World: r3wp

http://www.rebol.org/cgi-bin/cgiwrap/rebol/view-script.r?script=ean13.r
<--- did this one a year ago. it uses PDF maker to generate barcodes

it can also generate bitmapped barcodes. works only with EAN13 format 
though

hmm... seems I forgot to upload the version that actually can use 
PDF Maker :-)

New version! Try:
do http://home.tiscali.dk/john.niclasen/postscript/postscript.r
print postscript [page [path [linewidth 10 at 72x72 box 72 72]]]

I only test it on the screen under MacOS, where there is an automatic 
converter. Can someone test it on a PS printer?

how do you convert it? I can't make preview.app read it

ah, problem fixed

I do:

write %test.ps postscript [page [path [linewidth 10 at 72x72 box 
72 72]]]
and then open test.ps with Finder.

ok :)

Maybe box shouldn't be inside a path block, but be an instance of 
itself?

I have no idea...

What is best?
page [path [at 72 72 box 100 100]]
or 
page [box 72 72 100 100]

the first one is most readable

Try:
do http://home.tiscali.dk/john.niclasen/postscript/postscript.r

write %test.ps postscript [page [linewidth 5 path [setgray 0.5 at 
72.5 72 boxfill 72 72]]]

wonderful!

I guess, linewidth mean nothing in that example and can be left out. 
Sorry about that!

I wonder if it's possible to flip the coordinate system to match 
that of DRAW

I read something about that...

draw starts 0x0 at bottom left ?

you can write postscript functions that translate from one coordinate 
to another.

PostScript normally uses units of "points" for placing graphics on 
the page. I find it more convenient to work with centimeters. I got 
the following snippet of PostScript code from a public domain program 
called "GLE" which I believe is available at any large ftp site; 
I recommend this graphics program. By examining the PostScript output 
of that program I collected the following piece of PostScript code:


matrix currentmatrix /originmat exch def /umatrix {originmat matrix 
concatmatrix setmatrix} def [28.3465 0 0 28.3465 10.5 100.0] umatrix


What this basically does is rescale the page so that now all following 
commands will work as if the centimeter is the basic unit of length. 
This places (0,0) near the bottom left of the page and (21,24) near 
the top right of the page.


If you don't do this, then (0,0) is the bottom left corner of the 
page and (612,792) is the top right corner of the page (if you are 
using an 8 1/2 inch by 11 inch sheet of paper). These are the default 
PostScript units; 72 of these to an inch. 28.3465 to a centimeter, 
thus the numbers above in the last line of PostScript code.

taken from http://www.physics.emory.edu/~weeks/graphics/howtops1.html

it does?

John, what version is that script ?  I see 0.1.1

I think my isp heavily caches so I can't see new stuff.

version 0.2.0 now. Refresh!

New version with cm!
do http://home.tiscali.dk/john.niclasen/postscript/postscript.r

write %test.ps postscript [page [setcm linewidth 20 path [setgray 
0.5 at 2.5 2 boxfill 8 12]]]

setcm seems to influence font size. Try:
do http://home.tiscali.dk/john.niclasen/postscript/postscript.r

write %test.ps postscript [page [font [Times-Roman 1] setcm linewidth 
0.5 path [setgray 0.5 at 2.5 2 box 8 12] path [at 5x8 rotate 45 "Hello 
World!"]]]

AT can both be specified as a pair and 2 numbers.

I can't find the switch y-axis thing right now. Maybe a matrix is 
needed?

well, my postscript printer printed out a gray box!

Wow! :)

We're not all lost then! ;-)

Good news. :)

You should really put the %!PS header in.

Comments come last.

% mean comment.

I know.  It tells the printer what is coming.

whether it's postscript, pdf or whatever.

ahh, then I'll put it in now.
Just:
%!PS
?

sure.

%!PS-Adobe-3.0
%%Creator: postscript.r ver 0.2.0

done

so both "at 3x3" and "at 3 3" can be used?

yes

New version with line, try:
do http://home.tiscali.dk/john.niclasen/postscript/postscript.r

write %test.ps postscript [page [linewidth 5 path [setgray 0.8 line 
72x72 100x72 102.5 87.3 200x115]]]

again coords can be a pair or 2 numbers, also decimals.

setcm doesn't seem to work here...

When setcm is used, max coords is 20 or so to be within page.

21x24