[Tcl-bugs] [Tk] (chrstphrchvz) tkt (Open): On windows, arcs with small ' extent' can be drawn incorrectly

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Ticket Change [cf192d2919e2a134b065f4a4af10d28b71673a914e77921f2134594d96d5ffd1]
  [On windows, arcs with small 'extent' can be drawn incorrectly]
  By      chrstphrchvz
  For     Tk
  On      2025-10-18T21:50:49.287
  Details https://core.tcl-lang.org/tk/tinfo?name=cf192d2919e2a134b065f4a4af10d28b71673a914e77921f2134594d96d5ffd1
  Ticket  https://core.tcl-lang.org/tk/tktview/6051a9fca29285ce0b545c61413a713eeda33e01

Changed Fields
  icomment: For testing the near-360 degree behavior, I used the reporter's
            animated example with <tt>-extent 359.8</tt>. The animation should
            show a complete or almost-complete filled circle and not "flicker".

            François' approach is closer to the desired behavior, where arcs with
            an extent near 0 degrees still draw something (a point or line),
            rather than draw nothing as my approach does. Although his approach
            has the same issue as my first approach where an extent just under 360
            degrees may get treated as 0 degrees and not draw as expected, I think
            that is easy to fix. So for now I would propose François' approach
            combined with an adjustment to handle near-360 degree arcs properly;
            see [06a80feb].

            Regarding the other issues in [1081603], I do not know whether it is
            worth trying to get the arc drawing on Windows to match X11 exactly.
            Maybe such microscopic differences should be accepted as a limitation
            of the Win32 Tk port or the GDI functions it relies on.
  login:    chrstphrchvz

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