Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!pcrat!rick
From: rick@pcrat.UUCP (Rick Richardson)
Newsgroups: comp.text
Subject: Re: What features would you like in GNU troff?
Message-ID: <779@pcrat.UUCP>
Date: 10 Jun 89 04:03:15 GMT
References: <JJC.89May31220314@jclark.UUCP> <742@dtscp1.UUCP> <10959@orstcs.CS.ORST.EDU> <21@nx32s.anduk.co.uk>
Reply-To: rick@pcrat.UUCP (Rick Richardson)
Distribution: comp
Organization: PC Research, Inc., Tinton Falls, NJ
Lines: 47

In article <21@nx32s.anduk.co.uk> lee@nx32s.UUCP (0000-Liam R. Quin) writes:
>> From: rick@pcrat.UUCP (Rick Richardson) {Me}
>> Absolutely.  Using macros can get text to swim around bitmaps to the
>> left or right.  But I haven't figured out a way to make text swim
>> between arbitrary bitmaps placed anywhere in the output using just
>> macros.  Troff has to be taught this.

>  One way to do it is to implement `software traps' or call-out lists,
>  which are like traps but allow arguments.  You can implement these as
>  macros.
>  Then you can implement linked lists, and you can use use the call-outs to
>  scan the lists for boxes.
>  In any event, you still have fun including the bitmap, especially if
>  your troff doesn't support \B'bitmap xsize ysize' or something similar.

I don't think this works.  I want to be able to tell troff that there
are "holes" in the paper, and to skip the "holes" when justifying
text:
	This is a test of  a
	hole ******** in the
	page ********  being
	skipped magically.

I don't think you can do this with just macros.  You'd need a horizontal
trap.

Also, it isn't any great trick to do the actual include of bitmaps.
Troff doesn't need to be taught this; it can all be done via macros.
JetRoff does this via a ".BM" macro, whose basic arguments are:

	.BM bitmap_file_name file_type placement

e.g.:
	.BM picture.pcx pcx RJ
	.BM signature.pcx pcx L

Includes picture.pcx right justified (text swims left around the picture),
and includes signature at the left margin (text skips past the bitmap).
The macro takes care of determining the size of the bitmap and arranging
for troff skip by or around the bitmap.  This works fine for virgin
AT&T troff.

-- 
Rick Richardson | JetRoff "di"-troff to LaserJet Postprocessor|uunet!pcrat!dry2
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