Aandi, thanks for responding. All I am trying to do is implement HTML->PDF conversion and emulate a browser when it displays a mixture of text characters of various sizes.
> That would be ideal, but I think every common program is likely to simply > use the size of the second line. Nope, that won't work, see the attached image. The portions of line 1 gryphs hanging below the baseline overlap with the line 2 glyphs. Peter Persits Persits Software, Inc. http://www.persits.com ----- Original Message ----- From: "Aandi Inston" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, December 26, 2003 4:59 AM Subject: RE: [PDFdev] Default leading > > PDFdev is a service provided by PDFzone.com | http://www.pdfzone.com > _____________________________________________________________ > > > I have a question about a font's default leading, i.e. the distance > > between baselines. I have done some experimenting with the Distiller > > and can't quite figure out how it computes the default leading. > > For example...Where is the extra 1.52 coming from? > > It's important to realise where the decision making is done. Distiller > makes absolutely no decisions about text placement or leading. It is the > application or driver which is responsible for deciding where, exactly, > each character is placed. Distiller just preserves it. > > So what you are seeing is not in any sense the behaviour of > Distiller. It is the behaviour of Word and the PostScript driver, on > your particular combination of software and operating system. > > Better typesetting systems will allow the user to select a leading. > > > I am also facing a more complex problem - how to compute distances > > between lines of text of diffrent point size (e.g. line 1 is size 12 > > and line 2 is size 8). Apparently I need to take into account the > > upper line's descender value and lower line's ascender > > That would be ideal, but I think every common program is likely to simply > use the size of the second line. > > You are heading in two directions, and I'm not sure which it is: laying > out text, or typography? In the former case, developers make arbitrary > decisions in a vacuum, resulting in wildly different behaviour. In the > second, typography is a huge and complex subject, especially in the area > of hyphenation and justification. There seems little written down, but > pinning down someone who once set hot metal may help. Results vary > even more wildly, and most users won't notice the difference, but > professionals might be happier. You have to decide > which path you are going down... > > Aandi > > To change your subscription: > http://www.pdfzone.com/discussions/lists-pdfdev.html > >
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