One more idea

> could achieve this by improving the convex hull

take this "banana", the asterisks * are corners of the convex hull but the dots are not approached. 

  

* a

     *
  .  .
     .  *
  .
     .  *
   . 
    . *
  
* b

[download]

Now starting from the edge a-b you could construct a "convex" streak from a to b which keeps all other points "outside", just using the same algorithm like before and inverting the orientation.

Saying so I'm pretty sure there are already ready to use algorithms which do this in a time efficient way...

Cheers Rolf
(addicted to the Perl Programming Language and ☆☆☆☆ :)
Wikisyntax for the Monastery

In reply to Re^4: Polygon Creation -- Request for Algorithm Suggestions by LanX
in thread Polygon Creation -- Request for Algorithm Suggestions by golux

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.