X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1694" "Wed" "16" "June" "93" "22:38:32" "+0200" "Frank Mittelbach" "MITTELBACH@MZDMZA.ZDV.UNI-MAINZ.DE" nil "41" "Re: getting information about the x/y values for a given point" "^Date:" nil nil "6"]) Return-Path: Received: from sc.ZIB-Berlin.DE (mailserv) by dagobert.ZIB-Berlin.DE (4.1/SMI-4.0/1.9.92 ) id AA11105; Wed, 16 Jun 93 22:45:21 +0200 Received: from vm.urz.Uni-Heidelberg.de (vm.hd-net.uni-heidelberg.de) by sc.ZIB-Berlin.DE (4.1/SMI-4.0-sc/03.06.93) id AA02827; Wed, 16 Jun 93 22:45:19 +0200 Message-Id: <9306162045.AA02827@sc.zib-berlin.dbp.de> Received: from DHDURZ1 by vm.urz.Uni-Heidelberg.de (IBM VM SMTP V2R2) with BSMTP id 9503; Wed, 16 Jun 93 22:43:46 CET Received: from DHDURZ1 by DHDURZ1 (Mailer R2.08 R208004) with BSMTP id 9211; Wed, 16 Jun 93 22:43:41 CET Received: from DHDURZ1 by DHDURZ1 (Mailer R2.08 R208004) with BSMTP id 9209; Wed, 16 Jun 93 22:43:39 CET Reply-To: Mailing list for the LaTeX3 project Date: Wed, 16 Jun 93 22:38:32 +0200 From: Frank Mittelbach Sender: Mailing list for the LaTeX3 project To: Multiple Recipients of Subject: Re: getting information about the x/y values for a given point Status: R X-Status: X-Keywords: X-UID: 1053 > Subj: RE: getting information about the x/y values for a given point > i thought there was a way to do this x/y stuff. > there is something in the tex88 proceedings > which suggests that it can be done, i think as a two > oass procedure (which is no problem if we are messing > with labels and references). do people recall this > or shall i dig out the reference? I guess you mean the nice article by Alan Hoenig. While he actually discusses a lot of interesting line-oriented typsetting problems and their (partial) solutions within TeX, none of this comes near solving the general problem - putting some label in the text and - have a way of accessing the information where this label finally falls on the printed page. Even the limited possibilities that are possible within the TeX language itself are no real help since only what ends up in the final shipout counts and the only way to access this is using \specials and an external program. If for example one tries to masure the vertical point in the current galley this is only an approximation of the truth if at all. (Think of the galley that for example multicol uses, you would get interesting results if you would beleave in the values your macro would return then.) And for the horizontal position there is no way to determine it without modifying it at the same time (ie making the paragraph breaking less good). Beside even if there is a very complicated way of solving this problem within TeX I think the use of TeX's limited resources for this is the wrong approach. Whereas I feel that for specialized applications the extra effort of running an external program between two runs could be justified. Frank