[Octave-bug-tracker] [bug #62130] print with transparency, pdf ok but pdflatex fails

[George Apostolopoulos]

URL:
  <https://savannah.gnu.org/bugs/?62130>

                 Summary: print with transparency,  pdf ok but pdflatex fails
                 Project: GNU Octave
            Submitted by: gapost
            Submitted on: Wed 02 Mar 2022 11:25:20 AM UTC
                Category: Plotting
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
                 Release: 7.0.90
         Discussion Lock: Any
        Operating System: GNU/Linux

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Details:

Printing figures with transparency sometimes produces incorrect results with
pdflatex while pdf+svgconvert is ok.

== Example 1: rectangles ==


clear
close('all')
rectangle("position", [0.2 0.3 0.6 0.4], "facecolor", "b", "FaceAlpha",.3)
rectangle("position", [0.3 0.2 0.4 0.6], "facecolor", "r", "FaceAlpha",.3)
axis([0 1 0 1])
box on
title('print -dpdfcrop -svgconvert')
print -dpdfcrop -svgconvert rectangles
title('print -dpdflatexstandalone -svgconvert')
print -dpdflatexstandalone -svgconvert rectangles-latex
[out, txt] = system ("pdflatex rectangles-latex.tex")


In the file produced with "-dpdflatexstandalone" the transparency does not
come out right.

== Example 2: fill ==


close('all')
clear
x=linspace(-1,1,101);
s = 0.15;
y1 = exp(-(x/s).^2/2);
y2 = 0.75*exp(-((x-0.3)/0.15).^2/2);
hold on
h = fill([x 1 -1],[y1 0 0],'b', ...
  'FaceAlpha',.3);
set(h,'EdgeAlpha',.3); # this line causes bug
fill([x 1 -1],[y2 0 0],'r', ...
  'FaceAlpha',.3);
hold off
box on
title('print -dpdfcrop -svgconvert')
print -dpdfcrop -svgconvert curves
title('print -dpdflatexstandalone -svgconvert')
print -dpdflatexstandalone -svgconvert curves-latex
[out, txt] = system ("pdflatex curves-latex.tex")


Again the file produced with "-dpdflatexstandalone" is not ok.

Note that the problem in Ex. 2 appears only when setting 'EdgeAlpha'.

Attached are the pdf files produced in my system (Ububtu 20.04).

I used firefox built-in pdf viewer to view the pdfs (some programs may
interpret the files incorrectly).




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File Attachments:


-------------------------------------------------------
Date: Wed 02 Mar 2022 11:25:21 AM UTC  Name: rectangles-latex.pdf  Size: 18KiB
  By: gapost

<http://savannah.gnu.org/bugs/download.php?file_id=52945>
-------------------------------------------------------
Date: Wed 02 Mar 2022 11:25:21 AM UTC  Name: curves.pdf  Size: 10KiB   By:
gapost

<http://savannah.gnu.org/bugs/download.php?file_id=52946>
-------------------------------------------------------
Date: Wed 02 Mar 2022 11:25:21 AM UTC  Name: curves-latex.pdf  Size: 27KiB  
By: gapost

<http://savannah.gnu.org/bugs/download.php?file_id=52947>
-------------------------------------------------------
Date: Wed 02 Mar 2022 11:25:20 AM UTC  Name: rectangles.pdf  Size: 9KiB   By:
gapost

<http://savannah.gnu.org/bugs/download.php?file_id=52944>

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