidth,
    arrows=<->,
    MarkAngleRadius=1.0,
    LabelSep=0.75,
}

\tiny
% A
\pstMarkAngle{B}{A}{D}{$\theta$}\pause
% B
\pstMarkAngle{C}{B}{D}{$20^\circ$}\pause
% D
\pstMarkAngle{B}{D}{C}{$50^\circ$}\pause
\pstMarkAngle{A}{D}{B}{$30^\circ$}
\end{pspicture}

\end{frame}
\end{document}

I asked AlexG about it in a comment, he responded it but it seemed not to work. I got a compilation error saying that "/undefined in side" in either dvips phase or ps2pdf phase. I am not checked which phase produced the error exactly but latex successfully compiled it.

Answer 1

The preview package is the culprit. It seems to discard anything outside \PreviewEnvironment (pspicture in the present case) from being put into the Postscript output. I checked the PS output. The definitions of side and potocar didn't make it into it. If you remove the preview related lines everything is ok.