[bug #68062] __marching_cube__.m should not rely on "bitget()" returning "logical"

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URL:
  <https://savannah.gnu.org/bugs/?68062>

                 Summary: __marching_cube__.m should not rely on "bitget()"
returning "logical"
                   Group: GNU Octave
               Submitter: dasergatskov
               Submitted: Tue 17 Feb 2026 11:37:55 PM UTC
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: None
                  Status: None
             Assigned to: None
         Originator Name:
        Originator Email:
             Open/Closed: Open
         Discussion Lock: Unlocked
                 Release: dev
        Operating System: Any
           Fixed Release: None
         Planned Release: None


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Follow-up Comments:


-------------------------------------------------------
Date: Tue 17 Feb 2026 11:37:55 PM UTC By: Dmitri A. Sergatskov <dasergatskov>
__marching_cube__.m has a code that relies on "bitget()" function returning
"logical" type. Th is the case now, but not with Matlab-compatible "bitget()"
where return type is the same as input type ("uint16" in this particular
case). The diff:

diff -r 290f6519b733 scripts/plot/draw/private/__marching_cube__.m
--- a/scripts/plot/draw/private/__marching_cube__.m     Mon Feb 16 11:31:33
2026 +0100
+++ b/scripts/plot/draw/private/__marching_cube__.m     Tue Feb 17 18:32:53
2026 -0500
@@ -157,7 +157,8 @@
   ccedge = [vec(cedge(id)), id];
   ix_offset=0;
   for jj = 1:12
-    id__ = bitget (ccedge(:, 1), jj);
+    ## Make sure "id__" is logical egardless of "bitget" return type.
+    id__ = logical (bitget (ccedge(:, 1), jj));
     id_ = ccedge(id__, 2);
     [ix iy iz] = ind2sub (size (cc), id_);
     id_c = sub2ind (size (v), ix, iy, iz);

fixes that for me.

Dmitri.
-- 








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