From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.tex.context/17893 Path: main.gmane.org!not-for-mail From: Laurence Finston Newsgroups: gmane.comp.tex.context Subject: Re: [metapost] shading in meta[post/play] & PDF Date: Wed, 19 Jan 2005 11:59:27 +0100 (MET) Message-ID: References: <20050115210457.24F53127CC@ronja.ntg.nl> <41EE2FA8.4080002@guest.arnes.si> Reply-To: mailing list for ConTeXt users NNTP-Posting-Host: deer.gmane.org Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Trace: sea.gmane.org 1106211329 7380 80.91.229.6 (20 Jan 2005 08:55:29 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Thu, 20 Jan 2005 08:55:29 +0000 (UTC) Cc: mailing list for ConTeXt users , metapost@tug.org Original-X-From: ntg-context-bounces@ntg.nl Thu Jan 20 09:55:21 2005 Return-path: Original-Received: from ronja.vet.uu.nl ([131.211.172.88] helo=ronja.ntg.nl) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 1CrY64-0007Xf-00 for ; Thu, 20 Jan 2005 09:55:21 +0100 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by ronja.ntg.nl (Postfix) with ESMTP id 16A171276B; Thu, 20 Jan 2005 09:55:20 +0100 (CET) Original-Received: from ronja.ntg.nl ([127.0.0.1]) by localhost (ronja.vet.uu.nl [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 31498-06; Thu, 20 Jan 2005 09:55:20 +0100 (CET) Original-Received: from ronja.vet.uu.nl (localhost.localdomain [127.0.0.1]) by ronja.ntg.nl (Postfix) with ESMTP id BB81A1277B; Thu, 20 Jan 2005 09:53:25 +0100 (CET) Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by ronja.ntg.nl (Postfix) with ESMTP id 3F3621278F for ; Wed, 19 Jan 2005 11:59:37 +0100 (CET) Original-Received: from ronja.ntg.nl ([127.0.0.1]) by localhost (ronja.vet.uu.nl [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 24928-02-2 for ; Wed, 19 Jan 2005 11:59:36 +0100 (CET) Original-Received: from mailer.gwdg.de (unknown [134.76.10.26]) by ronja.ntg.nl (Postfix) with ESMTP id 60FAB1276B for ; Wed, 19 Jan 2005 11:59:36 +0100 (CET) Original-Received: from gwdu71.gwdg.de ([134.76.8.21]) by mailer.gwdg.de with esmtp (Exim 4.42) id 1CrDYj-00022T-EC; Wed, 19 Jan 2005 11:59:33 +0100 Original-Received: from localhost by gwdu71.gwdg.de (8.11.1/1.1.29.3/16Jun03-0924AM) id j0JAxRZ0000098748; Wed, 19 Jan 2005 11:59:27 +0100 (MET) X-Authentication-Warning: gwdu71.gwdg.de: lfinsto1 owned process doing -bs Original-To: Mojca Miklavec In-Reply-To: <41EE2FA8.4080002@guest.arnes.si> X-Virus-Scanned: (clean) by exiscan+sophie X-Virus-Scanned: by amavisd-new at ntg.nl X-Mailman-Approved-At: Thu, 20 Jan 2005 09:53:24 +0100 X-BeenThere: ntg-context@ntg.nl X-Mailman-Version: 2.1.5 Precedence: list List-Id: mailing list for ConTeXt users List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: ntg-context-bounces@ntg.nl Errors-To: ntg-context-bounces@ntg.nl X-Virus-Scanned: by amavisd-new at ntg.nl Xref: main.gmane.org gmane.comp.tex.context:17893 X-Report-Spam: http://spam.gmane.org/gmane.comp.tex.context:17893 On Wed, 19 Jan 2005, Mojca Miklavec wrote: > > How can I make shading inside metapost(play) to produce exactly what's > in the attached picture (smooth shades). Or more generally: how can I > "hardcode" some PS/PDF code in .mp, not (yet) supported by metapost(play)? > This is a very difficult question. For an excellent introduction to shading and other subjects I recommend: Jones, Huw. _Computer Graphics through Key Mathematics_. Springer-Verlag London Limited 2001. ISBN 1-85233-422-3. > > Here's the corresponding PostScript code: > Sorry, I don't know PostScript. > > >>The spheres drawn directly in PostScript as in the examples above still > >>have straight lines (well, I agree that with some mathematics it would > >>be possible to draw them with proper splines as well). > >> To the best of my knowledge, spline curves are drawn by means of calculating short line segments. You can make the "time" parameter as small as you like, but you can't make it 0. I believe plotters can draw genuine curves---and it's a lot more fun to watch them work (it's like magic). They're not so great at filling in regions, though. Much to my regret, the computer center here got rid of the plotter. They're probably as obsolete as the ENIAC now, except perhaps for very high-quality work. > Thank you, My pleasure. Laurence