[Octave-bug-tracker] [bug #60509] octave-cli fails to print figure when 'visible' is 'off'

[anonymous]

URL:
  <https://savannah.gnu.org/bugs/?60509>

                 Summary: octave-cli fails to print figure when 'visible' is
'off'
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Mon 03 May 2021 02:12:15 PM UTC
                Category: Plotting
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: None
                  Status: None
             Assigned to: None
         Originator Name: David Hülsmeier
        Originator Email: david.huelsmeier@uol.de
             Open/Closed: Open
                 Release: 6.2.0
         Discussion Lock: Any
        Operating System: GNU/Linux

    _______________________________________________________

Details:

Hi,

this error only occurs when using octave-cli, but not when using octave from
the command line.

After opening a new figure with visible 'off', fltk is automatically selected
as graphics toolkit.
This leads to a printing error.
After closing the  first graphic and setting the graphics toolkit to gnuplot,
the printing process works.

Code example:

graphics_toolkit('gnuplot')
graphics_toolkit                       %--> gnuplot (expected)
t = linspace(0,1); y = sin(2*pi*t*10);
figure(1,'visible','off') 
graphics_toolkit                       %--> fltk (bug; not expected)
plot(t,y)
print('-depsc2','-r300','bla.eps')     %--> error (see below)

close all            
graphics_toolkit('gnuplot')            
figure(1,'visible','off')  
graphics_toolkit % --> gnuplot         %--> gnuplot (as desired)
plot(t,y)
print('-depsc2','-r300','bla.eps')     %--> ok


Error msg:

error: print: figure must be visible or qt toolkit must be used with
__gl_window__ property 'on' or QT_OFFSCREEN feature available
error: called from
    __opengl_print__ at line 209 column 7
    print at line 757 column 16


Expected behavior:
The same graphics toolkit is used after the first call of "figures", and the
figure is drawn with the 'visible','off' property.

Tested on
- Ubuntu 21.04; GNU Octave, version 6.1.1~hg.2021.01.26
- ArcoLinux; GNU Octave, version 6.2.0






    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?60509>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/