vr:

My starting point finder (first horizontal bit on highest line) is *definitely* not a safe way to find a starting point. I knew that, but didn't really think of mentioning it.

Even worse: I was hoping the faults you found with the code was due to the missing entries in the %dirs hash, but some caused a bit of grief. I've got it going a little better, but I'm still testing it now. I'll post (yet another) version when I get the current kinks out.

One of the test cases with spindles in various directions:

$ perl ~/pm_1204060_b.pl ugly.2
Bounds X:0..13, Y:2..12
Original image (relocated, pixels set to '#'):

: ############## :   0
:    #           :   1
:    #           :   2
:    #######     :   3
:    ####        :   4
:    ####        :   5
: #######        :   6
:     ###        :   7
:       #        :   8
:       #        :   9
:       #        :  10
:                :  11
  12345678901234

Found a bit of horizontal top edge at 3, 0
Start point:

: ###+########## :   0
:    #           :   1
:    #           :   2
:    #######     :   3
:    ####        :   4
:    ####        :   5
: #######        :   6
:     ###        :   7
:       #        :   8
:       #        :   9
:       #        :  10
:                :  11
  12345678901234


Points rendered on blank canvas:

: yzABPONMLKJI   :   0
:    v           :   1
:    u           :   2
:    tSTUZYX     :   3
:    s  a        :   4
:    r  b        :   5
: opql  c        :   6
:     kjd        :   7
:       i        :   8
:       h        :   9
:       g        :  10
:                :  11
  12345678901234


Border points rendered on original polygon:

: yzABPONMLKJI## :   0
:    v           :   1
:    u           :   2
:    tSTUZYX     :   3
:    s##a        :   4
:    r##b        :   5
: opql##c        :   6
:     kjd        :   7
:       i        :   8
:       h        :   9
:       g        :  10
:                :  11
  12345678901234

[download]

...roboticus

When your only tool is a hammer, all problems look like your thumb.

In reply to Re^9: Polygon Creation -- Request for Algorithm Suggestions by roboticus
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.