Mark Gordon <mtg### [at] mailbagcom> wrote:
: Assume the polygon is defined as a sequence of points on its periphery. 
: A triplet of points on the edge of the polygon forms a "pointy bit" (my
: jargon) if the interior angle formed at the second point (as measured in
: the plane defined by the three points) is less than 180 degrees.  If the
: interior angle formed at the second point is greater than 180 degrees
: it's an, um, "anti-pointy bit". :-)  If it's exactly 180, you may as
: well remove the middle point as redundant.

  This doesn't work. A vertex of the polygon may lie inside the triangle.
If this is so, the triangle will be partially outside the polygon.
  Think about an 'L' made of 6 vertices. Now take the upper left vertex,
the lower left vertex and the lower right vertex. The triangle they define
"seems" to be inside the polygon, but it doesn't.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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