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- Newsgroups: comp.lang.postscript
- Path: sparky!uunet!gatech!purdue!mentor.cc.purdue.edu!news
- From: ab@nova.cc.purdue.edu (Allen B)
- Subject: Re: Unprintable regions - definitive answer sought
- Message-ID: <C1F709.C6A@mentor.cc.purdue.edu>
- Sender: news@mentor.cc.purdue.edu (USENET News)
- Organization: Purdue University
- References: <C1EMrJ.2M3@mnveger.uucp>
- Date: Mon, 25 Jan 1993 17:24:08 GMT
- Lines: 54
-
- In article <C1EMrJ.2M3@mnveger.uucp> michaelv@mnveger.uucp (Michael Vishchers)
- writes:
- > This may sound like a silly question, but I would like to know if i
- > can expect a point with given coordinates to have the same vertical and
- > horizontal distances from the lower left corner on any printer.
-
- The Red Book says (New page 151, old page 65) that you can,
- and it's close to right. The only problem you'll have is
- with registration and some broken interpreters. I
- recently heard of a non-Adobe implementation that
- seemed to have the origin consistently off the bottom
- left corner.
-
- > A problem arises when the printer has unprintable regions, i.e., cannot
- > print on the margins. What should I expect if I printed a square box
- > with sidelength 1 inch, placed at the origin ? If a printer cannot print
- > on, e.g., the left and bottom half inch of the paper, will I see a
- > smaller box with the upper right corner at (1 inch, 1 inch), or will I see
- > a full but translated box ?
-
- You will get the upper right corner of the box drawn in the
- right place, but those sides will end at the margin. You
- won't see the bottom or left side at all.
-
- In other words, the unprintable region won't be inked,
- but it should be handled correctly. Some devices have
- large unprintable regions, some have none (within the
- paper, I mean :-) ). I commonly print out signatures on a
- Linotronic, for instance, where the letter-sized pages
- are completely usable.
-
- > I couldn't find an answer in the FAQ or the Red Book, so does anyone know
- > if there is a standard behaviour ?
-
- I pointed to the Red Book, but I guess that doesn't quite
- explain it. Do you know what a clipping path is? Imagine
- there's a clipping poath at the margin (there probably
- is, actually) that keeps you from drawing outside of
- that. Now imagine the default coordinate system
- originates at the lower-left of the page and that the axes
- go right and up.
-
- In that situation, something drawn at 100, 100 should be
- 100 units up and right of the lower-left corner of the
- page. The registration of paper through the printer
- mechanism may make that slightly wrong, but it should be
- close. Print several sheets and see how much they vary.
-
- Something drawn very near the origin will get clipped by
- the clipping path (or the physical extent of the printing
- area, whichever is smaller), but will be in the correct
- place.
-
- ab
-