[Octave-bug-tracker] [bug #53073] OpenGL color LUT seems incorrect after a print() for the Qt graphics toolkit

[Dan Sebald]

URL:
  <http://savannah.gnu.org/bugs/?53073>

                 Summary: OpenGL color LUT seems incorrect after a print() for
the Qt graphics toolkit
                 Project: GNU Octave
            Submitted by: sebald
            Submitted on: Tue 06 Feb 2018 01:07:53 AM UTC
                Category: Plotting with OpenGL
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: dev
        Operating System: GNU/Linux

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Details:

With the Qt toolkit, after a print there is a shift in the color of a visible
plot that remains present until positioning the mouse or something else over
the figure window that causes a refresh of the graphics memory.  Note that it
doesn't have to be something that causes a redraw of the figure, just a
refresh of the memory.  I suspect that the LUT (or something similar) for the
graphics memory color map is somehow altered with the context switch from the
graphics driver device to the gl2ps print-driver device.  This does not happen
for FLTK.

Attached are two screenshots of

>> close all
graphics_toolkit qt
plot(1:50, "-o")
print test.pdf


prior to the print() and after the print (without positioning the mouse over a
figure header button, activating the figure, etc.).

I would guess that something needs to be done after the print to refresh the
video memory buffer, e.g., some openGl command to reactivate the current
context.



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File Attachments:


-------------------------------------------------------
Date: Tue 06 Feb 2018 01:07:53 AM UTC  Name:
pre-print-Screenshot_from_2018-02-05_18-56-47.png  Size: 141KiB   By: sebald

<http://savannah.gnu.org/bugs/download.php?file_id=43188>
-------------------------------------------------------
Date: Tue 06 Feb 2018 01:07:53 AM UTC  Name:
post-print-Screenshot_from_2018-02-05_18-58-18.png  Size: 138KiB   By: sebald

<http://savannah.gnu.org/bugs/download.php?file_id=43189>

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