Bugs item #396, was opened at 2005-08-01 17:17 You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=493&aid=396&group_id=106 Category: Fonts Group: v1.10b Status: Open Resolution: None Priority: 3 Submitted By: Henrik Tidefelt (tidde) Assigned to: Taco Hoekwater (taco) Summary: The bbox of Form XObjects is too small Initial Comment: Run the following source trough pdflatex, and look carefully at the top and bottom of the output characters. They are chopped off by just a little, and that is due to the bbox of the Form XObject being too small. The problem is not growing with the height of the box (putting "\parbox {1cm}{S\S\S\y}" in the box instead of "Sy"), so it shouldn't be a pt/bp confusion thing. <<<---------------------------- \documentclass{article} \newcommand{\smallbox}[1]{% \setbox0 = \hbox{#1}% \pdfxform attr { } resources{ } 0 \shipout\hbox{\pdfrefxform\pdflastxform} } \begin{document} \smallbox{Sy} \end{document} --------------------------->>> ----------------------------------------------------------------------

Comment By: Hans Hagen (hagen) Date: 2005-08-01 19:53

Message: Logged In: YES user_id=927 There is nothing wrong with xforms and changing xform behavior is quite dangerous after all these years. A non-tight boundingbox of chars is rather normal. A tex font has a limited number of heights and depths for a character so sometimes it's due to that limitation. Also, font designers may wish to lie about te boundingbox (for proper alignment purposes and such); its' rather normal to let curver lines stick out the bbox). Also side bearings play a role. So .. i'm not that sure if we're dealing with a bug here. More a side effect. ---------------------------------------------------------------------- Comment By: Martin Schröder (oneiros) Date: 2005-08-01 18:56 Message: Logged In: YES user_id=421 This is not a pdfTeX problem, but a font problem. Look at the output of this code: -------------------------- \pdfcompresslevel=0 \pagestyle{empty} \documentclass[a5paper]{article} \setlength{\fboxsep}{0pt} \setlength{\fboxrule}{0.01pt} \newcommand{\smallbox}[1]{% \fbox{#1}% \setbox0 = \hbox{#1}% \pdfxform 0 \pdfrefxform\pdflastxform } \begin{document} \Huge \smallbox{Sy} \end{document} -------------------------- You'll notice that the fbox has the same size as the bbox and cuts through the chars the same way. ---------------------------------------------------------------------- Comment By: Henrik Tidefelt (tidde) Date: 2005-08-01 17:52 Message: Logged In: YES user_id=2683 After thinking two more minutes, I recall that the size of the bbox agrees with the size of the TeX object in the box. Perhaps the font lies about the glyph sizes, so that they will be typeset nice and thight? In that case, that must be taken into account when generating Form XObjects. My solution to the problem at the moment is to add a bigpoint in every direction of the bbox. I don't see any harm in adding even more, so I could possibly make sure that the box is always big enough. However, I am afraid that I could run into new problems as this problem gets fixed in pdftex; just adding something mysterious to the bbox size to make it big enough would actually make things worse for my application, as I use the TeX depth information to locate the baseline. Therefore, I'd appreciate if either a documented, fixed, space was used, or that the same amount of space was added below and above (left and right). That way, the TeX origin could still be located. ---------------------------------------------------------------------- You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=493&aid=396&group_id=106