Re: bug in terminals affected by 'set size'

[Ethan M. <merritt@u.washington.edu>]

On Wednesday 05 October 2005 03:17 am, Robert Hart wrote:
> Basically your argument only makes sense if each terminal allows an
> explicit size argument in the term options. Then the "set size" option
> simply allows you to scale the plot within those bounds.

I agree.  So let's add a "size XX,YY" option to those terminals where
it is currently missing.  For pixel-based terminals this is trivial.
I've just done so for PBM.  [*]


For PostScript-like terminals it is a bit more complicated, since the
output file eventually needs the 4 corners of a bounding box rather
than just a width and height.  What would you prefer:

  set term post eps size XX,YY   

	more consistent with pixel-based terminals,
	but no explicit control over placement on page

  set term post eps boundingbox x1,y1,x2,y2

	corresponds exactly to what will appear in the *.eps file

For PostScript proper (as opposed to eps), I would prefer a different
approach.  I propose instead to update the patch #908040 that almost
made it into version 4.0, which breaks out the PostScript prolog text
into an external file that can be locally customized.  Then you could
have an A4 prolog, a USLetter prolog, and so on.  This mechanism allows
great flexibility in locally configuring the PostScript output without
having to modify gnuplot itself.  

The main stumbling block at the time was figuring out where to store
such an external file on a  MSWin box.  I am the wrong person to
sort this out, but I can't believe it's an insurmountable hurdle.



[*] Side Note: the generic bit-map routines in bitmap.c are in serious
need of clipping tests.  Right now if you select a too-small bitmap
dimension, the use of unsigned ints to represent coordinates bites in
a big way.  Any coordinate that tries to go negative wraps to a
ridiculously large number instead, essentially sending the code into
an infinite loop.  Try "set size .1,.1; set term pbm; test".
One more example of why I think we should try to rid the core 
routines of using "unsigned int" for coordinates.
 

-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195