Re: terminal quirks, wxt vs qt

[sfeam <sf...@us...>]

On Thursday, 26 June 2014 01:02:29 PM Allin Cottrell wrote:
> Playing with 5.0-rc1 on Linux, I noticed an asymmetry with the wxt and qt 
> terminals. Say you want to open a 3-D plot file and rotate the image 
> interactively. With term = wxt it's enough to do
> 
> gnuplot 3dfile -persist
> 
> but with term = qt (using qt 4, at any rate) you don't get interaction, 
> that requires a controlling terminal window, as in
> 
> xterm -e gnuplot gp3d.plt -
> 
> Sorry if I'm just repeating something well known, but this difference is 
> relevant if gnuplot is being launched by a third-party program; it's much 
> more elegant not to have to open a parent terminal window.

The difference is more profound than you describe.

"persist" mode does not support 3D rotation, because gnuplot itself does
not support true 3D rotation.  It draws successive 2D projections in 
response to mouse feedback requesting that the figure be redrawn at an
incrementally different viewing angle.  The point is that the "rotation"
is really a series of "replot" commands and as such can only be performed
while gnuplot is still running, not after it has exited.

What is misleading you is that the wxt does not really have a true 
"persist" mode (nor does the Windows terminal).  Instead it interprets
"persist"  as "don't really exit until the plot window is closed".

Terminals that have a true persist mode allow you do continue interactions
with the plot window after gnuplot has exited.  

Anyhow, you can get the same behaviour from the qt or x11 terminals,
but not by using "persist".  Use something like "pause mouse close" instead.

I am open to suggestions about whether the -persist option itself
should be re-implemented to mean exactly this.  There are downsides as
well, as this causes a proliferation of gnuplot processes if you create
multiple display windows.

	Ethan