Texture prevents JoinedCurve from closing

Question

Bug introduced in 11.3 or earlier and fixed in 12.1

I am running Mathematica 11.3 and would like to see if this behavior is still present in newer versions of Mathematica before submitting a bug report.

Here is my example code

triangle[txtrq_] := 
 Module[{arcs = {
     BSplineCurve[{{1, 0}, {1, Sqrt[3]/3}, {1/2, Sqrt[3]/2}},
      SplineWeights -> {1, Sqrt[3]/2, 1}], 
     BSplineCurve[{(*{1/2,Sqrt[3]/2},*){0, Sqrt[3]/3}, {0, 0}}, 
      SplineWeights -> {1, Sqrt[3]/2, 1}], 
     BSplineCurve[{(*{0,0},*){1/2, -Sqrt[3]/6}, {1, 0}}, 
      SplineWeights -> {1, Sqrt[3]/2, 1}]}, txtr}, 
  txtr = Graphics[{Thickness[1/8], RGBColor[1, 7/8, 0], 
     Line[{{{0, 1/2}, {1/2, 1}}, {{1/2, 0}, {1, 1/2}},
         {{0, 1/2}, {1/2, 0}}, {{1/2, 1}, {1, 1/2}}}]}, 
    PlotRange -> {{0, 1}, {0, 1}}]; 
  Graphics[{Sequence @@ If[txtrq, {Texture[txtr]}, {}], 
    RGBColor[1, 7/8, 0], 
    FilledCurve[arcs, 
     Sequence @@ 
      If[txtrq, {VertexTextureCoordinates -> 
         20 {{1, 0}, {1, Sqrt[3]/3}, {1/2, Sqrt[3]/2},
           (*{1/2, Sqrt[3]/2},*){0, Sqrt[3]/3}, {0, 0},
           (*{0, 0},*){1/2, -Sqrt[3]/6}, {1, 0}}}, {}]], 
    RGBColor[1/5, 1/2, 1], Thickness[1/50], 
    JoinedCurve[arcs, CurveClosed -> True]}, ImageSize -> 400]]

Note that I have commented out the first point in all but the first of the BSplineCurve structures in arcs and the corresponding points in the VertexTextureCoordinates. This is explained in the answers to this question.

Here is the output with the Texture and VertexTextureCoordinates removed:

triangle[False]

Here is the output with the Texture and VertexTextureCoordinates included:

triangle[True]

Note that the JoinedCurve is closed in the absence of the Texture in the FilledCurve. However, when the Texture is present in the FilledCurve, the JoinedCurve fails to close (the bottom right corner lacks its mitered join). It seems odd that an option to one graphics directive causes a problem in the rendering of another.

Does this behavior persist in newer versions of Mathematica?

Can you try adding Directive[JoinForm["Round"], CapForm["Round"]] before all the other primitives to see what happens? — J. M.'s missing motivation, Feb 02 '21 at 14:32
@J.M.'sennui: I tried adding Directive[JoinForm["Round"], CapForm["Round"]] and also JoinForm["Round"], CapForm["Round"], but neither changed the output at all. Did you expect that? — robjohn, Feb 02 '21 at 14:46
Yep, definitely a bug... let's wait for someone with 12.2 to confirm. — J. M.'s missing motivation, Feb 02 '21 at 14:47
@J.M.'sennui: I did an image difference, and there is a small difference at the two joins of both drawings: the round join is very small, but those joins are "Round". The caps are still "Butt". — robjohn, Feb 02 '21 at 14:58
@cvgmt: Thanks! If you would, would you please post an answer with both drawings as 12.2 renders them? — robjohn, Feb 02 '21 at 15:19
@DanielHuber: Thanks! I already have 12.1, but I need to update my OS before it will run. This adds a reason to do so. — robjohn, Feb 02 '21 at 22:00

score 7 · Accepted Answer · answered Feb 02 '21 at 15:42

7

The bug had been fixed. Here we attach the result.

$Version
(* 12.2.0 for Linux x86 (64-bit) (December 9, 2020) *)
Row[triangle /@ {True, False}]

answered Feb 02 '21 at 15:42

cvgmt

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Texture prevents JoinedCurve from closing

1 Answers1