These are interesting and important issues. I had no notion of the HZ algorithm, but I was dimly aware from my reading as a teenager of the "rivers" problem, and acutely conscious of its distracting effect from my reading. In my thinking about layout, I have been conscious of the need to be able to evaluate such issues at a high level. The only way such an evaluation can be done is by layout look-ahead. The page must be laid out before "rivers" can be assessed. (Finding them would be an interesting problem in itself - and no doubt part of HZ.)
Layout sometimes occurs in an environment of known available BPDimension and IPDimension, sometimes with only one dimension, and sometimes with neither. In the latter cases, the layout process is effectively a probe to see what the dimensional requirements range for this piece of layout is. However, problems like rivers, last page and footnotes turn all layout into probes, and all layout must potentially be undone and redone in the light of the knowledge gained.
Peter
Victor Mote wrote:
Hello all: I have been looking for some time for a source for the HZ (Hermann Zapf) algorithm which (as I understand) optimizes line breaks for multiple lines, looking for rivers, too many lines in a row ending in hyphens, etc. I think I first saw it referenced in Bringhurst's book, and that it was implemented by a European company that is now out of business. I understand that TeX implemented it or something similar, and that Adobe may have used the TeX algorithm in InDesign. The closest thing I have found to a source for the algorithm itself is that Knuth's "Digital Typography" may have it or at least a discussion of it.Do any of you have additional information on this, such as how to find the algorithm itself? Is it patented? Along these same lines, I recently acquired a book that may be helpful to others -- James Felici's "The Complete Manual of Typography" (Adobe Press) has a lot of good information both for users and developers. Chapter 10 on H&J was especially useful, and somewhat prompted the above questions. Victor Mote (mailto:[EMAIL PROTECTED]) Enterprise Outfitters (www.outfitr.com) 2025 Eddington Way Colorado Springs, Colorado 80916 Voice +1 (719) 622-0650, Fax +1 (720) 293-0044 --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
-- Peter B. West [EMAIL PROTECTED] http://www.powerup.com.au/~pbwest/ "Lord, to whom shall we go?" --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
