Hi Deri, At 2023-12-10T18:43:42+0000, Deri wrote: > On Saturday, 9 December 2023 19:25:27 GMT G. Branden Robinson wrote: > > When a line of output is "finished" and sent to the device > > (device-independent output is prepared for it), the vertical > > position advances by one vee, and, (in groff, if vertical position > > traps are not disabled,) any visible vertical position traps planted > > between the previous text baseline and the new one are sprung.[1] > > If one of these traps is what I term "the implicit page trap"[2], > > then the page is ejected and a new one started. > > Is this the problem? It does not make sense to start a new page until > groff "knows" there will be further output.
Changing that is a deeper, more intrusive change than I am proposing. It would affect approximately all page transitions processed by the formatter. Not saying that it's wrong or a bad idea, but it's significantly more ambitious than what I proposed. > So if the implicit page trap is triggered it should set a flag to > trigger the new page code if further output, other than "x trailer", > is output. This is an example of troff output:- > > x T pdf > x res 72000 1 1 > x init > p1 > x font 5 TR > f5 > s10000 > V12000 > H72000 > mr 0 0 0 > DFd > tline > n12000 0 > V792000 > H72000 > tline > n12000 0 > V792000 > p2 > x trailer > V792000 > x stop > > The V792000 and p2 are unnecessary unless there is further output. That's true, but my hunch is that most *roff users over the years to want to write within 1v of the page bottom use "local" vertical motions from a safe distance to do so. Hmmm, I was going to show you an exhibit involving `\V` but managed to surprise myself. Here's a counterexample. $ cat ATTIC/kiss-foot.tr .\" U.S. letter paper assumed .sp 65v Hello! This produces a ONE page PostScript document with "Hello!"'s text baseline sitting at the very boundary of the paper. And there is no blank second page. I had predicted one, so obviously there is more for me to understand here. (And another trip back to groff.texi with my text editor after that.) Obviously when the formatter performed a break and pushed the output line, it recognized that there was no more input, and didn't break the page as well. Here's the grout: $ groff -Z ATTIC/kiss-foot.tr x T ps x res 72000 1 1 x init p1 x font 5 TR f5 s10000 V792000 H72000 md DFd tHello! n12000 0 x trailer V792000 x stop (It even _SAYS_ there's a break after the text, with the 'n12000 0' documentary command.) I challenge you to explain! :D Regards, Branden
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