Message-ID:	<37AC37B8.B29A3614@unb.ca>
From:	Endlisnis <s257m AT unb DOT ca>
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Newsgroups:	comp.os.msdos.djgpp,comp.programming
Subject:	Re: Circle Drawing Algorithms
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Date:	Sat, 07 Aug 1999 13:43:40 GMT
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To:	djgpp AT delorie DOT com
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Andy Kilner wrote:

> What is the fastest circle algorithm available at the moment?

This is a snip of code from my graphics library.  It only draws 1/8th of the
circle and reflects the rest.  Also, no multiplication or trig is done and
only integers are used.

void _GraphixBase::Circle(short X, short Y, short Radius, byte Clr)
{
 short x=0;
 short y=Radius;
 short step=1-y;

 while(y>=x)
 {
  Pset(X+x, Y+y, Clr);
  Pset(X+y, Y+x, Clr);
  Pset(X+y, Y-x, Clr);
  Pset(X+x, Y-y, Clr);
  Pset(X-x, Y-y, Clr);
  Pset(X-y, Y-x, Clr);
  Pset(X-y, Y+x, Clr);
  Pset(X-x, Y+y, Clr);

  if (step<0) step += x+x+3;
  else
  {
   step += ((x-y)<<1)+5;
   y--;
   }
  x++;
  }
 }



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     (\/) Endlisnis (\/)
          s257m AT unb DOT ca
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