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From: sfeam <sfeam@users.sourceforge.net>
Newsgroups: comp.graphics.apps.gnuplot
Subject: Re: Transparent fillstyle for boxes with postscript
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Date: Fri, 15 Apr 2011 09:16:43 -0700
Organization: gnuplot development team
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Michael Hofmann wrote:

> Am 14.04.2011 17:59, schrieb sfeam:
>> Michael Hofmann wrote:
>>
>>> OK, but why *is* transparency working for "filledcurves" with
>>> PostScript, but *not* for "boxes"? I would expect it works for both,
>>> or for none.
>>
>> The same PostScript commands are used for both plot styles.
>> Perhaps you are noticing a difference between pattern-fill and
>> solid-fill?
> 
> I noticed that transparent pattern-fill with filledcurves works and
> wondered why transparent pattern-fill with boxes fails. Transparent
> solid-fill does not work for both.
> 
> However, pattern-fill with filledcurves in PostScript looks very
> different than pattern-fill with boxes.

I suspect that the difference you see is an artifact of whatever
viewer you are using to look at the PostScript.   Most viewers that
I know of handle pattern fill in rectangular areas OK, although you
may have to disable anti-aliasing.  But many/most of them do a bad
job in non-rectangular areas. More specifically, they do a bad job
of matching the pattern origin in adjoining tiles of a tiled region.

It may be that very recent versions of PostScript support some sort of 
higher-level command to control the rendering of adjoining pattern-fill
areas.  If so, that would be useful - but that's unknown territory for me.

	Ethan


> So I guess these are two
> different routines.
> 
> 
> Michael