[PATCH] x11 terminal respects the requested aspect ratio

[<gn...@di...>]

Hi all.

I tackled the long-standing issue of the x11 terminal not respecting the
requested plot aspect ratio. There have been many bugs about this on the
tracker. The main one appears to be

http://sourceforge.net/tracker/index.php?func=detail&aid=3331162&group_id=2055&atid=102055

I have a branch that handles this issue similar to the way the wxt
terminal does:

- inboard driver computes a particular x,y scale factors
- terminal ALWAYS respects this aspect ratio
- resizing the window does NOT touch the aspect ratio
- a replot is required to re-compute the scale factors

Similar to the qt terminal, I added a replot-on-resize option to make
things 'just work', at the expense of some extra cpu cycles.

The code works for my test cases, but I had to touch enough stuff to
make me concerned about cases that I missed. How are such changes
tested, usually? I didn't see a test suite.

The code is in a git repo at

https://github.com/dkogan/gnuplot

I'm also attaching a patch for a diff from the latest code in CVS, as
of Sep 2012.

As an aside, the main reason I'm touching the x11 terminal at all
(instead of just moving to wxt or qt) is that it appears to be much
faster than the newer terminals. Particularly, if you have a 3d plot
with lots of points, interactively rotating the data is noticeably much
snappier with x11. Is this expected?

dima