How should the venndiagram package be used? Or how can I avoid weird results?

In venndiagram.sty on lines 138, 140, 147, 159, 151, 153, the arguments of atan2 are in the wrong order. When I reverse them, one gets the desired results. What I mean is that the original arguments to atan2 were entered as (dx,dy), but they should be entered as (dy,dx).

Corrected passage: (lines 128-164)

  \def\fillOnlyA{%
    \begin{scope}
    \path[name path=A] (\@venn@Ax,\@venn@Ay) circle (\@venn@radius);
    \path[name path=BC] (\@venn@Bx,\@venn@By) circle (\@venn@radius)
      (\@venn@Cx,\@venn@Cy) circle (\@venn@radius);
    \path[name intersections={of=A and BC,name=ABintersect}]
      (ABintersect-1) ;
    \pgfgetlastxy{\@venn@AB@xi}{\@venn@AB@yi}
    \path (ABintersect-2);
    \pgfgetlastxy{\@venn@AB@xii}{\@venn@AB@yii}
    \pgfmathparse{atan2(\@venn@AB@yi-\@venn@Ay,\@venn@AB@xi-\@venn@Ax)}
    \let\@venn@start@i=\pgfmathresult
    \pgfmathparse{360+atan2(\@venn@AB@yii-\@venn@Ay,\@venn@AB@xii-\@venn@Ax)}
    \let\@venn@end@i=\pgfmathresult
    \path[name path=B] (\@venn@Bx,\@venn@By) circle (\@venn@radius);
    \path[name path=C] (\@venn@Cx,\@venn@Cy) circle (\@venn@radius);
    \path[name intersections={of=B and C,name=BCintersect}]
      (BCintersect-1);
    \pgfgetlastxy{\@venn@BC@x}{\@venn@BC@y}
    \pgfmathparse{atan2(\@venn@AB@yii-\@venn@Cy,\@venn@AB@xii-\@venn@Cx )}
    \let\@venn@start@ii=\pgfmathresult
    \pgfmathparse{atan2(\@venn@BC@y-\@venn@Cy,\@venn@BC@x-\@venn@Cx )}
    \let\@venn@end@ii=\pgfmathresult
    \pgfmathparse{atan2(\@venn@BC@y-\@venn@By,\@venn@BC@x-\@venn@Bx )}
    \let\@venn@start@iii=\pgfmathresult
    \pgfmathparse{atan2(\@venn@AB@yi-\@venn@By,\@venn@AB@xi-\@venn@Bx )-360}
    \let\@venn@end@iii=\pgfmathresult
    \path[fill=\@venn@shade] (ABintersect-1)
     arc[radius=\@venn@radius,
         start angle=\@venn@start@i,end angle=\@venn@end@i]
     arc[radius=\@venn@radius,
         start angle=\@venn@start@ii,end angle=\@venn@end@ii]
     arc[radius=\@venn@radius,
         start angle=\@venn@start@iii,end angle=\@venn@end@iii]
     -- cycle;
    \end{scope}
  }%

enter image description here


This is now fixed in venndiagram v1.1 which checks \pgfversion to determine what syntax to use for atan2, so venndiagram should now work with both pgf v2.0 and pgf v3.0.