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Bugs item #480, was opened at 2006-02-12 18:12 You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=493&aid=480&group_id=106 Category: None
Group: v1.30.0 Status: Open Resolution: Wont Fix Priority: 3 Submitted By: Ian Hutchinson (ihutch) Assigned to: Nobody (None) Summary: pdftex offset incorrect with \magnification. Patch included.
Initial Comment: Any plain tex file that uses \magnification gives incorrect text placement in pdf. This bug is present in the latest pdftex version 1.21a. It apparently was caused by the introduction of the new variables \pdfvoffset and \pdfhoffset. This bug was not present in older pdftex, e.g. version 3.14159-1.10b, which was part of tetex-2... A simple illustration of the problem is with the trivial file: \magnification \magstep3 %The following parindent and offset changes are not the cause of errors. %They are merely to illustrate them clearly by writing at top left. %Anything other than \magstep0 gives a placement error with pdftex 1.21a. \parindent 0pt \hoffset -1 truein \voffset -1 truein The top. \end With tex and xdvi, the words "The top." are placed at the immediate top left. With pdftex 1.21a and xpdf (or acroread) they are not. With earlier pdftex 1.10b (e.g.) they are. I had an extensive discussion on comp.text.tex with Heiko Oberdiek, most of which is at http://www.codecomments.com/Tex/message784423.html The gist of it is that backward compatibility with plain tex files is very important. As far as possible, it should be preserved transparently. Authors should not be required to hack their files in order for them to render the same in pdf as in dvi. Moreover there is a simple way to provide this compatibility. A reasonable way to fix the bug is to change pdftex.ini and hence pdftex.fmt. (The corresponding pdfetex files ought also to be fixed.) A proposed patched pdftex.ini file is attached. It consists simply of % Thomas Esser, 1998, 2004. public domain. \ifx\pdfoutput\undefined \else \ifx\pdfoutput\relax \else \input pdftexconfig \pdfoutput=1 \fi \fi \input plain \ifx\pdfoutput\undefined \else \ifx\pdfoutput\relax \else \catcode`@=11 \def\m@g{% \mag\count@ \hsize6.5truein\vsize8.9truein\dimen\footins8truein %These commands fix the pdf sizes to be in true units. \mag@fix\pdfhorigin \mag@fix\pdfvorigin \mag@fix\pdfpagewidth \mag@fix\pdfpageheight } \def\mag@fix#1{% #1=\expandafter\convert@truept\the#1\relax } \begingroup \catcode`P=12 \catcode`T=12 \lowercase{% \endgroup \def\convert@truept#1PT{% #1truept% }% }% \catcode`@=12 \fi \fi \dump \endinput I don't know who takes responsibility for pdftex.ini. But clearly this ought to be fixed for all distributions. I care most about tetex, because it is what I use. Thanks, Ian Hutchinson ---------------------------------------------------------------------- Comment By: The Thanh Han (hanthethanh) Date: 2006-10-23 20:49 Message: Logged In: YES user_id=710 oh yes, thanks Phil for the correction. In response to Ian Hutchinson: I am the maintainer of neither pdftex.ini nor pdftex, so I feel that someone else must make the decision. ---------------------------------------------------------------------- Comment By: Philip TAYLOR (chaa006) Date: 2006-10-23 20:21 Message: Logged In: YES user_id=3040 Thanh wrote : I propose that if someone changes magnification then he/she is suppposed to say \pdfhorigin=1in \pdfvorigin=1in Surely they should write \pdfhorigin = 1 true in \pdfvorigin = 1 true in should they not ? I always do, and it certainly has the intended effect. ** Phil. ---------------------------------------------------------------------- Comment By: Ian Hutchinson (ihutch) Date: 2006-10-23 19:49 Message: Logged In: YES user_id=3410 In response to hanthethanh, let me explain once again that the point is that TeX ought always to work the same with both dvi output and pdf output. The latest pdftex breaks that for all documents, old or new, that use \magnification. Of course there are many ways the authors can fix those documents by adding new commands. BUT THEY SHOULD NOT HAVE TO. TeX's archival integrity is far too valuable for us to accept it being broken by this incompatibility. I've shown how it can be transparently fixed. The correction just needs to be incorporated into the distributions ---------------------------------------------------------------------- Comment By: The Thanh Han (hanthethanh) Date: 2006-10-23 12:37 Message: Logged In: YES user_id=710 I propose that if someone changes magnification then he/she is suppposed to say \pdfhorigin=1in \pdfvorigin=1in or something similar. An undocumented trick is that if \pdfhorigin or \pdfvorigin is not set (or set to 0) when the first page is shipped out, then they will get 1in as the default value. To get zero origin(s), use 1sp instead of 0. ---------------------------------------------------------------------- You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=493&aid=480&group_id=106