From:	mert0407 AT sable DOT ox DOT ac DOT uk (George Foot)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Searching for a very specific algorithm
Date:	30 May 1997 03:38:05 GMT
Organization:	Oxford University, England
Lines:	17
Message-ID:	<5mli2t$fb2@news.ox.ac.uk>
References:	<338E2DAE DOT F88C30E AT sercomtel DOT com DOT br>
NNTP-Posting-Host:	sable.ox.ac.uk
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Alessandro Moure (moure AT sercomtel DOT com DOT br) wrote:
:         Hi all. I am developing a data manipulation tool kit and I am
: experiencing a hard time trying to find the area inside a closed,
: generic region. I have the points of the border line of the region
: stored in a vector. Does any body knows how to do it?
:        Thank you and please excuse my poor english.

This isn't really on-topic, but anyway... In 2D, given coordinates as X-Y
pairs you would, for each pair of adjacent points p[m] and p[n] calculate

a+=(p[m].x-p[n].x)*(p[m].y+p[n].y)/2;

making sure you zero a to start with.

-- 
George Foot <mert0407 AT sable DOT ox DOT ac DOT uk>
Merton College, Oxford
is what is __dpmi_int(), what it does, why
it is called here, and what I could be doing elsewhere in the program
that would cause it to hang. At this point I don't know what parameters
are being passed to lseek(), but will try finding out tomorrow.

In the meantime, any suggestions would be helpful.

BTW, This is running in a DOS window under Win/Lose-95, DJGPP 2.0.1
on a Pentium Pro.

Fred

--
---- Fred Smith -- fredex AT fcshome DOT stoneham DOT ma DOT us -- fred AT computrition DOT com ----
   "For the word of God is living and active. Sharper than any double-edged 
   sword, it penetrates even to dividing soul and spirit, joints and marrow; 
              it judges the thoughts and attitudes of the heart."  
---------------------------- Hebrews 4:12 (niv) ------------------------------

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