bugGNU Octave - Bugs: bug #39643, axes are not joined (onscreen)


bug #39643: axes are not joined (onscreen)

Submitter:  Dmitri A. Sergatskov <dasergatskov>
Submitted:  Thu 01 Aug 2013 12:49:02 PM UTC
Category:  Plotting with OpenGL Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Other
Status:  Confirmed Assigned to:  None
Originator Name:  Dmitri A. Sergatskov Open/Closed:  * Open
Release:  * dev Operating System:  * GNU/Linux
Fixed Release:  None Planned Release:  None
* Mandatory Fields

Add a New Comment Rich Markup

Jump to the original submission

Mon 28 Nov 2016 09:37:01 PM UTC, comment #9: 

I pushed the patch here:


The remaining issue is rendering line cap and/or line join properly onscreen. The approach proposed in bug #46739 (polygon based dashed lines) is probably the way to go.

Pantxo Diribarne <pantxo>
Group Member
Mon 28 Nov 2016 05:16:19 PM UTC, comment #8: 

Yes, test for gl2psLineJoin added in http://hg.savannah.gnu.org/hgweb/octave/rev/39f39eb4e476

Mike Miller <mtmiller>
Group Member
Mon 28 Nov 2016 04:44:33 PM UTC, comment #7: 

No objection to pushing the cset that is available now.

I notice you make use of HAVE_GL2PSLINEJOIN.  Who sets that variable?  Is there a test in configure.ac for it?

Rik <rik5>
Group administrator
Mon 28 Nov 2016 11:45:35 AM UTC, comment #6: 

May I push the patch and leave this report open until we find a solution for onscreen rendering?

Pantxo Diribarne <pantxo>
Group Member
Tue 22 Nov 2016 03:41:28 PM UTC, comment #5: 

I attached the resulting figure from ML 2015b

My understanding is that having the line join/cap right onscreen is only possible if we change our way to draw lines: instead of using GL_LINE objects we should draw lines using polygons.

In any event I think the change I propose is the right way to go for now even though it will only be effective once a new version of gl2ps is released and available.

Pantxo Diribarne <pantxo>
Group Member
Sun 20 Nov 2016 08:29:39 PM UTC, comment #4: 

I attached the png I obtain using Octave, the patch from comment #2 and the current dev version of gl2ps (see comment 27 in bug #48387).

Pantxo Diribarne <pantxo>
Group Member
Sun 20 Nov 2016 06:20:17 PM UTC, comment #3: 

For reference, here is some sample test code:

close all;
hax = axes ('linewidth', 10, 'box', 'on');
print tst_join.png

Could someone try the above code on Matlab and upload the resulting image?

Rik <rik5>
Group administrator
Fri 18 Nov 2016 04:08:08 PM UTC, comment #2: 

I was wondering if using LINE_STRIP to draw axes would do the trick for onscreen and printed figures, but LINE_STRIP which are used to draw line objects  don't do a better job to join line segments (at least on my linux/nouveau driver):

plot (rand (1,10), "linewidth", 10)

I attached a patch that makes use of a new gl2psLineCap function in the current dev of gl2ps. This will thus only enhance the printout figure.

(file #39010)

Pantxo Diribarne <pantxo>
Group Member
Thu 01 Aug 2013 02:00:12 PM UTC, comment #1: 

Drawing is done through OpenGL. FLTK-based drawing is not involved.

Michael Goffioul <goffioul>
Thu 01 Aug 2013 12:49:02 PM UTC, original submission:  

With fltk backend on Linux the axes lines are not joined in the corners. See attached for details; the axes width there set to  10 to make the problem more visible.

According to http://www.fltk.org/doc-1.3/drawing.html
If you don't specify a cap or join type you will get a system-defined default of whatever value is fastest.


so the bug might be OS (or even X11 server) dependent.

Dmitri A. Sergatskov <dasergatskov>


(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach Files:

Attached Files
file #39046:  tst_linewidth.png added by pantxo (17KiB - image/png)
file #39033:  tst_join.png added by pantxo (12KiB - image/png)
file #39010:  linecap.patch added by pantxo (3KiB - text/x-diff)
file #28733:  axes.png added by dasergatskov (9KiB - image/png)


Carbon-Copy List
  • -email is unavailable- added by mtmiller (Posted a comment)
  • -email is unavailable- added by rik5 (Posted a comment)
  • -email is unavailable- added by pantxo (Updated the item)
  • -email is unavailable- added by dasergatskov (Submitted the item)

    There are 0 votes so far. Votes easily highlight which items people would like to see resolved in priority, independently of the priority of the item set by tracker managers.

    Only project members can vote.


    Follow 9 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2021-03-26 pantxo Dependencies- bugs #60292 is dependent
    2018-04-24 rik5 Dependencies- bugs #53730 is dependent
    2017-10-05 pantxo StatusPatch Submitted Confirmed
        Summaryaxes are not joined axes are not joined (onscreen)
    2016-11-22 pantxo Attached File- Added tst_linewidth.png, #39046
    2016-11-20 pantxo Attached File- Added tst_join.png, #39033
    2016-11-18 pantxo Attached File- Added linecap.patch, #39010
        StatusNone Patch Submitted
    2013-08-01 dasergatskov Attached File- Added axes.png, #28733

    Back to the top

    Powered by Savane 3.12