🚀 go-pugleaf

In article <1991Feb22.171314.5128@motcad.portal.com> jtc@motcad.portal.com (J.T. Conklin) writes:
>In article <1991Feb21.225435.15664@cbnewsh.att.com> jlp@cbnewsh.att.com (jon.peticolas) writes:
>>From article <1991Feb20.161757.24206@motcad.portal.com>, by jtc@motcad.portal.com (J.T. Conklin):
>>> I have been observing that stroking an arc with a ``thick'' line results
>>> in some areas of white peeking through the line --- especially about the
>>> outside perimeter --- on two independant PostScript implementation.
>>
>>The closepath operator tells postscript that the ends of the path are
>>to be joined with a mitered connection. If they are not actually the
>>same point, the path will be completed with a straight line. This detail
>>is covered in chapter 3 of the Adobe blue book (in my admittedly outdated 
>>copy anyway).  Additional line joining details are covered in chapter 10.
>
>Thanks for the hints about closepath, as it solved a different problem with
>the example that occurs with Ghostscript --- A little sliver of  white is
>not filled at the point where the two ends of the arc should joins. 
>
>The original problem, was that little slivers of white were peeking
>through spaced evenly about the perimeter of the circle.  The vendor
>of the interpreter in question has admitted the problem and I hope
>they will be able to send me a fix soon.
>

You might like to try using setflat to fix this problem.  Setflat
controls how many straight line segments are used to approximate
the bezier curves used in PostScript.  In the case of the arc
operator, bezier curves are generated to approximate real circles
since PostScript doesn't have real circles.  The argument to setflat
controls the maximum error between the bezier and it's approximating
line segment as measured in device pixels.  Se if a 

	currentflat 5 div setflat

fixes your problem.  Even the adobe interpreters can be pushed too
far and exhibit similar problems.  Try the code below for an example
of this.

	currentflat 5 mul setflat
	144 setlinewidth
	300 300 18 0 180 arc
	stroke
	showpage

Of course decreasing the currentflat has performance implications
so be sure to put it back the way you found it after you've finished
with the critical part or your printer will take a performance hit.

						James Ashton.