Re: Release Plans

[Rik]

On 09/29/2013 10:03 AM, Daniel J Sebald wrote:
> On 09/26/2013 01:54 PM, John W. Eaton wrote:
>> On 09/26/2013 02:51 PM, Michael D. Godfrey wrote:
>>
>>> Now, what about the default graphics_toolkit? The GUI seems
>>> fine with fltk. Should this be the default? I know that there are
>>> arguments on both sides. In my case I now always use fltk.
>>
>> I'm OK with making OpenGL+FLTK the default:
>>
>> http://hg.savannah.gnu.org/hgweb/octave/rev/55680de6a897
>>
>> jwe
>
> I'm not clear on what is gained by OpenGL+FLTK.  If it is a gnuplot license issue, the license is pretty open, it's just that it predates the modern open source licenses and is too much trouble to go back and get approval to modify.  At least, that is my understanding of it.  It's seems like hegemony for it to not be an approved license.
>
There are definite advantages to using OpenGL rather than gnuplot for plotting.  We communicate with gnuplot at arm's length over a pipe.  This is both 1) slow, and 2) limits our ability to tweak things exactly as we please.  There are at least 2 bug reports on the performance of the interface.  Just for ballpark figures, I ran this benchmark of comet which repeatedly draws

graphics_toolkit gnuplot;
t = 0:.1:2*pi;
x = cos (2*t) .* (cos (t).^2);
y = sin (2*t) .* (sin (t).^2);
tic; comet (x,y, 0); toc
Elapsed time is 3.4761 seconds.
close all hidden
graphics_toolkit fltk
tic; comet (x,y, 0); toc
Elapsed time is 1.2542 seconds.

So, the OpenGL interface is roughly 3X faster.

As for the other, we are not able to get complete control of the plots we make with gnuplot.  I find all sorts of notes throughout the code about hacks done to try and compensate.  It also splits our limited developer time.  If we had only one plotting platform to support it would help.

As for visual issues, I think the plan is to unify behind Qt widgets so that the GUI and the plotting appear to belong to the same application.

--Rik