[comp.sys.dec] DECwindows PS previewer

eric@batcomputer.tn.cornell.edu (Eric Fielding) (09/20/89)

I am not sure if this is a problem with our PostScript code or the DEC PS
previewer.

We have been using the "dxpsview" PostScript previewer on a DECstation to look
at our PostScript files before sending them to a LaserWriter.  Large files 
sure plot faster than the print on the slow LaserWriter.  Some files, however,
don't work on the previewer that do print on the LaserWriter, ones that define 
a pattern fill via a setscreen procedure.  The relevant PS is this:

/bitison
{/ybit exch def /xbit exch def
bstring ybit bwidth mul
xbit 8 idiv add get
1 7 xbit 8 mod sub bitshift
and 0 ne} def
/setpattern
{/freq exch def
/bwidth exch def
/bpside exch def
/bstring exch def
/onbits 0 def /offbits 0 def
freq 0
{/y exch def /x exch def
/xindex x 1 add 2 div
bpside mul cvi def
/yindex y 1 add 2 div
bpside mul cvi def
xindex  yindex bitison
{/onbits onbits 1 add def 1}
{/offbits offbits 1 add def 0}
ifelse
} setscreen
offbits offbits onbits add div setgray
} def
/pat2 <0808080808080808> def
...
/pat22, etc.

We get an error only when we try to use the pattern file via this call:

 pat2 8 1 300 32 div setpattern  newpath 100 100 moveto 200 200 lineto
 200 100 lineto closepath fill

The error is:

	Error: dictfull; OffendingCommand: def

Is there some way to make the dictionary bigger or is there something wrong 
with the way our patterns are defined or is there probably a bug in dxpsview?

				++Eric Fielding
eric@jasper.tn.cornell.edu
eric@crnlthry.bitnet