Re: gnuplot graphics toolkit bugs

[Daniel J Sebald]

On 06/24/2015 07:45 PM, Tatsuro MATSUOKA wrote:
> Probably this is a bad news for some unix platforms.
>
> from KNOWN ISSUES for gnuplot 5.0
>
> * Mouse double-click to export terminal coordinates to the X11 clipboard no 
> longer works reliably, and may be deprecated in the future.

I'll look into this.


> For gnuplot 5.0, x11 terminal is not a reliable one.
> Now recommended terminal is the wxt or the qt terminal.

That's a premature statement, in my opinion.  x11 terminal is 
reliable--fallen out of favor would be more like it.  The reason that 
statement came about, I believe, is that wxt/qt have, let's say, more 
robust features for images and aliasing.  This is true, but in some 
sense it is an apples/oranges comparison.

For example, qt terminal uses QPixmap

http://doc.qt.io/qt-5/qpixmap.html

which is a feature of Qt to handle display of images.  However, this is 
at a very high level in which image elements are treated individually, 
not as a whole image.  Consequently, the user will find that the Qt 
terminal can be rather slow for large data sets.  x11 is very low level, 
so is much faster.  Yet, wxt is fast as well.

As I see it, gnuplot qt terminal is a good default for Octave as it has 
the same look and feel because it is Qt-based and is robust as far as 
platforms go.  The data crunchers/viewers may want to switch to wxt.  If 
wxt isn't available or has some quirk, x11 works nearly as well and is 
as fast.

One advantage of x11 is that it is low level and does not involve 
OpenGL.  In other words, any bugs in the OpenGL driver--which could be 
specific to one's hardware setup--don't show up in gnuplot's x11 terminal.

Dan