bugGNU Octave - Bugs: bug #50298, Zooming causes lines to be...


bug #50298: Zooming causes lines to be "dashed" until next redraw

Submitted by:  Pantxo Diribarne <pantxo>
Submitted on:  Mon 13 Feb 2017 09:59:04 PM UTC  
Category:  Plotting with OpenGL Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Regression
Status:  Fixed Assigned to:  None
Originator Name:  Open/Closed:  Closed
Release:  4.2.0 Operating System:  GNU/Linux

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Tue 21 Feb 2017 10:59:45 PM UTC, comment #2:

I see no dashed lines anymore when zooming on my system after this cset:


Closing report as fixed.

Pantxo Diribarne <pantxo>
Project Member
Wed 15 Feb 2017 05:27:39 PM UTC, comment #1:

I think there are two different things going on here. The 'dashed' line is likely to be an issue with the particular hardware and software setup of your computer. I don't see this particular issue.

I can reproduce the warning message. This deserves its own bug report so I made one at bug #50317.

Rik <rik5>
Project Administrator
Mon 13 Feb 2017 09:59:04 PM UTC, original submission:

On my system (Linux mint 17.3, integrated Intel graphics controller, Mesa DRI driver), trying to zoom in a simple plot as "plot (1:10)", leads to some lines not being drawn (horizontal or vertical), or "dashed" (oblique lines). With qt toolkit, simply changing the focus to another window is enough to have the figure redrawn correctly while with fltk one needs to use "drawnow".
This used to work well on the same machine in Octave 4.0.

Setting "linewidth" to some value greater than one, fixes the issue. So I tried to set the figure "graphicssmoothing" to "off" prior to plotting and it "fixes" the issue but then I get a bunch of warnings when drawing the zoombox:

or sometimes

and the zoom box is drawn opaque blue instead of transparent.

Pantxo Diribarne <pantxo>
Project Member


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    Follow 4 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2017-02-21 pantxo StatusWorks For Me => Fixed
        Open/ClosedOpen => Closed
    2017-02-15 rik5 StatusNone => Works For Me
        SummaryZoomming causes lines to be "dashed" until next redraw => Zooming causes lines to be "dashed" until next redraw

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