[pdftex] "xyz zoom" and "FullScreen"

[Michael Chapman]

I have for several months been producing a series of 'screen' PDF documents 
and (congratulating myself on their platform independence).

The documents open in 'fullscreen' mode.
The documents contain images that when clicked on, 'zoom'. That is that 
portion of the page enlarges to fill the full screen, at the same time making 
clear a small 'Return to Normal View' button that is just under each image.

Or so I thought.

>From recent experiments, I conclude that "xyz zoom 1500" (as in
\pdfdest name{MyPicture} xyz zoom 1500) does not produce an image that is 1.5 
times larger (i.e. 1500 / 1000 times larger). Rather it produces a page that 
is 1.5 times larger than the window size if the file had _not_ opened in 
fullscreen mode. (At a guess that would be 960x720 pixels as against 640x480 
pixels, but I have not got as far as measuring this.)

Is there anyway of accessing the user's screen size (other than FullScreen) 
to allow for predictable zooming?

The alternative of "This document may be viewed under MS, Mac or Linux _but_ 
is best viewed at a screen resolution of XXX x YYY" seems like a defeat!

Thanks,

	Michael Chapman


______________________________

The code used is:


\newcommand{\PIC}[4]{%
        %  Zoom (10=one) /  H-space  /  file   /   scale  
	\fontsize{3pt}{3pt}\selectfont
	\pdfdest name{Pic#3} xyz zoom #1%
00
	\hspace*{#2 in}
	\hyperlink{Pic#3}{\includegraphics[scale=#4]{#3}}
 
	\vspace{-1.5mm}
 
	\hspace*{#2 in}
	\Acrobatmenu{GoBack}{%
	\shadowbox{\colorbox{ButGrey}{\textsf{\emph{\textcolor{black}%
	{\rule{0pt}{4pt}%
	\hspace*{2mm}%
		\raisebox{1pt}{Revert to normal view} \hspace*{3mm}%
	%\rule{0pt}{1pt}
	}}}}\color{black}}}
	\fontsize{10pt}{12pt} \selectfont
}