Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!spool.mu.edu!uunet!mcsun!hp4nl!charon!piring.cwi.nl!jansteen From: jansteen@cwi.nl (Jan van der Steen) Newsgroups: comp.lang.postscript Subject: Re: Stroking thick lines about arcs Message-ID: Date: 22 Feb 91 10:56:07 GMT References: <1991Feb20.161757.24206@motcad.portal.com> Sender: news@cwi.nl Lines: 57 jtc@motcad.portal.com (J.T. Conklin) writes: >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. [text deleted...] >Is this behavior acceptable? I can't find any documentation on anything >like a stroke step parameter. Should the step size automagically get >smaller when stroking an arc of sufficient curvature? [program deleted...] >I would be interested to know if this prints without white specks in the >circle on a real Adobe Interpreter. I tested on: 1. Data Products LZR 2665 (39.0) 2. Agfa P3400PS (48.1) 3. Oce 6750 PS All three gave a closed arc with no white specks anywhere. The Data Products and Agfa have an official Adobe board, the Oce uses a PostScript clone. The GhostScript interpreter *did* give the effect you described. I could solve this by adding a "closepath" after the "arc" call: [...] newpath 0 0 radius points 3 div add 0 360 arc closepath % <<<<<<<< [...] And maybe you will also need to set the linejoin parameter: [...] 1 setlinejoin % <<<<<<<< newpath 0 0 radius points 3 div add 0 360 arc closepath [...] Jan van der Steen -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Jan van der Steen jansteen@cwi.nl Centre for Mathematics and Computer Science (CWI) Kruislaan 413, 1098 SJ Amsterdam, The Netherlands -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Jan van der Steen jansteen@cwi.nl Centre for Mathematics and Computer Science (CWI) Kruislaan 413, 1098 SJ Amsterdam, The Netherlands